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Relevant quotes: Relevant quotes

2023-10-02T19:18:46Z

Alexandre.laedermann: /* Conflict of interest */

=Anatomy=
An anomaly is not an abnormality. Diversity does not signify sickness ''Georges Canguilhem''

Know the normal before examining for the abnormal ''William Osler''

Humans are variable ''William Osler''

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The role of the infinitely small is infinitely large ''Louis Pasteur''

Do not look to things that you don’t want to find

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Don's act superior ''William Osler''

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Never listen to tales or slander a colleague/Never listen to a patient's criticism of another doctor ''William Osler''

Silence is the best weapon against slander ''William Osler''

Silence is power ''William Osler''

Speak only when you have something to say ''William Osler''

=Complications/errors=
The one who does not operate, who lies, and who does not follow his patients does not have complications

Good surgeons operate well: great surgeons know how to manage their own complications

Errors cannot be avoided ''William Osler''

Do not congratulate yourself for saving a patient from a trouble inflicted by you

=Conflict of interest=
Do not sacrifice mental independence ''William Osler''

The commercial promotion of drugs is lamentable ''William Osler''

The more conflit of interest you have, the less conflicted you are

=Cost/Value-Based Healthcare=
New equipment and new procedures may improve medical care, but seldom decrease the cost ''Mark M Ravitch'' (1919-1989)

It is the surgeon who benefits more from elective surgery

=Diagnosis=
Uncertainty is the rule in medicine ''William Osler''

=Education/teaching=
Intellectual laziness is a vice ''William Osler''

Believe nobody, question everything

If I have seen further it is by standing on the shoulders of giants ''Sir Isaac Newton'' Letter to Robert Hooke (5 February 1676)

Do not expect much from others ''William Osler''

We are influenced by those we admire ''William Osler''

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Medical common sense is rare ''William Osler''

The practical outcome of medical training is to help others ''William Osler''

The path of medical education follows the evolution of knowledge ''William Osler''

The teacher still has a lot to learn ''William Osler''

The surgical resident is like a mushroom: kept in the dark, fed shit, and expected to grow.

=Efficiency=

Resolve not to waste time ''William Osler''

Do first what has to be done ''William Osler''

or

I never put off till tomorrow what I can possibly do - the day after ''Oscar Wilde''

=Health=
To be in good health means being able to fall sick and recover ''Canguilhem''

Soap, water, and common sense are the best disinfectants ''William Osler''

Too much drugs mean they are all insufficient ''William Osler''

=Knowledge/Learning=
Knowledge is power ''Francis Bacon''

Knowing what to do provides imperturbability ''William Osler''

A student should be a citizen of the world ''William Osler''

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Learning is lifelong/Education is a life course ''William Osler''

Medicine is a difficult art to acquire ''William Osler''

Each case has a lesson/Learn from each patient ''William Osler''

Learn from your errors/Learn from your mistakes ''William Osler''

To know that you do not know is the best. To pretend to know when you do not know is a disease ''Lao-tzu'' Chinese philosopher (604 BC - 531 BC)

Pretending to know is a conceit ''William Osler''

It is not because things are difficult that we do not dare, it is because we do not dare that they are difficult ''Lucius Annaeus Seneca''

=Medical errors=
A man must be big enough to admit his mistakes, smart enough to profit from them, and strong enough to correct them ''John C Maxwell''

Experience is merely the name men gave to their mistakes ''Oscar Wilde''

=Medication/Drugs/Prescription=
Sola dosis facit venenum -The dose makes the poison ''Paracelsus'' (1493-1541)

Patients can get well without antibiotics ''Mark M Ravitch'' (1910-1989)

Most men die of their remedies, not of their disease ''Molière'' (1622-1673)

Extreme remedies are very appropriate for extreme diseases ''Hyppocrates'' (460-377 BC)

=Retirement=
The old should remember that they represent the past, and that the young represent the future ''William J Mayo'' (1861-1939)

=Results/Persistence=
Great works are performed not by strength but by perseverance ''Samuel Johnson''

Perfection is obtained by little effort ''Arab saying''

Perfection is not attainable, but if we chase perfection we can catch excellence ''Vince Lombardi''

Perfection is to be cultivated ''William Osler''

The enemy of good is better

Does absence of proof of efficacy provide proof of the absence of efficacy? ''John Marshall''

The first report of any new operation is rarely unfavorable ''Mark M Ravitch'' (1910-1989)

=Science=
Believe those who are seeking the truth; doubt those who find it ''André Gide''

In science, the credit goes to the man who convinces the world, not to the man the idea first occurs ''William Osler''

Every scientific truth is met initially by skepticism ''William Osler''

General acceptance of truth takes time ''William Osler''

Scientific education facilitates clinical work ''William Osler''

Simplicity is the ultimate sophistication ''Leonardo Da Vinci''

=Second opinion=
The more the doctors, the sadder the prognosis ''William Osler''

If two people agree, one of them is not a doctor ''Unknown''

=Statistics=
There are three kinds of lies: lies, damned lies, and statistics ''Mark Twain''

I only believe in statistics that I doctored myself ''Winston S. Churchill'' Former British Prime Minister

=Indication/Plan/Planning=
Doing something is sometimes worse than doing nothing ''Gail Waldby''

It is difficult to make the asymptomatic patient feel better ''Stanley O Hoerr'' (1909-1990)

The greatest triumph of surgery today… lies in finding ways for avoiding surgery ''Robert Tuttle Morris'' (1857-1945)

The most difficult thing is to do nothing ''Norman M Rich''

It takes five years to learn when to operate and twenty years to learn when not to ''Unknown''

You can always amend a big plan, but you can never expand a little one ''Harry S. Truman'' Former U.S. President

Plans are of little importance, but planning is essential ''Winston Churchill'' Former British Prime Minister

The feasibility of an operation is not the best indication for its performance ''Henry Cohen'' (1900-1977)

Never be the first but never be the last to accept change ''Angus B McLachlin'' (1908-1987)

=Teamwork=
Alone we can do so little, together we can do so much ''Helen Keller''

=Treatment=
“First the word, then the plant, lastly the knife” ''Aesculapius'' of Thassaly (1200 BC)

Care for the patient, not the disease/Put the patient before the disease ''William Osler''

The physician is only nature's assistant ''Galen''

Do not mess around with mother nature ''Jonathan Meakins''

=Surgery=
The simpler the procedure, the better the results ''Charles FM Saint'' (1886, 1973)

If it looks good, it might work. If it does not look good, it will never work ''William Silen''

If everything is going right you’ve done something wrong

A poor workman blames his tool

Blood brain barrier (BBB): the screen between the surgeon and anaesthetics

All bleeding eventually ceases ''Guy de Chauliac'' (1300-1368)

There are 4 degrees of intra-operative hemorrhage: 1. “Why did I get involved in this operation?” 2. “Why did I become a surgeon?” 3. “Why did I study to become a doctor?” 4. “Why was I born?” ''Alexander A Artemiev''

When in doubt drain Robert ''Lawson Tait'' (1845-1899)

The incision must be as long as necessary and as short as possible ''Theodore Kocher'' (1841-1917)

Big surgeon - big incision – small activity

Shoulder:Rotator Cuff Pathology/Thickness Rotator Cuff Tears/Posterosuperior Rotator Cuff Tears and Associated Pathologies

2023-03-29T14:36:51Z

Alexandre.laedermann: added video

==Bullet Points==

*The rotator cable explains why patients with most rotator cuff tears can maintain active forward flexion, and also why even after only a partial rotator cuff repair, good functional results can be achieved.
*The most important negative prognostic factor is high-grade fatty infiltration of the rotator cuff muscle bellies (grade 3 or 4 fatty infiltration).
*The tangent sign is an indicator of advanced fatty infiltration and is a predictor of whether a rotator cuff tear will be reparable.
*Full thickness disruption of the lateral tendon stump (B1) is the most frequent type of rotator cuff lesion, comprising approximately 90% of all surgically treated lesions.
*Musculotendinous junction lesions (C-type) or rare and characterized by an edema of the muscle belly. They are associated to calcific deposit (infraspinatus) or trauma (supraspinatus). Unrepaired, grade III lesions lead rapidly to grade 4 fatty infiltration of the muscle.
*Tendon retraction is classified according to Patte. Overreduction and lateral transposition of the tendon over the greater tuberosity may be unphysiological.
*Massive rotator cuff has different definitions in the literature, each having potential benefits or drawbacks.
*Massive rotator cuff tears comprise approximately 20% of all cuff tears and 80% of recurrent tears.
*The classification of Collin not only subclassifies massive tears but has also been linked to function, particularly the maintenance of active elevation.
*Non-surgical treatment is effective in patient with massive rotator cuff if the tear involves less than three tendons and do not involves the subscapularis (D-type).
*Biomechanical testing has consistently demonstrated the superiority of double-row constructs over single-row. However, there is no obvious difference clinically.
*There is actually no support for routine suprascapular nerve release when massive rotator cuff repair is performed.
*Functional outcome improved after revision rotator cuff repair and 70% or more of patients were satisfied or very satisfied. However, the prevalence of persistent defect (retear or non-healing) is 28% at six months and 40% at two years.
*Rotator cuff are irreparable when associated to true pseudoparalysis with the presence of lag signs (external rotation lag, drop, dropping, hornblower signs), femoralization of the humerus or acetabulization of the acromion, grade 3 or 4 fatty infiltration and tangent sign.
*The current literature does not support the initial use of complex and expensive techniques in the management of posterosuperior irreparable rotator cuff tears.

==Key Words==
Shoulder arthroscopy; Rotator cuff lesion; Partial repair; Tear pattern; Classification; Massive; Reparable and non-repairable; Irreparable; Imaging; Recurrent; Failed; Revision surgery; Open and arthroscopic approach; Conservative or non-operative treatment; Physiotherapy; Functional outcomes; Prognostic factors; Latissimus dorsi transfer; Subacromial spacer interposition; Balloon; Biceps tenotomy; Superior capsular reconstruction; Reverse arthroplasty; Magnetic resonance imaging (MRI) arthrography (MRA); Fosbury flop tear; New tear pattern; FUSSI; SAM.

==Anecdote==
===How double-row was born===
When Ian Lo was my Fellow in 2001-2002, he and I wrote 2 papers on my technique of arthroscopic non-linked double-row rotator cuff repairs. As far as I can tell, these were the first 2 published articles on arthroscopic double-row cuff repair. These were published in 2003 in The American Journal of Sports Medicine<ref>Lo IKY, Burkhart SS. Current concepts in arthroscopic rotator cuff repair. Am J Sports Med 2002;31(2):308-324</ref> and The Arthroscopy Journal.<ref>Lo IKY, Burkhart SS. Double row arthroscopic rotator cuff repair: Re-establishing the footprint of the rotator cuff. Arthroscopy 2002;19(9):1035-1042</ref> The technique was a non-linked double row repair that I had first done 8 years earlier, in 1995. However, the reason that I did my first arthroscopic double-row repair was not what you might think.......

My index double row repair patient was a 55-year-old female who had fallen and sustained a traumatic non-retracted tear of the supra- and infraspinatus. After I had done an arthroscopic acromioplasty and subacromial bursectomy, I still had trouble visualizing the greater tuberosity footprint because the torn tendon was quite redundant and extended far laterally. It seemed as if the redundant, unstable cuff tissue filled the entire subacromial space, making visualization very difficult. So, in order to stabilize the cuff and see the greater tuberosity well enough to properly prepare the bone, I placed a single anchor medially on the tuberosity and then passed the sutures from the anchor through the medial part of the cuff; then I tied the knot as a mattress stitch. This single fixation point on the medial part of the greater tuberosity controlled the "unstable" redundant tendon so that I could then see well enough to prepare the greater tuberosity bone bed. But it also allowed me to see that I would have enough tendon length to completely cover the greater tuberosity with the repair. So I placed 2 more medial anchors and completed the medial fixation of the tendon. Then I placed 2 lateral anchors to tack down the lateral flap of the tendon so that there was firm contact of the tendon to the bone between the two rows of anchors. At that point, the repair looked completely anatomic. In fact, it looked so good, that I resolved to start doing double-row repairs on torn cuffs whose tendons had enough redundancy to cover the greater tuberosity without undue tension. So, in retrospect, I did my first double row repair to control an unstable tendon so that I could visualize the operative field better, rather than intentionally trying to create a broader anatomic footprint with my repair. But this opened the door for further biomechanical research on double-row versus single-row repairs, and soon the biomechanical superiority of double row was apparent.

Steve Burkhart

==Biomechanics of the Posterosuperior Rotator Cuff==
A primary function of the rotator cuff is to work synergistically with the deltoid to maintain a balanced force couple about the glenohumeral joint. A force couple is a pair of forces that act on an object and tend to cause it to rotate. For any object to be in equilibrium, the forces must create moments about a center of rotation that are equal in magnitude and opposite in direction. Coronal and transverse plane force couples exist between the subscapularis anteriorly and infraspinatus and teres minor posteriorly. The rotator cuff force across the glenoid provides concavity compression, which creates a stable fulcrum and allows the periscapular muscles to move the humerus around the glenoid.

The rotator cable is a thickening of the rotator cuff that has been likened to a suspension bridge in which force is distributed through cables that are supported by pillars (the anterior and posterior attachments). The anterior rotator cable attachment bifurcates to attach to bone just anterior and posterior to the proximal aspect of the bicipital groove. The posterior attachment comprises the inferior 50% of the infraspinatus. With small central tears the cable attachments often stay intact and forces are transmitted along the rotator cable. The rotator cable also explains why patients with most rotator cuff tears can maintain active forward flexion, and also why even after only a partial rotator cuff repair, good functional results can be achieved.<ref>Burkhart SS, Nottage WM, Ogilvie-Harris DJ, Kohn HS, Pachelli A. Partial repair of irreparable rotator cuff tears. Arthroscopy 1994;10:363-70.</ref> 

However, in the setting of massive rotator cuff with rotator cable disruption and non-compensation by other humeral head stabilizers (i.e pectoralis major and latissimus dorsi), the moments created by the opposing muscular forces are insufficient to maintain equilibrium in the coronal plane, resulting in altered kinematics, instability, and ultimately in pseudoparalysis. Interestingly, only few patients with an irreparable rotator cuff tears developed pseudoparalysis and arthritis.This finding has at least two potential explanations. First, the subscapularis that may not be involved in these tears is the key factor of active forward flexion.<ref name=":1">Collin P, Matsumura N, Lädermann A, Denard PJ, Walch G. Relationship between massive chronic rotator cuff tear pattern and loss of active shoulder range of motion. J Shoulder Elbow Surg 2014;23:1195-202.</ref> 

Second, the rotator cable, has still an intact anterior attachment which is important for elevation. This may explain why patients can maintain active mobility, and also why even after only a partial rotator cuff repair, good functional results can be achieved.<ref name=":2">Denard PJ, Lädermann A, Brady PC, Narbona P, Adams CR, Arrigoni P, Huberty D, Zlatkin MB, Sanders TG, Burkhart SS. Pseudoparalysis From a Massive Rotator Cuff Tear Is Reliably Reversed With an Arthroscopic Rotator Cuff Repair in Patients Without Preoperative Glenohumeral Arthritis. Am J Sports Med 2015;43:2373-8.</ref>

Consequently, all the conditions for an imbalance in the force couples are not always met and subsequently loss of function is only occasionally seen.

==Clinical examination==
===Inspection===
Inspection has to rule out deformation, swelling (i.e Milwaukee shoulder syndrome, Figure) or hematoma (Video).

[[File:Milwalkee.png|thumb|Milwaukee shoulder syndrome is associated with intra-articular deposition of hydroxyapatite crystals and disruption of the rotator cuff. The Figure illustrates a patient with involvement of the left shoulder]]
[[File:Bossy épaule sénile hémorragique.mov|thumb|Hematoma related to massive rotator cuff tear.]]

===Palpation===
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===Range of Motion===
The patient must be examined not only in the standing position, but also supine on a table in order to block scapulothoracic movements, and look for all amplitudes (anterior elevation, abduction, internal rotation and external rotation elbow at the side and at 90 degrees of abduction).

===Tests for posterosuperieur rotator cuff lesions===
====Supraspinatus====
Supraspinatus is an external rotator.<ref name=":4">Inman VT, Saunders M, Abbott, MC. Observations on the function of the shoulder joint. J Bone Joint Surg Br. 1944;1:1-30.</ref> It also initiates abduction in conjunction with deltoid, serrates anterior and infraspinatus. The following tests are consequently not specific for the supraspinatus but are sensitive due to antalgique reflex. Superior rotator cuff insufficiency, present in complete tears, is usually associated with a positive Jobe manoeuver (empty can) (Video) and decreased strength in external resistance elbow at the side (Figure).<ref>Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. Am J Sports Med 1982;10:336-9.</ref>

[[File:Jobe test.mov|thumb|The Jobe test is performed by placing the patient's arms at 90 degrees of abduction within the scapular plane, maximally internally rotating the arms and resisting further abduction by the patient. A positive test occurs with localized pain to the affected arm.]]

[[File:cuff104_2.jpg|thumb|Testing of the strength in external resistance elbow at the side.]]

Testing of abduction strength in the champagne toast position, i.e., 30 degrees of abduction, mild external rotation, and 30 degrees of flexion, better isolates the activity of the supraspinatus from the deltoid than Jobe's “empty can” position (Figure 3).<ref>Chalmers PN, Cvetanovich GL, Kupfer N, Wimmer MA, Verma NN, Cole BJ, Romeo AA, Nicholson GP. The champagne toast position isolates the supraspinatus better than the Jobe test: an electromyographic study of shoulder physical examination tests. J Shoulder Elbow Surg 2016;25:322-9.</ref>
[[File:1562464235806-lg.jpg|center|thumb|900x900px|Testing at 30 degrees of abduction, 30 degrees of forward elevation, 90 degrees of elbow flexion, and mild external rotation replicates a “toast” position.]]
 

====Infraspinatus and Teres Minor====
=====Strength in External Rotation Elbow at the Side=====

Strength in external rotation elbow at the side of the supraspinatus, infraspinatus and teres minor represents approximately 10%, 70% and 20% of total external rotation strength, respectively.<ref>Gerber C, Blumenthal S, Curt A, Werner CM. Effect of selective experimental suprascapular nerve block on abduction and external rotation strength of the shoulder. J Shoulder Elbow Surg 2007;16:815-20.</ref> 

However, the function of the teres minor may become more important in the setting of a chronic infraspinatus tear, as its hypertrophy is commonly observed in these cases and probably compensates for external rotation weakness.

=====External Rotation Lag Sign=====
The external rotation lag sign (Figure and Video), described by Hertel, was designed to test the integrity of infraspinatus and supraspinatus tendons.<ref>Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996;5:307-13</ref>

The extent of internal rotation is recorded to the nearest 10 degrees degrees (10, 20, 30 and 40 degrees or above). An external rotation lag sign > 40 degrees seems to be the most reliable test for the teres minor.<ref name=":5">Collin P, Treseder T, Denard PJ, Neyton L, Walch G, Lädermann A. What is the Best Clinical Test for Assessment of the Teres Minor in Massive Rotator Cuff Tears? Clin Orthop Relat Res 2015;473:2959-66</ref>
[[File:1562464228129-lg.jpg|center|frame|A) The external rotation lag sign is performed seated with the elbow flexed to 90 degrees and the shoulder elevated 20 degrees in the scapular plane. The arm is passively taken to maximal external rotation minus 5 degrees to allow for elastic recoil. B) The patient was asked to maintain that position as the clinician released the wrist. A positive test is defined as any internal rotation of more than 10 degrees. Reproduced from Collin et al., with permission.]]

[[File:ERLS 2 N25 (converti).mov|thumb|External rotation lag sign.]]

=====Drop Sign=====
The drop sign (Figure and Video), also described by Hertel, is designed to assess the function of the infraspinatus.
[[File:1562464890613-lg.jpg|center|frame|A) The drop sign is a lag sign beginning from 90 degrees of abduction in the scapular plane, with elbow flexion of 90 degrees, and external rotation of the shoulder to 90 degrees. From this position, the patient is asked to maintain the position against gravity (MRC Grade 3). B) Failure to resist gravity and internal rotation of the arm is considered a positive drop sign. Reproduced from Collin et al., with permission.]]
[[File:1563115163992-lg.mp4|center|frame|Drop sign]]

=====Hornblower sign=====
The patient is asked to bring both hands to his mouth, but is unable to do so without abducting the affected arm (Video 5).
[[File:1562465141586-lg.mp4|center|thumb|Hornblower sign]]
 

=====Patte Test=====
The Patte test (Figure and Video ) is the only test that allowed to analyze the muscular strength of the teres minor in case of deficient infraspinatus.<ref>Patte D, Goutallier D. [Grande libération antérieure dans l'épaule douloureuse par conflit antérieur]. Rev Chir Orthop Reparatrice Appar Mot 1988;74:306-11.</ref> Walch et al. reported a 100% sensitivity and 93% specificity with the Patte test and teres minor fatty atrophy Grade 3 or greater.<ref name=":6">Walch G, Boulahia A, Calderone S, Robinson AH. The 'dropping' and 'hornblower's' signs in evaluation of rotator-cuff tears. J Bone Joint Surg Br 1998;80:624-8</ref>

[[File:1562465387058-lg.jpg|center|frame|A) The Patte test is performed by passively taking from a starting point of 90 degrees of abduction in the scapular plane, an elbow flexion of 90 degrees without external rotation. B) The patient is asked to perform external rotation of the shoulder from this position against resistance. A positive Patte test is defined as external rotation power less than MRC Grade 4. Reproduce from <ref name=":5" />, with permission.]]

[[File:2 Patte.mov|thumb|Patte test]]

=====Dropping Sign=====
The dropping sign of Neer had a 100% sensitivity and 66% specificity for teres minor involvement.<ref>Neer C. Cuff tears, biceps lesions, and impingement. In: Neer C, ed. Shoulder reconstruction. Philadelphia: W. B. Saunders Company; 1990:41-142.</ref><ref name=":6" />

[[File:Dropping Walch.mov|thumb|Dropping sign]]

==Imaging==

#REDIRECT [[https://wiki.beemed.com/view/Shoulder:Radiographic_Evaluation_of_Shoulder_Problems#Rotator_Cuff_Evaluation]<nowiki>]</nowiki>

==Classification==
The rotator cuff lesions are categorized into four major groups based on involvement of the bone (Type A), tendon (Type B), musculotendinous junction (Type C) or muscle insufficiency (Type D).

[[File:1562468648674-lg.png|thumb|600x600px|alt=|center|Classification of full-thickness rotator cuff lesions in the coronal plane. Reproduced from Lädermann et al.,<ref>Lädermann A, Burkhart SS, Hoffmeyer P, Neyton L, Collin P, Yates E, Denard PJ. Classification of full-thickness rotator cuff lesions: a review. EFORT Open Rev. 2017;1:420-430.</ref> with permission]]

===Type A: Bony Involvement===
While the majority of rotator cuff lesions involve the tendinous insertion, bony involvement is an important consideration. Bony involvement includes acute fractures, malunion/nonunion, and chronic bony insufficiency.

====A1. Acute Bony Involvement (Fractures and Avulsions)====
Isolated greater tuberosity fractures are considered uncommon, representing less than 5% of all operatively treated proximal humeral fractures.<ref>Court-Brown CM, Garg A, McQueen MM. The epidemiology of proximal humeral fractures. Acta Orthop Scand 2001;72:365-71.</ref> 

Isolated lesser tuberosity fractures are generally considered rare. Type A lesion of the greater or lesser tuberosity represent approximately 3.2% and 1.1% respectively of surgically treated rotator cuff lesions (Table). Tuberosity fractures are included in the accepted classification for proximal humeral fractures by Neer, in itself a modification of Codman’s original description. Because the greater and lesser tuberosity are the insertion site of the rotator cuff, even small tuberosity fractures or avulsions can represent substantial disruption of the rotator cuff and lead to functional impairment if displaced and left untreated. Historically, Neer proposed 10 mm of displacement as a threshold for operative intervention.<ref>Neer CS, 2nd. Displaced proximal humeral fractures. I. Classification and evaluation. J Bone Joint Surg Am 1970;52:1077-89.</ref> 

However, more recent investigation has recommended that a threshold of 5 mm should be used.<ref>Bono CM, Renard R, Levine RG, Levy AS. Effect of displacement of fractures of the greater tuberosity on the mechanics of the shoulder. J Bone Joint Surg Br 2001;83:1056-62.</ref> 

Displacement of greater than 5 mm can lead to bony impingement with loss of range of motion as well as loss of strength from compromise in the normal length–tension relationship of the rotator cuff. A traumatic mechanism is typical such as violent muscular contraction, impaction of the greater tuberosity beneath the acromion, or shearing against the anterior glenoid rim during a glenohumeral dislocation event. Thorough patient evaluation is required to make an appropriate treatment recommendation. Conservative therapy is limited to non- or minimally-displaced fractures. The ongoing development of arthroscopic techniques has led to multiple reports about arthroscopically assisted or total arthroscopic techniques in the treatment of these injuries.<ref>Greiner S, Scheibel M. [Bony avulsions of the rotator cuff : Arthroscopic concepts]. Der Orthopade 2011;40:21-4, 6-30.</ref>

====A.2 Tuberosity Malunion/Nonunion====
Tuberosity malunion or nonunion can be a sequela of either conservative treatment or surgical treatment of acute injuries. As noted previously, displacement effectively shortens the muscle-tendon unit such that the rotator cuff cannot function properly (Figures).
[[File:1562470234366-lg.jpg|center|thumb|750x750px|Schema of tuberoplasty for varus malunion of a surgical neck fracture. (A) Intact proximal humerus. (B) Varus malunion results in a medialized greater tuberosity and effectively decreases the resting tension in the rotator cuff. As a result, force generation is compromised. (C) The rotator cuff is detached, and a tuberoplasty is performed with a burr. (D) Reattachment of the rotator cuff laterally results in restoration of the rotator cuff length–tension relation. Reproduce from Lädermann et al.,<ref name=":44" /> with permission.]]
[[File:1562470238482-lg.jpg|center|thumb|750x750px|Schema of tuberoplasty for valgus malunion of 3-part proximal humeral fracture. (A) Intact proximal humerus. (B) Valgus impaction results in superior displacement of the greater tuberosity and effectively decreases the resting tension in the rotator cuff. As a result, force generation is compromised. (C) The rotator cuff is detached, and a tuberoplasty is performed with a burr. (D) Reattachment of the rotator cuff laterally results in restoration of the rotator cuff length-tension relation. Reproduce from Lädermann et al.,<ref name=":44" /> with permission.]]Various open techniques have been described for the management of the malunion of proximal humeral fractures, including prosthetic reconstruction, open corrective osteotomy, or arthroscopic capsular release followed by takedown of the rotator cuff from the malunited proximal humerus, tuberoplasty, and then rotator cuff advancement. Although the latter technique is technically demanding, it allows preservation of the native humeral head, which is associated with a low complication rate, and avoids concerns about long-term prosthetic survival in young patients (Video).<ref name=":13">Burkhart SS, Klein JR. Arthroscopic repair of rotator cuff tears associated with large bone cysts of the proximal humerus: compaction bone grafting technique. Arthroscopy 2005;21:1149.</ref><ref name=":44">Lädermann A, Denard PJ, Burkhart SS. Arthroscopic management of proximal humerus malunion with tuberoplasty and rotator cuff retensioning. Arthroscopy 2012;28:1220-9.</ref>
[[File:1563115162982-lg.mp4|center|thumb|720x720px|Video]]
 
[[File:1563115159736-lg.mp4|center|frame|Video]]
 

====Operative Technique====

The patient was placed in a beach chair or in a lateral decubitus position. A diagnostic arthroscopy is performed with an arthroscopic pump maintaining pressure at 50 mm Hg. The joint surfaces were inspected to rule out any incongruities. The articular side of the rotator cuff is carefully assessed with a probe searching for tears. Any capsular retraction is addressed at this point. A release of the rotator interval and superior glenohumeral ligament is performed with an electrocautery introduced from an anterior portal. This was followed by a release of the posterior, inferior, and anterior capsule 5 mm away from the labrum with an electrocautery introduced from the posterior portal while the surgeon is viewing from an anterosuperolateral portal. If still present, the intra articular part of the long head of the biceps tendon undergo either tenotomy or tenodesis. After treatment of any intra-articular pathology, such as loose body removal, attention is turned to the subacromial space. The lateral and posterolateral gutters are cleared. ny previously placed metal hardware are removed. While the surgeon is viewing from a posterior glenohumeral portal, the tuberoplasty is initiated. The arthroscope is then moved to the subacromial space, and the rotator cuff, if necessary, is sharply elevated from its malunited footprint by use of an electrocautery. Elevation of the rotator cuff consisted of the supraspinatus and anterior half of the infraspinatus, which is the part that overlies the proximally migrated tuberosity (Video). After elevation of the rotator cuff attachments, a burr is used to perform a tuberoplasty. The cuff is assessed for mobility and integrity and is then retensioned by advancing the cuff laterally on the greater tuberosity and performing a rotator cuff repair. The rotator cuff is advanced and repaired. A modified acromioplasty with a lateral bevel is routinely performed if not done previously.

===A.3 Tuberosity Insufficiency===

Tuberosity insufficiency can range from contained cystic bony defects within the tuberosity to the absence of the entire tuberosity. Cystic bony defects are often encountered during primary or revision rotator cuff repair. Such defects may be idiopathic, related to a patient's rotator cuff disease, or secondary to osteolysis from breakdown of bioreabsorbable anchors. These osseous defects reduce biological healing capacity and may decrease repair fixation strength. Bone grafting techniques are needed to address these defects.<ref name=":13" />
[[File:1562471498963-lg.jpg|center|thumb|500x500px|Computed tomography (CT) scan show greater tuberosity bone loss.]] 
In such a situation, a simple tendon rotator repair is usually unsuccessful, as a large bony defect significantly lowers the prognosis for primary repair.<ref>Moore DR, Cain EL, Schwartz ML, Clancy WG, Jr. Allograft reconstruction for massive, irreparable rotator cuff tears. Am J Sports Med 2006;34:392-6.</ref> 
One explanation might be that deltoid tension and therefore function is potentiated by the greater tuberosity, also called “deltoid wrapping”.<ref>Roche CP, Diep P, Hamilton M, Crosby LA, Flurin PH, Wright TW, Zuckerman JD, Routman HD. Impact of inferior glenoid tilt, humeral retroversion, bone grafting, and design parameters on muscle length and deltoid wrapping in reverse shoulder arthroplasty. Bulletin of the Hospital for Joint Disease 2013;71:284-93.</ref> 
Therefore, reconstruction of this combined bony and tendon defect may require both tendinous and bony reconstruction. In older patients, such insufficiency is most reliably addressed with reverse shoulder arthroplasty. However, reverse shoulder arthroplasty is not ideal for young patients as multiple studies have demonstrated increased complications in this patient population.<ref>Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: results after five to fifteen years. J Shoulder Elbow Surg 2013;22:1199-208.</ref><ref>Sershon RA, Van Thiel GS, Lin EC, McGill KC, Cole BJ, Verma NN, Romeo AA, Nicholson GP. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg 2014;23:395-400.</ref> 
Recently, a fresh frozen bony-tendinous allograft of the calcaneus and Achilles tendon has been proposed to address this difficult problem (Video). Long term results and larger series need to confirm this technique.<ref name=":14">Lädermann A, Denard P, Abrassart S, Schwitzguébel A. Achilles Tendon Allograft for an Irreparable Massive Rotator Cuff Tear with Bony Deficiency of the Greater Tuberosity: A Case Report. Knee Surg Sports Traumatol Arthrosc 2016;Jan 25.</ref>

===Surgical Technique===

Allograft Reconstruction with Calcaneum and Achilles Tendon for an Irreparable Massive Rotator Cuff Tear with Bony Deficiency of the Greater Tuberosity (Video). Under general anesthesia and interscalene nerve block, the patient is placed in the beach chair position, with the operative arm draped free. An open anterosuperior incision with a deltoid split is performed in order to expose the greater tuberosity defect. The long head of the biceps was already resected. The remaining posterosuperior rotator cuff was carefully dissected and the proximal humeral head is debrided. The quality of cuff tissue is usually poor (Figure).
[[File:1563115175999-lg.mp4|center|thumb|900x900px|Video]]
[[File:1562472470428-lg.jpg|center|thumb|600x600px|Lateral view of a right shoulder. Observe the bony defect in the greater tuberosity associated with the poor rotator cuff tendon quality.]]
 The Achilles tendon allograft with attached calcaneus is then prepared (Figure and Video).
[[File:1562474028794-lg.jpg|center|thumb|600x600px|The allograft is prepared with an Achilles tendon.]]
The calcaneus is shaped to fill proximal humeral head defect. If necessary, the Achilles tendon is then split longitudinally to decrease its thickness, with the deep layer used to reinforce the rotator cuff repair. Then, the bony portion of the allograft is secured to the humeral head with a 4 mm malleolar screw under fluoroscopic control (Figure).
[[File:1562474027986-lg.jpg|center|thumb|600x600px|Lateral view of a right shoulder. A malleolar screw fixes the calcaneum in the defect. The calcaneum is ready to reinforce the rotator cuff.]]
The native rotator cuff was then repaired onto the bony graft with a combination of an anchor and bone tunnels in the graft. The deep split of Achilles tendon is then sewn into the native posterosuperior rotator cuff to reinforce the repair (Figures and Video).
[[File:1562474087899-lg.jpg|center|thumb|600x600px|Final reconstruction.]]
Two years follow-up confirm bony and tendinous integration (Figures).
[[File:1562474024175-lg.jpg|center|thumb|600x600px|Anteroposterior X-ray of a right shoulder. The bony allograft is incorporated in the proximal humerus, filling the greater tuberosity defect.]]
[[File:1562474554815-lg.jpg|center|thumb|412x412px|Long term computed tomography (CT) arthrogram confirming the repair of the rotator cuff.]]
Postoperatively, the patient wears an abduction pillow for six weeks and is allowed to perform pendulum exercises. After six weeks the abduction pillow is discontinued and passive mobilization is allowed. Full activity return and strengthening was permitted at three months, with a progressive increase of loads.

===Type B: Full Thickness Tendon Lesion===
====B1: Lateral tendinous disruption====

Full thickness disruption of the lateral tendon stump is the most frequent type of rotator cuff lesion, comprising approximately 90.1% of all surgically treated lesions (Table 1). Tendinous lesions most commonly involve the posterosuperior cuff. Subscapularis tears are nevertheless found in 59% of arthroscopic rotator cuff repairs.<ref>Barth JR, Burkhart SS, De Beer JF. The bear-hug test: a new and sensitive test for diagnosing a subscapularis tear. Arthroscopy. 2006;22:1076-84.</ref> However, such tears are only full-thickness in 8.7% of cases, and are rarely isolated (Table 1).

=====Size of Tendon Lesion=====

Classifications for tear size include measurement in centimeters or number of tendons involved. This information can be derived from arthroscopy or magnetic resonance imaging and used to offer guidance on treatment and prognosis.<ref>Cofield RH. Rotator cuff disease of the shoulder. J Bone Joint Surg Am 1985;67:974-9.</ref><ref name=":15">Davidson J, Burkhart SS. The geometric classification of rotator cuff tears: a system linking tear pattern to treatment and prognosis. Arthroscopy 2010;26:417-24.</ref><ref name=":21">Gerber C, Fuchs B, Hodler J. The results of repair of massive tears of the rotator cuff. J Bone Joint Surg Am 2000;82:505-15.</ref><ref>Harryman DT, 2nd, Mack LA, Wang KY, Jackins SE, Richardson ML, Matsen FA, 3rd. Repairs of the rotator cuff. Correlation of functional results with integrity of the cuff. J Bone Joint Surg Am 1991;73:982-9.</ref><ref name=":16">Lädermann A, Denard PJ, Collin P. Massive rotator cuff tears: definition and treatment. International orthopaedics 2015;39:2403-14.</ref>

Once size is identified and if massive, it can be further classified according to Collin et al.<ref name=":1" />

=====Tendon Retraction=====

Patte devised a method of classifying tendon coronal retraction that is often used for research purposes.<ref>Patte D. Classification of rotator cuff lesions. Clin Orthop Relat Res 1990:81-6.</ref>

The retraction is due to tendon and muscle shortening that are not synchronous after tendon tear.<ref name=":10" />

Substance loss in the later stages of musculotendinous retraction may be because of either active shortening of the tendon substance, suggesting that overreduction and lateral transposition of the tendon over the greater tuberosity may be unphysiological.

=====Tear Pattern=====

Full-thickness posterosuperior tears come in a variety of patterns. The most common categories include crescent tears, L and reverse L-shaped tears, and U-shaped tears accounting for respectively 40%, 30% and 15% of posterosuperior rotator cuff lesions.<ref name=":15" />

Recognition of these tear patterns is most useful for anatomic restoration during repair. Crescent tears have good medial to lateral mobility and are amenable to a double-row repair. Longitudinal tears (L and reverse L-shaped tears, and U-shaped tears) have greater mobility in 1 plane and typically require margin convergence to achieve complete repair. Finally, massive contracted tears have also been described. These tears have limited medial to lateral and anterior to posterior mobility and typically require advanced mobilization techniques (i.e. interval slides) to achieve repair.

=====Releases for the Rotator Cuff=====

In clinical practice, rotator cuff tears may present with a wide spectrum of size and mobility. Many massive rotator cuff tears may be reparable without releases and, in contrast, some small rotator cuff tears may require releases. Release is only required if tear may not be reduced to the footprint anatomically as it would otherwise unnecessarily increase the complexity of the procedure. Releases may be divided into bursal sided releases, articular sided releases (i.e. capsular release) and interval slides.

=====Double-Row Versus Single-Row Cuff Repair=====

Biomechanical testing has consistently demonstrated the superiority of double-row constructs.<ref>Hohmann E, König A, Kat CJ, Glatt V, Tetsworth K, Keough N. Single- versus double-row repair for full-thickness rotator cuff tears using suture anchors. A systematic review and meta-analysis of basic biomechanical studies. Eur J Orthop Surg Traumatol. 2018;28:859-868.</ref>

Within the domain of level I mid-term and short-term studies, double-row repair (Video) showed significant better UCLA score only (American Shoulder and Elbow Surgeons (ASES), Constant, WORC, and SANE scores showed no significance). This may correlate weakly with the significant lower partial-thickness retear rates of double-row repairs. In contrary, long-term level III studies showed a direct correlation of both functional outcomes and cuff structural integrity, with significant superiority of double-row over single-row repair techniques.<ref>Sobhy MH, Khater AH, Hassan MR, El Shazly O. Do functional outcomes and cuff integrity correlate after single- versus double-row rotator cuff repair? A systematic review and meta-analysis study. Eur J Orthop Surg Traumatol. 2018;28:593-605.</ref>

=====Margin Convergence=====

Margin convergence to bone can be used in L or V tears. This technique accomplishes margin convergence between the two leaves of the cuff, and at the same time it anchors the cuff to bone, providing very secure fixation. Margin convergence to bone has the mechanical strain reduction advantage of margin convergence coupled with strong fixation to bone. This provides a very secure component to the overall fixation construct.

=====Load Sharing Rip Stop Construct=====

Double-row repair is not possible in the setting of medially based tears, lateral tendon loss, or limited tendon mobility. Load sharing rip stop constructs demonstrated improved functional outcomes with reasonable healing rates in an otherwise challenging subset of rotator cuff tears.<ref name=":22">Noyes MP, Lädermann A, Denard PJ. Functional Outcome and Healing of Large and Massive Rotator Cuff Tears Repaired With a Load-Sharing Rip-Stop Construct. Arthroscopy. 2017 Sep;33(9):1654-1658.</ref>

This suture technique combines the advantages of a rip stop suture tape and load sharing properties of a double-row repair and has biomechanically superior properties compared to a single-row repair (Figure and Video).<ref>Denard PJ, Burkhart SS. A load-sharing rip-stop fixation construct for arthroscopic rotator cuff repair. Arthrosc Tech 2012;1:e37-42.</ref>
[[File:1562475768794-lg.jpg|center|thumb|700x700px|Anchor-based rip-stop rotator cuff repair for rotator cuff tear with lateral tendon loss. (A) A suture has been placed as an inverted mattress stitch in the rotator cuff. Two medial anchors have also been placed, and sutures from these anchors are passed medial to the rip-stop stitch. (B) Prior to tying of the sutures from the medial anchors, the rip-stop stitch is secured to bone with 2 lateral anchors. (C) Tying the suture limbs from the anchors completes the repair. Reproduce from Noyes et al., with permission.]]
[[File:1563115214642-lg.mp4|center|thumb|900x900px|Video]]
[[File:1563115230318-lg.mp4|center|thumb|900x900px|Video]]

=====Massive Posterosuperior Rotator Cuff Tears=====

======Prevalence======
Massive rotator cuff tears comprise approximately 20% of all cuff tears and 80% of recurrent tears.<ref name=":23">Lo IK, Burkhart SS. Arthroscopic revision of failed rotator cuff repairs: technique and results. Arthroscopy 2004;20:250-67.</ref><ref>Burkhart SS, Danaceau SM, Pearce CE, Jr. Arthroscopic rotator cuff repair: Analysis of results by tear size and by repair technique-margin convergence versus direct tendon-to-bone repair. Arthroscopy 2001;17:905-12.</ref>

=====Definition and Classification of Massive Rotator Cuff Tears=====

Historically a massive rotator cuff tear has been described as a tear with a diameter of 5 cm or more as described by Cofield or as a complete tear of two or more tendons as described by Gerber (Figure).<ref>Cofield RH. Subscapular muscle transposition for repair of chronic rotator cuff tears. Surg Gynecol Obstet 1982;154:667-72.</ref><ref name=":21" />

The former in particular is usually applied at the time of surgery. In an attempt to provide a preoperative MRI-based classification, Davidson et al. defined a massive tear as one with a coronal length and sagittal width greater than or equal to 2 cm.<ref name=":15" />

Unfortunately, these systems are vulnerable to error due to variation in patient size and arm position at the time of measurement. It is more appropriate to define the size of a tear in terms of the amount of tendon that has been detached from the tuberosities. While the Gerber definition helps account for variability in size, there are exceptions to the complete two tendons requirement and this classification does not distinguish different patterns or predict function. Additionally, in using the term “massive”, there is a connotation of difficulty and irreparability. While challenging, most massive rotator cuff tears are reparable and other factors like the tendon retraction, atrophy, arthritis, and mobilization must be considered. Thus, in addition to the number of tendons involved, some authors proposed at least one of the two tendons must be retracted beyond the top of the humeral head (i.e Patte 3 for the supraspinatus in the coronal plane).<ref name=":16" />

Such classification also takes advantage of 3-dimensional information on tear pattern, providing guidance on treatment technique.
{| class="wikitable"
|+
!Author
!Description
!Limitation(s)
|-
|Cofield
|5 cm or more
|No 3-dimensional information, variation in patient size and arm position
|-
|Gerber
|≥ 2 complete tendons
|No 3-dimensional information
|-
|Davidson
|Coronal length and sagittal width ≥ 2 cm
|Variation in patient size and arm position
|-
|Lädermann
|≥ 2 complete tendons, 1 tendon with > Patte 2 retraction
|
|}
Table 2: Different Classification of Massive Rotator Cuff Tears

 Once a massive rotator cuff tear is identified, it can be further classified according to Collin et al. In this subclassification, the rotator cuff is divided into five components: supraspinatus, superior subscapularis, inferior subscapularis, infraspinatus, and teres minor (Figure).
[[File:1562478202097-lg.jpg|center|thumb|600x600px|The rotator cuff is divided into 5 components: supraspinatus, superior subscapularis, inferior subscapularis, infraspinatus, and teres minor.]]
Rotator cuff tear patterns can then be classified into 5 types: type A, supraspinatus and superior subscapularis tears; type B, supraspinatus and entire subscapularis tears; type C, supraspinatus, superior subscapularis, and infraspinatus tears; type D, supraspinatus and infraspinatus tears; and type E, supraspinatus, infraspinatus, and teres minor tears (Figure).<ref name=":1" />
[[File:1562478202102-lg.jpg|center|thumb|600x600px|Rotator cuff tears classified by the involved components: type A, supraspinatus and superior subscapularis tears; type B, supraspinatus and entire subscapularis tears; type C, supraspinatus, superior subscapularis, and infraspinatus tears; type D, supraspinatus and infraspinatus tears; and type E, supraspinatus, infraspinatus, and teres minor tears.]]
This classification not only subclassifies massive tears but has also been linked to function, particularly the maintenance of active elevation, offering more information than the traditional six sagittal segments of Patte’s classification.

=====Rotator Cuff Incarceration in the Glenohumeral Joint=====
Case of a complete rotator cuff tendon avulsion with glenohumeral joint incarceration after significant trauma to the shoulder have been described.<ref>Dodson CC, Bedi A, Sahai A, Potter HG, Cordasco FA. Complete rotator cuff tendon avulsion and glenohumeral joint incarceration in a young patient: A case report. J Shoulder Elbow Surg. 2010;19:e9–e12.</ref>

[[File:Incarceration sup.png|thumb|Anteroposterior radiograph of the left shoulder demonstrates superior subluxation as evidenced by the decrease in the interval between the acromion and the superior aspect of the humeral head. Coronal fast-spin echo magnetic resonance image (MRI) demonstrates an avulsion of the supraspinatus tendon, which is draped over the superior labrum and extends into the glenohumeral joint. The humeral head is subluxated superolaterally.]]

=====Suprascapular Nerve Neuropathy and Massive Rotator Cuff Tear=====
Recently there has been growing interest in the relationship between suprascapular neuropathy and massive rotator cuff tears. Theoretically, medial retraction of posterosuperior rotator cuff tears can place excessive traction on the suprascapular nerve.<ref>Albritton MJ, Graham RD, Richards RS, 2nd, Basamania CJ. An anatomic study of the effects on the suprascapular nerve due to retraction of the supraspinatus muscle after a rotator cuff tear. J Shoulder Elbow Surg 2003;12:497-500.</ref>

However, clinical diagnosis is beset with uncertainties as the potential symptoms of suprascapular nerve neuropathy, namely, pain, weakness, and atrophy, are inseparable from those of massive rotator cuff tear. There is actually no support for routine suprascapular nerve release when repair is performed for several reasons. First, it is clearly demonstrated that repair of repair without release leads to satisfactory results. Moreover, the prevalence of suprascapular nerve neuropathy in case of massive rotator cuff tears in a prospective study is low (2%).<ref name=":17">Collin P, Treseder T, Lädermann A, Benkalfate T, Mourtada R, Courage O, Favard L. Neuropathy of the suprascapular nerve and massive rotator cuff tears: a prospective electromyographic study. J Shoulder Elbow Surg 2014;23:28-34.</ref>

====Treatment Options for Massive Rotator Cuffs====
It should be remembered that nonoperative treatment is successful in many cases. When surgery is indicated, the primary aim is restoration of force couples and anatomic or partial repair of the rotator cuff to its footprint. However, a number of factors (refusal of the patient, biologic factors, characteristics of the tear, etc) can make these goals difficult, impossible, or unwanted to achieve. Fatty infiltration, rotator cuff retraction, and poor tendon compliance are common in patients with massive rotator cuff tears. In these situations, other approaches have been advocated, with varying degrees of success.<ref>Berhouet J, Collin P, Benkalfate T, Le Du C, Duparc F, Courage O, Favard L; Société d'Orthopédie de l'Ouest. Massive rotator cuff tears in patients younger than 65 years. Epidemiology and characteristics. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:S13-8.</ref>

These include physical therapy,59,60 subacromial decompression and palliative biceps tenotomy (subacromial debridement),61 muscle transfer,62 and reverse shoulder arthroplasty.63 However, there are no randomized controlled trials comparing these various options and recommendations are mainly based on retrospective case series and the surgeon’s own experiences.<ref name=":24">Collin PG, Gain S, Nguyen Huu F, Lädermann A. Is rehabilitation effective in massive rotator cuff tears? Orthopaedics & traumatology, surgery & research : OTSR 2015;101:S203-5.</ref><ref name=":26">Zingg PO, Jost B, Sukthankar A, Buhler M, Pfirrmann CW, Gerber C. Clinical and structural outcomes of nonoperative management of massive rotator cuff tears. J Bone Joint Surg Am 2007;89:1928-34.</ref><ref name=":25">Walch G, Edwards TB, Boulahia A, Nove-Josserand L, Neyton L, Szabo I. Arthroscopic tenotomy of the long head of the biceps in the treatment of rotator cuff tears: clinical and radiographic results of 307 cases. J Shoulder Elbow Surg 2005;14:238-46.</ref><ref name=":27">Gerber C, Rahm SA, Catanzaro S, Farshad M, Moor BK. Latissimus dorsi tendon transfer for treatment of irreparable posterosuperior rotator cuff tears: long-term results at a minimum follow-up of ten years. J Bone Joint Surg Am 2013;95:1920-6.</ref><ref>Wall B, Nove-Josserand L, O'Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am 2007;89:1476-85.</ref>

=====Conservative Treatment=====
Many patients with massive rotator cuff tears respond favorably to nonsurgical treatment. Nevertheless, patients must be aware that despite clinical improvement, future treatment may be impacted by progression of glenohumeral osteoarthritis and fatty infiltration as well as narrowing of the acromiohumeral distance. In a series of 19 patients with massive rotator cuff tears treated nonoperatively the average Constant score was 83% at a mean follow-up of 48 months. However, 50% of “reparable” tears became “irreparable” during this period.<ref name=":26" />

The mainstay of nonoperative treatment includes nonsteroidal anti-inflammatory drugs, subacromial corticosteroid injections, and physical therapy. The protocol of rehabilitation focused habitually on global deltoid reconditioning and periscapular strengthening. Although certain authors proposed that re-education of the anterior deltoid muscle to compensate for a deficient rotator cuff is the cornerstone, we attach more importance to solicitation of stabilizing muscles of the glenohumeral joint with an approach based on exercises in high position. In this position, the deltoid, which acts synergistically with the remaining rotator muscles, has no upward component and participates in the articular coaptation.<ref name=":24" />

In general, nonoperative management is attempted for six months before considering surgery. Younger patients (<60 years of age), however, may be immediate candidates for surgery based on the high risk for progression with conservative treatment. If after six months, symptoms have not improved, the chances of success with further nonoperative treatment decreases and operative treatment may be considered for older patients. It is unclear if it is exercise alone or exercise in combination with other interventions during the recovery process that offers the greatest benefit. In a recent prospective cohort of 45 patients suffering from pseudoparalysis with a radiographically confirmed massive rotator cuff tears, Collin and al. found after a follow-up of 48 months that the mean Constant score improved from 43 to 56 points and the mean forward flexion improved from 76 degrees to more than 160 degrees after completion of the program. They also demonstrated that effectiveness of physical therapy is related to the size and location of the lesion; if the tear involved the posterosuperior rotator cuff (B type), or only two tendons or less, most patients regained active anterior elevation that persisted for 48 months. The anterior rotator cuff is the key of anterior active elevation as only 20% of patients with MRCTs, but an intact subscapularis, develop pseudoparalysis.

=====Surgical (Operative) Treatment=====
For older patients surgery is considered when nonoperative treatment fails. Additionally, we often consider surgery as first line treatment in young patients because there is a high rate of progression with conservative treatment and for tears involving the anterior rotator cable since this area is most important to maintenance of forward elevation.

======Arthroscopic Rotator Cuff Repair======
The approach is to repair all of the rotator cuff that can reasonably be brought back to the tuberosities without excessive tension, and to address all potential causes of persistent pain or factors threatening the repair. The goal of a repair, even if partial, is to restore force couples and to re-establish the “suspension bridge”. In this theory, complete closure of the defect is less important than restoration of a stable fulcrum for normal shoulder kinematics. Although shoulder strength may not improve after this intervention, function is usually enhanced because of relief from pain caused by mechanical impingement. Additionally, although complete healing of massive tears is not always achievable, we believe that partial healing of the cuff may prevent secondary extension of the tear.

======The Acromion and Biceps======
Over the last decade, arthroscopic acromioplasty has been widely performed as an adjuvant to rotator cuff repair, to increase subacromial space and thereby decrease wear of the repaired tendon.<ref name=":0">McFarland EG, Matsen FA 3rd, Sanchez-Sotelo J. Clinical Faceoff: What is the Role of Acromioplasty in the Treatment of Rotator Cuff Disease? Clin Orthop Relat Res. 2018;476(9):1707-1712</ref><ref>Neer CS 2nd. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. J Bone Joint Surg Am. 1972;54(1):41-50</ref> Acromioplasty has the potential advantages of decreasing strain on the repaired tendon by changing the vector of the deltoid muscle, improving the healing response by increasing bone-marrow derived cells, creating more working space for rotator cuff repair<ref name=":0" /> and possibly to lower the reoperation rate.<ref>MacDonald P, McRae S, Leiter J, Mascarenhas R, Lapner P. Arthroscopic rotator cuff repair with and without acromioplasty in the treatment of full-thickness rotator cuff tears: a multicenter, randomized controlled trial. J Bone Joint Surg Am. 2011;93(21):1953-60</ref> However, recent studies reported no direct clinical benefits of adjuvant acromioplasty in the short- or mid-terms,<ref>Bond EC, Maher A, Hunt L, Leigh W, Brick M, Young SW, Caughey M. The role of acromioplasty when repairing rotator cuff tears-no difference in pain or functional outcome at 24 months in a cohort of 2,441 patients. N Z Med J. 2017;130:13-20.</ref><ref>Chahal J, Mall N, MacDonald PB, Van Thiel G, Cole BJ, Romeo AA, Verma NN. The role of subacromial decompression in patients undergoing arthroscopic repair of full-thickness tears of the rotator cuff: a systematic review and meta-analysis. Arthroscopy. 2012;28:720-7.</ref><ref>Ketola S, Lehtinen J, Arnala I, Nissinen M, Westenius H, Sintonen H, Aronen P, Konttinen YT, Malmivaara A, Rousi T. Does arthroscopic acromioplasty provide any additional value in the treatment of shoulder impingement syndrome?: a two-year randomised controlled trial. J Bone Joint Surg Br. 2009;91(10):1326-34</ref><ref>Ketola S, Lehtinen JT, Arnala I. Arthroscopic decompression not recommended in the treatment of rotator cuff tendinopathy: a final review of a randomised controlled trial at a minimum follow-up of ten years. Bone Joint J. 2017;99-B(6):799-805</ref><ref>Kolk A, Thomassen BJW, Hund H, de Witte PB, Henkus HE, Wassenaar WG, van Arkel ERA, Nelissen RGHH. Does acromioplasty result in favorable clinical and radiologic outcomes in the management of chronic subacromial pain syndrome? A double-blinded randomized clinical trial with 9 to 14 years' follow-up. J Shoulder Elbow Surg. 2017;26:1407-15.</ref><ref>Mardani-Kivi M, Karimi A, Keyhani S, Hashemi-Motlagh K, Saheb-Ekhtiari K. Rotator Cuff Repair: Is there any role for acromioplasty? Phys Sportsmed. 2016;44:274-7.</ref><ref>Paloneva J, Lepola V, Karppinen J, Ylinen J, Äärimaa V, Mattila VM. Declining incidence of acromioplasty in Finland. Acta Orthop. 2015;86:220-4.</ref><ref>Saltychev M, Äärimaa V, Virolainen P, Laimi K. Conservative treatment or surgery for shoulder impingement: systematic review and meta-analysis. Disabil Rehabil. 2015;37:1-8.</ref><ref>Shin SJ, Oh JH, Chung SW, Song MH. The efficacy of acromioplasty in the arthroscopic repair of small- to medium-sized rotator cuff tears without acromial spur: prospective comparative study. Arthroscopy. 2012;28:628-35.</ref> suggesting that the procedure should be performed only in selected patients. The morphology of the scapula and of the humerus is highly variable and bone removal may not be routinely necessary. Avoiding acromioplasty and particularly detaching the coracoacromial ligament may be preferable regarding alteration of the coracoacromial arch, as it might cause significant anterosuperior translation or even escape of the humeral head,<ref>Su WR, Budoff JE, Luo ZP. The effect of coracoacromial ligament excision and acromioplasty on superior and anterosuperior glenohumeral stability. Arthroscopy. 2009;25:13-8.</ref><ref>Wiley AM. Superior humeral dislocation. A complication following decompression and debridement for rotator cuff tears. Clin Orthop Relat Res. 1991:135-41.</ref> weakening of the deltoid origin<ref>Katthagen JC, Marchetti DC, Tahal DS, Turnbull TL, Millett PJ. The Effects of Arthroscopic Lateral Acromioplasty on the Critical Shoulder Angle and the Anterolateral Deltoid Origin: An Anatomic Cadaveric Study. Arthroscopy. 2016;32:569-75.</ref> and adhesions between the raw exposed bone on the undersurface of the acromion and the underlying tendon.<ref>Liu J, Hughes RE, Smutz WP, Niebur G, Nan-An K. Roles of deltoid and rotator cuff muscles in shoulder elevation. Clin Biomech (Bristol, Avon). 1997;12:32-38.</ref><ref>Goldberg BA, Lippitt SB, Matsen FA 3rd. Improvement in comfort and function after cuff repair without acromioplasty. Clin Orthop Relat Res. 2001;142-50.</ref><ref name=":28">Romeo AA, Loutzenheiser T, Rhee YG, Sidles JA, Harryman DT 2nd, Matsen FA 3rd. The humeroscapular motion interface. Clin Orthop Relat Res. 1998;120-7.</ref> In addition, even if the role of the lateral overhanging has been recently emphasized,<ref>Moor BK, Wieser K, Slankamenac K, Gerber C, Bouaicha S. Relationship of individual scapular anatomy and degenerative rotator cuff tears. J Shoulder Elbow Surg. 2014;23:536-41.</ref><ref>Nyffeler RW, Werner CM, Sukthankar A, Schmid MR, Gerber C. Association of a large lateral extension of the acromion with rotator cuff tears. J Bone Joint Surg Am. 2006;88:800-5.</ref> it is still unknown if a lateral acromioplasty to decrease critical shoulder angle (CSA)<ref>Moor BK, Bouaicha S, Rothenfluh DA, Sukthankar A, Gerber C. Is there an association between the individual anatomy of the scapula and the development of rotator cuff tears or osteoarthritis of the glenohumeral joint?: A radiological study of the critical shoulder angle. Bone Joint J. 2013;95-B:935-41.</ref> is a safe procedure that could improve clinical outcome. Complete anterior acromioplasty is not advisable in the setting of a massive tear as it may lead to postoperative anterosuperior migration of the humeral head. The acromiohumeral arch is probably a component of human evolution used to compensate the deficiency of the superior rotator cuff.<ref name=":4" /> Consequently, when and how should acromioplasty should be performed is still debated.<ref>Voisin JL, Ropars M, Thomazeau H. The human acromion viewed from an evolutionary perspective. Orthopaedics & traumatology, surgery & research : OTSR 2014;100:S355-60.</ref> The type of acromioplasty has to be correlated to our actual practice. A recent dynamic evaluation of subacromial impingement revealed that impingement is not anterior as previously believed and that detachment of the coracoacromial ligament is not necessary.<ref>Lädermann A, Chagué S, Preissmann D, Kolo FC, Rime O, Kevelham B, Bothorel H, Charbonnier C. Guided versus freehand acromioplasty during rotator cuff repair. A randomized prospective study. Orthop Traumatol Surg Res. 2020:;106(4):651-659</ref> Moreover, it has been shown that acromioplasty significantly reduces dynamic subacromial impingement compared to preoperative situation.<ref>Lädermann A, Chagué S, Preissmann D, Kolo FC, Zbinden O, Kevelham B, Bothorel H, Charbonnier C. Acromioplasty during repair of rotator cuff tears removes only half of the impinging acromial bone. JSES Int. 2020:29;4:592-600.</ref> Furthermore, Gerber et al. advocated that adjuvant acromioplasty is necessary in shoulders with high critical shoulder angle (preoperative CSA≥34 degrees), and found that insufficient acromial resection (postoperative CSA≥35 degrees) is associated with significantly worse abductor strength and higher retear rate.<ref>Gerber C, Catanzaro S, Betz M, Ernstbrunner L. Arthroscopic Correction of the Critical Shoulder Angle Through Lateral Acromioplasty: A Safe Adjunct to Rotator Cuff Repair. Arthroscopy. 2018;34:771-780.</ref>

A tenotomy or tenodesis of the long head of the biceps should be performed in the setting of a massive rotator cuff tear. There is evidence suggesting that the long head of the biceps tendon may be a source of pain and contributes to the discomfort. In a large series, Walch et al. observed an increase in the Constant score from 48.4 preoperatively to 67.6 after arthroscopic biceps tenotomy. At last follow-up, 87% of patients were satisfied or very satisfied with the result. However, the acromiohumeral interval decreased by a mean of 1.3 mm during the follow-up period.<ref name=":25" />

======Repair Techniques======

Unfortunately, even if reinsertion of the tendon on the bone is achievable, it is often difficult to reliably achieve long-term healing with a structurally intact repair.<ref>Zumstein MA, Jost B, Hempel J, Hodler J, Gerber C. The clinical and structural long-term results of open repair of massive tears of the rotator cuff. J Bone Joint Surg Am 2008;90:2423-31.</ref>

In the setting of a massive tear, a double-row repair improves long-term functional outcome.<ref>Carbonel I, Martinez AA, Calvo A, Ripalda J, Herrera A. Single-row versus double-row arthroscopic repair in the treatment of rotator cuff tears: a prospective randomized clinical study. Int Orthop 2012;36:1877-83.</ref><ref>Connelly TM, Shaw A, O'Grady P. Outcome of open massive rotator cuff repairs with double-row suture knotless anchors: case series. Inter Orthop 2015;39:1109-14.</ref><ref name=":29">Denard PJ, Jiwani AZ, Lädermann A, Burkhart SS. Long-term outcome of arthroscopic massive rotator cuff repair: the importance of double-row fixation. Arthroscopy 2012;28:909-15.</ref>

However, this should not be performed at the expense of over-tensioning as application of a double-row repair to a tendon with poor tendon length and excursion may lead to medial failure.<ref name=":10" />

======Augmentation======

Graft augmentation may improve healing in massive rotator cuff tears, but add significant cost and time to the procedure.<ref>Barber FA, Burns JP, Deutsch A, Labbe MR, Litchfield RB. A prospective, randomized evaluation of acellular human dermal matrix augmentation for arthroscopic rotator cuff repair. Arthroscopy 2012;28:8-15.</ref>

The choice of graft is influenced by several factors including mechanical properties, host response and potential for ingrowth. Scaffolds provide mechanical support and have biological properties that may favorably influence cell proliferation and differentiation, hopefully improving tendon-to-bone healing. Currently, scaffolds derived from dermis, small intestinal submucosa, skin, fascia lata, and pericardium have been processed and marketed for augmentation in the repair of massive tears. Biological grafts are preferred, when compared to synthetic grafts, due to the unknown host response to synthetic grafts. An important factor in the longevity and strength of a graft is the amount of ingrowth.

======Results of Primary Repairs======

Results following arthroscopic repair of massive rotator cuffs have previously been reported.<ref name=":30">Denard PJ, Lädermann A, Jiwani AZ, Burkhart SS. Functional outcome after arthroscopic repair of massive rotator cuff tears in individuals with pseudoparalysis. Arthroscopy 2012;28:1214-9.</ref><ref name=":31">Lädermann A, Denard PJ, Burkhart SS. Midterm outcome of arthroscopic revision repair of massive and nonmassive rotator cuff tears. Arthroscopy 2011;27:1620-7.</ref>

For primary repair, improvements are observed in forward flexion (132 degrees vs 168 degrees), pain (6.3 v 1.3), UCLA score, (15.7 v 30.7) and American Shoulder and Elbow Surgeons score (41.7 v 85.7) (P<.001). A good or excellent outcome is obtained in 78% of cases. Similar results are noticed after repair of type A, B and C massive rotator cuff tears.<ref name=":29" />

After revision repair, mean active forward elevation improves by 15 degrees, from 136.0 degrees ± 51.9 degrees (range, 30 to 180 degrees) at baseline to 151.4 degrees ± 41.5 degrees (range, 30 to 180 degrees) at final follow-up (P=.019). The mean pain score improves by 3.1 points, from 5.0 ± 2.4 points at baseline to 1.9 ± 2.3 points at final follow-up (p<.001). The mean American Shoulder and Elbow Surgeons (ASES) score improves from 45.7 ± 17.8 at baseline to 75.5 ± 20.3 at final follow-up (P<.001). The mean UCLA score also improves, from 16.7 ±4.9 at baseline to 26.4 ± 6.9 at final follow-up (P<.001). According to the UCLA score, functional results are excellent in 15% of cases, good in 35%, fair in 25%, and poor in 25%. Seventy-nine percent of the patients are satisfied, and 32 patients (60%) returned to their previous activities.<ref name=":31" />

======Revision Rotator Cuff Repair======
'''Introduction'''

Failure of tendon healing after rotator cuff repair is common, reported in approximately 20% of cases depending on tear size.<ref>Collin P, Abdullah A, Kherad O, Gain S, Denard PJ, Lädermann A. Prospective evaluation of clinical and radiologic factors predicting return to activity within 6 months after arthroscopic rotator cuff repair. J Shoulder Elbow Surg 2015;24:439-45.</ref>

Tear recurrence can be related to various factors such as: 1) inadequate strength of the initial repair construct, 2) biological failure to heal despite strong initial fixation, and 3) inappropriate post-operative rehabilitation causing structural failure of the repair.<ref>Boileau P, Brassart N, Watkinson DJ, Carles M, Hatzidakis AM, Krishnan SG. Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? J Bone Joint Surg Am 2005;87:1229-40.</ref><ref>Cho NS, Moon SC, Jeon JW, Rhee YG. The influence of diabetes mellitus on clinical and structural outcomes after arthroscopic rotator cuff repair. Am J Sports Med 2015;43:991-7.</ref><ref>Chung SW, Oh JH, Gong HS, Kim JY, Kim SH. Factors affecting rotator cuff healing after arthroscopic repair: osteoporosis as one of the independent risk factors. Am J Sports Med 2011;39:2099-107.</ref><ref>Clement ND, Hallett A, MacDonald D, Howie C, McBirnie J. Does diabetes affect outcome after arthroscopic repair of the rotator cuff? J Bone Joint Surg Br 2010;92:1112-7.</ref>

While functional outcome has been correlated with postoperative rotator cuff integrity many patients maintain a satisfactory outcome despite structural failure.<ref name=":32">Jost B, Zumstein M, Pfirrmann CW, Gerber C. Long-Term Outcome After Structural Failure of Rotator Cuff Repairs. J Bone Joint Surg Am 2006;88:472-9.</ref>

The ideal treatment for a recurrent tear is thus not completely defined.

'''Initial Radiological Findings'''

The goal of imaging studies is to confirm the site of the recurrent tear. Trantalis et al. reported five patients with retearing of the cuff after double-row rotator cuff repair. All five patients had retearing medial to the medial row if sutures were placed near the musculotendinous junction of the supraspinatus.<ref name=":33">Trantalis JN, Boorman RS, Pletsch K, Lo IK. Medial rotator cuff failure after arthroscopic double-row rotator cuff repair. Arthroscopy 2008;24:727-31.</ref>

Hayashida et al. observed that the prevalence of complete retearing of the tendon after a double-row rotator cuff repair is similar around the medial anchors with a well-preserved footprint.<ref name=":35">Hayashida K, Tanaka M, Koizumi K, Kakiuchi M. Characteristic retear patterns assessed by magnetic resonance imaging after arthroscopic double-row rotator cuff repair. Arthroscopy 2012;28:458-64.</ref>

Another point of interest is the quality of the tendon.<ref>Denard PJ, Burkhart SS. Techniques for managing poor quality tissue and bone during arthroscopic rotator cuff repair. Arthroscopy 2011;27:1409-21.</ref>

A significant and growing number of rotator cuff repairs are performed in individuals with poor rotator cuff tissue quality. Djurasovic reported an incidence of 30% (24 on 80) of poor rotator cuff tissue quality (graded subjectively at the time of surgery).<ref name=":36">Djurasovic M, Marra G, Arroyo JS, Pollock RG, Flatow EL, Bigliani LU. Revision rotator cuff repair: factors influencing results. J Bone Joint Surg Am 2001;83-A:1849-55.</ref>

At the same time, the muscle undergoes intrinsic degeneration. After a retear, Deniz et al. found that fatty infiltration and atrophy continued to worsen significantly.<ref name=":18">Deniz G, Kose O, Tugay A, Guler F, Turan A. Fatty degeneration and atrophy of the rotator cuff muscles after arthroscopic repair: does it improve, halt or deteriorate? Arch Orthop Trauma Surg 2014;134:985-90.</ref>

However, fatty infiltration of the supraspinatus does not seem to be a determinant factor in tendon healing. Park et al. did not find significant relationship between preoperative supraspinatus fatty infiltration and postoperative tendon healing. Contrarily, it seems that fatty infiltration of infraspinatus and subscapularis are highly significant factors (P<.001).<ref name=":37">Park JS, Park HJ, Kim SH, Oh JH. Prognostic Factors Affecting Rotator Cuff Healing After Arthroscopic Repair in Small to Medium-sized Tears. Am J Sports Med 2015;43:2386-92.</ref>

Another point is the bone quality. Oh et al. demonstrated that bone mineral density within the greater tuberosity decreases in patients with rotator cuff tears. In another retrospective study that investigated the relationship between greater tuberosity osteopenia and chronicity of rotator cuff tears, Cadet et al. found that there were significantly greater osteopenic changes in the greater tuberosity in patients with chronic retracted rotator cuff tears.<ref>Cadet ER, Hsu JW, Levine WN, Bigliani LU, Ahmad CS. The relationship between greater tuberosity osteopenia and the chronicity of rotator cuff tears. J Shoulder Elbow Surg 2008;17:73-7.</ref>

However, this localized osteoporosis may not influence tendon healing. In a recent study, Park et al. did not observe after primary repair that bone mineral density influenced final results.<ref name=":37" />

Nevertheless, the greater tuberosity in revision cases can also be deficient due to anchor removal or perianchor cyst formation. Kim et al. observed in a retrospective case series of two hundred and nine patients bone cyst formation in 97 instances (46.4%), and these authors questioned the utility of bioabsorbable anchors because of possible interference with revision surgery. Consequent bone lysis can be noticed after trauma. Lädermann et al. reported massive bone resorption after osteosynthesis of the greater tuberosity leading to combined tendon and bony insufficiency and pseudoparalysis/pseudoparesis.

When milestones of typical post-operative recovery are not met, analysis of rotator cuff repair should be considered and a multi-modal evaluation is required. The goal of imaging studies is to confirm the site of the recurrent tear (Figure)86,92 the type of failure (e.g. in continuity), and if possible, it’s cause.<ref name=":35" /><ref>Mellado JM, Calmet J, Olona M, Ballabriga J, Camins A, Pérez del Palomar L, Giné J. MR assessment of the repaired rotator cuff: prevalence, size, location, and clinical relevance of tendon rerupture. European radiology 2006;16:2186-96.</ref><ref>McCarron JA, Derwin KA, Bey MJ, Polster JM, Schils JP, Ricchetti ET, Iannotti JP. Failure with continuity in rotator cuff repair "healing". Am J Sports Med 2013;41:134-41.</ref>
[[File:1562480510006-lg.jpg|center|thumb|600x600px|Figure 25. Six patterns of anatomic deficiency associated with failed rotator cuff repair. (A) Failure of tendon healing; (B) poor tendon quality; (C) fatty infiltration/atrophy; (D) retear medial to the medial row of fixation; (E) bone defects in the greater tuberosity after anchor removal, or perianchor cyst formation and (F) bony and tendinous insufficiency. Reproduced from Lädermann et al., with permission.]]
Other points of interest are the quality of the bone (tuberosity deficiency), tendon, and muscle, and whether further surgery is feasible.<ref name=":14" /><ref name=":18" />

Standard shoulder radiographs, including anteroposterior, axillary lateral and scapular Y (outlet) views, may demonstrate decreased acromiohumeral distance, glenohumeral arthritis, subacromial spurs, acetabularization of the acromion, femoralization of the humeral head, and implant or anchor migration.<ref name=":38">Hartzler RU, Sperling JW, Schleck CD, Cofield RH. Clinical and radiographic factors influencing the results of revision rotator cuff repair. International journal of shoulder surgery 2013;7:41-5.</ref><ref name=":7" />

It can also be used to rule out chondrolysis, anchor migration or prominence, and acromial fracture. Among evaluation techniques, the most widely accepted reference standard is magnetic resonance imaging which allows visualization of the tendons and does not involve radiation exposure. Intra-articular contrast may be used in association with magnetic resonance imaging to increase the sensitivity for detecting a recurrent tear.<ref>de Jesus JO, Parker L, Frangos AJ, Nazarian LN. Accuracy of MRI, MR arthrography, and ultrasound in the diagnosis of rotator cuff tears: a meta-analysis. AJR American journal of roentgenology 2009;192:1701-7.</ref>

Postoperative magnetic resonance imaging images are difficult to interpret; inadequate coverage of the greater or lesser tuberosity may indicate partial healing and not a recurrent full-thickness tear.<ref name=":39">Khazzam M, Kuhn JE, Mulligan E, Abboud JA, Baumgarten KM, Brophy RH, Jones GL, Miller B, Smith M, Wright RW. Magnetic resonance imaging identification of rotator cuff retears after repair: interobserver and intraobserver agreement. Am J Sports Med 2012;40:1722-7.</ref><ref>Saccomanno MF, Cazzato G, Fodale M, Sircana G, Milano G. Magnetic resonance imaging criteria for the assessment of the rotator cuff after repair: a systematic review. Knee Surg Sports Traumatol Arthrosc 2015;23:423-42.</ref><ref>Motamedi AR, Urrea LH, Hancock RE, Hawkins RJ, Ho C. Accuracy of magnetic resonance imaging in determining the presence and size of recurrent rotator cuff tears. J Shoulder Elbow Surg 2002;11:6-10.</ref>

Furthermore, only 10% of re-attached tendons generate a normal magnetic resonance imaging signal. Thus, a common finding is the presence of an intermediate signal within the tendon indicating granulation tissue or of a low-intensity signal produced by fibrous tissue.<ref name=":39" /><ref>Zanetti M, Hodler J. MR imaging of the shoulder after surgery. Radiologic clinics of North America 2006;44:537-51, viii.</ref>

These signal changes may persist for longer than six months, due to tissue remodeling, and seem to have no clinical implications.<ref>Tudisco C, Bisicchia S, Savarese E, Fiori F, Bartolucci DA, Masala S, Simonetti G. Single-row vs. double-row arthroscopic rotator cuff repair: clinical and 3 Tesla MR arthrography results. BMC musculoskeletal disorders 2013;14:43.</ref><ref>Gerber C, Schneeberger AG, Perren SM, Nyffeler RW. Experimental rotator cuff repair. A preliminary study. J Bone Joint Surg Am 1999;81:1281-90.</ref>

Finally, the evaluation of magnetic resonance imaging scans is made difficult by the normal leakage of fluid into the subacromial space after the opening of the rotator interval and passage of instruments through the tendon, which may contain artifacts generated, for instance, by metal anchors or high-strength sutures. These factors, together with the high cost of magnetic resonance imaging, lend considerable appeal to ultrasound as a method for evaluating rotator cuff repair, even if its effectiveness is operator-dependent.<ref>Ok JH, Kim YS, Kim JM, Yoo TW. Learning curve of office-based ultrasonography for rotator cuff tendons tears. Knee Surg Sports Traumatol Arthrosc 2013;21:1593-7.</ref>

Computed tomography arthrogram can also be used to aid in the identification of recurrent rotator cuff tears when neither ultrasound or magnetic resonance imaging are options.<ref>Nazarian LN, Jacobson JA, Benson CB, Bancroft LW, Bedi A, McShane JM, Miller TT, Parker L, Smith J, Steinbach LS, Teefey SA, Thiele RG, Tuite MJ, Wise JN, Yamaguchi K. Imaging algorithms for evaluating suspected rotator cuff disease: Society of Radiologists in Ultrasound consensus conference statement. Radiology 2013;267:589-95.</ref>

Failure after rotator cuff repair was previously believed to occur during the first three months.<ref>Kluger R, Bock P, Mittlbock M, Krampla W, Engel A. Long-term survivorship of rotator cuff repairs using ultrasound and magnetic resonance imaging analysis. Am J Sports Med 2011;39:2071-81.</ref><ref>Miller BS, Downie BK, Kohen RB, Kijek T, Lesniak B, Jacobson JA, Hughes RE, Carpenter JE. When do rotator cuff repairs fail? Serial ultrasound examination after arthroscopic repair of large and massive rotator cuff tears. Am J Sports Med 2011;39:2064-70.</ref>

While the majority of retears do occur within the first three months, it has now been demonstrated retears can occur up to six months after repair.<ref>Barth J, Fotiadis E, Barthelemy R, Genna S, Saffarini M. Ultrasonic evaluation of the repair integrity can predict functional outcomes after arthroscopic double-row rotator cuff repair. Knee Surg Sports Traumatol Arthrosc 2015;23:376-85.</ref><ref>Iannotti JP, Deutsch A, Green A, Rudicel S, Christensen J, Marraffino S, Rodeo S. Time to failure after rotator cuff repair: a prospective imaging study. J Bone Joint Surg Am 2013;95:965-71.</ref><ref>Kim JH, Hong IT, Ryu KJ, Bong ST, Lee YS, Kim JH. Retear rate in the late postoperative period after arthroscopic rotator cuff repair. Am J Sports Med 2014;42:2606-13.</ref>

Recent prospective studies have confirmed that ultrasound has a high sensitivity and specificity for detecting a recurrent rotator cuff tear compared to magnetic resonance imaging.In a study comparing magnetic resonance imaging and ultrasound after rotator cuff repair, Codsi et al. found 92% agreement with a coefficient of 0.70.<ref>Codsi MJ, Rodeo SA, Scalise JJ, Moorehead TM, Ma CB. Assessment of rotator cuff repair integrity using ultrasound and magnetic resonance imaging in a multicenter study. J Shoulder Elbow Surg 2014;23:1468-72.</ref>

Similarly, Collin et al. reported that ultrasound had 80% sensitivity and 98% specificity compared to magnetic resonance imaging.<ref>Collin P, Yoshida M, Delarue A, Lucas C, Jossaume T, Lädermann A; French Society for Shoulder and Elbow (SOFEC). Evaluating postoperative rotator cuff healing: Prospective comparison of MRI and ultrasound. Orthopaedics & traumatology, surgery & research : OTSR 2015;101:S265-8.</ref>

=====Treatment=====

======Non Surgical (Conservative) Treatment of Failed Rotator Cuff Repair======
Jost et al. evaluated 20 patients with a failed rotator cuff repair at a mean follow-up of 38 months and reported that the adjusted Constant score and shoulder simple value averaged 83% and 75%, respectively.<ref name=":32" />

Namdari et al. demonstrated a successful outcome in 54% of patients (defined by an American Shoulder and Elbow Surgeons score of more than 80 points) and a mean 15 point improvement in the American Shoulder and Elbow Surgeons score at a mean of 52 months postoperative. Finally, the same group compared the two and ten year results for patients with known structural failures of rotator cuff repair. The average long-term American Shoulder and Elbow Surgeons score was 79 points (range, 50 to 95 points) and the average visual analog scale pain score was 2.2 points (range, 1 to 4 points); both scores were unchanged from those at two years. The average simple shoulder test score was 9.2 points (range, 6 to 12 points), and the average age-adjusted Constant score was 73 points (range, 59 to 90 points).<ref>Paxton ES, Teefey SA, Dahiya N, Keener JD, Yamaguchi K, Galatz LM. Clinical and radiographic outcomes of failed repairs of large or massive rotator cuff tears: minimum ten-year follow-up. J Bone Joint Surg Am 2013;95:627-32.</ref>

======Surgical (Operative) Treatment Revision Rotator Cuff Repair======
'''Surgical Technique'''

The alarming retear rate indicates that several surgical options can be considered which must be individualized to the patient. For example, in the setting of an acute traumatic retear in a physiologically young, healthy, active and non-pseudoparalytic patient, arthroscopic revision surgery is generally recommended. Techniques to enhance mechanical fixation, such as linked load-sharing rip-stop constructs should be considered.<ref name=":22" />

Augmented repair using scaffold devices derived from autografts,46,119,120 allograft,121 xenograft extracellular matrix122 or synthetic matrices such as poly-l-lactide grafts123 have been used to offer a structural support of the repair during the crucial healing period and to improve healing rates. The scientific literature does not contain enough data to justify any systematic associated augmentation techniques. Tendon transfers may be used in patients without advanced glenohumeral arthritis who have significant loss of external rotation strength and maintain anterior active elevation.62,124 If the patient is young, pseudoparalytic and suffers from a combined bony and tendinous rotator cuff insufficiency, calcaneum and Achilles tendon allograft could be considered.40

Finally, whereas primary pseudoparalysis responds well to arthroscopic rotator cuff repair, persistent pseudoparalysis after a previous attempt at rotator cuff repair may be more predictably managed with reverse shoulder arthroplasty. Denard et al. reported that pseudoparalysis/pseudoparesis was reversed in the revision setting in only 43% of patients with a low rate (54%) of satisfaction.<ref name=":2" />

In contrast, Boileau et al. found that anterior elevation was reliably restored with reverse shoulder arthroplasty after failed rotator cuff repair and 73% of patients were satisfied.<ref>Boileau P, Gonzalez JF, Chuinard C, Bicknell R, Walch G. Reverse total shoulder arthroplasty after failed rotator cuff surgery. J Shoulder Elbow Surg 2009;18:600-6.</ref>

'''Clinical and Radiological Results After Revision Rotator Cuff Repair'''

The clinical results of are summarized in Table 3. Overall, range of motion improved, except in one series of open rotator cuff repair.94 Functional outcome improved in all series and 70% or more of patients were satisfied or very satisfied.<ref name=":38" />

'''''Table 3: Clinical Results of Revision RCR'''''
[[File:1562481228568-lg.jpg|alt=|none|thumb|720x720px]]
 '''Complication'''

The short- to intermediate-term incidence of complications, including subsequent revision surgery, after revision rotator cuff repair is relatively low, around ten percent in this review (Table). However, most studies primarily considered reoperation a complication and did not examine complications such as hematoma, hardware failure, and postoperative stiffness. The prevalence of postoperative complications is therefore probably higher than reported. The prevalence of non-healing or retear was around 40% (range, 0 to 62%) in the four studies with postoperative imaging.<ref>Agrawal V. Healing rates for challenging rotator cuff tears utilizing an acellular human dermal reinforcement graft. International journal of shoulder surgery 2012;6:36-44.</ref><ref>Lenart BA, Martens KA, Kearns KA, Gillespie RJ, Zoga AC, Williams GR. Treatment of massive and recurrent rotator cuff tears augmented with a poly-l-lactide graft, a preliminary study. J Shoulder Elbow Surg 2015;24:915-21.</ref><ref>Keener JD, Wei AS, Kim HM, Paxton ES, Teefey SA, Galatz LM, Yamaguchi K. Revision arthroscopic rotator cuff repair: repair integrity and clinical outcome. J Bone Joint Surg Am 2010;92:590-8.</ref><ref name=":40">Shamsudin A, Lam PH, Peters K, Rubenis I, Hackett L, Murrell GA. Revision versus primary arthroscopic rotator cuff repair: a 2-year analysis of outcomes in 360 patients. Am J Sports Med 2015;43:557-64.</ref>

Furthermore, these tears may progress with time; Shamsudin et al. reported a prevalence of defect of 28% at six months and of 40% at two years. If revision is planned, patients have to be aware of the high prevalence of persistent structural defect. Moreover, retear rate after reoperation continues to deteriorate with time.<ref name=":40" /><ref>Vastamaki M, Lohman M, Borgmastars N. Rotator cuff integrity correlates with clinical and functional results at a minimum 16 years after open repair. Clin Orthop Relat Res 2013;471:554-61.</ref>

Structural failure does not always result in clinical failure. Many patients with partial healing of the cuff and a residual defect will be much improved after surgery. Characteristics associated with successful and unsuccessful results after structural failure of rotator cuff repair are poorly understood. Retear or non-healing of tendons is rather frequent and surgery is rarely proposed because this condition is often well tolerated with marked clinical improvement in comparison with the preoperative state.<ref>Namdari S, Donegan RP, Chamberlain AM, Galatz LM, Yamaguchi K, Keener JD. Factors affecting outcome after structural failure of repaired rotator cuff tears. J Bone Joint Surg Am 2014;96:99-105.</ref>

One reason for clinical failure is probably the non-restoration of balanced force couples and the suspension bridge system of force transmission in the shoulder. The location (involvement of the subscapularis on which the rotator cable is attached) and the size (more than two tendons) are the primary determinant of rotator cuff function.

'''Risk Factors for Postoperative Poorer Results'''

Several patient-related factors appear to be associated with poorer results. The most important factor seems to be poor preoperative range of motion. Female sex and, in one study, if the surgery was performed on the dominant arm, were negatively associated with postoperative outcome.<ref name=":34">Chuang MJ, Jancosko J, Nottage WM. Clinical outcomes of single-row arthroscopic revision rotator cuff repair. Orthopedics 2014;37:e692-8.</ref><ref name=":41">Piasecki DP, Verma NN, Nho SJ, Bhatia S, Boniquit N, Cole BJ, Nicholson GP, Romeo AA. Outcomes after arthroscopic revision rotator cuff repair. Am J Sports Med 2010;38:40-6.</ref><ref name=":31" />

There is still controversy about certain risk factors such as age of patients. Disease-related factors included patients with a recurrent tear after the revision repair, preoperative visual analogue scale pain score greater than five, and poor preoperative range of motion. The range vary from less than 90 degrees in the studies from Denard et al. and Piasecki et al. to 140 degrees in the study of Chuang et al.<ref name=":30" /><ref name=":34" /><ref name=":41" />

The latter factor has been reported in almost all series and is probably the most important preoperative indicator. In addition, acromiohumeral distance (less than seven mm) can be associated with a satisfactory outcome.<ref name=":38" />

There is controversy about patients with more than one prior surgery, with one study reporting that this negatively impacted results and another study reporting that it did not.<ref name=":31" /><ref name=":41" />

Operative-related factors like poor tendon quality is associated with poorer results.<ref name=":36" /><ref name=":23" />

One study compared outcomes between massive and non-massive tears and did not find any significant difference in terms of post-operative anterior elevation, pain, or functional outcome.<ref name=":31" />

'''Post-revision Rehabilitation'''

In all studies, subjects took part in standardized rehabilitation protocols. Most studies did not allow immediate overhead passive motion. Most studies recommend sling during 6 weeks. Strengthening is delayed until six to sixteen weeks post-operatively. Full return to activity was not allowed until four to twelve months.

====B2: Medial Tendinous Disruption====
Disruption of the tendon medial to an intact lateral tendon stump has been reported in primary chronic and acute cases or postoperatively as a failure medial to the medial row.<ref name=":33" /><ref>Loew M, Magosch P, Lichtenberg S, Habermeyer P, Porschke F. How to discriminate between acute traumatic and chronic degenerative rotator cuff lesions: an analysis of specific criteria on radiography and magnetic resonance imaging. J Shoulder Elbow Surg 2015;24:1685-93.</ref>

Regarding the former, it is now understood that the infraspinatus insertion is quite broad and wraps around from posterior to anterior to occupy much of the lateral greater tuberosity. Therefore, such descriptions of a lateral tendon stump remaining may, in fact, represent a torn supraspinatus with an intact infraspinatus.

Full thickness defects medial to an intact footprint of the rotator cuff can be seen following a rotator cuff repair (Figure). Trantalis et al. described 5 patients with medial failure following a double-row rotator cuff repair. Such failure results from overtensioning during repair and is very difficult to manage with revision repair. These lesions do not produce muscular edema, except in traumatic cases with important and acute retraction of the muscle and the remnant of the tendon (Figure); its origin is then either retraction (which may appear in some hours) or neurological lesions (noted after some weeks).<ref>Fleckenstein JL, Watumull D, Conner KE, Ezaki M, Greenlee RG Jr, Bryan WW, Chason DP, Parkey RW, Peshock RM, Purdy PD. Denervated human skeletal muscle: MR imaging evaluation. Radiology 1993;187:213-8.</ref>

===B3: Tendon to Tendon Adhesion: “Fosbury Flop Tear”===

The Fosbury flop tear occurs from a full thickness tear that has flipped upon itself and adhered medially (Figure 26).<ref name=":42">Lädermann A, Denard PJ, Kolo FC. A new tear pattern of the rotator cuff and its treatment: Fosbury flop tears. International journal of shoulder surgery 2015;9:9-12.</ref>
[[File:1562482685626-lg.jpg|center|thumb|600x600px|Figure 26. Figure: Illustration of a “Fosbury flop tear” development. Reproduced from Lädermann et al., with permission.]]

=====Prevalence=====
In a prospective study spanning one-year, Lädermann et al. reported five patients with full or partial-thickness rotator cuff lesions in a series of 97 (5 % incidence rate). Radiologically, these lesions showed a thicker than normal tendon stump on the bursal-side of the retracted supraspinatus tendon in a superomedial orientation.<ref name=":42" />
[[File:1562482680697-lg.jpg|center|thumb|600x600px|Figure 27. Coronal T1 weighted image of a right shoulder that demonstrates (black arrow) an abnormally thickened supraspinatus (9.5 mm). Reproduced from Lädermann et al., with permission.]]
[[File:1562483248519-lg.jpg|center|thumb|600x600px|Figure 28. Coronal T1 weighted MRA image with fat saturation of a right shoulder demonstrates adhesions between the bursal side of the tendon and the wall of the subacromial bursa (red arrow), and abnormal orientation of the fibers stump (yellow arrow). Reproduced from Lädermann et al., with permission.]]
Additionally, patients with this lesion were also found to have an accumulation of fluid in the superomedial part of the subacromial bursa as well as adhesions between the wall of the subacromial bursa and the tendon of the supraspinatus. Since the original description, another group verified the same entity.<ref>Nakamizo H. Arthroscopic repair for subacromial incarceration of a torn rotator cuff. AP-SMART 2015;2:90-4.</ref>

=====Surgical Technique=====
A diagnostic arthroscopy is performed with an arthroscopic pump maintaining pressure at 50 mm Hg. The biceps is tenotomized or tenodesed. Attention is then turned to the posterosuperior rotator cuff (supraspinatus and infraspinatus tendons). The appearances of the tears are unusual with ulcerations on the bursal surface (anemone like) and what initially appeared to be a thickened lateral tendon stump (Figure and Video).
[[File:1562483266291-lg.jpg|center|thumb|600x600px|Figure 29. Arthroscopic view of a right shoulder through lateral portal after bursectomy and creation of a bone socket for medial row anchor placement. The supraspinatus tendon is unusually thick and has the appearance of ulcerations and flanges of the bursal side (sea anemone appearance, black arrow). H, hole of the tap; HH, humeral head; SS, supraspinatus tendon. Reproduced from Lädermann et al., with permission.]]
[[File:1563115158292-lg.mp4|center|thumb|600x600px|Video 13.]]
 After a progressive dissection, however, medial adhesions of the bursal layer is found. A complete excavation of the rotator cuff must be performed by skeletonizing the scapular spine medially, removing any bursal leaders (false insertions into the internal deltoid fascia) laterally, and debriding the fibrofatty bursa overlying the rotator cuff. These steps allow identification of the lateral tendon stump which is reversed upon itself and scarred medially. Once identified the tendon stump is unfolded (Video) and subsequently repaired to the lateral bone bed.

====B4: Tendon to Acromion Adhesion====
Disruption of the lateral tendon stump can be followed by adhesion under the acromion, the coracoid process or the coracoacromial arch (Figure). These adhesions are most pronounced in revision situations, but may also be observed in primary cases, particularly in the setting of a massive contracted rotator cuff tear.<ref name=":28" />
[[File:1562484138603-lg.jpg|center|thumb|700x700px|Figure 30. A) A coronal view of a right shoulder computed tomography (CT) arthrogram shows a probable B2 rotator cuff lesion with a Patte 3 retraction. b) The arthroscopic view through lateral portal revealed after partial debridement that the tendon was not retracted but actually had adhered under the acromion. Reproduced from Lädermann et al., with permission.]]

===Type C: Musculotendinous Junction Lesion===
Isolated ruptures of the musculotendinous junction are rare in the rotator cuff, but have a dramatic impact on functional outcome. Such lesions have been observed in all muscles of the rotator cuff, affecting the infraspinatus muscle in half of cases, followed by the supraspinatus in 31% of cases, the subscapularis in 25%, and the teres minor in 19% of cases (more than one muscle is occasionally involved).<ref>Taneja AK, Kattapuram SV, Chang CY, Simeone FJ, Bredella MA, Torriani M. MRI findings of rotator cuff myotendinous junction injury. AJR American journal of roentgenology 2014;203:406-11.</ref>

These lesions can been classified into 3 stages. Grade I injuries are a muscular strain that heals without adverse sequelae. Grade II injuries are partial ruptures without tendon retraction. Grade III injuries are complete ruptures at the musculotendinous junction. The acute phase of these injuries are associated with severe inflammation, leading to a highly characteristic bright signal on T2 weighted magnetic resonance imaging (Figure 31).<ref>Zarins B, Ciullo JV. ACute muscle and tendon injuries in athletes. Clinics in sports medicine 1983;2:167-82.</ref>
[[File:1562484142491-lg.jpg|center|thumb|700x700px|Figure 31. Axial and sagittal T2-weighted FATSAT magnetic resonance imaging (MRI) images demonstrating a type C rotator cuff lesion with an intact tendon, a stage 3 rupture of the musculotendinous junction, and huge edema of the muscle. Reproduced from Lädermann et al., with permission.]]
Edema of rotator cuff muscle with an intact tendon-bone insertion is infrequent. It has been described in cases of denervation, such as compression of the suprascapular nerve, Parsonage Turner syndrome, in other rare and non-specific conditions.<ref>Ludig T, Walter F, Chapuis D, Mole D, Roland J, Blum A. MR imaging evaluation of suprascapular nerve entrapment. European radiology 2001;11:2161-9.</ref><ref>Bredella MA, Tirman PF, Fritz RC, Wischer TK, Stork A, Genant HK. Denervation syndromes of the shoulder girdle: MR imaging with electrophysiologic correlation. Skeletal radiology 1999;28:567-72.</ref>

Complete musculotendinous junction ruptures have only been described in the infraspinatus and the supraspinatus.<ref>Walch G, Nove-Josserand L, Liotard JP, Noel E. Musculotendinous infraspinatus ruptures: an overview. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:463-70.</ref><ref>Hertel R, Lambert SM. Supraspinatus rupture at the musculotendinous junction. J Shoulder Elbow Surg 1998;7:432-5.</ref><ref>Lädermann A, Christophe FK, Denard PJ, Walch G. Supraspinatus rupture at the musclotendinous junction: an uncommonly recognized phenomenon. J Shoulder Elbow Surg 2012;21:72-6.</ref>

Possible causes for musculotendinous junction infraspinatus lesion are calcific tendinitis or previous cortisone injection. On the other hand, rupture of the other muscles seem to be due to trauma or inlet impingement syndrome. There is little information about the clinical results of grade 3 musculotendinous junction lesions.

====Type C with Reverse Fosbury Flop Tear====
Exceptionally, a lesion of the musculotendinous junction can develop a Fosbury pattern and heals, for its tendon part, on the humerus or even coracoid process.<ref>Tirefort J, Cunningham G, Lädermann A. Reverse Fosbury Flop Tear of the Rotator Cuff. Case Reports in Orthopedics 2017;2017:3635897.</ref>
[[File:1562484351328-lg.jpg|center|thumb|600x600px|Figure 32. Coronal T2 weighted image with fat saturation of a right shoulder. A tear at the musculotendinous junction (green arrow) as well as a muscular edema (white arrows in the frame) are observed. Reproduced from Tirefort et al., with permission.]]
[[File:1562484588402-lg.jpg|center|thumb|600x600px|Figure 33. Coronal T1-weighted (A) and axial T2-weighted (B) with fat saturation of a right shoulder. The supraspinatus flopped on itself (white dotted line) and healed on the anterior humerus (white arrows). Reproduced from Tirefort et al., with permission.]]
[[File:1562484589524-lg.jpg|center|thumb|600x600px|Figure 34. Arthroscopic view of a right shoulder viewed from posterior portal. A) The supraspinatus tendon had the appearance of ulcerations and flanges of the bursal side (sea anemone appearance, black arrows) and, B) after debridement of the flanges, the tendon that flopped on itself and the long head of the biceps and healed on the anterior humerus had an unusual orientation (HH, humeral head; LHB, long head of the biceps; SS, supraspinatus tendon). Reproduced from Tirefort et al., with permission.]]
[[File:1562484592294-lg.png|center|thumb|600x600px|Figure 35. Illustration of a "Fosbury flop tear" (A) and of a "reverse Forsbury flop tear" (B). Reproduced from Tirefort et al., with permission.]]
 

===Type D: Muscle Insufficiency===

====D1: Fatty Infiltration and Muscle Atrophy====
One of the most important prognostic factor for rotator cuff repair is nonfunctional muscle bellies. Muscle quality is most commonly classified according to Goutallier et al. to determine the extent of injuries based upon the degree in which fat is present in the muscle. They proposed a 5 stage classification system of fatty infiltration. Additionally, they demonstrated that multiple muscles develop fatty degeneration, even if they were not directly impacted by the original lesion.<ref name=":9" />

With the advent of MRI, however, the classification was extrapolated to the most lateral parasagittal image on which the scapular spine was in contact with the scapular body (Y view).<ref>Fuchs B, Weishaupt D, Zanetti M, Hodler J, Gerber C. Fatty degeneration of the muscles of the rotator cuff: assessment by computed tomography versus magnetic resonance imaging. J Shoulder Elbow Surg 1999;8:599-605.</ref>

The mean time to tendon rupture observed for stage 2 fatty infiltration is 3 years for the supraspinatus and 2.5 years for the infraspinatus and the subscapularis when their tendons ruptured. The mean time observed to grade 3 and 4 fatty infiltration is 5, 4, and 3 years for the supraspinatus, the infraspinatus, and the subscapularis, respectively.<ref>Melis B, Nemoz C, Walch G. Muscle fatty infiltration in rotator cuff tears: descriptive analysis of 1688 cases. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:319-24.</ref>

Zanetti et al. described a radiographic tangent sign to quickly and reliably assess the presence or absence of supraspinatus atrophy on MRI. This sign is a reliable method for evaluating the presence or absence of muscle atrophy using the sagittal plane and is moreover significantly related to the level of fatty infiltration within the supraspinatus muscle.<ref name=":11" />

It has been reported to be a predictor of whether a rotator cuff tear will be repairable.<ref name=":12" />

Thomazeau et al. proposed calculating the occupation ratio of the supraspinatus muscle belly using MRI. This was calculating by comparing the supraspinatus fossa volume to total supraspinatus muscle belly volume and computing the ratio. This ratio was found to be significantly decreased in patients with repairable rotator cuff tears.<ref name=":20" />

Inability to obtain a complete repair of the supraspinatus was associated with a positive tangent sign (30% irreparable) versus a negative tangent sign (6.3% irreparable, OR = 6,3, P =0.0102) and with Goutallier grade 3-4 fatty infiltration of the supraspinatus (42.9% irreparable) versus grade 0-2 fatty infiltration (5.7% irreparable, OR = 11.8, P =0.001).<ref name=":8" />

Rotator cuff repair should thus be performed before the appearance of fatty infiltration (Stage 2) and atrophy (positive tangent sign) and as soon as possible in older patients when the tear involves multiple tendons.<ref>Melis B, DeFranco MJ, Chuinard C, Walch G. Natural history of fatty infiltration and atrophy of the supraspinatus muscle in rotator cuff tears. Clin Orthop Relat Res 2010;468:1498-505.</ref>

====D2: Neurological impairment====
Isolated suprascapular nerve neuropathy is a condition associated with acute and chronic shoulder girdle traction injuries, compressive lesions such as paralabral cysts and compressive ligaments, as well as large or massive rotator cuff tears (Figure 36). In the latter situation, the proposed mechanism involves traction of the nerve caused by retraction of the supraspinatus against its fixed points on the suprascapular and spinoglenoid notches. However, clinical diagnosis is beset with uncertainties as the potential symptoms of suprascapular nerve neuropathy, namely, pain, weakness, and atrophy, are inseparable from those of rotator cuff tear. Currently, there is no support for routine suprascapular nerve release as the prevalence of suprascapular nerve neuropathy in the setting of a massive rotator cuff tear was very low (2%) in a recent prospective study.<ref name=":17" />
[[File:1562485382488-lg.jpg|center|thumb|600x600px|Figure 36. Sagittal view of a patient suffering from suprascapular neuropathy. A) T1 sequences reveal fatty infiltration and B) T2 FATSAT sequences demonstrate muscle edema.]]

====D3: Tumors====
Numerous tumors, such as an arthrosynovial cyst, intramuscular lipoma, or a calcified hematoma, can developed at the expense of the muscular tissue and cause muscular insufficiency (Figure 37).<ref>Lädermann A, Genevay M, Abrassart S, Schwitzguebel AJ. Supraspinatus Intramuscular Calcified Hematoma or Necrosis Associated with Tendon Tear. Case Rep Orthop 2015;2015:496313.</ref>
[[File:1562485402714-lg.jpg|center|thumb|600x600px|Figure 37. A) Schema of a D rotator cuff insufficiency.
B) Coronal T2-weighted SPAIR magnetic resonance imaging (MRI) image of a right shoulder showing a B2D3 lesion with an intramuscular arthrosynovial cyst. 
C) Coronal T2-weighted PD
D) sagittal T1-weighted image demonstrating D3 rotator cuff lesion with a calcified hematoma in the supraspinatus and an intramuscular lipoma of the subscapularis, respectively. Reproduced from Lädermann et al., with permission.]]
These impairments can be as isolated or be associated with other rotator cuff lesions. Management may require treatment of the associated mechanical stress in addition to rotator cuff repair.

==Irreparable Rotator Cuff Tears==

===Introduction===
One of the most challenging issues in shoulder surgery is the management of symptomatic irreparable rotator cuff tears. The literature reports that 12% of posterosuperior rotator cuff tear are not repairable.<ref name=":8" />

The latter condition when symptomatic can be managed with several approaches without clear evidence based guidelines. For example, the same patient with a D type irreparable rotator cuff tears according to Collin et al. may be offered physiotherapy, partial repair, tendon transfer, superior capsular reconstruction, subacromial spacer (balloon), or even a reverse shoulder arthroplasty (RSA) depending on multiple factors, including, geography, surgeon experience, implants costs, etc. Moreover, even if it is reported that these surgical procedures have different indications, they are often applied to patients with similar problems indiscriminately.

===Definition of an Irreparable Rotator Cuff Tears & Clinical and Imaging Findings===
The definition of an irreparable rotator cuff varies widely. Furthermore, with advances in anchors, suture strength, techniques of release and repair with load-sharing rip-stop fixation, etc, the definition continues to evolve. Two situations can be faced; the first one consists of a patient who has a contra-indication to cuff repair, and the second scenario is intra-operative when a complete repair is not physically possible. While most rotator cuff tears can be repaired, some lesions are not reparable or should not be repaired. Imaging studies play a critical role in preoperative assessment, evaluation of the defects and selection of the correct treatment for an irreparable rotator cuff tears. The following clinical and radiological preoperative factors that have been clearly associated with postoperative clinical or radiological failure should be considered before attempting repair.

===Clinical Examination===
Pseudoparalysis was defined as a chronic inability to actively elevate the arm beyond 90 degrees with full passive forward flexion.<ref>Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-86.</ref>

It is nevertheless important to note that this correspond to functional limitation associated or not with an antero-superior escape and not just to pain inhibition. Several studies purport to reverse pseudoparalysis although it represents mainly pseudoparesis cases. When pain inhibition or slight stiffness limits the patient from elevating the shoulder, the limited motion is not secondary to complete cuff deficiency.<ref>Tokish JM, Alexander TC, Kissenberth MJ, Hawkins RJ. Pseudoparalysis: a systematic review of term definitions, treatment approaches, and outcomes of management techniques. J Shoulder Elbow Surg 2017;26:e177-e87.</ref>

Anatomically, pseudoparalysis requires the disruption of at least of rotator cable attachment which in the study of Collin et al. was found in only 2.9% of massive D-type cases. This means that pseudoparalysis of the posterosuperior rotator cuff cases involved usually the whole posterior cuff (33.3% of pseudoparalysis found in E-type irreparable rotator cuff tears).<ref name=":1" />

In addition to pseudoparalysis, the presence of lag signs (external rotation lag, drop, dropping, hornblower signs) is also associated with non-reparability.<ref>Axe JM. Tendon transfers for irreparable rotator cuff tears: An update. EFORT Open Rev 2016;1:18-24.</ref>

===Treatment===

====Non-Surgical (Conservative) Treatment====
As patients with posterosuperior irreparable rotator cuff tears do not have anterosuperior escape, many respond favorably to nonsurgical treatment which should be attempted for six months before considering surgery. If after this adequate period of time symptoms have not improved, the chances of success with further non-operative treatment decreases and operative treatment may be considered. The mainstay of non-operative treatment includes nonsteroidal anti-inflammatory drugs, subacromial corticosteroid injections, and physical therapy. Levy et al. prospectively assessed 17 patients with clinically and radiographically diagnosed irreparable rotator cuff tears that underwent an anterior deltoid training program.<ref name=":19">Levy O, Mullett H, Roberts S, Copeland S. The role of anterior deltoid reeducation in patients with massive irreparable degenerative rotator cuff tears. J Shoulder Elbow Surg 2008;17:863-70.</ref>

By 9 months, the mean Constant score improved from 26 to 63, and the forward flexion improved from 40° to 160°. In another prospective cohort of 45 patients suffering from pseudoparalysis with a radiographically confirmed D-type rotator cuff tear, Collin et al. found after a follow-up of 48 months that 14 of 15 patients had substantial improvement in active forward elevation to above 90 degrees.<ref name=":24" />

The protocol of rehabilitation focused habitually on a multimodal physical therapy program with global deltoid reconditioning and periscapular strengthening.<ref>Ainsworth R. Physiotherapy rehabilitation in patients with massive, irreparable rotator cuff tears. Musculoskeletal care 2006;4:140-51.</ref>

Certain authors propose that reeducation of the anterior deltoid muscle to compensate for a deficient rotator cuff is the cornerstone of successful non-operative treatment.<ref name=":19" />

The promising results has nevertheless not been confirmed.<ref>Yian EH, Sodl JF, Dionysian E, Schneeberger AG. Anterior deltoid reeducation for irreparable rotator cuff tears revisited. J Shoulder Elbow Surg 2017;26:1562-5.</ref><ref name=":24" />

====Surgical (Operative) Treatment====
In the absence of a gold standard surgical solution, treatment of irreparable rotator cuff tears has proven to be quite challenging, adding to the surgeon’s dilemma regarding the choice of patient and treatment option. Younger active patients (<60 years of age) with traumatic tears, may be immediate candidates for surgery based on the high risk for progression with conservative treatment. Surgical approaches have been advocated, with varying degrees of success. The surgical options include arthroscopic debridement, partial repair, biceps procedure, superior capsular reconstruction, muscle transfers, biodegradable subacromial spacer interposition, biological augmentation and reverse shoulder arthroplasty. Despite all these options, irreparable rotator cuff tears are difficult to manage and treat effectively. There are no high levels of evidence prospective trials comparing these various options and therefore recommendations are mainly based on retrospective case series, surgeon experiences, and expert opinions.

=====Long Head of the Biceps Tenotomy or Tenodesis +/- Partial Repair=====
This procedure includes biceps tenotomy or tenodesis, partial repair if evaluation has deemed the remaining tendon to be of good quality, and associated procedures such as distal clavicle resection if necessary. Tenotomy or tenodesis of the long head of the biceps should consistently be performed, as biceps tendinopathy is observed in 92% of rotator cuff lesions.<ref>Boileau P, Maynou C, Balestro JC, Karataglis D, Papadopoulos P. [Long head of the biceps pathology]. Rev Chir Orthop Reparatrice Appar Mot 2007;93:5S19-53.</ref>

There is evidence suggesting that this structure is a source of pain and contributes to the symptomatology of patients with irreparable rotator cuff tears. Walch et al. reported statistically significant improvements in the Constant score with an isolated biceps tenotomy (Constant score 48 points preoperatively to 68 points at follow-up (P < .0001)) which has been confirmed by numerous authors.<ref name=":25" />

The aim of this procedure is to repair all of the rotator cuff tendon that can reasonably be brought back to the tuberosities without excessive tension, and to address all potential causes of persistent pain or factors threatening the repair. The goal of a partial repair is to restore force couples, to re-establish the “suspension bridge”, and to prevent secondary extension of the tear. In this theory, complete closure of the defect is less important than restoration of a stable fulcrum for normal shoulder kinematics. Although having little effect on improvement in shoulder strength after this intervention, eliminating various pain generators usually enhances function. Although a partial cuff repair is conducted, the role of the biceps tenotomy should not be overlooked in the patient improvements observed.<ref>Boileau P, Baque F, Valerio L, Ahrens P, Chuinard C, Trojani C. Isolated arthroscopic biceps tenotomy or tenodesis improves symptoms in patients with massive irreparable rotator cuff tears. J Bone Joint Surg Am 2007;89:747-57.</ref>

Acromioplasty is not advisable in the setting of an irreparable rotator cuff tears as it may lead to postoperative antero-superior migration of the humeral head. Tuberoplasty has been proposed as an alternative to classic subacromial decompression in order to preserve the integrity of the coracoacromial arch.<ref>Scheibel M, Lichtenberg S, Habermeyer P. Reversed arthroscopic subacromial decompression for massive rotator cuff tears. J Shoulder Elbow Surg 2004;13:272-8.</ref>

Although the results in compensated tears and low-demand patients are promising,176 it is currently unknown if the positive effect with regards to pain relief is due to the tuberoplasty or to the concomitant performed bursectomy, synovectomy and biceps treatment. Partial repair provides good clinical outcomes, comparable to those reported with biceps sacrifice and subacromial decompression. The main purported benefit of repairing part of the cuff is its potential to slow or halt further tear progression and to increase the strength of the shoulder. All series of partial repair reported a significant improvement in functional scores, while reporting a rate of radiological repair failure around 50% (Table 4).<ref>Berth A, Neumann W, Awiszus F, Pap G. Massive rotator cuff tears: functional outcome after debridement or arthroscopic partial repair. J Orthop Traumatol 2010;11:13-20.</ref><ref>Chen KH, Chiang ER, Wang HY, Ma HL. Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Factors Related to Greater Degree of Clinical Improvement at 2 Years of Follow-Up. Arthroscopy 2017;33:1949-55.</ref><ref>Cuff DJ, Pupello DR, Santoni BG. Partial rotator cuff repair and biceps tenotomy for the treatment of patients with massive cuff tears and retained overhead elevation: midterm outcomes with a minimum 5 years of follow-up. J Shoulder Elbow Surg 2016;25:1803-9.</ref><ref>Galasso O, Riccelli DA, De Gori M, De Benedetto M, Orlando N, Gasparini G, Castricini R. Quality of Life and Functional Results of Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears. Arthroscopy 2017;33:261-8.</ref><ref>Godeneche A, Freychet B, Lanzetti RM, Clechet J, Carrillon Y, Saffarini M. Should massive rotator cuff tears be reconstructed even when only partially repairable? Knee Surg Sports Traumatol Arthrosc 2017;25:2164-73.</ref><ref>Henry P, Wasserstein D, Park S, Dwyer T, Chahal J, Slobogean G, Schemitsch E. Arthroscopic Repair for Chronic Massive Rotator Cuff Tears: A Systematic Review. Arthroscopy 2015;31:2472-80.</ref><ref>Shon MS, Koh KH, Lim TK, Kim WJ, Kim KC, Yoo JC. Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Preoperative Factors Associated With Outcome Deterioration Over 2 Years. Am J Sports Med 2015;43:1965-75.</ref><ref>Yoo JC, Ahn JH, Koh KH, Lim KS. Rotator cuff integrity after arthroscopic repair for large tears with less-than-optimal footprint coverage. Arthroscopy 2009;25:1093-100.</ref>

Long-term benefit in prevention of head migration has not been demonstrated.

'''''Table 4: Results of partial repair of irreparable rotator cuff tear.'''''
[[File:1562487859066-lg.jpg|thumb|720x720px|†: Constant score, ‡: American Shoulder and Elbow Surgeons (ASES) score, NA: non available.|alt=|none]]

=====Tendon Transfer=====
Tendon transfers have been described in the management of an irreparable rotator cuff tears, however, the outcomes reported have been inconsistent. The results of new transfers involving the lower trapezius transfers have not been well described with mainly anatomical or biomechanical data and will not be described in this review article. L'Episcopo and latissimus dorsi transfer are reported to reconstitute the posterior force couple. L’Episcopo first described the technique of transfer of the latissimus dorsi and teres major tendons in children with obstetric palsy.<ref>L’Episcopo J. Tendon transplantation in obstetrical paralysis. Am J Surg 1934;25:122-5.</ref>

The procedure involves transferring both tendons laterally and posteriorly on the humerus, such that the function of the transfer changes from internal to external rotation. Boileau et al. analyzed recently 26 patients (2 with glenohumeral arthritis) and found a gain in active external rotation of 26 degrees and an improvement in adjusted Constant score from 63.6% to 86.9% (P < .001).<ref>Boileau P, Baba M, McClelland WB, Jr., Thelu CE, Trojani C, Bronsard N. Isolated loss of active external rotation: a distinct entity and results of L'Episcopo tendon transfer. J Shoulder Elbow Surg 2017.</ref>

The integrity of the remaining internal rotators are of utmost importance as patients after a L’Episcopo transfer loose significant internal rotation and may not reach the back anymore. Latissimus dorsi transfer has been initially proposed for irreparable rotator cuff tears as an open procedure to improve control of external rotation in young and high demand patients with an intact subscapularis.<ref>Gerber C. Latissimus dorsi transfer for the treatment of irreparable tears of the rotator cuff. Clin Orthop Relat Res 1992:152-60.</ref>

Namdari et al. in a review found that patients followed for mean of 46 months had a mean adjusted Constant score of 46 preoperatively compared with 73 postoperatively (p < 0.001). The mean active external rotation improved from 17 degrees to 27 degrees which is statistically significant (p < 0.001) but not clinically significant. As proposed by Gerber, isolated latissimus dorsi transfer with or without reverse shoulder arthroplasty is mainly to "restore control of external rotation in selected patients" rather than active external rotation itself.<ref>Gerber C, Pennington SD, Lingenfelter EJ, Sukthankar A. Reverse Delta-III total shoulder replacement combined with latissimus dorsi transfer. A preliminary report. J Bone Joint Surg Am 2007;89:940-7.</ref>

It is also important to keep in mind that the results of the open technique are superior in case of an intact or repairable subscapularis and a hypertrophic teres minor.<ref>Costouros JG, Espinosa N, Schmid MR, Gerber C. Teres minor integrity predicts outcome of latissimus dorsi tendon transfer for irreparable rotator cuff tears. J Shoulder Elbow Surg 2007;16:727-34.</ref><ref>Namdari S, Voleti P, Baldwin K, Glaser D, Huffman GR. Latissimus dorsi tendon transfer for irreparable rotator cuff tears: a systematic review. J Bone Joint Surg Am 2012;94:891-8.</ref>

In other words, latissimus dorsi transfer in D-types irreparable rotator cuff tears is efficient but only indicated in selected patients having an isolated loss of external rotation, a preserved forward elevation above 90°, an intact or repairable subscapularis an ideally a hypertrophic teres minor. Conversely, latissimus dorsi transfer gives unpredictable results in E-type latissimus dorsi transfer and potentially a L’Episcopo transfer is superior in those cases. Recently, indications and techniques have evolved and arthroscopic procedures have been proposed to hopefully limit humeral head upper migration and to restore anterior active elevation.<ref>Grimberg J, Kany J, Valenti P, Amaravathi R, Ramalingam AT. Arthroscopic-assisted latissimus dorsi tendon transfer for irreparable posterosuperior cuff tears. Arthroscopy 2015;31:599-607 e1.</ref>

The same group has observed in a prospective series of 25 patients with a follow-up of 12 months an improvement in mean Constant score from 44 points preoperatively to 65 postoperatively, a slight improvement (10 degrees) in external rotation but a radiological failure rate of 43%.<ref>Bonnevialle N, Joudet T. [Massive Rotator Cuff Lesions]. Société Francophone d'Arthroscopie. Marseille2017.</ref>

=====Posterior rotator cuff insufficiency=====
Currently, the most commonly used transfer for an irreparable type D or E massive rotator cuff tears is latissimus dorsi transfer. The ideal candidate is a patient who has maintained active anterior elevation, but lacks control of the arm in space in external rotation (simple weakness in external rotation is not a sufficient indication for surgery), and who also has an intact subscapularis and no glenohumeral arthritis. Results are disappointing in patients with subscapularis insufficiency. In addition, results have been disappointing in the setting of preoperative teres minor tears or atrophy. Gerber et al. reported long-term results at a mean of 147 months. The mean simple shoulder value (SSV) in 46 shoulders increased from 29% preoperatively to 70%, the relative Constant score improved from 56% to 80%, and the pain score improved from 7 to 13 points (p < 0.0001 for all).<ref name=":27" />

However, there is no proof that latissimus dorsi transfer gives better long-term results than a simple partial rotator cuff repair. Effectively, 60% of type E massive rotator cuff tears do not lose control of the arm in external rotation. Consequently and despite large series recently published, indications for this type of surgery are rare.<ref name=":1" />

=====Superior Capsular Reconstruction=====
Superior capsular reconstruction with either fascia lata autograft, dermal allograft patch or long head of the biceps is a solution that could prevent superior humeral head migration and restore the shoulder muscle force couples (Video of Superior Capsular Reconstruction with Long Head of the Biceps "The Chinese Way").<ref name=":3">Mihata T, Lee TQ, Watanabe C, Fukunishi K, Ohue M, Tsujimura T, Kinoshita M. Clinical results of arthroscopic superior capsule reconstruction for irreparable rotator cuff tears. Arthroscopy 2013;29:459-70.</ref><ref>Burkhart SS, Denard PJ, Adams CR, Brady PC, Hartzler RU. Arthroscopic Superior Capsular Reconstruction for Massive Irreparable Rotator Cuff Repair. Arthrosc Tech 2016;5:e1407-e18.</ref><ref>Boutsiadis A, Chen S, Jiang C, Lenoir H, Delsol P, Barth J. Long Head of the Biceps as a Suitable Available Local Tissue Autograft for Superior Capsular Reconstruction: “The Chinese Way”. Arthroscopy Techniques 2017.</ref>
[[File:1563115166796-lg.mp4|center|thumb|650x650px|Video 14.]]
The superior capsule is believed to be important in maintaining humeral head depression and compensating for the dynamic effect of the rotator cuff muscles. However, the superior capsule is an inconsistent structure constituted by a confluence a various ligaments, that is in continuity in only 27% of the cases (Video that shows an L-shape left rotator cuff lesion with an intact superior capsule).<ref>Pouliart N, Somers K, Eid S, Gagey O. Variations in the superior capsuloligamentous complex and description of a new ligament. J Shoulder Elbow Surg 2007;16:821-36.</ref>
[[File:1563119074281-lg.mp4|center|thumb|677x677px|Video 15.]]
No articles reported on the mid- or longer-term clinical and radiological results. Mihata et al. in a small series of 23 patients using fascia lata autograft found at a mean follow-up of 34 months an increased in forward flexion from 84° to 148° (P < .001) and external rotation increased from 26° to 40° (P < .01). Twenty patients (83%) at most recent follow-up had an intact graft without retear.<ref name=":3" />

Denard et al. reported in a series of 59 patients using a dermal allograft with a minimum follow-up of 1 year an increase in forward flexion from 130 degrees preoperative to 158 degrees postoperative, an improvement in American Shoulder and Elbow Surgeons (ASES) score from 44 to 78 and a 55% failure rate. In all cases, a biceps tenotomy or tenodesis was performed.<ref>Denard PJ, Brady PC, Adams CR, Tokish JM, Burkhart SS. Preliminary Results of Arthroscopic Superior Capsule Reconstruction with Dermal Allograft. Arthroscopy 2018;34:93-9.</ref>

=====Subacromial Balloon Interposition=====
The biodegradable spacer (balloon shape) is arthroscopically implanted between the acromion and the humeral head. The subacromial spacer has been designed to create a physical barrier between tissues in the subacromial space and keep the humeral head depressed when the rotator cuff is not efficient to facilitate deltoid action, thus permitting improvement in glenohumeral joint motion with significant pain reduction. At 5 years follow-up, a recent study on the subacromial spacer with an associated biceps tenotomy reported that 85% of the patients showed a clinically significant improvement of at least 15 points in Constant score, while 62% showed at least 25 points of improvement.<ref>Senekovic V, Poberaj B, Kovacic L, Mikek M, Adar E, Markovitz E, Maman E, Dekel A. The biodegradable spacer as a novel treatment modality for massive rotator cuff tears: a prospective study with 5-year follow-up. Arch Orthop Trauma Surg 2017;137:95-103.</ref>

Deranlot et al. described in a series of 37 patients (39 shoulders) a significant improvement of the Constant score from 45 preoperatively to 76 at a mean of 33 months follow-up. In their study, 92% of the shoulders also underwent a long head of biceps tenotomy.<ref>Deranlot J, Herisson O, Nourissat G, Zbili D, Werthel JD, Vigan M, Bruchou F. Arthroscopic Subacromial Spacer Implantation in Patients With Massive Irreparable Rotator Cuff Tears: Clinical and Radiographic Results of 39 Retrospectives Cases. Arthroscopy 2017;33:1639-44.</ref>

====marche pas=====

=====Biological Augmentation=====
These techniques involve using a graft (allo, auto, or xeno) or synthetic patch to bridge the defect in the rotator cuff and improve connection of the tendon remnant at least at the border of the original footprint. During this procedure, the torn rotator cuff tendons are released, mobilized, and undergo a partial repair. The graft is then sutured on top of the residual defect between the lateral margin of the medial fixed rotator cuff tendon and its native insertion site on the lateral footprint and humerus. A systematic review confirm that this approach improved function with a high rate of structural integrity rates on MRI at 12-month minimum follow-up.<ref>Lewington MR, Ferguson DP, Smith TD, Burks R, Coady C, Wong IH. Graft Utilization in the Bridging Reconstruction of Irreparable Rotator Cuff Tears: A Systematic Review. Am J Sports Med 2017;45:3149-57.</ref>

=====Achilles Tendon-Bone Block Allograft for Massive Rotator Cuff Tears With Bony Deficiency of the Greater Tuberosity=====
In patients aged >60 years, reverse shoulder arthroplasty is an acceptable solution. However, because of longevity concerns, reverse shoulder arthroplasty is not an ideal option for young patients. Achilles tendon–bone block allograft has been described as an alternative to reverse shoulder arthroplasty in a young patient with greater tuberosity and rotator cuff deficiency. There has also been growing interest in utilizing the Achilles tendon allograft for superior capsular reconstruction.
[[File:Achilles-calcaneus graft.mp4|thumb|Video of a calcaneum and Achilles tendon allograft for a secondary migration of greater tuberosity following osteosynthesis of proximal humeral fracture.]]
 

=====Reverse Shoulder Arthroplasty=====
Reverse shoulder arthroplasty has emerged as a treatment for irreparable rotator cuff tears. Two recent systematic reviews confirmed that this is a reliable procedure to improve mobility and strength, producing an improvement in pain and postoperative outcome scores.<ref>Petrillo S, Longo UG, Papalia R, Denaro V. Reverse shoulder arthroplasty for massive irreparable rotator cuff tears and cuff tear arthropathy: a systematic review. Musculoskelet Surg 2017;101:105-12.</ref><ref>Sevivas N, Ferreira N, Andrade R, Moreira P, Portugal R, Alves D, Vieira da Silva M, Sousa N, Salgado AJ, Espregueira-Mendes J. Reverse shoulder .arthroplasty for irreparable massive rotator cuff tears: a systematic review with meta-analysis and meta-regression. J Shoulder Elbow Surg 2017;26:e265-e77.</ref>

Moreover, reverse shoulder arthroplasty yielded benefits considered cost-effective when compared with other treatments, especially in elderly patients with irreparable rotator cuff tears.<ref>Kang JR, Sin AT, Cheung EV. Treatment of Massive Irreparable Rotator Cuff Tears: A Cost-effectiveness Analysis. Orthopedics 2017;40:e65-e76.</ref>

Reverse shoulder arthroplasty should be considered in older patients for whom long period of immobilization and rehabilitation is undesirable.<ref>Lädermann A, Denard PJ, Tirefort J, Collin P, Nowak A, Schwitzguebel AJ. Subscapularis- and deltoid-sparing vs traditional deltopectoral approach in reverse shoulder arthroplasty: a prospective case-control study. Journal of orthopaedic surgery and research 2017;12:112.</ref>

Even if the rate of complications was high in the two above mentioned systematic reviews, a dramatic decrease has been observed with new designs and better techniques.<ref>Lädermann A, Lo EY, Schwitzguebel AJ, Yates E. Subscapularis and deltoid preserving anterior approach for reverse shoulder arthroplasty. Orthopaedics & traumatology, surgery & research : OTSR 2016;102:905-8.</ref>

Recently, the complication rate has been reported to be lower. However, caution should still be exercised when offering reverse shoulder arthroplasty to young patient that are often disappointed by the results.<ref>Ernstbrunner L, Suter A, Catanzaro S, Rahm S, Gerber C. Reverse Total Shoulder Arthroplasty for Massive, Irreparable Rotator Cuff Tears Before the Age of 60 Years: Long-Term Results. J Bone Joint Surg Am 2017;99:1721-9.</ref><ref>Virk MS, Nicholson GP, Romeo AA. Irreparable Rotator Cuff Tears Without Arthritis Treated With Reverse Total Shoulder Arthroplasty. Open Orthop J 2016;10:296-308.</ref>

====Conclusion====
Various surgeries are proposed for similar posterosuperior irreparable rotator cuff tears and preoperative patient' clinical evaluation. There is no panacea for primary treatment and patients must be aware, in case of palliative or non-prosthetic option, of an alarming rate of structural failure (around 50%) in the short term (Table 5).

'''''Table 5: Results of the different techniques of irreparable rotator cuff tear treatment from representative series'''''
[[File:1562520882562-lg.jpg|center|thumb|720x720px|†: Constant score, ‡: American Shoulder and Elbow Surgeons (ASES) score, NA: non available.|alt=]]
The initial use of complex and expensive techniques in management of posterosuperior irreparable rotator cuff tears is actually not supported. Further prospective and comparative studies with large cohort populations and long-term follow-up are necessary to establish effectiveness of expensive or complicated procedures such as SCR, biological augmentation or subacromial spacer as reliable and useful alternative treatment for irreparable rotator cuff tears. 

==What would Codman have thought about this?==

Rupture of the supraspinatus tendon

CHAPTER V

Now that we have considered the shoulder from the anatomic and pathologic points of view, we come to the clinical study of the lesions which may be identified by special groups of symptoms as definite entities. It seems to me that the practice of medicine might be greatly simplified if an official list of clinical entities was constantly maintained by some great medical association. Our literature and our methods of medical education are greatly hampered by synonyms. McCarthy has recently pointed out in Surg. Gyn. and Obst., February, 1932, that there is great need for such a list of malignant conditions. Pathologic entities and clinical entities are not the same. Clinical entities are the practical working diagnoses on which rational treatment may be based. I feel that the Registry of Bone Sarcoma has served such a purpose so far as the nomenclature of bone tumors is concerned, and that this fact alone has done much to crystallize our working knowledge of the diagnoses and treatment of bone lesions.
I shall try in this book to make a. similar list of the lesions of the shoulder which have such distinctive characters that they may be recognized clinically and given appropriate treatment. For instance, I recognize as significant clinical entities, complete rupture of the supraspinatus tendon, partial rupture of the supraspinatus tendon, calcified deposits in the tendons of the short rotators, and tendinitis of the short rotators; and I do not recognize muscular rheumatism, neuritis, or idiopathic monarticular arthritis of the shoulder, as entities of sufficient clinical frequency or importance to make them demand special forms of treatment, although these terms are much more frequently used as diagnoses on which physicians base their therapeutics. If an official list existed I would ask to have my new entities added and the old ones at least put in small type. The reader is referred to the Index.

Click for large image

CHART I

Excluding obvious diagnoses such as tumors, fractures and dislocations, most painful shoulders may be classed under the four diagnoses indicated in large type, although each entity merges into the two which adjoin it. For example, calcified deposits are probably a product of tendinitis, but if large in amount, they alter the clinical picture, both in prognosis and in the character of treatment required. If the deposits are very small, they may be negligible, and the clinical picture be that of a "frozen shoulder" due to tendinitis, lendinitis may also be confused with its other neighbor, because a "rim rent" may precipitate the inflammation which results in the frozen shoulder. In a similar way the line between partial and complete ruptures is difficult to draw; e.g., some cases of partial ruptures do not show much restriction of motion. Even complete ruptures may be confused with calcified deposits, as in Case 76, where the tendon was torn through a partially calcified area. Pathologically, too, there is some reason to believe that calcified deposits may be caused originally by small ruptures, and that the defects left after the deposits have disappeared may later lead to rupture. Nevertheless, although these entities are difficult to separate in borderline cases, typical instances are very clearly distinguished for purposes of treatment as well as in prognosis. There are also suggestive variations in sex, age, and occupation among the patients subject to these conditions.

This chapter discusses the most serious of these entities. As far as I know, I was the first writer to call attention to this lesion, and it seems to me that I can best introduce the rest of the book by reprinting here my first article, so that we may thus start at the beginning, so far as the history of this particular entity is concerned.

----------------------------------------------------

Reprinted from the Boston Medical and Surgical Journal, Vol. clxiv, No. 20, pp. 708-710, May 18, 1911

COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON. OPERATIVE TREATMENT WITH REPORT OF TWO SUCCESSFUL CASES

In a paper on "Stiff and Painful Shoulders," published in the Boston Medical and Surgical Journal for May 31, 1906, in speaking of rupture of the supraspinatus tendon in connection with subacromial bursitis, I presupposed, on anatomic grounds, the probable symptoms of such rupture as follows:

"One theoretical symptom (since the supraspinatus is put out of action) should be the persistence of passive and loss of active abduction. I am not ready to say this as yet, however, because in most cases the pain is so great that spasm prevents even passive motion, and later adhesion takes the place of spasm. When rupture of the tendon does take place, it probably is only partial and a Y-shaped attachment still remains to perform part of the function. In a similar way, the quadriceps may extend the femur when the patella is broken if the lateral expansions of its tendon are not torn. Nevertheless, I believe that the active function of the supraspinatus is important in elevation of the arm."

Since this paragraph was written I have had two cases of complete rupture of the supraspinatus tendon on which I have operated, and in both of which I was able not only to demonstrate the existence of the anatomical lesion in conjunction with the above symptoms, but succeeded by suturing the tendon to the tuberosity in bringing about complete restoration of the function of abduction. I have also, in a number of cases, verified the clinical diagnosis of a partial rupture such as depicted in the accompanying figure, which was produced in the other articles which I have written on this subject. (The reader is referred to the articles appearing in the Boston Medical and Surgical Journal for Oct. 22 and 29, Nov. 5,12,19 and 26, and Dec. 3, 1908. The figure alluded to is not repeated here.)
This partial rupture is the common lesion, and, as I have explained, the remaining portion of the tendon is competent to take up the function when the sensitiveness due to the reparative process about the point of rupture has disappeared. The curious deposits of lime salts sometimes shown in the X-ray, and spoken of by Painter and Baer, are, I believe, faulty attempts at repair of these tiny ruptures of the tendon.
The following two cases are quite definite because they present complete rupture of the tendon of the supraspinatus. Therefore, the function of active abduction was almost entirely lost.

CASE 1.—Mrs. J. A. Aged fifty-two. Born in Scotland. Referred by Dr. Kent, of Dorchester, March 7, 1909.
Patient had always been a healthy, hard-working woman and had practically never been sick. On Oct. 3 of the previous year, i.e., five months before I saw her, while she was hanging recently washed clothes on the line in her yard, she endeavored to toss over a heavy blanket and felt something snap in her shoulder as she threw her arm up. She felt an intense pain and her arm fell and "hung by her side for a while." She was examined later by Dr. Kent, who found no thickening or ecchymosis. An X-ray was negative. Since then she had not been able to abduct the arm and had suffered much pain at night and somewhat during the day. The symptoms were in general those which I have described as the symptoms of adherent subacromial bursitis. The following points were, however, noticeably different.
(1) There was little atrophy of the deltoid, and it even appeared hypertrophied on account of the apparent swelling of the joint beneath. (2) Under the fibers of the deltoid, beneath the acromion and over the joint, there was a distinct deep fluctuation as if the whole bursa were full of fluid. (3) The ability to start abduction was absent, but when the arm was passively abducted to about 140°, the patient, by a strong contraction of the deltoid, could prevent the arm from falling for an instant, but the slightest downward pressure made it drop to the side. External rotation was about one-half the normal.
Operation.—March 11, 1909. Usual incision between fibers of deltoid. Roof of bursa abnormally thick with granulation-like bodies on its under surface. Escape of straw-colored fluid, about one-half ounce. The floor of the bursa was found communicating with the joint, because practically the whole supraspinatus was torn from its insertion and retracted inwards. The biceps tendon was exposed over the articular surface, but was apparently uninjured. For about one-half inch on the lower visible portion it was bright pink; the rest of it was normal in appearance. By holding the bursa wide open,
pulling down on the arm and raising the elbow from the table, the retracted end of the supraspinatus could be seen. This was caught with a tenaculum and pulled down enough to suture with four heavy silk threads to the remaining portion still attached to the tuberosity. This could not be done exactly, but was done nearly enough so that it seemed possible for repair to take place along the silk sutures. A little gap was also left on each side, which was not covered with tendon substances. It was in a sense a suture a-distance. When the operation was completed it seemed as if there was a fair possibility of the supraspinatus obtaining enough attachment to enable it to perform its function, although the base of the bursa would necessarily remain a rough instead of a smooth surface. Dr. Kent gave ether, Dr. Vincent assisting. Dr. J. J. Putnam and Dr. M. P. Smith-wick present.
June 9, 1909. Looks very strong and well. Sleeps well. Arm aches at times but not much. Pain in stormy weather (after use). Gets good use out of arm and does her own work. Can button back of dress and do her own hair. Real free abduction to 135°. Fair rotation. Muscles developing well and deltoid is strong. Very much pleased with result.
This patient was demonstrated to the Interurban Orthopedic Club, March 25, 1911. The arm is perfectly well and the function is perfect. The only abnormal sign is that the deltoid is unusually prominent due to the presence of joint fluid in the bursa.

CASE 2.—Mr. D. R. Aged forty. Hostler. Referred by Dr. John Homans, Dec. 21, 1910.
Patient is a strong, wiry Irishman. He has always been well. About three and one-half months previously, he had been saddling a horse in the stable and while tightening the girth he felt something in his shoulder give way and he fell to the floor. There was immediate loss of power in the arm, but lie managed to finish saddling the horse without raising that arm. That night he consulted Dr. Luce, of Canton, who found no ccchymosis, but thought there was slight crepitus. An X-ray a little later was negative. The hip was also hurt by his fall, so that for some time he was more bothered by that than he was by his shoulder and he was obliged to use crutches for several weeks. At the time he presented himself to me for examination the symptoms were at first sight those of the adherent type of subacromial bursitis, but on more careful examination the same signs that were present in the previous case were demonstrable, that is, (1) Relatively slight atrophy of the deltoid and an appearance of hypertrophy. (2) Fluctuation over the region of the bursa beneath the deltoid producing a "verwblbung" of the latter. (3) The persistence of nearly normal passive abduction with no active abduction. When the arm was passively abducted, the patient by a strenuous exertion of the deltoid could hold the head of the bone on the glenoid and thus prevent the arm from falling immediately. (4) In this case a distinct depression could be felt just above the tuberosity at the point where the tendon was torn away from the latter. A definite diagnosis was made and the members of the Boston Orthopedic Club invited to examine the case and witness the operation.
Operation.—Jan. 10, 1911, at the Massachusetts General Hospital.
As in the previous case, when the fibers of the deltoid.and the thickened roof of the bursa were incised, there was an escape of straw-colored fluid and the bursa was found to be in communication with the true joint. The supraspinatus had retracted so far that at first it could not be seen, and one looked directly at the articular surface of the bone with the uninjured biceps tendon lying across it. With some difficulty the supraspinatus tendon was caught with a tenaculum, freed and pulled forward. It was then sutured "a-dis-tance" to the tuberosity with heavy silk prepared with paraffine after the manner of Lange. As in the previous case, the retracted tendon could not be entirely united, but enough strands of silk were put in to make it possible for the function of the tendon to be replaced.
Convalescence was normal and the patient was not allowed to use the arm in abduction for three weeks, but since then has been using it with more or less freedom. He was shown to the Interurban Orthopedic Club on March 25, and the following condition noted at that time:
Patient is working every day—can chop wood and do other "chores" without pain. He can easily place his hand on top of his head or behind his back. Full abduction of the humerus on the scapula is, however, weak, and although he can elevate his arm, he cannot hold it in an abducted position against a downward pull of even moderate force. The strength of the arm in other respects is excellent and the patient is well satisfied. The function of the supraspinatus is fully as good as it was in Case 1, at the same length of time after the operation.
I have seen only one other case in which I have made a diagnosis of complete rupture of the supraspinatus, and as I have not been able to persuade this patient to allow me to operate, his present condition is very instructive as compared to the two cases mentioned above.
In spite of the fact that the patient is a powerful man with an extremely well-developed deltoid, he is now, four years after the injury, still unable to start abduction. As in the other cases, however, when the arm is passively abducted so that the patient's deltoid acts in the same line of force as the axis of the humerus and the remaining short rotators {i.e., subscapularis, teres minor, infraspinatus), the head of the humerus obtains a fairly firm contact with the glenoid so that the weight of the arm can be held by a great effort of will on the part of the patient. The slightest pull downward on the arm, however, will overcome what little power he has, and as soon as the fulcrum on the glenoid is lost, the arm drops to the side.
It will be necessary for those readers who are interested in this subj ect to refer to the articles mentioned above to thoroughly understand this one, but, best of all, they should look for themselves at dissecting-room subjects, because injuries to this tendon are so common that I have never had any difficulty in finding examples of it in a single set (20) of dissecting-room subjects.
The injury, as I have explained, is usually confined to a partial rupture of not more than one-quarter to one-half inch in breadth. Such complete cases as these three which I have reported are exceptional. The smaller ruptures, which are not of sufficient mechanical importance to interfere greatly with the function of the arm, are best considered with the subacromial bursitis which they cause. It must be understood that these ruptures are beneath the serous base of the bursa, which may or may not be torn through. If it is torn through, a communication is established between the bursa and the true joint.
In operating for subacromial bursitis, if on entering the bursa one finds straw-colored joint fluid, a careful search will usually demonstrate a small opening into the true joint at the point of rupture. In only one case has it seemed worth while to me to make an attempt to suture one of these small ruptures. Usually these heal satisfactorily if the inflamed portion of the bursa over them is clipped away with scissors. I am convinced, nevertheless, that suture is necessary in long-standing complete cases such as those cited above. The one which was not sutured has a decidedly impaired function and for two years was unable to work.
I have never seen the tendons of the other short rotators ruptured except in conjunction with that of the supraspinatus. Twice I have seen a longitudinal split between the tendon of the subscapularis and that of the supraspinatus. (End of 1911 paper.)

FIGURE 38. RUPTURE OF THE SUBSCAPULARIS
Sketch by Mr. Aitkin of a specimen found and prepared in the dissecting room by my former assistant, Dr. T. W. Stevenson. It illustrates a rupture of the subscapulars without rupture of the supraspinatus, and is instructive from several points of view. This is the only instance of an exception to the statement in the last paragraph which has come to my knowledge in the twenty-two intervening years. It gives a very good idea of how the insertion of the supraspinatus, which in this specimen was intact, normally fills the sulcus at the anatomic neck, and covers the tuberosity, thus leaving a perfectly smooth exterior contour beneath the base of the bursa. In this case the bursa has been thoroughly dissected away in order to show the superficial fibers of the tendons passing over the tuberosity and becoming continuous with the periosteum below. In Chapter X it will be shown how these fibers cover up and hold together the fragments in comminuted fractures.
The figure also gives a good idea of the manner in which the supraspinatus emerges from under the coraco-acromial ligament and acromion. The lower or inner edge of the muscle has been rather sharply dissected, but in the undissected specimen this edge blended with the upper portion of the subscapularis. Below this, one sees that most of the subscapularis has been torn away from the conjoined tendinous cuff, so that the biceps tendon, running through its groove between the two tuberosities, is exposed at the left edge of the gap. Internal to the biceps tendon we see the lesser tuberosity, from most of which the subscapularis fibers have been evulsed. The knobby character of the surface of the exposed tuberosity is shown; an appearance usually found in old cases where the tuberosity is exposed by evulsion of the fibers of any of the other tendons. (See frontispiece and Fig. 40.) In other words, this knobby look is the superficial appearance of the "excrescences" or "volcanoes" spoken of on page 91, and also shown in Plate V, Fig. 1.
In the upper half of the gap above the excrescences is the exposed cartilage of the joint. If this gap extended outward from the biceps tendon, instead of inward, it would represent the condition which we usually see; i.e., rupture of the supraspinatus rather than of the subscapularis. It is not unusual to find in the dissecting room extensive tears involving both tendons, but it is very unusual to find the subscapularis involved alone, as in this case. One can readily picture how easy it would be to produce such a condition as this by forcibly performing external rotation in a case of "frozen shoulder."
This diagram also gives an excellent idea of the coracoid process, coraco-clavicular and coraco-acromial ligaments, as well as of the conjoined origin of the internal or short head of the biceps, and of the cornco-brachialis muscles. It also shows the insertion of the pectoralis minor, the tendon of which protrudes as a stub at the inner side of the coracoid process in this diagram.

Although it is over twenty years since the above paper was written, I have very little of importance to add or subtract from it. I followed the two cases for many years and the results continued to be satisfactory. Although the second case never had perfect function in his shoulder, he could do all sorts of farm and stable work without complaint. As he worked for a neighbor, I had frequent opportunity to observe him for over ten years.
There is a point in the quoted paragraph which might cause confusion. At that time, 1906, I did not realize that the stooping posture was such a great help in testing mobility in the scapulo-humeral joint. One may get the impression, when examining a patient in the upright position, that scapulo-humeral adhesions exist, and yet in the stooping posture, positive proof will be given that the joint is movable. It is important for the reader to understand at once that scapulo-humeral passive mobility is a sine qua non for the diagnosis of a complete rupture of the supraspinatus, and that in the stooping posture this mobility is much less inhibited by pain and spasm. I did not fully appreciate this point in 1906, and even in 1911 I had hardly grasped it, and did not accent it enough in the above paper. It will be discussed later in this chapter.
The only other point which I desire to correct is in the next to the last paragraph. I do not think I was justified in making such a general statement as "usually these heal satisfactorily if the inflamed portion of the bursa over them is clipped away with scissors," for I am still in doubt as to how to treat the incomplete ruptures.
I have really little more than I had in 1911 to give to the profession in this book, except that repeated experience with the same signs, symptoms, operative findings and follow-up have increased my confidence in the accuracy of my former observations and opinions. During these years I have only operated upon about forty belated cases, although I have made the diagnosis over a hundred times. My results have been good but by no means perfect, because I never see these cases in their early stages, when I am sure the operations would be easy and the results entirely satisfactory. This book aims to try to teach the practicing physicians, who see the cases soon after the injury, how to recognize this lesion immediately, and to rush the patient to a competent surgeon as promptly as if the patient had a broken arm—a much less disabling accident. As in acute appendicitis, early recognition and prompt operation are of the utmost importance. The remainder of this chapter will therefore be devoted to a more detailed discussion of the symptoms.

FIGURE 39. RUPTURE OF THE SUPRASPINATUS
A schematic posterior view of a case of ruptured supraspinatus, to show the posterior short rotators and the sulcus and eminence formed where rupture of the supraspinatus has occurred. The acromion has been sawed off at its base. The reader should study the frontispiece and the next figure in connection with this one.

The size of the rent in the tendon is an important factor since the degree of the severity of each symptom may vary with the extent of the rupture. It seems best to discuss first the symptoms of those cases where the rent is large, as in the two cases which I first reported and which I have called "complete." This means that at least that portion of the conjoined tendinous insertions supplied by the supraspinatus has been torn away, with or without portions of the adjacent tendons. These are the cases which should certainly have the benefit of immediate operation. I do not at present advocate operating upon incomplete cases, for it is likely that after a few months they may heal in whole or in part. On the other hand, there is good reason to believe that the complete ruptures which make an open communication between the joint and the bursa never do heal entirely unless sutured. In other words, the symptoms have had to be pretty pronounced in order to make me willing to operate. It is significant that almost invariably the rent in the tendon has been found to be larger than anticipated. I have perhaps been over-conservative in deciding to operate, but the reader must remember that I have taken the responsibility of doing an operation which is not generally practiced, and naturally I have been somewhat cautious. It is my sincere belief, however, that a small exploratory incision is harmless and that the practice of promptly making such an incision in acute, doubtful cases is to be encouraged, provided the operator has carefully studied the anatomy of the region.
Almost all surgical operations which are now standard procedures had similar histories. Many human sacrifices were required to teach us not to delay when the symptoms strongly suggested appendicitis, perforated duodenal ulcers or intestinal obstruction. The fact that death occurs when we procrastinate in these serious cases has made us, in the public eye, more to blame for delay than for making negative explorations. The surgeon who does explorations on these injured shoulders might be criticized today and yet a few years hence be blamed for the failure to do them. Moreover, the laboring man with a shoulder injury has not yet been educated to dread this particular lesion as he has been to fear appendicitis.

FIGURE 40. X-RAY OF SPECIMEN SHOWN IN FRONTISPIECE Owing to the fact that it had been dissected, air has entered both the joint and the bursa, somewhat after the manner indicated in the cover design. It suggests appearances which we might see if we used air or opaque fluid injections in the bursa and joint. It shows a little irregularity on the surface of the tuberosity, which in the painting gives the appearance that I have called a " volcano "; i.e., a small eminence which has a craterlike place in its center. These little eminences are found in many old cases of ruptured supraspinatus. They may represent a productive osteitis due to irritation from contact with the acromion during elevation. The figure also shows two small caverns such as those illustrated in Plate V, Fig. 1 and Fig. 2. I am not sure just what these caverns indicate.

The account of symptoms given in my 1931 paper before the American College of Surgeons was presented in a twenty-minute talk, and while I still think it accurate, I am not satisfied with its arrangement nor with the amount of detail its time limit permitted. The immediate symptoms were not separated as they should have been from those that supervene later in the course of the disability. The early signs should have been emphasized, because success in treatment must depend largely on prompt diagnosis. It is easy enough to recognize one of these cases when atrophy has developed and the lapse of time has shown the persistent character of the lesion, but to make the diagnosis on the day of, or on the day after, an injury is quite another matter.
Probably insurance records would show that 80 or 90 per cent of employees complaining of shoulder "strains," return to work within three months. Certainly we could not recommend exploratory incision of the bursa in all of these cases in order to detect perhaps 10 or even 20 per cent where the rupture would be complete. When we have learned just what to do when we find minor ruptures or tendinitis, it may become wise to make such incisions as a routine, but at present the bill for negative explorations would be far too large. I contend that it is possible to detect the severe cases.

CERTAIN CONDITIONS, SYMPTOMS AND SIGNS WHICH INDICATE COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON AND WHICH SHOULD BE PRESENT WITHIN TWENTY-FOUR HOURS AFTER THE ACCIDENT.

(1) Occupation—labor.
(2) Age—over 40.
(3) No symptoms in shoulder prior to accident.
(4) Adequate injury—usually a fall.
(5) Immediate sharp, brief pain.
(6) Severe pain on following night.
(7) Loss of power in elevation of the arm.
(8) Negative X-ray.
(9) Little, if any, restriction when stooping.
(10) Faulty scapulo-humeral rhythm.
(11) A tender point,
(12) a sulcus, and
(13) an eminence
(14) at the insertion of the supraspinatus,
(15) which cause a jog,
(16) a wince and
(17) soft crepitus as the tuberosity
(18) disappears under the acromion when the arm is elevated, and usually also, as it reappears during descent of the arm.

Here are eighteen conditions to be fulfilled—an especially exacting syndrome. If such a syndrome is present I do feel that not only is exploration indicated but that it should be strongly urged, for immediate suture should be a simple and successful operation. Delay means retraction of the tendon and a much more serious problem.

I feel confident that this syndrome must exist, although I admit that I have never seen one of these cases within twenty-four hours of an injury. My best way of knowing the immediate symptoms is from the accounts of the patients or of their physicians given weeks or months after the injuries. Moreover, since these same symptoms are found at varying periods from three weeks to many years after the accidents, and do not vary much with the lapse of time, either in quality or in degree, it is likely that they were present at first. In a case in which they were all typical I should be positive of the diagnosis, and should urge operation. If several of the conditions were not fulfilled, it would influence me against operation, but if there were doubt, a negative exploration, if correctly performed, is a trivial matter, although the patient must be hospitalized in case a rupture is found.
If suture is done he should remain in the hospital for about ten days; if the exploration is negative he might well be discharged in twenty-four hours. These eighteen points will be discussed in more detail in numerical order.

(1) Occupation. The great majority of cases must belong to the laboring classes, for I have seen only one case in a person whose occupation did not or had not required heavy work. This suggests that overuse as well as increased liability to accident may be a contributory cause. The occupations are given serially in the following paragraph because if they were tabulated the list would not give the same impression of sequence which is presented by patients as they come for examination. On looking over these occupations the reader should contrast them with those in the following three paragraphs which are the occupations of patients who have had calcified deposits, tendinitis and partial rupture.

COMPLETE RUPTURE OP THE SUPRASPINATUS (100 Cases) Women 8%

Housewife, hostler, plasterer, street cleaner, housewife, coal-heaver, waiter, paper cutter, laborer, housewife, marble worker, currier, cooper, housewife, stationary engineer, two laborers, longshoreman, wrecker, teamster, two laborers, steamfitter, three laborers, truck driver, stock fitter, cook, stableman, painter, two laborers, truck driver, laborer, lineman, lather, farmer, three laborers, harness maker, wood molder, planer, electrician, plumber, mechanic's helper, laborer, roofer, laborer, longshoreman, riveter, two laborers, porter, cooper, two laborers, steamfitter, laborer, lather, steamfitter, laborer, stationary engineer, laborer, store clerk, carpenter, laborer, night watchman, longshoreman, laborer, taxi driver, lineman, laborer, painter, coal-heaver, laborer, foreman, truck driver, laborer, construction, painter, laborer, rubber worker, laborer, painter, laborer, carpenter, meat cutter, floor layer, stitcher, two laborers, housewife, foreman, laborer, store clerk, burnisher, teamster, laborer.

CALCIFIED DEPOSIT (100 Cases) Women 34%

Housewife, two no occupation, two physicians, chemist, physician, superintendent, two physicians, business, no occupation, business, manufacturer, architect, business, three physicians, milk delivery, supervisor, ironworker, housewife, filing clerk, physician, machinist, histologist, housewife, physician, business, no occupation, physician, no occupation, pipefitter, stenographer, no occupation, physician, garage, postman, business, waitress, musician, shipper, laborer, bookkeeper, machine tender, porter, teacher, laborer, housewife, broker, housewife, business, baker's helper, two salesmen, organist, weaver, housewife, shoemaker, forewoman, box-maker, two laborers, housewife, shoe machinist, farmer, housewife, advertising, paper mill, housewife, surgeon, real estate, advertising, housewife, machinist, boxmaker, store manager, wool handler, laborer, physician, truck driver, shoe worker, teacher, knitting mills, housewife, plasterer, laborer, shoe stitcher, clerical, physician, treasurer, investments, laborer, housewife, laborer, beauty parlor, manufacturer, salesman, manufacturer.

TENDINITIS (100 Cases) Women 58%

Two housewives, two no occupation, army officer, two housewives, carpenter, tailor, nurse, no occupation, tailor, nurse, business, P. O. clerk, secretary, three housewives, no occupation, physician, maid, coppersmith, merchant, housewife, jeweler, minister, harnessmaker, housewife, hostler, tailoress, storekeeper, priest, no occupation, photographer, housewife, professor, housewife, carpenter, starter, housewife, shoe laster, housewife, two no occupation, housewife, roofer, civil engineer, two housewives, cigar maker, judge, shoe manufacturer, no occupation, nurse, three housewives, physician, housewife, laborer, two housewives, physician, two housewives, store clerk, housewife, social worker, housewife, insurance broker, factory worker, two housewives, desk work, social worker, salesman, food checker, housewife, consulting engineer, banker, physician, invalid, two housewives, nurse, laundry, writer, surgeon, two housewives, two physicians, foreman, lawyer, grocer, executive secretary, nurse, public accountant, no occupation.

PARTIAL RUPTURE (100 Cases) Women 11%

Three laborers, farmer, carpenter, eight laborers, baker, plumber, laborer, housewife, two laborers, carpenter, housewife, painter, laborer, mechanic, garage, two laborers, writer, three laborers, physician, laborer, carpenter, teamster, laborer, carpenter, laborer, machinist, laborer, housewife, teamster, cook, stone mason, bricklayer, carpenter, three laborers, store, housewife, laborer, mechanic, housewife, store clerk, cook, machine oiler, laborer, two housewives, insurance, store, business, janitor, hoisting engineer, painter, meat cutter, three laborers, florist, two laborers, ironworker, nurse, gardener, shoe factory, clerk, plasterer, lawyer, laborer, no occupation, student, bartender, manager, housewife, laborer, foreman, bricklayer, horseman, two laborers, nurse, farmer, machinist, real estate, gardener, laborer, housewife, tailor.

Both occupation and sex are of importance in the diagnosis of shoulder conditions. Men who have done heavy labor are typical subjects for complete ruptures of the supraspinatus, and women of the so-called "leisure class," for tendinitis (frozen shoulder). Calcified deposits are more characteristic of the class who have gainful but not laborious occupations (the white collar class) ; i.e., they are not usually found in inactive people. Partial ruptures are also in the main characteristic of men of the laboring group, but they may occur in the more active and athletic members of the leisured class, both in men and in women.
These observations were already made from general impressions in the course of my practice, but they are in part confirmed by the above analysis of the occupations of 400 cases. The detailed accounts which each patient has given of his or her occupation and other activities, are of even greater weight in confirming my own impressions. For instance, the term housewife may apply to a woman who does all the work and washing for a large family, or to a lady who scarcely uses her arms, or to an active wife who plays golf, sends out her washing and only occasionally uses her kitchenette. The percentage of women varies greatly in the different classes, eight per cent, eleven per cent, fifty-eight per cent and thirty-four per cent. The eight cases of complete rupture and eleven of the fifteen cases of partial rupture were women whose work was really laborious. The fifty-eight tendinitis cases were chiefly women of the leisure class and the thirty-four calcified cases were active single women or wives.

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(2) Age. The four clinical entities also affect different age groups. Young persons below twenty-five seldom have any of these conditions. Apparently in young people the tendon is stronger than the bone in which it is inserted, and stresses, which in later life would break the tendon, cause fracture of the bone or separation of the tuberosity. Chart I shows that the four entities affect, in the main, persons in the latter half of life, and that the occurrence of tendinitis both of the calcified and uncalcified forms precedes the peaks of incidence of the ruptures, partial and complete, by about five to ten years. The curves of the two forms of tendinitis, calcified and uncalcified, have their peaks at the same period, but the rise of the curve is distinctly earlier in the calcified form. These facts suggest that injuries of the tendon prior to the thirtieth year either are rare or that the tendons are capable of normal repair. Then follows a period when repair is uncertain and is apt to be complicated by the deposit of calcium. Later even this incomplete repair fails.

WOMEN—CHART III

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If we chart separately the male and female cases there is a marked contrast. The curve of the female cases suggests that tendinitis, both calcified and uncalcified, may be related to the menopause or to the age when the teeth begin to loosen. By comparison of the two charts we find that calcified deposits apparently occur somewhat earlier in males than in females, and their occurrence tends to diminish at the period when they are highest in the female. The contrast of Chart II and Chart III makes it very clear that the more serious forms of rupture of the supraspinatus are characteristic of the male toward the end of his laboring days. The period of life shown in all the curves is that in which the teeth are usually in decay. If these charts are made without separating the cases in four entities the contrast between the ages of males and females is even greater, so that the coincidence with the menopause is more striking.

MEN—CHART IV

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(3) The history of a previously painless and useful arm is unreliable for two main reasons. First,—previous troubles may have been forgotten. Men of the laboring classes put up with a great deal of soreness and pain and forget it easily. Such a matter as an attack of bursitis years before, may readily be forgotten. I would rather
have the history of previous troubles from a man's wife than from the man himself. I am inclined to think that in many cases where complete rupture has occurred, there may have been previous minor troubles, which might have indicated either partial rupture of a few fibers, or a "calcined deposit." However, my records do not show this, for in only nine of a hundred cases could a history of previous trouble be obtained.
The second reason is that men may lie as well as forget. The statements of employer and fellow workmen are sometimes more accurate than the patient's own. Patients may conceal previous trouble to avoid losing compensation.
The other shoulder should always be examined in these cases, for occasionally one finds signs of a partially ruptured tendon or of chronic bursitis there, although no complaint is made of symptoms. This would, of course, be very suggestive of preexisting disease in the injured shoulder. However, we must not forget that a rupture may occur as a bona fide injury in degenerated or diseased tendon.
(4) Adequate injury seems pretty well illustrated by the following brief accounts of the accidents in twenty-one successive cases which were proved by operation, and in seventy-nine others in which the diagnosis was made but not proved.

ACCIDENTS (Operated Supraspinatus Cases)

57. "Fell taking down an old gallery."
75. "On this date (Aug. 25, 1922) he was engaged with others in hoisting lumber, when a plank slipped off the hoist and struck him in the side knocking him down."
83. "On Jan. 17th, 1923, he fell downstairs and injured his left shoulder."
88. "On Feb. 1st, 1926, while at work he was pulling a heavy case along the floor with a hook. The hook slipped and as he caught his balance he felt something snap in his shoulder accompanied and followed by intense pain."
89. " When getting off truck caught his hand in fly wheel. Cuts of hand."
96. "On April 4th, 1927, he slipped on a concrete floor and injured his left shoulder."
97. "On Nov. 8th, 1926, he was pushing a freight car with another man, using bars. His bar slipped and he fell down wrenching his left shoulder."
98. "Six weeks ago he had slipped on the ice while at work and had injured his right shoulder. He fell on his back striking his elbow, but had no bruise on the elbow. (It is probable he threw up his arm to get his balance.)"
102. "On Nov. 2nd, 1927, he was piling some 100-lb. sacks of beans with another man who stood above him and received the sacks as he threw them up. On one throw the other man failed to connect with the sack and the entire weight came on the patient's right arm. He felt something in his shoulder snap with a sharp pain."
106. "On January 20th, 1928, he was cranking his truck, which he uses to deliver cans of ice cream. The engine backfired and he felt a sharp pain in his right shoulder."
107. "On Jan. 18th, 1928, she fell on the floor of the kitchen where she works and dislocated her left shoulder."
108. "At some time in July (date uncertain) while at work he was turning a board and felt something snap in his right upper arm about the middle, in the region of the long head of the biceps. There was a sharp pain which went away in a few minutes."
112. "On March 10, 1928, he was wheeling a barrow up into a barn when he slipped and fell forward on the barrow, but did not let go of the handles."
115. "On August 21st, 1928, about 1.30 P.M., slipped and fell from piazza roof, striking the edge of the piazza floor with his right arm in abduction. Had immediate pain in shoulder and arm."
119. "Day before Thanksgiving, Nov., 1928, fell off staging three feet high. Walked backwards off."
123. "On Jan. 14th, 1929, he slipped on an icy platform and hit on his left elbow."
127. "On Oct. 17, 1929, was handling 2x4 lumber and stepped in a hole. Fell against left shoulder on pile of lumber, hitting on elbow."
128. "He slipped on the ice near a building and fell, striking the side of his right shoulder against a low step. This is what he says, but such a fall as that would probably be impossible. It is more likely that he threw his arm up as he fell."
129. "On October 24th, while piling some pipe, he was standing on a pile of pipe which rolled under his feet and he fell between two piles of pipes."
185. "He slipped on the ice and fell. After he got up, he found that he could not raise the left arm."
137. "On May 13, 1930, he had a fracture near the left elbow which healed satisfactorily and he went back to work about September 1st. On October 7th, in Andover, he fell and dislocated his left shoulder."

ACCIDENTS (Unoperated Supraspinatus Cases)

". . . he was doing some overhead work standing on a support twelve or fifteen inches high. The support slipped and he fell on his right hand and elbow, and then forward on his shoulder." ". . . he was pulling on a rope which suddenly gave way. He fell to the ground with his right arm below and behind him. He felt a sharp pain in the shoulder as if a bone had broken." ". . . he fell about ten feet while at work and injured his shoulder." ". . . he had been hit by an automobile, knocked down and taken to the Boston City Hospital. His shoulder had been injured." ". . . he was cranking his truck, and had a kick back. He thinks the handle struck him on the lower part of his upper right arm, but his shoulder was w.renched." "... when walking in a dark passageway, he stepped over some steps and in trying to save himself caught with his left arm on the wall, but kept his feet. He had a violent pain in his left shoulder but pulled himself together and went to his next job." ". .. he was struck on the left shoulder by a falling bale of hemp while at work. He was knocked down and much shaken up, but pulled himself together and continued to work the rest of the afternoon with his right hand." "Fell off wagon when unloading barrels. Hurt badly at time and went to Camb. Relief Hosp." ". . . he was lifting a barrel and something snapped in his shoulder, since which he has been unable to work." ". . . he tripped on a rolling log and fell injuring his left shoulder." ". . . he fell down some stairs and injured his right shoulder." ". . . the employee slipped on a loose plank and injured his left shoulder and right foot." ". . . he was pulling on a chain fall and something slipped in the right shoulder." ". . . he was jammed between a moving truck and the side of a building. Fortunately, he was near the corner of the building and the moving truck carried him around the corner, squeezing him from side to side as it did so. His left arm immediately became powerless." ". . . he fell from a staging and injured his right shoulder and has not yet recovered the use of it for anything requiring the function of abduction." ". . . he was filling a wagon with coal when the horses started and he fell in between the wagon and the side of the coal-pocket." ". . . he fell forward at the top of a flight of stairs and injured his shoulder as he supposed by hitting some beams." "A frame which he was moving dropped and to prevent it striking his feet stepped aside, losing his balance and falling to the floor." ". . . she felt something snap in her shoulder (left) when raising some wet clothes on a pole to put them in a laundry machine." ". . . while raking grass on a steep bank, he slipped and injured his left shoulder." ". . . as he was stepping out of a tip cart on the hub of the wheel, he slipped and fell heavily to the ground injuring his left shoulder and also his right shoulder to some extent." ". . . the employee was carrying a plank with another man, when one of the planks on which he was walking gave way, letting part of his body through the pier so that he sustained injuries to his left shoulder, arm and leg." ". . . she fell over a bag of soles and injured her right shoulder." ". . . he slipped off a plank and fell headlong to the floor, about four feet." ". . . large heavy car six or eight feet on the side. On this occasion the car skipped the track in spite of his efforts to prevent it, striking him on the left arm." ". . . he says that he was using his truck to load heavy rubber bales weighing about 350 lbs. each. He had put the edge of his truck under one such bale and reached forward with his right hand to pull the bale toward him on to the truck. As he pulled, he felt something give in his right shoulder." ". . . he was helping with other men, to pull a heavy truck, when he felt something give way in his right shoulder." "He was carrying a roll of leather and fell on the floor in the room where he usually worked." ". . . he fell from his truck and injured his left shoulder." ". . . he fell thirty feet from a staging and was badly bruised all over." ". . . he was on a lumber pile helping to load a truck. He was using a pick to drag the lumber. The pick slipped and he felt a sudden pain and something snapped in his arm at the right shoulder. His arm fell limp at his side." ". . . he slipped on some stairs and injured his left shoulder. . . ." ". . . fell among some barrels in the hold of a vessel and struck his right shoulder again." Had had previous similar accident six years ago, and never full use of arm since. ". . . while working in a meat market in Nantucket, he slipped on going out of the ice chest and injured his right shoulder." ". . . while carrying rubbish on an incline in the factory where he works, he fell and injured his right shoulder. As he says, 'it went dead immediately.'" "He was piling wool at the time, lost his balance and fell from one bale to some other bales not far below. As he fell he felt something snap in his shoulder which did not hurt him very badly at the time. . . ." ". . . slipped on ice in street." ". . . while working on a flat-car he fell and struck his right shoulder on the side of the car." "While at work in the factory in Lawrence ... he was in an elevator holding a heavy plank in both hands to steady it. One end of the plank was on the floor of the elevator and it stood vertically. Some one below started the elevator downward and then upward. As it went up it thrust the top of the plank violently against the top of the well. This shattered the heavy plank just above his hands with extreme violence and he was thrown into the corner of the car in a heap." ". . . he fell off the back of a load of straw and injured his shoulder." ". . . he again fell downstairs—only a few steps—and again injured his right shoulder." " Slipped and fell, and a box or case fell over on him." ". . . while directing some work where a floor was being replaced and the boards were up, he tripped on a beam and fell on his right side against another beam, probably breaking some ribs." ". . . he received an injury to his left shoulder when trying to move a large rock with a pitchfork. He felt something snap in his shoulder joint and suffered a sharp, severe pain at the same time." "He injured his right shoulder by falling from a truck." ". . . he was pulling some lumber off a truck and when it slid off quicker than he expected he fell backward and injured his left shoulder." ". . . he fell four feet, striking on the pavement, and inj ured his left shoulder." "... he slipped on an oily floor, and hurt his right shoulder and left shin." ". . . he fell from a staging about six feet to the floor below, and injured his right shoulder." ". . . he fell from a ladder and sustained injuries to the left shoulder and ribs." ". . . he was on a roof sawing a plank, and was standing on an extension ladder, which fell with him thirty-one feet to the ground. His right shoulder was injured, and his nose was cut" "Strap from machine fell off wheel and hit patient on right shoulder." ". . . he was working with others on a bridge in Rumford, Maine, helping to receive some cement in a frame from a bucket. In some manner, the bucket swung in the wrong direction and the patient fell from the bridge a distance of fifty feet." ". . . he was lifting a concrete block and felt something give in his left shoulder." ". . . he fell injuring his left shoulder." ". . . he had started to crank a hoisting truck when the starter began to work and the crank flew round and struck him on the right shoulder." "Slipped on ice." "Fell yesterday and sustained a contusion over outer end of right clavicle." ". . . while helping to unload a truck, a derrick knocked down a platform above him, and something, probably a heavy plank, fell on him and others working with him. He was knocked out by the blow, and cannot describe exactly the manner in which the plank struck him, but he knows it injured his shoulder and elbow and there was blood streaming down his arm." "He was pulling hard on a gunny sack, which gave way, and he fell over and thinks he struck his right shoulder." ". . . she tripped and fell on the floor at her work. She dislocated her right shoulder, bruised her knees severely and cut her face." "He was standing on stony ground swinging a sledge hammer, when he had to step back quickly. As he did so, he lost his footing and the sledge hammer, which he was swinging, carried on around his body so that his left shoulder was in an awkward position. He felt something snap in the left shoulder."

One may interpret the mechanism which produces this injury in several ways, but a sudden character is common to all of the accidents, which are generally falls. It is my belief that the rupture usually takes place from sudden elevation of the arm in attempting to regain balance, particularly if the hand is at the same time grasping a heavy object. Under these conditions a tremendous strain must be suddenly thrown on this little tendon as it attempts to quickly overcome the inertia of the arm, and perhaps, in addition, that of some heavy object held in the hand. In my first case, the woman attempted to throw a heavy, wet blanket over a clothes-line. It seems to me that this case, like a "slowed down movie," typifies the kind of strain which occurred in most of the other accidents. I believe that the even more sudden effort to regain balance during a fall caused the damage, probably before the patients struck the ground. For anatomic reasons one cannot, in falling, strike on the supraspinatus, because it is protected by the acromion.
Undoubtedly, however, in some cases, the tendon may have been torn in conjunction with dislocations, because of the leverage of the humerus on the fulcrum of the acromion. This mechanism will be explained in Chapter IX.

(5) A sharp pain in the shoulder at the time of the accident is almost always spoken of, although occasionally complaint of it is not volunteered. Sometimes patients say that they have felt something actually snap and think that they have broken a bone. Sometimes they feel that something has struck them on the shoulder. It has been explained on page 9 in the chapter on anatomy that histories of striking on the head of the humerus are unreliable because the acromion intervenes, and on page 144 that in falling, the arm is usually raised before the top of the shoulder can strike the ground. Consequently it seems to me that these tendons must usually be ruptured by indirect violence or sudden efforts of the muscles to overcome the inertia of the dependent arm, especially if there is a weight as a pick or shovel in the hand at the time, or the hand grasps something to save the man a fall. Often the fall is so sudden and the man so confused that the only thing he can understand is that he has hurt his shoulder and attributes the pain to having hit something as he fell.

(6) So far as I can judge from histories, there is then usually an interim of a few hours after the acute, immediate pain has somewhat subsided before the more severe pain comes on. Often the employee does not even consult a doctor at once, but tries to work the day out, favoring his arm. Perhaps he does not report the accident to his foreman. In the evening the pain becomes worse, and later in the night intolerable. He calls the doctor, or sits up in a chair, or "walks the floor." Next day he is pretty sure to report that he cannot work, but may persuade an accommodating foreman to let him "hang around" for a day or two until he gets better. These patients usually think the injury of no great consequence and expect "to have it wear off." This hopefulness is generally confirmed by the doctor's opinion, who perhaps may never have heard that such lesions occur. This attitude of mind of both patient and doctor is the main cause of delay in diagnosis and appropriate treatment.
It seems to me that the following theory is the probable explanation of the interim between the sharp pain when rupture occurs and the intense pain which appears some hours later. These tendons are not very vascular, and when they tear, there is probably very little bleeding; what there is, would come from the tissue between the bursa and the tendon. The interim spoken of would come during the period it would take this slight hemorrhage to distend the joint and bursa somewhat, i.e., enough to start a tension pain. This would create some spasm, and the tension caused by this would stop the slight bleeding. It would take several nights or perhaps a week for tension and spasm to subside and the hemorrhage to absorb. During this period the acute pain would continue.

(7) Inability to raise the arm is a constant symptom, but one must be on guard not to mistake unwillingness for inability. After almost any shoulder injury there may be pain when attempt is made to raise the arm, owing to the fact that the head of the humerus has to be forced upward to gain its fulcrum on the glenoid. The mere fact that the muscles have to exert tension to do this, causes pain in whatever structure about the shoulder may be injured. Therefore, the examiner must be sure that an honest effort is made to ignore the pain and elevate the humerus. It takes experience to tell whether such an effort is made, and one judges it by the degree of tension palpable in the deltoid. Even in the case of trivial injuries, such as ruptures of a few fibers of the supra- or infraspinatus, the symptom of inability to raise the arm may be pronounced, simply from the fact that the power to exert the appropriate muscles is inhibited by sensitiveness to pain. As explained on page 59, the deltoid needs the assistance of the supraspinatus and of the short rotators to hold the head of the bone on its fulcrum in order to have proper direction for its power; If the supraspinatus is torn, contraction of the deltoid brings the arm upward on the vertical axis of the humerus, and the amount the shoulder is raised will depend on the amount that the scapula, moving via the. sterno-clavicular joint and at the acromio-clavicular joint, can rise and rotate on the chest wall.
Formerly I thought that it was necessary to have this symptom of inability to raise the arm absolutely demonstrable in order to make the diagnosis of rupture of the supraspinatus, but experience has shown that, even when the supraspinatus is torn across its full width, the other short rotators can sometimes hold the head of the humerus on its fulcrum sufficiently to permit the patient to weakly perform elevation. However, as will be explained under No. 10, this elevation is never accomplished with a normal scapulo-humeral rhythm.

(8) A negative X-ray is almost always reported after these in juries. I believe that in the near future we shall be able to make the X-ray of more use in this diagnosis, either by using injections into the joint of non-radiable fluid, or by developing a soft tissue technique which will show the rupture. However, at present, negative X-rays are the rule, for ruptures which do not involve the bony facet of insertion are not shown in the film. A negative X-ray is of some positive importance, however, for it rules out the two conditions which are likely to make confusion in the diagnosis, that is, fracture of the
greater tuberosity and the presence of calcified material in the tendon. In long-standing cases changes in the structure of the trabec-ulae of the tuberosity which may be shown by the X-ray do take place. These are described on page 92.

(9) In the symptom complex of this condition, lack of restriction of motion takes a very important part, and this lack of restriction can be best determined when the patient is stooping from the hips with the knees extended. The patient should stoop (Fig. 47) to the horizontal position, letting the arms hang loosely toward the floor. In this position the deltoid is relaxed and there is no fulcrum needed in order to have the arm passively raised, i.e.-, brought forward into complete elevation (quadruped extension) ; in fact, even if this is not passively done, the patient has to exert but little muscular power
to swing the arm forward into this position. This he is usually able to do without much pain. The examiner may then hold one hand on the scapula and with the other raise the lower end of the humerus, so that he takes the full weight of the arm and permits the patient to stand upright with the arm still in complete elevation. Such a procedure eifectually rules out restriction from adhesions. Even if the supraspinatus is torn, the patient can retain the arm in this up right position. If he stoops again he can lower it without much pain, and then if he rises to the upright position with the arm relaxed,
the humerus will, by gravity alone, come into its normal position at the side of the body.
When I say that lack of restriction is an essential symptom, I must not be taken too literally, for there is often, in fact usually, in these cases, a very little restriction in extreme elevation and in rotation, probably due to the presence of fluid.

(10) Faulty scapulo-humeral rhythm is a sine qua non for this diagnosis. When one sees a patient who in raising the arm lets it ascend to the horizontal while maintaining (quadruped) flexion of the scapulo-humeral joint, and then slowly and painfully (perhaps with a little help) proceeds to complete elevation by motion in the scapulo-humeral joint, and finds that when the patient 'allows the arm to descend, he keeps the scapula and humerus fixed in (quadruped) extension until he reaches the horizontal, and then quickly flexes it, a presumptive diagnosis oi rupture of the supraspinatus
can be made. Ascent in flexion, descent in extension, might be a slogan for students to learn in this connection. To express this lack of scapulo-humeral rhythm in other words, we may say that the normal ratios of the movements of the joints in elevating the arm, explained on page 59, disappear. Instead, in the first part of the movement only the motions of the scapula on the chest wall are concerned; then the relations of the humerus and scapula change, wholly above the horizontal. In the descent of the arm the reverse is the case—no scapulohumeral motion takes place above the horizontal, but all below it. While the symptom is a sine qua non to the diagnosis of complete rupture of the supraspinatus, it is also present in most cases of minor ruptures and in many cases of calcified deposits. It therefore is an indispensable but not a pathognomonic sign.

(11) The tender or sensitive point is not complained of by the patient as a rule, and in fact he is unconscious of its exact location until the examiner finds it, when he usually says: "You have your finger right on it." Without your aid in locating it he will perhaps know that there is a tender point, but locate it deep under the acromion or even in the spasmodic deltoid muscle down near its point of insertion. In fact, the lower portion of the deltoid is usually also tender. Examination of this part of this muscle in all these patients nearly always shows that there is some thickening and sensitiveness, as compared to the normal side. In the old, chronic cases the sensitiveness at the point of rupture may not be very noticeable, and even when the exact point is pressed the patient will hardly admit that it is tender. Presumably in fresh cases it would be especially sensitive.

FIGURE 41. POSITION OF HANDS FOR EXAMINATION OF SHOULDER

The left thumb lies along the depression below the spine of the scapula and the tip of the forefinger is just anterior to the acromion. The other three fingers cross and hold the clavicle. Thus the shoulder girdle is firmly held and any motion of the scapulo-humeral joint is at once detected.

In speaking of the 11th, one is necessarily obliged to consider the remaining symptoms, since the tender point is at the gap between the ends of the torn tendon, and this gap is the reason for the sulcus and eminence, which may be felt just anterior to the edge of the acromion, when the arm is in dorsal flexion. If the examiner remembers his anatomy, the tender point, sulcus and eminence will be found to be at or near the insertion of the tendon of the supraspinatus. It is the passing of this irregular sulcus and eminence under the acromion and acromio-clavicular ligament which causes a jog, a wince, and a soft crepitus, as the sensitive, irregular base of the bursa disappears under the acromion when the arm is brought forward by the examiner. The two figures (41 and 42) present the condition, it seems to me, more vividly than could any description. However, I will give a few brief additional points under each one of the remaining headings.

FIGURE 42. TIP OF FINGER PRESSING ON EMINENCE AND ON SULCUS
The plane of this diagram is halfway between the coronal and sagittal.It is, perhaps, the most important diagram in the book for the reader entirely to understand, for it is the ability to put the finger in this position which enables one to make the clinical diagnosis of rupture of the supraspinatus tendon. The dotted line represents the contour of the bursa. Compare this with Figure 44, which shows the contour of the bursa when filled with the calcified material, and also with Plate II, Fig.3, which shows a large calcified deposit in exactly the situation in which the rupture lies in this diagram. In this one the sulcus is immediately under the tip of the finger and the' eminence just external to it, but in Figure 3 the eminence would be just under the finger. Therefore, as explained on page 148, the tender point in a case of rupture is represented by a depression, but in cases of calcified deposit, by an eminence at the corresponding position.

(12) The sulcus is just about big enough to be filled by the tip of the finger, as indicated in the diagram. It is nearly always found to be larger at operation than one would guess from palpation before incision.

(13) The eminence is an eminence only by contrast with the sulcus. It consists of normal tuberosity with perhaps a remnant of the tendon attached to it. In elderly men without injury to the shoulder one can often feel the tuberosity because the tendon is more or less atrophied, so that at times it is hard to be sure whether the tendon is torn or merely atrophic. However, in most cases of ruptured supraspinatus the eminence is conspicuously large and one is quite sure of its existence. It is well to say here that the eminence which is found in cases of calcified deposit is not on the tuberosity itself, but proximal to the tuberosity in the tendon at just the point where ruptures so often occur. Furthermore, the tenderness is usually greater on the eminence in cases of calcified deposit than it is on the eminence in the cases we are speaking of.

(14) As may be seen under Pathology, the supraspinatus is nearly always torn if any of the other short rotators are, but it is very common to have portions of the adjacent tendons torn, so that the tenderness, eminence and sulcus may be a little internal or external to the mid-point of the insertion of the supraspinatus itself. This latter may be determined pretty accurately by placing the forearm in flexion and drawing a line from the mid-point of the flexure of the elbow to the mid-point of the head of the humerus. The bicipital groove lies about its own width external to this line, and the supraspinatus is on the top of this line and to the outer side of it for about three-quarters of an inch. The insertion of the infraspinatus is just external and also partly in front of that of the supraspinatus, for, as explained in Fig. 6, the two insertions nearly cross each other. The insertion of the teres will be found nearly exactly on the mid-point of the head of the humerus on its outer aspect. Be careful, in determining this, that the forearm is flexed at. the elbow and held straight forward. The insertion of the subscapu-laris can be determined by putting the arm in the anatomic position and placing the examiner's forefinger just external to the tip of the coracoid process, which is always palpable, as shown in Fig. 6.

(15) The jog is noticeable to the patient himself, and sometimes is visible as well as palpable to the examiner.

(16) The patient nearly always winces as the jog occurs, but in long-standing cases he may not do so.

(17) The soft crepitus is not like the crepitus in fractures. It is of a more velvety, gristly character. When one has become familiar with it, it is easily distinguished from the kind of crepitus often found in the shoulders of old working men, which resembles the crepitus one frequently feels over the prepatclla and olecranon bursas and about the other joints.

(18) When the sulcus, eminence and tender point have once passed beneath the acromion as the arm is elevated, there is a sense of relief on the part of the patient which is usually apparent in his countenance. When the arm is almost fully elevated (there is often so much fluid in the joint and bursa that absolutely complete elevation is not attained), the patient is relatively comfortable. His pain will appear again when flexion occurs at the level of the shoulder, after the arm has descended with humerus and scapula locked, to a horizontal position. At this time the jog and crepitus are usually again palpable. As this occurs the patient leans toward the affected side and lowers the whole arm quite suddenly.
These eighteen symptoms must be present soon after the accident, but the difficulty is to estimate the degree of the rupture at this time. Partial ruptures must give much the same symptoms as complete ones at this stage, and the degree of spasm must vary, as well as the courage of the patient as he makes a voluntary effort to raise the arm. Immediate diagnosis cannot be easy at this stage. However, the progress of the case makes the diagnosis easier and easier, although valuable time elapses. If exploration is not done these symptoms remain the same and the following points in the course of the case will tend to confirm the diagnosis.

Character of Pain. Practically every patient whom I have seen has given the history that during the first few nights after the accident the pain was severe or intense. Gradually this severe pain changes to a nagging, annoying one, sufficient to greatly interfere with the night's rest, but bearable without drugs. It is usually located near the deltoid insertion far below the actual lesion. Pain of this character continues week after week and with but little change for many months. It is aggravated by the attempt to work, and the patient's resistance to it is gradually lowered as he becomes more and more worn out by restless, painful nights. I am convinced that this pain is very severe as well as prolonged, for I have heard many strong laboring men state that they have never suffered such pain in their lives. It is more the persistence of it than the pain at any one time which wears them out. They often say: "If I could only get a good night's rest I could work during the day." Practically they find that working during the day gives them bad nights, and therefore nearly all of them, in spite of their courage, give up work after a time. Of the series of a hundred cases, only eighteen stated that they had worked for even a brief period. They say that they may go to sleep for a while, but wake with pain in the shoulder or in the region of the insertion of the deltoid, and that they have great difficulty in getting the arm into a comfortable position again. When they do, they go to sleep only to wake up in a few hours for another change of position. Sometimes they get up and walk about or apply hot water bags or other household remedies. It is very characteristic of these cases to have complaint of pain out of proportion to the physical signs, and therefore they receive little sympathy.

Atrophy of the spinati, as shown by prominence of the spine of the scapula, always occurs after these injuries, but does not appear for about three weeks. After it has once appeared it persists, and is apparent for a long time even in the operated cases.
In very few of the cases that I have seen years after the injury was it absent. The atrophy may be more conspicuous in the infraspinatus, which is the larger muscle. Whether the fact that the infraspinatus is always also atrophied, is due to the crossing of its fibers of insertion with those of the supraspinatus so that they are always also torn to some degree, or is due to the fact that the two muscles are supplied by the same nerve, i.e., the suprascapular, I do not know, but it is a fact that atrophy of both is a constant sign. Of course atrophy of these muscles occurs in any chronic condition of real severity affecting a shoulder joint, so that the presence of atrophy does not necessarily indicate this diagnosis, but its absence would he strong evidence against it. In a few long-standing cases I have seen only a small amount of atrophy. It is usually very pronounced. As a rule the deltoid is not much atrophied and may even be hypertrophied.
The general condition of the patient is a factor in diagnosis, for he gets into a vicious circle. He is out of work so that all the muscles of his body become enfeebled. He often cannot afford good food, and he may, therefore, be ill-nourished. Add to this the constant depletion of his energy from restless, painful nights, and we may readily account for the fact that while previously he was a strong, healthy man, he now appears haggard and unhappy.
The mental condition also is poor, for worry on account of inability to work, and that he may never be able to work again, is enhanced by the fact that the physician he consults is unable to tell him the cause of his trouble, and all attempts to relieve him by ordinary remedies absolutely fail. Seeing these cases months after their accident, I am frequently told, "Nothing they have done has done it any good."
The actual physical deterioration from worry is still further aggravated by the doubt that is thrown on their veracity by the physicians employed by the insurer. Usually by the time they are sent to see me some months later, their attitude of mind is defensive, and they at once begin to express their disgust with being told that they ought to go to work and think less about the pain.
This attitude of mind becomes still worse when they are actually accused of hysteria or malingering. They say they want to work. "Do you think I would lie around like this if I could earn $24.00 a week?" They become embittered at their treatment by society in general in spite of the fact that they may still be receiving their compensation.
At length they may lose their self-respect, and brooding over their hard luck take to drink. My second patient was such a case. He had had a good job which he enjoyed; after his injury became discouraged, and evidently decided to let things go and to use up what money he had saved, in drinking as much as he had a mind to. The person for whom he formerly worked, instead of losing sight of him, looked him up, and, realizing that he must have some real trouble with the shoulder, sent him to a doctor who referred him to me. The result of the repair of his tendon was not only that he was able to work, but that he refrained from drinking and worked for ten or more years for the same people who formerly employed him.
Unfortunately the attitude of the relatives of such an old man with a disabled shoulder is apt to become somewhat like that of the doctors who have been unable to diagnose and relieve him. His own family after a while get to think of him as a burden, and since they can see nothing the matter, such as a limp or a deformity, are inclined also to think that he has "laid down" before his time. In recent years, however, we see more signs of sympathy, for the compensation such patients may receive will perhaps be the chief support of the family.
Undoubtedly many such cases eventually turn up as recipients of charity and eventually die in state institutions. It is not surprising to me that the material reported in this book, which was accumulated by Dr. Akerson at a hospital for the indigent, shows such a high percentage of instances of these lesions.
I would venture to predict that if one should see the patients who are chronic nuisances to industrial insurance boards, and the physicians connected with the administration of compensation for industrial injuries, most of those complaining of shoulder disability would have this particular lesion.

Some patients may continue to work. There are rare individuals who, in spite of the disability, have the courage and otherwise sound health to continue to work in spite of the soreness, awkwardness, loss of power, and painful and restless nights. About one-fifth of my series attempted to work for a time before they gave in and sought compensation. I have no doubt that there are others who have never given in.
This is a lesion which tries a man's character, and, since it usually occurs in later life, is often the cause of permanent incapacity, for even if the use of the arm returns in good measure at the end of a year, the patient's habit of work has been destroyed, his muscles have become soft. If he has the courage to go to work again, he will find it difficult to get a job. Those courageous men who do work in spite of the lesion, become more or less free of serious symptoms in from two to five years. As has been explained under Pathology, compensatory changes take place so that the eminence absorbs, the sulcus partially fills, and an excess of fluid allays friction. After several years even the night discomfort disappears, and weakness in abduction, atrophy of the spinati, friction rubs, the fluid sign and occasional pain in certain positions may be the only aftermaths of the injury.

Hypertrophy of the Deltoid. Perhaps it would be better to make this heading "well-developed deltoid as contrasted to the spinati," for the hypertrophy is not striking except when compared to the condition of the spinati. It is a fact that, in the long-standing cases, the deltoid itself is as well developed, or even more so, than that of the other side. I explain this because it has to do most of the abducting work of the arm unaided by the supraspinatus. It not only misses its help, but acts at a disadvantage as explained in Fig. 3. Hence it retains its development or even hypertrophies. My third case had a deltoid like a ham, but at the end of five years he could only feebly perform abduction and could not raise even a slight weight in that hand above his head. He had refused operation.

The Fluid Sign. Among the auxiliary signs and symptoms I find some help from what I call "the fluid sign." I had studied shoulders for many years before I realized how fluid in the true shoulder joint behaves. When the arm is by the side, the fluid sags in the relaxed axillary portion of the capsule. When the arm is elevated the axillary portion of the capsule is stretched tightly below the rounded head of the bone, and the fluid is driven upward where the capsule is now relaxed. In case there is a rupture of the supra-spinatus tendon, the fluid is forced through the gap and distends the bursa in the subdeltoid portion beneath the upper fibers of the deltoid.
Stand behind one of these patients, who is holding both arms as straight as he can toward the ceiling, and you will see that the contours of the two shoulders are quite different. When there is a considerable amount of synovial secretion, absolute complete elevation of the arm is prevented by the mass of fluid. Another interesting point is that when there is fluid the friction is largely prevented as the arm is elevated. When it subsides pain reappears. This phantom improvement by the formation of fluid is not uncommon.
Patients who continue to work in spite of their pain develop fluid, as do people with various affections of the knee. The fluid continually pumping in and out of the bursa dilates it and a true hydrops may result (p. 478). One finds in long-standing cases that the bursa is very large. (See case Fig. 44.) Some fluid, from a dram to an ounce, is a constant operative finding in these cases. It may not be noticed when the bursa is first opened, but if one elevates the arm and puts the axillary portion of the capsule on the stretch, the thick, straw-colored fluid runs out of the wound. Sometimes there is enough to distend the bursa even in the anatomic position, and when the first incision into the bursa is made, it obscures the field and has to be sponged out.
This behavior of the fluid was forced on my attention when I used to put the arm in abduction after suture. This caused the weeping wounds described on p. 248, and this serious and annoying complication led me to reason out the facts.

INCOMPLETE RUPTURE

Although there is no sharp anatomic distinction between complete and incomplete rupture, there is the practical one that cases of the former will not recover completely unless the tendon is sutured, while cases of the latter may heal in a natural manner. One which is typically complete involves the whole supraspinatus tendon, with perhaps parts of the adj acent tendons. One which is typical of the incomplete form need neither involve the whole width nor run through the whole thickness of the tendon. In its minimum phase it may be only an evulsion of a few fibers from the tuberosity; in its maximum phase it would be a borderline case of complete rupture. In its acute phase it may be definitely due to trauma; in its chronic phase the tendinitis overshadows the traumatic history.
The reader who has the patience to finish this book will inevitably remain confused about the lines of distinction which I have attempted to draw among the six most common clinical entities which affect the shoulder, i.e., complete and incomplete tendon ruptures, rim rents, calcified deposits, tendinitis and arthritis. In fact, I must leave the reader puzzled, for I am still puzzled myself. I can only confront him with the puzzle—show him that there is a puzzle. Personally, I believe that these rim rents and incomplete ruptures are the cause of the great majority of sore shoulders, and yet I believe they usually occur in degenerated tendons. For example, a man might have degenerative changes in both shoulders without symptoms and then, after trauma to one tendon, have severe local symptoms without any signs of trouble in the other shoulder.
One cannot even divide complete and incomplete lesions by the criterion of whether or not there is a direct communication from the bursa to the joint through the rupture, for the size of the opening is important also. Yet splitting hairs on a definition is not worth while. Practically, it is convenient to say that when one opens the roof of the bursa and finds the cartilage of the joint exposed to view through a rent in the floor of the bursa, we are dealing with a complete rupture. If there is no communication at all or only a small hole in the base of the bursa, we would class the case as incomplete. Of course the persistence of a direct communication between the joint and the bursa, even if small, is a most important point, because it alters the mechanics, as indicated on the cover of this book. Yet the size of the hole is also important if it is large enough to permit erosion of the joint cartilage (Plate VII, Fig. 8) by friction on the acromion.
It seems to me highly probable that incomplete rupture is much more common than complete. Since I have only operated upon cases where very pronounced symptoms existed, I have naturally found many more instances of the complete form, but in my observations on the cadaver, or on living cases in the clinic, I have much more often found incomplete lesions. I have not kept a numerical account and therefore cannot give the exact number or even the proportion.
Dr. Akerson's statistics give the best measure we have, but are subject to the criticisms on page 65. Similar observations may be made by any one having access to autopsy material. Moreover, when the economic importance of this lesion is appreciated, and the principles of efficiency become applied to the practice of medicine, such observations must be made.
I am inclined to think the table on page 469 also gives a low proportion of the incomplete ruptures, because so many cases in the other classes probably had this lesion besides the lesion which caused their classification. For instance, rupture of the supraspinatus is a not uncommon complication of dislocation and of circumflex paralysis, and many of the minor unclassified cases may have also been instances of this lesion. On the other hand, I have usually found at operation that the rupture was more extensive than I had previously thought, so that a good proportion of the supposed incomplete type may have been complete.
Referring to the chapter on Pathology, it will be seen that incomplete ruptures of four kinds are described:
(a) A few of the lower fibers on the joint side, together with the synovial reflection, may be torn out; these I call "rim rents."
(b) Some of the central fibers may be parted without tearing either the joint side or the bursal side of the tendon.
(c) The rupture may extend vertically through the whole tendon, making a communication between the joint and the bursa, without involving the whole breadth of the tendon.
(d) The fibers on the bursal side may be eroded without complete communication with the joint.
I believe that type (a) is synonymous with the cases so frequently found at autopsy where the sulcus is bare and eburnated, i.e., the condition I speak of as "rim rents." I think that type (b) may be the precursor of calcified deposits. Types (c) and (d) may be among the cases which give "tendinitis" symptoms out of proportion to the traumatic history.
Since I do not intentionally operate on incomplete ruptures, what I have to say in regard to these minor lesions is more theoretic than what has been stated concerning the complete ruptures.
All four varieties should be distinguished from the complete form by the persistence of considerable power in elevation, because the mechanics of the pull of the supraspinatus are not greatly altered. I have not operated unless there was decided loss of power.
The other cardinal symptoms, jog, crepitus, atrophy, sulcus, eminence and local tenderness, will be present, although any one of them or all of them may be found in less pronounced degree than in the complete cases. Type (c) might be recognizable, as the fluid sign should be present because joint and bursa communicate.
The diagnosis of the incomplete type is therefore made chiefly by the persistence of a considerable amount of power in the elevated or abducted arm and some doubt about the presence of some of the other symptoms and signs. Complete cases are usually so absolutely typical that no doubt remains. Complete cases do not form adhesions, while many incomplete cases do.
If the surgeon is sufficiently informed about the anatomy, pathology and surgery of this particular region, I believe that when in doubt he should explore the bursa through a half-inch incision. If he finds a communication through into the joint, let him close it, but if no opening exists, let him back out, for we do not yet know what to do to these incomplete ruptures.
Before closing this chapter, I may say that I believe these lesions to be the most common form of shoulder injury. My slogan has been that complete rupture of the supraspinatus is the most common cause of prolonged disability from industrial accidents to the shoulder. I feel that I have proved this at least to my own satisfaction. I may now add that the incomplete form accounts for the majority of minor shoulder disabilities. This I have not proved, for I do not operate on these cases, but the frequent presence of broadened sulci found in any .series of autopsies in elderly people is convincing to me. The clinical examination of employees with sore shoulders often shows symptoms suggestive of this lesion. Possibly opaque fluid injected in the joints might confirm the diagnosis. I have not felt justified in doing this, for exploration seems to me quite as free from danger. I certainly should try this experiment on patients now if I had in mind some definite plan for relieving them, if I did find broadened sulci indicative of incomplete ruptures, but I do not yet conceive of a plan by which to promptly cure them.
The appearance that I think opaque fluid in the joint would show in cases of complete rupture is indicated in the cover design.

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FREQUENCY OF COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON

There are certain reasons for believing that this is a far more common lesion than is generally appreciated.
1. The writer's personal experience.
2. The statistics of Dr. Akerson.
3. The lack of attention paid to lesions of the shoulder in general; i.e., of end result studies of large series of shoulder injuries.

1. Personal Experience. The above chart shows that the writer's experience in operating upon these lesions was confined to two periods of about three years each, when attentive study was given to relatively large groups of shoulder cases. In the first period (1911 to 1913 inclusive) an intensive study was made of the shoulder cases at the Massachusetts General Hospital. The author resigned from that hospital in 1914 and was not reappointed until 1929. Other activities and a period in the army during the war intervened, without opportunity to operate on such cases, although I continued to make occasional impartial examinations for the Industrial Accident Board. In 1926, owing to the interest of Dr. Henry C. Marble and Dr. W. A. Bishop, who are directors of Insurance Clinics, I again gave intensive study to a group of shoulder cases, and the chart again ran to a peak. This led to increased interest in other clinics, so that other surgeons (e.g., Dr. Wilson) began doing these operations, which accounts for the decline at the end of my chart, although the rate of frequency, if we included other surgeons' cases, would not show this decline.
In other words, the chart shows that whenever I gave intensive study to a group of shoulder injuries, I was able to diagnose some of these cases and to demonstrate them by operation. My work received little attention after the first period but since the second, largely owing to the changes brought about by the Workmen's Compensation Laws, the importance of the lesion is becoming recognized by industrial surgeons in this state. I do not know just how many cases were seen during these two periods, and therefore cannot give the exact percentage of the cases examined which were instances of this lesion, although the limits may be stated pretty positively. For instance, the first fifteen cases were found among less than 200 patients, and the second fifteen cases were from an uncertain number, but probably less than 100. This means that the frequency of occurrence was about 7%% to 15% of all shoulder lesions that came under my observation.
By referring to my records for the twenty years since I recognized the first case, I find that I have seen in all about one thousand shoulder cases. Of these more than one hundred have been positively diagnosed as instances of complete rupture and many more as incomplete. This would justify an estimate of between 10% and 20%. It would require an amount of labor disproportionate to the present object to go over these records to apportion the exact percentage, since it is sufficiently clear that I have made this diagnosis in not less than 10% and perhaps more than 20% of all shoulder cases. If cases of partial rupture were included the percentage would be at least doubled.
The figures in the annual Reports of the Industrial Accident Board help us only in a negative way, for this diagnosis is not classified. Their tabulations of the durations of disability are not carried over from year to year, so that we cannot obtain a list of the cases in which disability is protracted. This is unfortunate, for this list would probably be largely composed of cases of rupture of the supraspinatus.
The report of the Industrial Accident Board for the year 1928, Table 7, gives the following figures in regard to shoulder injuries. It is supposed to cover every accident occurring in industry in this state.

The last two columns, "Sprains and Strains," and "All Other," are the ones which would probably contain most of these ruptures, although a large number must be included under dislocations and fractures. If we double the figures where both shoulders were injured, the total of the two columns would be 748, five per cent of which would be thirty-seven. During the same period, July 1, 1927, to June 30, 1928, I personally made the diagnosis in seventeen cases which were referred to me by Insurance Clinics or by the Board for "Impartial Examination." Since I probably see but a small fraction of these shoulder injuries of doubtful diagnoses which occur annually in this state, the estimate of thirty-seven is surely a minimum one. The maximum reasonable estimate would double this and also include twenty-five per cent of the 125 dislocations. It seems to me pretty well proved that not less than thirty-seven and very likely more than one hundred injuries of this type occur annually among Massachusetts employees.
At first sight thirty-seven, or even a hundred, neglected shoulder injuries in a state of 4,200,000 inhabitants does not seem a very serious matter, but as each insured case may cost the state $4,000 for compensation (aside from the pain endured and the economic loss of productive effort in labor), the amount of money involved is considerable (37 X $4,000 = $148,000). This fact mates this obscure injury more interesting, and, if we multiply by 100, still more so. My opinion is that the larger figure is a more accurate estimate. If we included partial ruptures which heal after a few months, but which cause a large total of lost time, the annual expense to the state for injuries of this small tendon can be reasonably estimated to be over half a million. Furthermore, there must be many such injuries which are not industrial.
In addition to the above reasons for believing that this lesion is not rare, I may say that in a single set of twenty dissecting room subjects I have always been able to demonstrate one or more instances. When I have been asked to speak to small groups of doctors or students, I have usually been able to find a subject on whom to demonstrate the diagnostic signs of this lesion, by asking at adj acent clinics for cases complaining of inability to raise their arms. I feel quite confident that I can demonstrate (recognized or unrecognized) instances of this lesion by examination of the cases under treatment in the out-patient departments of any large general hospital in any city of the United States, and, in fact, probably in most parts in the world, where there are many persons over forty doing laboring work. This does not necessarily mean that there are large numbers, for each case is apt to be a patient for several years, meanwhile going from one hospital to another in search of relief.
2. Dr. Akerson's statistics, already given on page 67, give us a maximum estimate, because nearly all the observations were made on elderly subjects of the laboring class, in whom a previous injury could only be assumed, for there were no histories negative or positive of accidents. There is a splendid chance for a clinical research at the Long Island Hospital, in future, to correlate autopsy findings with retrospective histories of shoulder injury, taken from patients before death comes. It would be a time-consuming job, but it would help us to decide the important question of whether these lesions can occur without injury, and it might lead to the saving of many thousands of dollars, not only in compensation, cost of medical care and economic loss, but in maintenance of the indigent. Dr. Akerson's work might in this way lead to a saving of more than the cost of his entire department. Similar opportunities exist in like institutions from one end of the country to the other.
3. The Lack of Attention to Shoulder Injuries. There is a voluminous literature on fractures and dislocations (especially on habitual dislocations) of the shoulder, but, with the exception of Dr. Meyer's work (loc. cit.) and an investigation now being undertaken by Dr. Fowler of Evanston, 111., I know of no systematic observations from autopsy findings in this part of the body. Nor are there any serious studies of similar clinical cases. If the End Result system of organization existed in our hospitals and insurance clinics, these cases of prolonged disabilities would be automatically revealed, studied and eventually prevented by early operation.
Thus my confidence that these lesions are common is enhanced because no one has evidence to. contradict me, and a few support me. It is clear that Dr. Meyer finds similar lesions, although he explains them as the results of attrition. Dr. Fowler will, I believe, as he has already told me, confirm some of my findings and give support to those of Dr. Akerson.

ARGUMENT

This book is not written to show that I have had good results in this class of cases. My argument is merely that this lesion exists; is not uncommon; has characteristic symptoms which permit accurate diagnosis; and, since I have been able by suture of the tendons to greatly relieve a few cases, even though the diagnosis was belated, it is highly probable that the prolonged and trying symptoms from which these patients suffer, when not operated upon, might be prevented by early diagnosis and the prompt use of a minor surgical operation, which should not be difficult, if promptly done.
If I can offer reasonable evidence for the clauses italicized, it seems to me that the conclusions in the last clause of the above paragraph would be sustained sufficiently to justify prompt exploratory operation when the symptoms suggest this diagnosis.

POSSIBLE ACCURACY OF DIAGNOSIS

I have already established the existence of this lesion, endeavored to estimate its frequency and have described the characteristic symptoms. Evidence is now offered to sustain the statement that accurate diagnosis is possible. The following extracts, taken verbatim from my pre- and post-operative reports to insurance companies, show that a'positive diagnosis of this lesion may be made. Every case operated upon during the last sixteen years, in which I have demonstrated a complete rupture of the supraspinatus, is given. Even in the cases operated upon prior to 1916, one may find that my definite pre-opera-tive diagnoses in the records of the Massachusetts Hospital are correct, in all but five cases in which the diagnosis was simply " subacromial bursitis." With each of the abstracts given below the case number is stated. The reader will find further information about each of these cases by referring to these numbers in the Table on pages 255 to 260 in Chapter VIII.

CASE No. 57.
Preop. Diag. "The injury which he sustained two years ago, I believe to have been a rupture of the supraspinatus tendon and the upper portion of the capsule of the shoulder joint."
Op. Findings. "As soon as the bursa was opened it was apparent that the entire supraspinatus tendon had been torn away, for the cartilage of the bone showed where the supraspinatus tendon should be. A small stub of the tendon still remained attached to the tuberosity. Further exploration showed not only that the supraspinatus tendon, but the upper portion of the infraspinatus tendon was also torn, but the subscapularis was intact. The long tendon of the biceps could be seen crossing the field just at the edge of the subscapularis. The proximal portion of the supraspinatus had retracted so far into the subacromial space that only a rather unsatisfactory portion of it could be pulled upward and attached to the stub on the tuberosity. It was evident that the atrophy which had taken place in the two years left practically no hope of the restoration of the complete function of the muscle or tendon."

CASE NO. 75.
Preop. Diag. " I have no hesitation in making a diagnosis of rupture of the supraspinatus tendon, nor in advising an operation to suture it and clean off the ragged vegetations at the edges of the old rupture."
Op. Findings. " Showed supraspinatus entirely torn off and retracted far under acromion. Biceps tendon lying at inner edge of rupture."

CASE NO. 88.
Preop. Diag. "I feel that the diagnosis of subacromial bursitis is correct, but that the underlying cause of the bursitis was a ruptured supraspinatus tendon. This has now partially healed—enough to renew the power of abduction but not enough to make the point of rupture smooth. The result is an irregularity on the base of the bursa which in abduction impinges on the acromion and acromio-clavicular ligament."
Op. Findings. "On opening the bursa the ruptured supraspinatus tendon was beautifully demonstrated, the tendon having been torn from the tuberosity, leaving none of the original attachment on the bone. It had retracted about a half inch and the torn end could be seized with a tenaculum."

CASE NO. 88.
Preop. Drag. " He has the following signs indicating that his trouble is a ruptured supraspinatus tendon and his history is typical of this lesion.
"1. There is an acutely tender spot on the greater tuberosity at the normal point of insertion of this tendon.
"2. I can, I believe, feel at this point a sulcus where the tendon is torn.
"3. There is a painful jog in the motion as he raises his arm.
"4. There is velvety crepitus as he does this.
"5. After the arm has been elevated one can easily pull it down, although the deltoid muscle can be felt strongly contracted.
"6. There is a feeling of fullness under the upper part of the deltoid as if there was fluid in the bursa."
Op. Findings. "Free straw-colored fluid. Cartilage of head of humerus and the greatly swollen and injected biceps tendon visible on retracting the margins of wound in deltoid. The tear of the supraspinatus tendon was complete and the tendon of the infraspinatus was also almost completely torn. The proximal ends had retracted so as to be barely reached by Allis forceps to enable passing a suture."

CASE NO. 89.
Preop. Diag. "Patient presents to me typical symptoms of supraspinatus. He can abduct his arm slowly and with a hitch which gives an obvious sudden change in the relative position of the humerus and the scapula. He cannot maintain his arm extended against any considerable pressure."
Op. Findings. "Routine bursal incision disclosed a very extensive tear of the supraspinatus tendon. The biceps tendon had disappeared and could not be located except possibly as a few fibers in the anterior part of the joint."

CASE NO. 96.
Preop. Diag. "Examination shows pretty typical signs of a ruptured supraspinatus tendon, except that the friction rub is masked by the presence of joint fluid in the bursa. The outlines of the bursa are visible through a heavy deltoid as evidence of this fluid. It is well shown when the patient attempts to abduct the arm. The arc of abduction cannot be performed without a typical jog in the motion. The patient himself feels this and complains of pain during it. There is tenderness over the bursa."
Op. Findings. "Routine bursal incision showed a typical rupture of the supraspinatus tendon which did not involve either the subscapularis or the infraspinatus; making a gap pulled away from the tuberosity of about one-half inch width. Through this, on opening the bursa, the cartilage of the head of the humerus was visible. By retracting a little, the biceps tendon could be seen to the inner side, greatly congested."

CASE No. 97.
Preop. Diag. "Diagnosis. Rupture of supraspinatus tendon (left) complete and of severe grade. The same on right but incomplete and partially repaired. Probably rupture of the long heads of both biceps tendons."
Op. Findings. "The supraspinatus tendon was completely ruptured -and the upper portion of the subscapularis also. The biceps tendon had disappeared, evidently having been torn off the glenoid and retracted into its groove."

CASE No. 98.
Preop. Diag. "Examination shows very typical tenderness, crepitus, abduction weakness and the jog in motion typical of a ruptured supraspi-natus tendon in the right shoulder."
Op. Findings. "Routine bursal incision showed the supraspinatus was completely ruptured and also a part of the tendon of the subscapularis over the biceps tendon, and also a portion of the infraspinatus. The joint cartilage was exposed for about a half inch to the outer side of the bicipital groove and there was a tag of tendon still attached to the tuberosity just external to the groove."

CASE No. 102.
Preop. Diag. "Examination shows a decided atrophy of the muscles about the right shoulder, tenderness and irregularity of the tissue over the greater tuberosity, a painful jog in the motion of abduction, free external rotation, persistence of passive and loss of active complete abduction. These signs and the history are characteristic of rupture of the supraspinatus tendon. He also has' a rupture of the long head of the biceps, if one may judge by the contour of the belly of the muscle."
Op. Findings. "Free joint fluid found in bursa, which was large. The supraspinatus tendon was about half torn away from the tuberosity and the torn tendon retracted only about one-half inch, exposing a small extent (about) one-quarter inch of the edge of the joint cartilage. The opening was not large enough to view the tendon of the biceps, so I made an incision about one-half inch long into the bicipital groove and identified the biceps tendon. It was large and normal in appearance, so that it is likely that the apparent atrophy of the outer belly of the muscle in this case was due to simple disuse from reflex pain."

CASE NO. 106.
Preop. Diag. "Examination of the right shoulder shows typical signs of a rupture of the supraspinatus of considerable degree. One can feel the sulcus on the facet of insertion from which the tendon has been evulsed. There is fluid in the bursa."
Op. Findings. "The roof of the bursa was thickened. When incised, free straw-colored fluid escaped, about one dram. The supraspinatus was found torn from its attachment and retracted far under the acromion. About one-half of the insertion had evulsed from the facet. The other half was torn about one-half inch from the facet, leaving a thickened, irregular, whitish mass about the size of a large lima bean attached to the tuberosity."

CASE No. 107. Reported in text.

CASE No. 108.
Preop. Diag. "The diagnosis is fairly certain of a partial rupture of the supraspinatus, and also a rupture of the long head of the biceps."
Op. Findings. "The complete supraspinatus tendon had been torn close to the tuberosity and was retracted about an inch and a half. The infraspinatus and subscapularis were intact, but the biceps tendon had been torn completely off the glenoid and had retracted part way, instead of wholly into the sheath, leaving a frayed end protruding at the edge of the articular surface. In repairing I used this by sewing the supraspinatus to it and the subscapularis, anchoring the biceps tendon in its groove as I did so."

CASE No. 112.
Preop. Diag. "Examination shows the following: A slight atrophy of the intrinsic muscles of the shoulder, a soft crepitus which occurs with a snap just as the tuberosity passes under the acromion in abduction, a tender point on the greater tuberosity at the insertion of the supraspinatus tendon, a tendency of the scapula to follow the motions of the humerus, a flaccid condition of the outer head of the biceps muscle. These signs indicate that he has torn the supraspinatus tendon from its attachment on the tuberosity, and probably has also torn the biceps tendon from its adjustment on the glenoid."
Op. Findings. "This displayed a perfectly typical complete rupture of the supraspinatus tendon without rupture of either the subscapularis or infraspinatus. The biceps tendon was slightly frayed at its inner edge where there were two small papilloma-Iike, whitish excrescences, the size of one-quarter of a pea. The stub of the ruptured tendon was still attached to the tuberosity, but had worn down to a falciform edge; similar falciform edges showed on the lateral aspect of the tear; i.e., the unruptured edges of the subscapularis and infraspinatus. By lifting the edge towards the subscapularis, a pinkish, inflamed biceps tendon was demonstrated. A few fibers of the outer portion of this had been ruptured as spoken of before. There was only a moderate amount of joint fluid seen at any time. The edges of the torn surfaces were refreshed, and the parts sutured in place with three heavy braided silk sutures."

CASE No. 115. See history on page 389

CASE No. 119.
Preop. Diag. "Typical ruptured supraspinatus tendon. Atrophy, crepitus, jog, fluid, loss of power very great. Biceps O. K. Rotation free, tender sulcus."
Op. Findings. " The tendon was much thicker than usual and less retracted, so that the triangular gap was longer transversely than vertically. . . . There was quite a stub on the tuberosity, enough to suture. The biceps tendon was so badly damaged that there were but a few strands of it left and these were adherent to the roof of the joint. Most of the tendon had retracted into the groove and become adherent there. None was left crossing the joint surface and none was seen in the joint, although it might have been imbedded there behind the head."

CASE No. 123.
Preop. Diag. " This patient has the typical symptoms of a rupture of the supraspinatus tendon of considerable extent, but not enough to prevent his having a fair amount of power in abduction—although with pain. He has atrophy of the spinati, scapulo-humeral spasm, a j og in the motion of abduction, the fluid sign with limitation in complete abduction, a tender, palpable defect on the greater tuberosity where the tendon should be attached."
Op. Findings. "An exploratory incision a half inch long was first made and it was at once apparent that the supraspinatus and the infraspinatus tendons were evulsed from their facets, leaving no stubs of tendon. The biceps tendon, which was double at this point, was greatly swollen and inflamed and presented as soon as the roof of the bursa was opened. To its inner side the subscapularis and the inner portion of the tendinous expansion of all the tendons lay intact, and to its outer side was bare joint cartilage and the top and posterior portion of the greater tuberosity from which the tendons had been torn. The facets were smooth and the superficial parts of them had not been carried away by the tendons. The incision was enlarged to an inch and a half and a good view of the field obtained. It was found that the teres minor had also been evulsed. The whole posterior part of the capsule and conjoined tendon of the above muscles was retracted downward and outward. It was impossible to draw this back and to suture it in place."

CASE No. 127.
Preop. Diag. "At my first examination I did not make the diagnosis in this case, although it had been suggested by Dr. Marble, but on my second
examination, seventeen days later, I wrote, 'H--- is better, but I have
changed my opinion about the diagnosis. I am now quite confident that he has a ruptured tendon and should be operated upon. I think Dr. Marble was correct in his original diagnosis.' "
Op. Findings. "A small exploratory incision was first made over the point of tenderness. As soon as the roof of the bursa was incised, an irregular, whitish mass of tendon about as large as a thumb nail popped out of the incision. It proved to be the proximal portion of the torn tendon and was about one-quarter inch thick. It evidently turned on itself as the arm was abducted and caused the catch which the patient himself could accurately localize, There was about a tablespoonful of straw-colored fluid in the bursa. The incision was then enlarged to about two inches and a good view of the lesion obtained. This case differed from others on which I have operated in that the tear did not involve the whole thickness of the tendon, but left a very thin layer toward the joint surface so that there was not a demonstrable communication with the true joint. However, the layer was so thin that the cartilage could be seen through it. The ruptured portion formed a little flap about a square inch in extent, attached only to the proximal end and evulsed on the distal end from the facet of insertion. I have seen similar cases in the cadaver where the distal end had not evulsed. It is a fact that lamination of the tendon is found in many cases, but this is the first one on which I have operated where the laminated portion evulsed without the lower surface also tearing. The free portion seemed rather necrotic but was clearly rather recently ruptured. The torn surface was rather bulbous, as if partially healed. Near the lesion and to its inner side was a streaked, red area which was excessively tender when touched, but the torn end itself had no sensation and was not so made by the novo-caine. It is to be assumed, therefore, that the pain in these cases is not due to the tissue pinched but to the uninjured tissue on the tuberosity which does the pinching."

CASE No. 128.
Preop. Diag. " My opinion is very strong that he has a ruptured supraspinatus, but I am a little uncertain as to whether it is not a renewed injury in an old lesion. X-ray is very strong evidence of this. Clinically, I should not suspect it. In either case I should advise immediate operation as soon as arrangements can be made."
Op. Findings. "On opening the bursa there was found to be evidence of old inflammation in the bursa, as well as recent light adhesions. The supraspinatus was torn away from the tuberosity to the extent of about one-half inch, and little of the bursal floor remained untorn, but there was a gap directly into the joint through which the cartilage could be seen. This gap was about one-quarter of an inch in extent. The tendon had retracted very little and I was able to close it with four silk sutures, two of heavy silk and two of light silk."

CASE No. 129.
Preop. Diag. "Signs of ruptured supraspinatus tendon were present at my previous examination, but they are much more prominent now than they were at that time. He has a very distinct crepitus, sulcus, eminence, scapulo-humeral spasm, tenderness at the border of the tuberosity; localized tenderness, atrophy of the supraspinatus, sign of fluid when both arms are elevated. I agree with Dr. Marble in the diagnosis and would advise operation in this man's case."
Op. Findings. "The bursa was first opened by a half-inch exploratory incision. A small amount of free fluid escaped and it was readily seen that the supraspinatus tendon was ruptured and greatly retracted. . . . The tendon was partly evulsed and partly ruptured at the 'palisade junction.' The complete tendon was involved with possibly some of the infraspinatus. As in another recent case (H--- ) there was still some tissue remaining
on the joint side so that the cartilage was partly covered with a turgid, deep-red, softish tissue containing a few obvious whitish tendinous bands. One of these was especially noteworthy because it was very sensitive, and the patient winced when it was touched. I excised it because it did not seem to be of sufficient strength to make up for its sensitiveness. The biceps tendon lay to the inner side of the rupture buried in inflamed synovial folds, but not injured, unless the strand of tendon above alluded to had been stripped off it. The bulk of the proximal end of the supraspinatus tendon had retracted far under the acromion and could barely be drawn into the field."

CASE NO. 135.
Preop. Diag. " I feel very confident that he has a rupture of the supraspinatus tendon. I am not sure that there was not a previous rupture and that this latter accident merely increased the trouble. However, there is no question in my mind but that his chances will be much better if his bursa is explored and suture is done, if the tendon is ruptured."
Op. Findings. "No blood or fluid on opening bursa. A complete rupture of the supraspinatus, with extension across the bicipital groove, about one-half inch into the subscapularis. Definite indications that the rupture was fairly recent; i.e., very little separation between the distal and proximal portions. Stub of tendon still attached to the tuberosity over most of its extent. No new-formed falciform edge. Biceps tendon flattened and superficially reddened in portions beneath rupture. Parts satisfactorily sutured together with pedicle silk; five stitches. In my opinion, the condition found indicated a recent rupture of a tendon which had already been partially ruptured."

CASE No. 137.
Preop. Diag. "Examination shows that this patient has a symptomless, chronic bursitis, with crepitus in the right shoulder. The left shoulder shows the typical signs and symptoms of a rupture of the supraspinatus tendon. Since he has considerable power in abduction—although the abduction is painful, and accompanied with a jog and crepitus—I am inclined to think that the rupture is not extensive enough to involve the adjoining tendons. Even though this man is sixty-two, and it is four months since the injury, I would advise him to have the tendon sutured to the tuberosity."
Op. Findings. "A one-half inch exploratory incision was made and the bursa opened. Rupture of the supraspinatus throughout its whole extent was disclosed. The rupture extended also, to a slight extent, into the insertion of the infraspinatus. The sulcus and tuberosity were bare, except for a very slight amount of tag of tendon near the edge of the bicipital groove. The incision was enlarged to two and one-half inches to permit suture."

ERRORS IN DIAGNOSIS

But a skeptical reader may now ask for a statement of how many cases I have operated upon under this diagnosis and have failed to find a complete rupture of the tendon. I give below a similar set of verbatim extracts from the records of nine cases during the same sixteen years, the only ones in which I have made a positive diagnosis and have not been confirmed by the operative findings.

CASE No. 76.
Preop. Diag. "I believe this patient has a ruptured supraspinatus tendon, at the point of the insertion of the tendon in the tuberosity. This diagnosis is consistent with the X-ray appearances seen in the films taken by Dr. George. These films show an irregular opacity in the area of the bursa, which may be due to extravasated blood or to crumbs of bone torn off the tuberosity."
Op. Findings. The operative notes in this case have been lost, but I clearly remember that the condition proved to be a case of calcified deposit which had recently ruptured into the bursa, leaving a defect in the tendon very similar to a true rupture, but containing blood and calcified material.

CASE NO. 80.
Preop. Diag. "This is unquestionably a case of ruptured supraspinatus tendon of considerable extent, but the main symptoms are due to a tuft of synovial granulations from the remnant of the supraspinatus tendon still attached to the tuberosity."
Op. Findings. " The walls were much thickened and there were synovial tags in the region, over the tuberosity, showing more or less chronic inflammation. The tender point, which could be felt prior to the operation and was thought to be a tag of tendon remaining on the tuberosity, proved to be a rounded elevation, markedly circumscribed and about one-half inch in diameter, slightly longer in the axial direction than the transverse. This was acutely tender when pressed on. It was incised and found to be the insertion of the tendon of the supraspinatus attached to an osteophyte at the edge of the joint cartilage. There was no direct evidence of a rupture of the supraspinatus tendon. If there had been one, it must have healed. No communication with the joint was demonstrated. The essential pathology was probably the hypertrophic arthritis which was evident in other joints. (Patient's age was 77.)"

CASE NO. 91.
Preop. Diag. "The history and symptoms are typical of a ruptured supraspinatus tendon in the right shoulder, with some adhesions of the bursa, or blocking of the motion by the remains of the torn tendon impinging on the acromion. I think the latter."
Op. Findings. "The base of the bursa was deeply congested and swollen, but there was no demonstrable tear of the tendon of the supraspinatus. There were light adhesions in the bursa which were broken up with the finger. The short rotators and capsule were greatly contracted and were slowly stretched until full external rotation and abduction could be attained, and the wound closed."

CASE No. 105.
Preop. Diag. " I have little doubt that this patient has a rupture of the supraspinatus tendon of considerable extent."
Op. Findings. " Incision through the roof of bursa with the escape of about one dram of clear, straw-colored fluid. Exploration revealed an intensely inflamed zone on the greater tuberosity, approximately the size of a half dollar with red periphery and white center, resembling the condition seen in calcified cases. An inflamed fold moved back and forth over this as the patient's arm was moved. This fold was excised. The point of the knife was used to puncture the tendon in several places in the inflamed area with the purpose of allowing a new blood supply by attaching the scar to the inflamed base. There was no indication that the supraspinatus tendon had been ruptured."

CASE No. 110.
Preop. Diag. "The whole tuberosity is tender and it is hard to find a definite spot from which one can say the tendon has been torn. With the exception of this, his symptoms are fairly characteristic of a ruptured supraspinatus. From the relaxed condition of the biceps muscle and particularly of its outer head, I am inclined to feel that the biceps tendon is torn from its attachment on the glenoid. Indeed this may be the main lesion.
"I should advise inspection of his bursa under local anaesthesia and suture of the tendons if they are found torn. If there is no tear in the base of the bursa, I should advise opening the joint between the supraspinatus and the subscapularis and inspecting the tendon of the biceps.
"Remarks. This case is atypical in the age of the patient (17). Ruptured supraspinatus lesions are usually in elderly men. The character of the accident is unusual; sudden abduction efforts are more common as causes. There has been comparatively little pain, especially in the first week, and usually one has a history of swelling over the bursa in the first few days. Palpation over the tuberosity is a little atypical. For these reasons I cannot be as positive as I sometimes am, but I am sufficiently certain of a rupture to feel that in the boy's place I would want to have an exploration. Little harm would be done if this is negative, which I am confident it will not be."
Op. Findings. "The exploratory instrument was first introduced into the bursa, which was found to be full of adhesions and consisted of a series of pockets of walled synovia. Through the exploratory instrument it could be definitely determined that the bursa had been subacutely inflamed, but that there was no tear in the supraspinatus tendon. There was no fluid in the bursa. As both Dr. Baker and I thought that the biceps tendon was probably torn, the incision was enlarged to about one and a half inches, and the bicipital groove was incised. It did not contain the tendon, which evidently had retracted downward. The arm was put through the accustomed motions of rotation and abduction while a finger was introduced into the bursa to break up all the adhesions existing there. When the adhesions had been broken, which was easily done, the motion of the arm was normal. No steps were taken to repair the biceps tendon."

CASE No. 111.
Preop. Diag. "The shoulder presents typical signs of a ruptured supraspinatus tendon of a considerable degree. He has my fluid sign— characteristic velvety crepitus, a jog in motion, a tender irregularity on the greater tuberosity and weakness in abduction. He is able, however, with a little coaxing, to abduct the arm, but has very irregular action of the humerus on the scapula as he does this. There is still some ecchymosis in the anterior portion of the arm over the bicipital region, as if after the injury blood may have escaped down the tendon sheath; the tendon, however, appears to be intact."
Op. Findings. "Exploration of the bursa showed no fluid. No communication was found between the bursa and the joint. The bursa was adherent over about half the extent of the lower portion. On separating the adhesions it was evident that the supraspinatus had been torn, but had spontaneously healed; the tissues were red and swollen with white patches here and there. I therefore closed the wound in the usual manner without doing anything in the way of an operation."

CASE No. 120.
Preop. Diag. "The left shoulder presents very typical signs of an extensive rupture of the supraspinatus and possibly of the long head of the biceps. There is slight but decided atrophy—consistent with a history of two weeks. There is a very tender point on the tuberosity, scapulo-humeral spasm, a j og in motion and the fluid sign. In the stooping position the patient can abduct and hold the arm abducted as he straightens up."
Op. Findings. "Routine bursal incision. Adhesions prevented easy access, for roof was stuck to base over an area as large as a quarter over the greater tuberosity. These were separated and showed that the tendon of the supraspinatus was bright red, swollen, and covered with tags of vascular adhesions. The line of demarcation of the affected area was very sharp on the outer side, so that the contrast between the yellowish white to the right and the turgid red at the left was very decided. It suggested an infarction. Although there was some free fluid in the bursa there was no communication through the inflamed area to the joint. The supraspinatus tendon, if ruptured at all, must have been torn beneath the base of the bursa without communicating with the bursa. Several small incisions were made with the point of the knife to relieve tension in the tendon. Through one of these a tiny bit of white nondescript tissue protruded. This was saved for pathologic examination j I am pretty sure it was necrotic tendinous substance. The wound was closed as usual without endeavoring to suture the roof of the bursa. The pathology found at this operation may be explained in two ways, or as a combination of both ways. There was certainly an acute bursitis with recent adhesions, but it was impossible for me to say positively that this localized acute inflammation over the site of the supraspinatus tendon was due to a rupture of the tendon beneath the base of the bursa. It might have been due, as suggested by the evidence of osteitis shown in the X-ray, to a chronic necrotic process in the tendon. The extrusion of the bit of necrosed tendon from the incision also supports this. So does the symptomless condition in the well shoulder. It seems to me that if we accept the man's history that the condition of the shoulder was O. K. before he helped lift the case, that the whole picture can be explained by the supposition that there was a necrotic process going on in the tendon which had weakened it so that it partially evulsed without tearing into the bursa. This would explain all which was found at the operation, and my opinion is that this theory truly does account for the facts. I have had several other similar cases and have frequently seen evidence of such lesions in the cadaver."

CASE No. 126.
Preop. Diag. August 12, 1929. "I have little doubt that this patient has a mild rupture of the supraspinatus, but as the power in abduction is good, operation need not be considered. It is probably not an extensive rent. I suspect both from the clinical signs and from the X-ray that he has had an old lesion here for some years. It seems to me that the best plan of treatment would be to let him rest a few weeks and to have him attend your clinic three times a week for massage. If he does not feel able to go to work again in a month, let me see him again." Sept. 22, 1929. "Examination is as on August 19th. My opinion that he has a small rupture of the supraspinatus is somewhat strengthened by the fact that the symptoms have not improved. As he is only forty-two, I am inclined to advise an exploratory incision under novoeaine to confirm the diagnosis and, if necessary, to suture the tendon. The spot at which he complains of tenderness is so localized that it seems likely we shall find some lesion at this region."
Op. Findings. Oct. 23, 1929. "Under local ansesthesia no rupture of the tendon was demonstrated. The walls of the subacromial bursa were thickened and the bursa contained a little fluid. There was nothing found which indicated any recent injury other than the presence of this chronic bursitis. The wound was closed after taking out a small specimen of the synovial lining for pathologic examination." (This showed chronic inflammation.)

CASE NO. 181.
Preop. Diag. "In my opinion, he has a chronic subacromial bursitis in consequence of a rupture of the tendon of the supraspinatus."
Op. Findings. "A half-inch exploratory incision showed that the roof of the bursa was thickened and adherent to the floor beneath. The wound was enlarged to about one and one-half inches and the adhesions freed, partly by cutting and partly by tearing with the finger. Several small bursal sacs had replaced the usual large one. These sacs lay beneath the adhesions which permitted a certain amount of motion. The adhesions were red and inflamed looking. There were one or two small calcified deposits which were wiped out. The periphery of the bursa outward and backward under the acromion was more normal in appearance and not adherent. The total area involved by the adhesions was about the size and shape of a fifty-cent piece over the greater tuberosity and insertion of the supraspinatus tendon. The most acute tenderness was felt at this point, although there was a little sensitiveness over the bicipital groove. Two or three tags of inflamed serosa were removed for examination and a very small bit of tendon at the point where the adhesions centered was clipped out for examination."

In most of these nine cases, although there was not a complete rupture, there was some evidence of partial rupture beneath the base of the bursa. However, I did not confirm this supposition by cutting through the base, for it seemed to me that its tissue formed a bridge over the gap which would assist in healing the tendon. I am inclined now to think that I have been too conservative, for several of these cases had long convalescences, and it might have been wiser to explore beneath the base of the bursa.
At the danger of repetition, I wish to state that I do not intentionally operate, unless I think the ruptures are complete, because I feel confident that where the rupture is complete, healing will not take place unless suture is done. I am not sure enough of what the treatment of partial ruptures should be, to make me urge operation, even if I were sure of the diagnosis. Therefore, the above nine cases may be considered to be errors in diagnosis, although by no means as negative explorations. The difficulty is to tell beforehand whether or not there is actually a complete rupture which needs suture. I think the fact that during a period of sixteen years I made the diagnosis correctly twenty-one times, and incorrectly in only nine cases, shows that the diagnosis is not difficult. When in doubt, such a trivial operation as exploration would be justified, even if the proportion of errors was three to one.
In several of the nine cases it is to be noted that the mistake could have been avoided by more reliance on the fact that if there are decided restricting adhesions the diagnosis is not established. In the first case the X-ray indicated the presence of a calcified deposit and should have warned me not to make the mistake, although I should have operated at any rate. In several of the other cases where a mistake was made, the notes indicate that I was in decided doubt about the diagnosis before the operation, and, therefore, the incision as a matter of fact was "exploratory."

END RESULTS IN OPERATED CASES

We next come to the clause "since I have been able to relieve a few cases even though the diagnosis was belated." By referring to pp. 255-260, the reader may see that, excluding cases where there was a coincident fracture of considerable extent, I have operated on thirty-seven cases. In four of these the tendon was retracted to such a degree that I could not even attempt a suture. I have been unable to trace two patients operated upon about twenty years ago. Deducting these six cases we have thirty-one in which an attempt was made to suture the tendon. The results have been as follows: poor, four; fair, seven; good, twenty. That is, two out of every three operations were successful in that the results enabled the patients to return to work, although in most cases only after the elapse of months.
A very few, but not many, of my results have been perfect in the sense that the arm was just as useful and just as painless as before the injury; but many of them have been good in the sense that the arms have been relatively painless and quite, if not completely, useful. When I have written "good" I mean that the operation was well worth doing. When I have written "fair" it should convey that, in my opinion, there was some improvement from the operation, but that it was hardly worth doing. "Poor" means that the sum total of relief of the suffering of the patient was not sufficient to compensate for the pain and trouble which were incident to the recovery. There have been no bad results in the sense that any joint was made worse by the operation, but in at least two of the "fair" cases (Cases 83 and 112, see p. 175) the patient's point of view would have been that the result was poor, because his symptoms were not improved in spite of his post-operative pain.
There are many factors to account for the lack of perfection in the results, such as the age, the length of time the operation has been delayed, coincident disease, and above all, the desire of the patient to get well. The non-industrial patient is more readily pleased by improvement which lacks perfection than is the employee, who prefers compensation and no work, to double the pay plus work which would undoubtedly cause some pain and discomfort.
This compensation factor always causes some delay in the convalescence. Hard times have the same effect.
However, my argument does not need to show that all results should be perfect. I could give many excuses for the failures, but will be contented to present the following table.

In three of the four poor results, the tear was very extensive and the repair unsatisfactory; three had weeping wounds from excessive fluid drainage without frank sepsis (see p. 248), and all four had secondary operations. The seven cases of fair results were all improved to a considerable extent but have not actually gone to work again permanently.
There was one death which might possibly be attributed to the operation. This patient, Case No. 123, was drowned while in bathing at one of the beaches three weeks after I did an exploratory operation. The operation had shown that the tendons were too badly injured to admit of any attempt at repair. The wound healed by first intention, and as the patient enjoyed going in bathing I permitted him to do so about ten days after the operation. On the twenty-first day he was drowned. He was known to have had a heart lesion. The medical examiner reported "Death by drowning," and did no autopsy. I myself can see no connection between the operation and the drowning, but two doctors offered testimony at the Industrial Accident Board that the patient had had pulmonary embolism from the operative wound. The Board, however, did not accept their testimony, because there was no autopsy or other reason to support their diagnosis.
I feel that the proportion of good results is a sufficient reason for advising this operation, even in late cases. With greater experience and improved technique it is likely that the percentage of good results will be increased, but, as in many other surgical conditions, prompt recognition and treatment will be of greater importance than the difference in surgical skill between experienced and inexperienced operators, provided the pathologic condition is thoroughly understood.

END RESULTS IN UNOPERATED CASES

As most of my cases have been "industrial" the question of compensation becomes an important factor in estimating the period of disability. Cases who have no prospect of compensation will unquestionably go to work sooner; for instance, Case 119, a painter who had his own shop, began doing some work within a month after his operation. On the other hand in some cases, the compensation becomes equivalent to an old age pension. I have spent much time and money in tracing the unoperatcd cases of both partial and complete rupture, and have obtained enough information to venture the estimates on page 124 as to the probable costs of each. My estimate of $300,000.00 for 100 cases of complete rupture is also sustained by figures on ten patients on whom I did operate and therefore established the diagnosis. In five of these (delayed) cases the operation was a practical failure, but the patients were no worse off in consequence, and therefore were in a similar status to those in which no operation was done. In the other five the operation was essentially successful.

(The law limits total compensation to $1,000 so that these figures do not cover the period the patient is still disabled after his compensation ceases. The figures also include all medical and surgical charges.)

Case 96 in the first group had a delayed convalescence but eventually was able to go to work again as a steamfitter. Case 127 in the second group was a similar one. The reader may shift either case to the other group if he is disposed to exaggerate either average figure. Although it would not be fair to use the second group at all in computing the cost of 100 unoperated cases, by using it we may obtain an average minimum figure — $2,143.00. Therefore, the figure for 100 cases must be somewherebetween$200,000.00and$4-00,000.00.
Pain and disability are difficult to estimate in figures; these estimates are presented to impress on the reader that this lesion is important.

REFERENCES

BTTCHOLZ, C. H., Der Abriss der Supraspinatusshue, Arch. f. klin. Chir., Berlin, 1922, cxxi, 255-264.
CODMAN, E. A., Abduction of the Shoulder. An interesting observation in connection with Subacromial Bursitis and Rupture of the Supraspinatus, Boston Med. and Surg. Jour., 1912, clxvi, no. 24, 890-891; Also: Complete Rupture of the Supraspinatus Tendon. Operative Treatment with Report of Two Successful Cases, Boston Med. and Surg. Jour., 1911, clxiv, no. 20, 708-710; On Stiff and Painful Shoulders, As Explained by Subacromial Bursitis and Partial Rupture of the Tendon of the Supraspinatus, Boston Med. and Surg. Jour., 1911, clxv, no. 4, 115-120; The Pathology and Treatment of Lesions in and about the Shoulder Joint. The Industrial Doctor, 1926, iv, No. 8,121-131; Obscure Lesions of the Shoulder; Rupture of the Supraspinatus Tendon, Boston Med. and Surg. Jour., 1927, cxcvi, no. 10, 381-387.
FOWLER, E. B., Rupture of Spinati Tendons and Capsule repaired by new operation, Illinois M. J., 1932, lxi, 332-334.
KITCHEN, A. S., Surgery of the Supraspinatus Muscle, Journ. Michigan M. Soc,
1920, xix, 64-67.
METER, A. W., Absence of the Tendon of the Long Head of the Biceps. Jour. Anat. and Phys., 1913-1914, xlviii; Also: Anatomical Specimens of Unusual Clinical Interest, Am. J. Orthop. Surg., 1915, xiii, 86; Unrecognized Occupational Destruction of the Tendon of the Long Head of the Biceps Brachii, Arch. Surg.,
1921, ii, p. 130; Further Observations Upon Use-Destruction in Joints, Jour. Bone and Joint Surg., 1922, iv, p. 491; Evidences of Attrition in the Human Body, Proc. Am. Assn. Anatomists, Anat. Rec, 1923, xxv, 142; Further Evidences of Attrition in the Human Body, Proc, Am. Assn. Anatomists, Anat. Rec, xxvii, 211, 1924; Further Evidences of Attrition in the Human Body, Am. Jour. Anat., 1924, xxxiv, 241; Spontaneous Dislocation of the Tendon of the Long Head of the Biceps Brachii, Arch, of Surg., 1926, xiii, 109; Spon
taneous Dislocation and Destruction of Tendon of Long Head of Biceps Brachii j Fifty-nine Instances, Arch, of Surg., 1928, xvii, no. 3, 493-506; The Minuter Anatomy of Attrition Lesions, Jour. Bone and Joint Surg., xiii, 841, 1931.
WARNER, F., Injury to Tendons and Joints, Intn. J. Surg., N. Y., 1918, xxxi, 196. WILSON, P. D., Complete Rupture of Supraspinatus Muscle. J. A. M. A., 1931, 483.

So far as I know there is at present no literature on the subject of this chapter which deserves serious study, except that comprised in the above references. I have no doubt that Doctor Meyer and I refer to the same lesions which were studied by Doctor Akerson and can be found by any one who wishes to look for them in similar material. Doctor Meyer's attention has been focused on the long head of the biceps; mine has been focused on the supraspinatus. Probably both of us are in a measure right, and in great measure wrong, but at least we have opened up the field for future students who wish to relieve persons incapacitated by lesions in this region of the body.

NON-OPERATIVE TREATMENT OF RUPTURE OF THE SUPRASPINATUS
TENDON

I think every general surgeon who could see one of the complete cases at operation would agree that no form of physiotherapy could influence beneficially one of these lesions, except in a subjective way. The subjective symptoms might possibly be alleviated to a certain degree by massage or by diathermy, but as a matter of fact, nearly all patients say that these agents are of little help. From the very nature of the lesion, manipulations and forced exercises can do no good and might do some harm. If it is determined that a patient is not to have an operation, there are two rational plans of treatment: (1) Fixation in elevation to relax the tendon, improve the blood supply and approximate the torn ends; (2) Gentle "stooping exercises" to help nature smooth off the irregular surface of the lesion. This is merely an aid to nature's own partially successful method.
Fixation in elevation, to be effective, would necessarily have to be instituted soon after the injury, and would require at least three weeks. It would be useless in old cases, yet even in the old cases one can see, when the bursa is open on the operating table, that there is a tendency toward approximation of the torn ends of the tendon as the arm is abducted. Of course, in these old cases the proximal end is retracted and cicatrized in its retracted position. Even prolonged fixation in such cases could accomplish little except in possibly diminishing the size of the defect. This tendency to approximation observed at operation in old cases, when the arm is abducted, shows that it is probable that if the rupture were small, this treatment, if immediately instituted, would be worth while. If I were the patient, I would prefer incision and suture to this problematical and uncomfortable, even if reasonable, plan.

The "stooping exercise" method is founded on the pathologic findings described in Chapter III. Clearly nature has developed this method of absorption of the tuberosity to restore function after this accident, for as these patients, after a year or two of misery, improve somewhat, it is fairly clear that this method of smoothing off the eminence and sulcus which caused the jog is the best she can do. Nature's plan is the combination of this slow smoothing-off of the tuberosity and meanwhile increasing the supply of fluid, which, as the lower portion of the capsule becomes tense in any action, is forced up to the site of friction.
The idea of the stooping exercises is to begin this process with the weight taken off the arm so that the irregular surface is not forced up under the acromion by muscular tension. If the patient stands and elevates the arm, the very point which is sore becomes the fulcrum on the acromion for the deltoid to exert its power. When the patient stoops with the arm relaxed, the scapula can be abducted on the humerus without the need of the fulcrum either on the glenoid or acromion. Gravity takes the place of the power of the deltoid.
It is clear that until a patient can swing his arms freely in the stooping position without pain, he is not ready to use the arm when standing.
To patients who refuse operation I explain these mechanics and impress on them what I have said in the last paragraph. I also try to teach them to sleep with the arm abducted, with the hand behind the head. Palliatives in the form of drugs or physiotherapy are not often required in these cases. The pain is always bearable, if they do not increase it with work or exercise which make a fulcrum of the sore point. I think I can accomplish more with these patients by explanation of the mechanics of their trouble than I can with any palliative measures. Show a workman the normal function of the joint, the necessity of the supraspinatus to maintain the fulcrum on the glenoid, the tendency, without it, for the fulcrum to ride on the sore spot where it touches the acromion, the changed action of the weight of the arm when stooping or lying with the hand behind the head, and, as a rule, he will get your drift. He knows about levers and weights. When he understands his condition, he will get rid of the fear element and realize that though his arm is impaired, he has not really lost the use of it. He has learned that he has lost the use of certain motions unless he is willing to stand the pain. This education has more therapeutic value than drugs or electrical treatment. Massage, of course, may do good in stimulating the nutrition of the tissues, but it cannot unite the tendon.

It has seemed to me best to present my operations on the shoulder tabulated in this way, rather than to give complete case histories of each patient. Many of the cases have been used in the text to illustrate different points, sometimes only the occupation being used and perhaps in another place the preoperative diagnosis given to compare with the operative findings, etc. Under the comments at the right of this table the page numbers are given when the individual cases are referred to in the text. Should any one desire to do so, he could, by referring to these pages, make up brief individual case histories. As a rule, the cases which have been spoken of in the text are those in which the result was poor or fair. Those which I have considered good, lack detail. On the whole, compared with the results of the cases in the rest of the table, the outcome in the cases of complete rupture has been relatively poor. The reader is urged to bear in mind that in all the cases on which I have operated my attempts were more or less delayed, for only cases 18, 27, 42, 49,106,115,127, 128, 129 and 135 were done within two months of the accident. In cases 49 and 115 suture was impossible, and cases 27 and 42 could not be traced over a period of years, although the immediate results were good. I probably should not have written this book at all had the results all been good, for one of my chief objects is to urge prompt diagnosis and immediate operation.
Some of the cases marked "poor" actually did obtain some improvement. For instance, Case 88 worked over a year after the operation and then had another accident, so that his total compensation was the maximum allowed by law. Case 89 has worked steadily as a watchman after he had made a settlement with the insurer. I feel that I have certainly not exaggerated the benefits of surgery in these delayed cases, for I am sure something was accomplished in all of them, even in cases such as number 115 where no suture was attempted, for at least a definite diagnosis was made, as a basis for a settlement. If, as I hope, eventually the profession comes to realize the importance and frequency of this lesion, and the laboring class becomes educated to take it seriously, exploration through a small incision will be the rule in doubtful cases. When the insurance companies become interested in the problem, I shall be glad to cooperate in making a more extensive survey of the economic side than that which is presented on page 176.

REFERENCE

Wilson and Fowler have modified my operative methods. References to their articles will be found at the end of Chapter V.

OPERATIVE TREATMENT OF RUPTURE OF THE SUPRASPINATUS
TENDON

The best time to operate would be immediately after the injury. When in doubt of the diagnosis, exploratory incision of the bursa should be done. The technique of this incision is the same as that which has just been described for use in cases of calcified deposits. Practically the whole base of the bursa can be inspected through this incision and the exact extent of the rupture determined. The incision is then enlarged inward or outward at either end for a half-inch, depending on the direction of the tear. On account of the herringbone structure of the deltoid it makes little difference whether or not the enlargement of the incision is at an angle with the first one. A good exposure can be obtained with an incision one and one- half to two inches in length. Do not enlarge upward farther than the coraco-acromial ligament.
Assuming that the operation is done soon after the accident, it would seem that no special directions would be needed. The surgeon knowing the normal relations would restore them by appropriate sutures and close the wound in his favorite manner. It seems to me that this immediate operation would be very easy, but I have not been able to operate on one of these cases in an early stage.
In general the operation has two main objects: the repair of the tendon to give power to the arm, and the making of a frictionless lower bursal surface to relieve inflammation and pain. Perhaps the latter is more important, for even a powerful arm, if painful, is not as useful as an arm which is rather weak in the power of abduction but not painful. It is important to keep these two objects in mind, for although in some cases both can be attained, it is sometimes necessary to take a choice between them, because the tissues may be so damaged and retracted that good approximation is impossible. In such a case we may wish to discard all hope of restoring power and devote our whole effort to trying to allay friction. For instance, the tuberosity could be excised wherever it is free from tendinous attachment, and hence is useless. This might diminish the pain by removing the eminence.
One must not feel too discouraged, however, about his repair work, for on several occasions I have opened a bursa a second time and found a smooth base and no visible sign of my suture, which, at the end of my previous operation, had appeared rough and clumsy with the ends of the tendons not even approximated but held "a distance." (See p. 245.) Even in a certain number of the delayed cases which I have operated upon, there has been little difficulty in making a satisfactory suture aiming for both objectives, but in other cases, there was little or no hope of making a smooth, even suture which would leave no rough eminence or sulcus. The latter is particularly likely to be the case where the tendon is evulsed from the tuberosity, leaving no stub to hold the stitches. In a few cases the retraction was so great that no suture could be attempted at all.

Special Points and Special Difficulties

I have found that in the old cases on which I have operated, it is seldom easy, often difficult and sometimes impossible to repair the tendon. It seems best to list the difficulties and then to discuss each.

Position on table
Mobilizing the tendons
The long head of the biceps.
Drilling the tuberosity or removing it.
Suturing the rent.
Formation of a new sulcus.
Frictionless surface
Material of suture.
Shape of needles.
Closure of bursa. Disposal of fluid.
Postoperative treatment.
1. The arrangement of the position of the patient on the table to permit proper mobilization of the arm during the operation, is an important factor in technique. The point of the shouldeT is a difficult region on which to work, for both the surgeon and the assistants. It slinks away and the patient's head and neck seem to wish to take its place. (See Fig. 50.) I should like to stress the importance of so placing a heavy sand bag under the shoulder and another under the corresponding hip that the patient is half turned on his side, while the head, with the face turned away, is at a lower level than the point of the shoulder. The shoulder should be slightly over the edge of the table toward the operator, so that the arm may be allowed to hang down in a position of dorsal flexion when desired. This position throws the distal portion of the supraspinatus tendon forward for the maximum distance from under the acromion.
The operator and assistant stand on the same side of the table, while the anaesthetist and nurse with the instrument table are on the other side. A second assistant is welcome, and often almost necessary, because the first assistant must at times give his entire attention to holding the arm and the nurse may be occupied with retractors. Much of the facility with which the operation is conducted depends on the assistant who holds the arm, for his ability to rotate just at the right time will enable the operator to put his needle at just the right point in the somewhat small field. Since the lips of the incision do not move appreciably, the operative field is really controlled by the assistant as he rotates the humerus, bringing this side of the rent or that into a position which the operator desires.
The maneuver already described, of letting air into the joint and bursa, is often a great help. The position in which to place the sutures is best illustrated by a diagram. (Fig. 52.) While this is the ideal, it is seldom possible to carry it out exactly, for too often the retracted, stiffened tissues cannot be worked into nice apposition.

FIGURE 52. METHODS OF PLACING SUTURES
a illustrates the writer's suggestion that the biceps tendon may be sutured to the supraspinatus in some cases when the former has been already torn from the edge of the glenoid, b, c, and d suggest the method of placing the sutures in the ruptured supraspinatus and in the tuberosity. The ideal is c, for in this case the lines of incision have been carried up on each side of the supraspinatus to mobilize it. d illustrates Dr. Wilson's method of cutting a slot to receive the supraspinatus tendon, e and / offer a suggestion for operation in a case where the short rotators have been entirely evulsed from the head of the humerus. Fascia lata might be passed through a drill hole and through a slot over the tuberosity to form an anchorage for the tendons.

2. Mobilizing the tendons. When one considers that each one of the short rotators is separated from the other by a definite bony partition through most of its extent, and it is only the last three-quarter inch which is welded with the others into the terminal conjoined tendon or cuff (Fig. 10), it would seem easy to isolate any one tendon so that the more or less elastic muscle belly could be stretched enough to bring the tendon down again to the tuberosity and suture it there. However, if you try this on a normal shoulder at autopsy, you will find it is not easy, and when you try it on a ruptured tendon in which operation has been delayed for many months, you will find it impossible.
In the first place, you are cramped for room by the acromion and coraco-acromial ligament so that you cannot see the muscle bellies even in the normal shoulder. In the second place, if you dissect back more than an inch on either the supraspinatus or infraspinatus, you run the risk of wounding the suprascapular nerve, and if you do, you may lose your power in those muscles forever.
In order to get at these tendons more effectively, I used to use the "sabre-cut incision," which gave a perfect exposure and every possible opportunity. (Plate VIII.) Even then the mobilization was only a little more satisfactory, so I have given up this incision. Practice has given me a little more confidence, and I believe now I can do almost as well through the simple routine incision. Dr. William Rogers has suggested removing the deltoid attachment with the periosteum from the acromion and suturing them back at the end of the operation." This seems rational, but I have not tried it and do not know whether one may rely on having the deltoid origin anchor again satisfactorily. I have sometimes thought that a subcutaneous osteotomy of the base of the acromion might mobilize it enough even without division of the coraco-acromial and acromioclavicular ligaments to allow easy access. The trouble with any incision which mobilizes the acromion is the long period which one must wait for union to occur before moving the joint. I am inclined at present to do all the mobilizing I can through the routine incision, and I find that I am constantly improving in my ability to do this.
It is probably best to remove the falciform edge of new tissue and to refresh the edges of the tendon itself. I attribute some of my imperfect results to my failure to do this. One learns by experience to put the suture back of the falciform edge, for the latter has no strength and the stitch at once tears out. One is tempted not to remove the edge because it is obviously difficult to close the rent without using it, and it seems folly not to save all the tissue one can. It might be contended that the falciform edge may have more tendency to unite than the real tendon substance, which has very little blood supply, so that perhaps I may be wrong in recommending the removal of this new tissue with which nature is attempting to repair the damage. The method of closure which seems to me the best is illustrated in Fig. 52.

3. The long head of the biceps. The problems connected with how to deal with the long head of the biceps when it is found exposed, owing to the retraction of the ruptured tendons, are not a few. I can only discuss them and do not pretend to solve them. Although I am not in agreement with some of Meyers' views on the importance of the role of the biceps tendon in shoulder injuries, I feel that his observations ought to be known to every one who operates on these cases. To my mind, the rupture of the supraspinatus is the primary and important lesion which uncovers the biceps tendon, makes it slip a little at the top of the bicipital groove and to tend to be caught between the tuberosity and the acromion. At any rate, one often finds it a conspicuous, pink, inflamed-looking, swollen band lying across the j oint cartilage at the bottom of the rent. ( Plate VIII.) The portions exposed in the rent look inflamed; those covered by the remaining intact part of the capsule are white, glistening and normal. It is pretty obvious that our suture should cover up the biceps tendon without interfering with it otherwise. It usually lies just under the inner edge of the rent, but if any of the subscapularis fibers are involved, it lies entirely exposed. Sometimes it is not found at all, for it has been torn away from its glenoid attachment and has retracted down the bicipital groove. Sometimes it is split in two, longitudinally. Often it is flattened and frayed at the edges. Varying proportions of it may be ruptured. It may be composed of indefinitely separated longitudinal strands, some of which have become welded into the capsule. It may have little, rice-like tags on its edge. However, almost always the parts which do not become exposed in the gap left by the supraspinatus are normal in appearance.
When it has ruptured from the glenoid, it may be held high in the groove by a few remaining bands, and we can capture it and pull it up. What shall we do with it? We might try to suture it back on the glenoid, or rather on the fibrocartilage which surrounds the glenoid. Or we might attach it to the proximal portion of the supraspinatus, or to the capsule, or anchor it in the groove, or excise a part of it and use it to repair the supraspinatus. We might even take a relatively normal biceps tendon, clip its attachment off the glenoid, anchor the tendon in the groove, and then use the redundant portion to fill the gap in the supraspinatus. (Fig. 52a.) This would give the biceps muscle a fixed origin, and we would at the same time obtain a firm attachment for our supraspinatus. We should only have lost whatever function the long head of the biceps has from having its attachment on the glenoid rather than on the humeral head; i.e., the outer head of the biceps would no longer be of use in motions of the humerus on the scapula, but could still apply its power in flexing the forearm on the humerus. What then is this function which we should lose so far as scapulo-humeral motion is concerned?
The function of the biceps muscle is fourfold. First, it is a flexor of the forearm on the humerus. Second, it is one of the flexors (or extensors?) of the whole arm on the scapula; in a sense, therefore, it is a weak abductor or elevator of the arm. Third, the external insertion on the tubercle of the radius enables it to act as a supinator of the radius and hand. Fourth, the long head of the biceps passing through the intertubercular groove helps to retain the head of the bone on the glenoid, and stabilizes the head in the various degrees of rotation, as the arm is elevated. This function is well illustrated by the findings in two of my cases, which at operation showed that except for the subscapularis, the whole of the capsule with the tendons of the supraspinatus, infraspinatus and teres minor had been evulsed, yet the head did not tend to dislocate; apparently it was held in the joint'by the long head of the biceps, and by that only. We lose nothing in the first function, little in the second, none in the third and but a problematic amount in the fourth, by using it in the way suggested in Fig. 52a.
So far as the action of the shoulder joint is concerned, particularly with reference to the functions of flexion of the arm on the scapula and of the forearm on the humerus, the origin of the short head of the biceps from the coracoid process is more important than that of the long head from the edge of the glenoid. The coracoid origin is sufficient to give power in these motions; the long head is chiefly a stabilizer and one of secondary use so far as the application of power is concerned. For instance, in cases in which the long head of the biceps is ruptured and no other lesion has occurred, the function of the shoulder remains almost normal.
The short rotators are sufficient to maintain the fulcrum on the glenoid in most positions of the arm, but where these short rotators are damaged, I am confident that the long head serves a very useful purpose in guiding the head of the humerus and restraining it from forging upward and getting its fulcrum on the acromion. I therefore regard it as important to keep the long head of the biceps intact if possible.
I have notes that in some of my operated cases, the biceps was torn away from its glenoid attachment. In such cases in future I intend to search for the distal end of the tendon and to anchor it with stitches in the bicipital groove, and also to the supraspinatus tendon, thus abandoning any idea of retaining its stabilizing function and being content with retaining its power as a flexor of the forearm. At present I see no good mechanical way of re-attaching it to the glenoid so as to make it function in guiding the head of the humerus as the latter is abducted. One is apt to think of the long head of the biceps moving up and down in the intertubercular groove, but this is not what actually happens. The humerus moves up and down on the tendon; it is not the tendon which moves through the groove. (See Fig. 52.) On the whole, I should say that if the operator finds that the biceps is so damaged that he thinks it will not in future form a smooth cord on which the humerus can ride up and down, he had better use it, as described above, to replace the lost substance in the supraspinatus.

4. What shall we do if we find there is no stub of supraspinatus tendon left on the tuberosity to which we may suture the proximal portion? In long-standing cases we find a tuberosity completely bare of tendinous substance, and perhaps somewhat eroded. Since this tuberosity is useless unless we can suture the tendon to it, it might as well be removed. I have not hitherto excised the tuberosity in cases in which I could not suture, but it might be well to do so. Such an excision would make the surface which must ride under the acromion less apt to cause friction. Nature does exactly this by causing recession of the tuberosity. As a rule I have drilled two holes in the tuberosity with an ordinary shoemaker's awl, and passed a heavy silk suture through these holes and the tendon so as to draw the tendon as nearly as possible to the facet of insertion of the supraspinatus. This can usually be accomplished, but occasionally the supraspinatus is so retracted that I cannot quite draw it down to the bone.
I have on several occasions made a sort of plastic so that I covered the suture with part of the roof of the bursa, believing that the repair of the tendon comes not from the tendon itself, but from the adj acent synovial membrane which is much richer in vascular supply.

5. Another operative problem is how to repair the rent. As explained in the chapter on pathology, these rents are in a general way triangular, with the base on the humerus and the apex retracted, the apex being usually the center of the supraspinatus, and the sides the lateral expansions which are united to the neighboring tendons. The ideal way to close would be to bring the center of the apex to the center of the base, but if the retraction is great and the base is small, the triangle is so prolonged upwards that one is tempted to close the gap from side to side until very near the base, and then to make
the last suture a triangular stitch. This method is easier, but it does not bring back the normal relations. However, it is a feasible method to use where there is much retraction. The exact way in which to put the sutures does not seem important, that is, whether they are mattress sutures or interrupted or continuous.

6. Formation of a new sulcus. If the reader will refer to Chapter IV, and especially to Plate VI, Figs. 3-4, and their legends concerning the remarkably effective method which nature has devised to attach the supraspinatus tendon to its facet, he will feel great doubt as to whether the surgeon will ever be able to imitate it with any degree of success. We need much study and experimental work before we can rely on being able to create a line of living cement such as the "blue line," with its pores for the finger-like processes. At present, from what we know of histology, it seems doubtful
whether in adult life such a method of union of tendon to bone can ever be achieved. However, we know that tendon can form a fairly firm cicatricial attachment to raw bone. What is the best practical way to secure this ?

If it were possible, we should wish to have the new tendon form on the raw surfaces of the sulcus and of the tuberosity down to the actual edge of the joint cartilage. When I drill the tuberosity I try to drill it as far as the cartilage edge, and I usually erode the bone of the sulcus with the point of a knife or curette, so that the tendon will have a little better chance to become attached by granulation. Dr. Philip Wilson has improved on my operation by cutting a slot around the cartilage edge and drilling through the base of the tuberosity. He then passes a slip of fascia lata through the drill holes to be attached above to the supraspinatus. He thus makes a more ideal suture, so that the tendon fills the entire sulcus and thus gains a firm hold on the tuberosity. It remains to be seen whether nature will tolerate such attachments indefinitely.

7. A frictionless surface for the base of the bursa is a most important point. Dr. Wilson's method has this advantage. It would be repetition to discuss this further, but I should like to repeat that even in those cases where the suture at the end of the operation has seemed rough, it may nevertheless be so changed by the healing process that a surface is produced which at a later operation appears smooth and normal.

8. I use silk sutures because I want them to endure long enough for new, strong, scar tissue or tendinous substance to form over them. I use a fairly heavy pedicle silk for the main suture, which passes through the holes in the tuberosity or between the proximal and distal portions of the tendon. I have on four occasions reopened the bursa later to remove these silk stitches because the patient complained of pain. The following are the findings in these four cases:

CASE 18
Mr. R. H. S. Age 60. M. G. H. No. 181765 E. S., Mar. 26, 1912. A typical case of complete rupture of the supraspinatus, one and one-quarter inches wide. Although much retracted, the tendon was caught and sutured in place with three mattress sutures. The functional result was good, but he continued to have more or less pain, apparently from the formation of a considerable amount of dense inflammatory tissue about the site of suture. On Feb. 13,1913, under novocaine, the bursa was again opened and the tendon was found not only completely repaired, but there was a large amount of dense hypertrophic, callous-like tissue about the sutures. This mass impinged on the acromion in abduction; most of it was removed with the scissors and a new opening made through the supraspinatus into the joint, so that some of the synovial fluid could flow into the bursa and lubricate it. The result of this operation has been satisfactory. Twelve years later, on June 9, 1925, he called to see me because of a slight injury to his left shoulder. The right, on which I had operated, had given him no trouble in the intervening years, although he had worked steadily as a coachman.

CASE 29
Mr. M. M. W. Age 39. M. G. H. No. 184216 W. S., Aug. 5, 1912. A clear case of badly ruptured supraspinatus tendon. The tendon was sutured with heavy silk and function was restored. During the following year he had much pain on use of the arm in his work as a laborer. The bursa was again explored and the silk sutures and some of the chronic inflammatory tissues lying about them were removed. I also made a new opening into the true joint to permit the fluid to flow into the bursa. This was followed by improvement but not by complete relief. No late report. Note that entire repair of the rupture had taken place.

CASE 88
Mr. T. M. Age 50+. Operated on at Faulkner Hospital, July 24, 1926, six months after his injury. The supraspinatus, infraspinatus and part of the subscapularis were found to be torn away, exposing the biceps tendon, which was greatly inflamed. There was much fluid in the joint. A very unsatisfactory suture was made, and the tuberosity had to be drilled. The arm was put up in abduction. Mild sepsis occurred and there was much fluid drainage, so that the wound took several weeks to heal. Some of the deep sutures were taken out. In spite of this the result at first was good, and he returned to his work after five months. He worked for a year and three months, although in some pain, and then had another slight injury. On July 2, 1928,1 again explored the bursa and found that most of the sutures had pulled away, leaving the condition practically as bad as at the first operation. This was as bad a result as I have ever had. The patient was for a time benefited, but in the end gained nothing by the operation, for I did not attempt a second suture.

CASE 112
Mr. A. C. Age 62. Operated on at the Trumbull Hospital on June 11, 1928, three months after his injury. A typical complete rupture of the supraspinatus was found and satisfactorily sutured. The immediate result appeared to be good. However, the patient would not go to work again, complained bitterly of pain on use of the arm and became very neurasthenic. On Feb. 7, 1929, I again explored the bursa, thinking that if I took out the deep sutures some of the irritation might be relieved. My notes say:
"I operated on him yesterday under novocaine ansesthesia. Dr. B. E. Wood was present and Dr. Stevenson assisted. Incision was made just inside the old scar and the bursa was opened. It was clearly shown that the former suture had been effective in restoring the insertion of the tendon. Moreover, the floor of the bursa was smooth and shiny, and there did not appear to be any cause for friction over the site of the suture. One heavy silk suture could be seen just below the transparent synovial lining of the base of the bursa; this was easily pulled out, but the other two sutures were buried deeply in the new-formed tendon and were found and removed with difficulty, as I was anxious not to weaken the tendon in so doing. In two of the sutures the knots were apparently untied; in one the knot was still present, but almost untied. At first I thought that the knots of the two untied ones had been left behind, but on reflection I think it is more reasonable to suppose that they had become untied as the tissues increased in amount and grew into the knots, which were cut very short. Yet it is possible that they broke off and remained in, although the total amount of silk in the untied ones appears greater than in the tied one by more than double. At any rate, very little silk could have been left behind.
"I did not feel satisfied that the silk was causing any trouble, for there appeared to be no inflammation about it, and the tender point of which the patient complained was nearly a half-inch away from the sutures, on the edge of the greater tuberosity close to the bicipital groove. That there was some inflammation at this point was made clear by finding a little crumbly, soft, cheesy tissue close to the synovial sheath of the biceps tendon, which in certain positions bulged slightly. The repair of the tendon was weakest at this point, and I fear that my search for the sutures weakened it still more, although not to an extent sufficient to interfere with function, and recompensed by the finding of this suspicious tissue. Two tiny bits of this tissue were saved for pathologic examination. (Plate V, Fig. 5.) The patient still claimed to be unable to work in January, 1931.
Since three out of four cases, which were explored a year or so after the first operation, showed not only firm tendons but hyper-trophied ones, it seems to me that it is proved that suture may be effective. In each case I was surprised to see how well nature had restored the even convexity of the floors of the bursae, which at the completions of the operations had been quite irregular and rough at the suture lines. All four cases, if operated on immediately after their injuries, might have had excellent results; as it was, although two of the four cases had good results, little was gained by the other two patients, unless they may take some satisfaction as demonstrators of the fact that these tendons even when badly broken may be repaired.

9. The shape of the needles is dictated by the shape of the field of operation and by the fact that a tremendous strain is put on them. They must be either fully curved or half curved, not over a half-inch long and with very strong shank and eye. One has to
work between the acromion and the tuberosity, where there is very little room, so that even a curved needle such as is used in ordinary operations is too large to be turned about in this space.

10. Shall we close the roof of the bursa or shall we merely close the muscle, leaving the roof of the bursa free to allow the synovial secretions to seep into the areolar tissue?
As I have previously stated, there is usually in these cases a considerable synovitis with a large amount of fluid. If the bursa is closed tight, this fluid forms under tension and causes pain. Closure also tends to keep blood in the bursa which would otherwise be washed out by the fluid itself. I prefer the idea of leaving the roof of the bursa unsutured to allow this fluid to escape, but I am not prepared to say positively that it is not better to suture the bursa and allow free motion after the operation to pump fluid out between the stitches. The fact is, in cases where there is much fluid (and these cases are usually those that have continued to work in spite of the friction and pain), the fluid seeps into the soft tissues to an extent which causes marked swelling and sometimes induces an edema and suggestion of sepsis. This used to be a frequent complication when I put the arm in elevation, permitting the lower side of the capsule to be held tense and therefore driving the fluid up toward the wound. Now that I treat them without restraint, I do not have this complication

11. The postoperative treatment. I find that my tendency has been, as the years go by, to allow more motion and to allow it sooner. I usually pad the axilla with a small pillow and then let the arm lie on it in a position a little more abducted than that in which the arm rests in a sling, contriving as best I can to keep the hand away from the front of the abdomen, because the tendency of the patient after these operations is to get the arm in a strongly internally rotated position, and therefore the recovery of the power of external rotation is slow. After the first night is over, I remove the dressing and let the patient put the arm in any comfortable position which he can find. Each day I exercise it in a way which is difficult to describe, but which is a matter of personal touch. The general purpose of the exercises is to let the patient bend his body from the hips with the arm relaxed, as described under the stooping exercises (Fig. 47). As in treating fractures near joints, I try to make the patient do as much active and passive motion of the arm as I believe I can without displacing the fragments. It is impossible to lay down more definite directions, but I may say that by the end of the first week I expect the patient to be able to bend his body at the hips to a right angle, and to let both the injured and well arm fall in a relaxed position at right angles to his body. By twisting his body from side to side so as to make one shoulder higher than the other, alternately, he can also move the joint without contracting the shoulder muscles. During the second week he is encouraged to swing the arms a little in both directions in this stooping position. The wound should be soundly and completely healed and the patient discharged from the hospital in from ten days to two weeks. After that he is encouraged to take the stooping exercises.
If the patient is cooperative and understands the mechanics of the operation and can use common sense in taking his exercises, he gets on fairly smoothly, but there is pain of an annoying although not of a serious degree, not only for weeks but for months. I do not think this would be the case where the operation was done immediately after the accident. In convalescence it is a good rule to restrain the patient from exercising his arm in the erect position until he has learned to abduct it freely and strongly in the stooping position. (See Fig. 47.) In long-standing cases the nerves of the region have already become sensitized and are slow in returning to a normal condition. Much of this postoperative soreness in the delayed cases is due to the sensitiveness and synovitis acquired between the date of the injury and that of the operation.

THE SABRE-CUT INCISION

Reprinted from the Bos. Med. & Surg. Jour., Mar. 10, 1927. It does not differ greatly from Kocher's posterior incision, but is more appropriate after a preliminary exploratory cut anterior to the joint.

FIGURE 1

"Sabre-cut" seemed an appropriate name for this incision, for it might well be made by the downward cut of a sabre on top of the shoulder. An incision is made through the acromio-clavicular joint and continued with a saw through the base of the acromion. The anterior point of the incision would be continuous with a previous routine bursal exploratory incision. When the acromion has been sawed through, an epulet of tissue, consisting of the deltoid muscle and the acromion process from which it arises, is formed to be pulled outward and downward. This step is accomplished' with ease, for it is only held by a little areolar tissue and a few fibers of the trapezius attached to the upper margin of the detached portion of the acromion. The upper posterior fibers of the deltoid must be separated a little to gain mobility. In sawing the base of the acromion one must bear in mind the suprascapular nerve which supplies the supra- and infra-spinatus muscles and lies between them, a little below the saw-cut. It is deep enough to be out of the way of the saw but not of gross carelessness.

FIGURE 2

The second diagram shows the structures exposed when this epulet is pulled downward and outward. Even without dissection one can identify the subscapularis, supraspinatus and infraspinatus as they emerge to join together their tendinous expansions beneath the base of the bursa. To one unfamiliar with this dissection the smooth convex surface of this base appears to be the articular surface of the humerus. The subacromial and subcoracoid or coraco-humeral bursse are nicely shown. As explained in previous papers, they are often intercommunicating and are always functionally one bursa although frequently, as in this instance, separated by one of the diaphanous nictitating folds. Notice the separated portion of the acromion and see how easily it will fit back into place.

FIGURE 3

The third diagram is identical with the last except that the supraspinatus and capsule have been cut across into the true joint and the ends of the supraspinatus depicted as retracted. The stub of the tendon is still attached to the tuberosity beneath the base of the bursa, while the muscular belly is retracting into the supraspinatus fossa. The glenoid and the articular surface of the humerus are exposed, with the long head of the biceps arising from the superior edge of the glenoid lying across the cartilaginous surface of the head of the humerus.
This is exactly the condition I have found at operation again and again in the living, except that there is seldom so much of a stub of tendon still attached to the tuberosity. Quite frequently it is entirely evulsed from the latter, requiring drilling of the tuberosity to resuture it. I have always found the base of the bursa to be torn across with the tendon. The point of least resistance appears to be about the subbursal portion of the tendon. In fact the tendon itself is very short, the muscle fibers beginning within a half-inch of the attachment.
In the long-standing cases on which I have operated the biceps tendon is found inflamed, swollen and bright pink in color, forming a striking contrast with the white articular surface of the humerus. Sometimes it is apparently absent entirely, having been evulsed and then retracted downward into its sheath.
To close this incision the parts are sutured back into place in the reverse order of these diagrams. It is probably safer to wire the acromion process, although catgut in the soft parts holds it well. I do not advise attempting to close the bursa even in the exploratory operation; a stitch or two in the muscle holds the edges in sufficient apposition and excess fluid may drain into the areolar tissue.

The pendulum will probably swing in future toward postoperative treatment in abduction and back again to adduction. Dr. Wilson now uses abduction after the sabre-cut incision and complete repair of the insertion into the bone by the use of fascia lata. It is possible that this method has the advantage of creating a larger gap between the head of the humerus and the acromion and the coraco-acromial ligament, because reunion of the mobilized acromion process would take place at a higher level, since it is pressed upward by the abducted humerus.

The Sabre-Cut Incision. Although I have personally given up the sabre-cut incision for cases of rupture of the supraspinatus, it is still used by others, especially by Dr. Wilson. It gives a splendid opportunity to repair the tendon or any other structure in the shoulder joint, but it is really a major operation, while the one I use is a minor one. The main reasons why I seldom use it are three. In the first place, I have learned to work through the routine incision in such a way that I can do the operation without cutting any ligaments or bone. This improvement has come about not only from doing the operation in dorsal flexion, but by using the method of rotating the humerus so that each desired point is placed in the middle of the small incision at the appropriate moment for a stitch. One assistant has to manipulate the arm in unison with the wishes of the surgeon. In the second place, I have found that after division and suture the acromio-clavicular joint may remain somewhat unstable.
A third reason is less technical and more in the domain of human nature. In Industrial Surgery there is not a frank understanding between surgeon and patient as in their ordinary professional relation. The patient is apt to have the element of compensation too strongly in mind, as compared to a cooperative tendency to make the best of the surgeon's attempt to better an injured limb, although both know it may never again be "as good as new." The extent of the sabre-cut incision exaggerates in the patient's mind the degree of the injury and the scar would certainly be impressive to a commission or jury.

Frontispiece

RUPTURE OF THE SUPRASPINATUS TENDON

FRONTISPIECE

THANKS to Dr. F. B. Mallory I was able to obtain the autopsy specimen of a case of a completely ruptured supraspinatus, from which this painting was made by Mr. Aitkin.
The skin and subcutaneous tissues were removed; then the fibers of the deltoid separated and held apart by retractors as in the usual routine incision. The diamond-shaped area between the two retractors is the floor of a rather large bursa. Nearly the whole right half of this floor retains its normal, smooth, whitish appearance, but in the left-hand portion of the base or floor is a roughly triangular area which represents the gap formed by the retracted supraspinatus tendon. At the right of this triangular gap, the long head of the biceps appears just beneath the falciform edge of the portion of the musculo-tendi-nous cuff formed by the subscapularis. In the left angle of the triangular area is seen a falciform edge formed by some of the superficial fibers of the infraspinatus. Just superior to this are a few vertical fibers of the deep posterior part of the supraspinatus which have not been evulsed. This was a. very thin, tenuous bit of tissue. The remaining central portion is roughly divided into three parts. The upper, bluish third is the exposed cartilage of the true joint. On its shiny surface near the very edge of the true joint cartilage, we see the high light of the reflection of the window. The lower third of this central space shows a typical "volcano" on the tip of the tuberosity, such as those depicted in Plate V, Figure 1, and in Figures 36 and 40. Between this "volcano" and the cartilage, and also occupying about one-third of the central area and bounded on the right by the margin of the biceps tendon, and on the left by the film-like, untorn edges of the infraspinatus and supraspinatus, we see a red, granulation-like irregular surface. This is the pathologically changed facet of insertion of the supraspinatus tendon and of a portion of that of the infraspinatus from which the tendons have been torn. Compare Figure 40, which is the Rontgen picture of the same specimen.
It must be understood that this picture represents the result of an injury experienced, in all probability, many years before; the tuberosity is in the recessing stage, and the edges of the torn tendons have become smooth by becoming falciform. The distal stub of the supraspinatus tendon, which was probably present in the first few months after the injury, being functionless, has disappeared. The proximal end of the tendon has retracted upward and could only be demonstrated if the newly formed falciform edge of the whole rent were removed. Even in this old case it could be isolated, pulled down and attached to the tuberosity, although with difficulty. One can readily imagine the pain which this patient endured during the first few years after his injury from the mere mechanical irritation from the tuberosity striking on the edge of the acromion during efforts at elevation of the arm, although nature has gradually nearly smoothed off the former prominent tuberosity, and, by partial healing of the edges of the torn structures, has made a new base of approximately spherical surface to pass under the acromion. The writer's operative efforts have mostly been concerned with relieving the results of such conditions. When the general practitioner has learned to recognize the symptoms of these lesions within a few days of their occurrence, suture of such torn tendons will be easily and successfully accomplished.

==References==
<references />

File:Achilles-calcaneus graft vs.mp4

2023-03-29T11:59:12Z

Alexandre.laedermann:

Video of a calcaneum and Achilles tendon allograft for a secondary migration of greater tuberosity following osteosynthesis of proximal humeral fracture.

File:Achilles-calcaneus graft.mp4

2023-03-29T05:35:49Z

Alexandre.laedermann:

Achillis and calcaneum allograft for combined bony and tendinous rotator cuff insufficiency.

Shoulder:Rotator Cuff Pathology/Thickness Rotator Cuff Tears/Posterosuperior Rotator Cuff Tears and Associated Pathologies

2023-02-23T09:37:00Z

Alexandre.laedermann: /* Surgical (Operative) Treatment */

==Bullet Points==
*The rotator cable explains why patients with most rotator cuff tears can maintain active forward flexion, and also why even after only a partial rotator cuff repair, good functional results can be achieved.
*The most important negative prognostic factor is high-grade fatty infiltration of the rotator cuff muscle bellies (grade 3 or 4 fatty infiltration).
*The tangent sign is an indicator of advanced fatty infiltration and is a predictor of whether a rotator cuff tear will be reparable.
*Full thickness disruption of the lateral tendon stump (B1) is the most frequent type of rotator cuff lesion, comprising approximately 90% of all surgically treated lesions.
*Musculotendinous junction lesions (C-type) or rare and characterized by an edema of the muscle belly. They are associated to calcific deposit (infraspinatus) or trauma (supraspinatus). Unrepaired, grade III lesions lead rapidly to grade 4 fatty infiltration of the muscle.
*Tendon retraction is classified according to Patte. Overreduction and lateral transposition of the tendon over the greater tuberosity may be unphysiological.
*Massive rotator cuff has different definitions in the literature, each having potential benefits or drawbacks.
*Massive rotator cuff tears comprise approximately 20% of all cuff tears and 80% of recurrent tears.
*The classification of Collin not only subclassifies massive tears but has also been linked to function, particularly the maintenance of active elevation.
*Non-surgical treatment is effective in patient with massive rotator cuff if the tear involves less than three tendons and do not involves the subscapularis (D-type).
*Biomechanical testing has consistently demonstrated the superiority of double-row constructs over single-row. However, there is no obvious difference clinically.
*There is actually no support for routine suprascapular nerve release when massive rotator cuff repair is performed.
*Functional outcome improved after revision rotator cuff repair and 70% or more of patients were satisfied or very satisfied. However, the prevalence of persistent defect (retear or non-healing) is 28% at six months and 40% at two years.
*Rotator cuff are irreparable when associated to true pseudoparalysis with the presence of lag signs (external rotation lag, drop, dropping, hornblower signs), femoralization of the humerus or acetabulization of the acromion, grade 3 or 4 fatty infiltration and tangent sign.
*The current literature does not support the initial use of complex and expensive techniques in the management of posterosuperior irreparable rotator cuff tears.

==Key Words==
Shoulder arthroscopy; Rotator cuff lesion; Partial repair; Tear pattern; Classification; Massive; Reparable and non-repairable; Irreparable; Imaging; Recurrent; Failed; Revision surgery; Open and arthroscopic approach; Conservative or non-operative treatment; Physiotherapy; Functional outcomes; Prognostic factors; Latissimus dorsi transfer; Subacromial spacer interposition; Balloon; Biceps tenotomy; Superior capsular reconstruction; Reverse arthroplasty; Magnetic resonance imaging (MRI) arthrography (MRA); Fosbury flop tear; New tear pattern; FUSSI; SAM.

==Anecdote==
===How double-row was born===
When Ian Lo was my Fellow in 2001-2002, he and I wrote 2 papers on my technique of arthroscopic non-linked double-row rotator cuff repairs. As far as I can tell, these were the first 2 published articles on arthroscopic double-row cuff repair. These were published in 2003 in The American Journal of Sports Medicine<ref>Lo IKY, Burkhart SS. Current concepts in arthroscopic rotator cuff repair. Am J Sports Med 2002;31(2):308-324</ref> and The Arthroscopy Journal.<ref>Lo IKY, Burkhart SS. Double row arthroscopic rotator cuff repair: Re-establishing the footprint of the rotator cuff. Arthroscopy 2002;19(9):1035-1042</ref> The technique was a non-linked double row repair that I had first done 8 years earlier, in 1995. However, the reason that I did my first arthroscopic double-row repair was not what you might think.......

My index double row repair patient was a 55-year-old female who had fallen and sustained a traumatic non-retracted tear of the supra- and infraspinatus. After I had done an arthroscopic acromioplasty and subacromial bursectomy, I still had trouble visualizing the greater tuberosity footprint because the torn tendon was quite redundant and extended far laterally. It seemed as if the redundant, unstable cuff tissue filled the entire subacromial space, making visualization very difficult. So, in order to stabilize the cuff and see the greater tuberosity well enough to properly prepare the bone, I placed a single anchor medially on the tuberosity and then passed the sutures from the anchor through the medial part of the cuff; then I tied the knot as a mattress stitch. This single fixation point on the medial part of the greater tuberosity controlled the "unstable" redundant tendon so that I could then see well enough to prepare the greater tuberosity bone bed. But it also allowed me to see that I would have enough tendon length to completely cover the greater tuberosity with the repair. So I placed 2 more medial anchors and completed the medial fixation of the tendon. Then I placed 2 lateral anchors to tack down the lateral flap of the tendon so that there was firm contact of the tendon to the bone between the two rows of anchors. At that point, the repair looked completely anatomic. In fact, it looked so good, that I resolved to start doing double-row repairs on torn cuffs whose tendons had enough redundancy to cover the greater tuberosity without undue tension. So, in retrospect, I did my first double row repair to control an unstable tendon so that I could visualize the operative field better, rather than intentionally trying to create a broader anatomic footprint with my repair. But this opened the door for further biomechanical research on double-row versus single-row repairs, and soon the biomechanical superiority of double row was apparent.

Steve Burkhart

==Biomechanics of the Posterosuperior Rotator Cuff==
A primary function of the rotator cuff is to work synergistically with the deltoid to maintain a balanced force couple about the glenohumeral joint. A force couple is a pair of forces that act on an object and tend to cause it to rotate. For any object to be in equilibrium, the forces must create moments about a center of rotation that are equal in magnitude and opposite in direction. Coronal and transverse plane force couples exist between the subscapularis anteriorly and infraspinatus and teres minor posteriorly. The rotator cuff force across the glenoid provides concavity compression, which creates a stable fulcrum and allows the periscapular muscles to move the humerus around the glenoid.

The rotator cable is a thickening of the rotator cuff that has been likened to a suspension bridge in which force is distributed through cables that are supported by pillars (the anterior and posterior attachments). The anterior rotator cable attachment bifurcates to attach to bone just anterior and posterior to the proximal aspect of the bicipital groove. The posterior attachment comprises the inferior 50% of the infraspinatus. With small central tears the cable attachments often stay intact and forces are transmitted along the rotator cable. The rotator cable also explains why patients with most rotator cuff tears can maintain active forward flexion, and also why even after only a partial rotator cuff repair, good functional results can be achieved.<ref>Burkhart SS, Nottage WM, Ogilvie-Harris DJ, Kohn HS, Pachelli A. Partial repair of irreparable rotator cuff tears. Arthroscopy 1994;10:363-70.</ref> 

However, in the setting of massive rotator cuff with rotator cable disruption and non-compensation by other humeral head stabilizers (i.e pectoralis major and latissimus dorsi), the moments created by the opposing muscular forces are insufficient to maintain equilibrium in the coronal plane, resulting in altered kinematics, instability, and ultimately in pseudoparalysis. Interestingly, only few patients with an irreparable rotator cuff tears developed pseudoparalysis and arthritis.This finding has at least two potential explanations. First, the subscapularis that may not be involved in these tears is the key factor of active forward flexion.<ref name=":1">Collin P, Matsumura N, Lädermann A, Denard PJ, Walch G. Relationship between massive chronic rotator cuff tear pattern and loss of active shoulder range of motion. J Shoulder Elbow Surg 2014;23:1195-202.</ref> 

Second, the rotator cable, has still an intact anterior attachment which is important for elevation. This may explain why patients can maintain active mobility, and also why even after only a partial rotator cuff repair, good functional results can be achieved.<ref name=":2">Denard PJ, Lädermann A, Brady PC, Narbona P, Adams CR, Arrigoni P, Huberty D, Zlatkin MB, Sanders TG, Burkhart SS. Pseudoparalysis From a Massive Rotator Cuff Tear Is Reliably Reversed With an Arthroscopic Rotator Cuff Repair in Patients Without Preoperative Glenohumeral Arthritis. Am J Sports Med 2015;43:2373-8.</ref>

Consequently, all the conditions for an imbalance in the force couples are not always met and subsequently loss of function is only occasionally seen.

==Clinical examination==
===Inspection===
Inspection has to rule out deformation, swelling (i.e Milwaukee shoulder syndrome, Figure) or hematoma (Video).

[[File:Milwalkee.png|thumb|Milwaukee shoulder syndrome is associated with intra-articular deposition of hydroxyapatite crystals and disruption of the rotator cuff. The Figure illustrates a patient with involvement of the left shoulder]]
[[File:Bossy épaule sénile hémorragique.mov|thumb|Hematoma related to massive rotator cuff tear.]]

===Palpation===
This subsection does not exist. You can ask for it to be created, but consider checking the search results below to see whether the topic is already covered.

===Range of Motion===
The patient must be examined not only in the standing position, but also supine on a table in order to block scapulothoracic movements, and look for all amplitudes (anterior elevation, abduction, internal rotation and external rotation elbow at the side and at 90 degrees of abduction).

===Tests for posterosuperieur rotator cuff lesions===
====Supraspinatus====
Supraspinatus is an external rotator.<ref name=":4">Inman VT, Saunders M, Abbott, MC. Observations on the function of the shoulder joint. J Bone Joint Surg Br. 1944;1:1-30.</ref> It also initiates abduction in conjunction with deltoid, serrates anterior and infraspinatus. The following tests are consequently not specific for the supraspinatus but are sensitive due to antalgique reflex. Superior rotator cuff insufficiency, present in complete tears, is usually associated with a positive Jobe manoeuver (empty can) (Video) and decreased strength in external resistance elbow at the side (Figure).<ref>Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. Am J Sports Med 1982;10:336-9.</ref>

[[File:Jobe test.mov|thumb|The Jobe test is performed by placing the patient's arms at 90 degrees of abduction within the scapular plane, maximally internally rotating the arms and resisting further abduction by the patient. A positive test occurs with localized pain to the affected arm.]]

[[File:cuff104_2.jpg|thumb|Testing of the strength in external resistance elbow at the side.]]

Testing of abduction strength in the champagne toast position, i.e., 30 degrees of abduction, mild external rotation, and 30 degrees of flexion, better isolates the activity of the supraspinatus from the deltoid than Jobe's “empty can” position (Figure 3).<ref>Chalmers PN, Cvetanovich GL, Kupfer N, Wimmer MA, Verma NN, Cole BJ, Romeo AA, Nicholson GP. The champagne toast position isolates the supraspinatus better than the Jobe test: an electromyographic study of shoulder physical examination tests. J Shoulder Elbow Surg 2016;25:322-9.</ref>
[[File:1562464235806-lg.jpg|center|thumb|900x900px|Testing at 30 degrees of abduction, 30 degrees of forward elevation, 90 degrees of elbow flexion, and mild external rotation replicates a “toast” position.]]
 

====Infraspinatus and Teres Minor====
=====Strength in External Rotation Elbow at the Side=====

Strength in external rotation elbow at the side of the supraspinatus, infraspinatus and teres minor represents approximately 10%, 70% and 20% of total external rotation strength, respectively.<ref>Gerber C, Blumenthal S, Curt A, Werner CM. Effect of selective experimental suprascapular nerve block on abduction and external rotation strength of the shoulder. J Shoulder Elbow Surg 2007;16:815-20.</ref> 

However, the function of the teres minor may become more important in the setting of a chronic infraspinatus tear, as its hypertrophy is commonly observed in these cases and probably compensates for external rotation weakness.

=====External Rotation Lag Sign=====
The external rotation lag sign (Figure and Video), described by Hertel, was designed to test the integrity of infraspinatus and supraspinatus tendons.<ref>Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996;5:307-13</ref>

The extent of internal rotation is recorded to the nearest 10 degrees degrees (10, 20, 30 and 40 degrees or above). An external rotation lag sign > 40 degrees seems to be the most reliable test for the teres minor.<ref name=":5">Collin P, Treseder T, Denard PJ, Neyton L, Walch G, Lädermann A. What is the Best Clinical Test for Assessment of the Teres Minor in Massive Rotator Cuff Tears? Clin Orthop Relat Res 2015;473:2959-66</ref>
[[File:1562464228129-lg.jpg|center|frame|A) The external rotation lag sign is performed seated with the elbow flexed to 90 degrees and the shoulder elevated 20 degrees in the scapular plane. The arm is passively taken to maximal external rotation minus 5 degrees to allow for elastic recoil. B) The patient was asked to maintain that position as the clinician released the wrist. A positive test is defined as any internal rotation of more than 10 degrees. Reproduced from Collin et al., with permission.]]

[[File:ERLS 2 N25 (converti).mov|thumb|External rotation lag sign.]]

=====Drop Sign=====
The drop sign (Figure and Video), also described by Hertel, is designed to assess the function of the infraspinatus.
[[File:1562464890613-lg.jpg|center|frame|A) The drop sign is a lag sign beginning from 90 degrees of abduction in the scapular plane, with elbow flexion of 90 degrees, and external rotation of the shoulder to 90 degrees. From this position, the patient is asked to maintain the position against gravity (MRC Grade 3). B) Failure to resist gravity and internal rotation of the arm is considered a positive drop sign. Reproduced from Collin et al., with permission.]]
[[File:1563115163992-lg.mp4|center|frame|Drop sign]]

=====Hornblower sign=====
The patient is asked to bring both hands to his mouth, but is unable to do so without abducting the affected arm (Video 5).
[[File:1562465141586-lg.mp4|center|thumb|Hornblower sign]]
 

=====Patte Test=====
The Patte test (Figure and Video ) is the only test that allowed to analyze the muscular strength of the teres minor in case of deficient infraspinatus.<ref>Patte D, Goutallier D. [Grande libération antérieure dans l'épaule douloureuse par conflit antérieur]. Rev Chir Orthop Reparatrice Appar Mot 1988;74:306-11.</ref> Walch et al. reported a 100% sensitivity and 93% specificity with the Patte test and teres minor fatty atrophy Grade 3 or greater.<ref name=":6">Walch G, Boulahia A, Calderone S, Robinson AH. The 'dropping' and 'hornblower's' signs in evaluation of rotator-cuff tears. J Bone Joint Surg Br 1998;80:624-8</ref>

[[File:1562465387058-lg.jpg|center|frame|A) The Patte test is performed by passively taking from a starting point of 90 degrees of abduction in the scapular plane, an elbow flexion of 90 degrees without external rotation. B) The patient is asked to perform external rotation of the shoulder from this position against resistance. A positive Patte test is defined as external rotation power less than MRC Grade 4. Reproduce from <ref name=":5" />, with permission.]]

[[File:2 Patte.mov|thumb|Patte test]]

=====Dropping Sign=====
The dropping sign of Neer had a 100% sensitivity and 66% specificity for teres minor involvement.<ref>Neer C. Cuff tears, biceps lesions, and impingement. In: Neer C, ed. Shoulder reconstruction. Philadelphia: W. B. Saunders Company; 1990:41-142.</ref><ref name=":6" />

[[File:Dropping Walch.mov|thumb|Dropping sign]]

==Imaging==
#REDIRECT [[https://wiki.beemed.com/view/Shoulder:Radiographic_Evaluation_of_Shoulder_Problems#Rotator_Cuff_Evaluation]<nowiki>]</nowiki>

==Classification==
The rotator cuff lesions are categorized into four major groups based on involvement of the bone (Type A), tendon (Type B), musculotendinous junction (Type C) or muscle insufficiency (Type D).

[[File:1562468648674-lg.png|thumb|600x600px|alt=|center|Classification of full-thickness rotator cuff lesions in the coronal plane. Reproduced from Lädermann et al.,<ref>Lädermann A, Burkhart SS, Hoffmeyer P, Neyton L, Collin P, Yates E, Denard PJ. Classification of full-thickness rotator cuff lesions: a review. EFORT Open Rev. 2017;1:420-430.</ref> with permission]]

===Type A: Bony Involvement===
While the majority of rotator cuff lesions involve the tendinous insertion, bony involvement is an important consideration. Bony involvement includes acute fractures, malunion/nonunion, and chronic bony insufficiency.

====A1. Acute Bony Involvement (Fractures and Avulsions)====
Isolated greater tuberosity fractures are considered uncommon, representing less than 5% of all operatively treated proximal humeral fractures.<ref>Court-Brown CM, Garg A, McQueen MM. The epidemiology of proximal humeral fractures. Acta Orthop Scand 2001;72:365-71.</ref> 

Isolated lesser tuberosity fractures are generally considered rare. Type A lesion of the greater or lesser tuberosity represent approximately 3.2% and 1.1% respectively of surgically treated rotator cuff lesions (Table). Tuberosity fractures are included in the accepted classification for proximal humeral fractures by Neer, in itself a modification of Codman’s original description. Because the greater and lesser tuberosity are the insertion site of the rotator cuff, even small tuberosity fractures or avulsions can represent substantial disruption of the rotator cuff and lead to functional impairment if displaced and left untreated. Historically, Neer proposed 10 mm of displacement as a threshold for operative intervention.<ref>Neer CS, 2nd. Displaced proximal humeral fractures. I. Classification and evaluation. J Bone Joint Surg Am 1970;52:1077-89.</ref> 

However, more recent investigation has recommended that a threshold of 5 mm should be used.<ref>Bono CM, Renard R, Levine RG, Levy AS. Effect of displacement of fractures of the greater tuberosity on the mechanics of the shoulder. J Bone Joint Surg Br 2001;83:1056-62.</ref> 

Displacement of greater than 5 mm can lead to bony impingement with loss of range of motion as well as loss of strength from compromise in the normal length–tension relationship of the rotator cuff. A traumatic mechanism is typical such as violent muscular contraction, impaction of the greater tuberosity beneath the acromion, or shearing against the anterior glenoid rim during a glenohumeral dislocation event. Thorough patient evaluation is required to make an appropriate treatment recommendation. Conservative therapy is limited to non- or minimally-displaced fractures. The ongoing development of arthroscopic techniques has led to multiple reports about arthroscopically assisted or total arthroscopic techniques in the treatment of these injuries.<ref>Greiner S, Scheibel M. [Bony avulsions of the rotator cuff : Arthroscopic concepts]. Der Orthopade 2011;40:21-4, 6-30.</ref>

====A.2 Tuberosity Malunion/Nonunion====
Tuberosity malunion or nonunion can be a sequela of either conservative treatment or surgical treatment of acute injuries. As noted previously, displacement effectively shortens the muscle-tendon unit such that the rotator cuff cannot function properly (Figures).
[[File:1562470234366-lg.jpg|center|thumb|750x750px|Schema of tuberoplasty for varus malunion of a surgical neck fracture. (A) Intact proximal humerus. (B) Varus malunion results in a medialized greater tuberosity and effectively decreases the resting tension in the rotator cuff. As a result, force generation is compromised. (C) The rotator cuff is detached, and a tuberoplasty is performed with a burr. (D) Reattachment of the rotator cuff laterally results in restoration of the rotator cuff length–tension relation. Reproduce from Lädermann et al.,<ref name=":44" /> with permission.]]
[[File:1562470238482-lg.jpg|center|thumb|750x750px|Schema of tuberoplasty for valgus malunion of 3-part proximal humeral fracture. (A) Intact proximal humerus. (B) Valgus impaction results in superior displacement of the greater tuberosity and effectively decreases the resting tension in the rotator cuff. As a result, force generation is compromised. (C) The rotator cuff is detached, and a tuberoplasty is performed with a burr. (D) Reattachment of the rotator cuff laterally results in restoration of the rotator cuff length-tension relation. Reproduce from Lädermann et al.,<ref name=":44" /> with permission.]]Various open techniques have been described for the management of the malunion of proximal humeral fractures, including prosthetic reconstruction, open corrective osteotomy, or arthroscopic capsular release followed by takedown of the rotator cuff from the malunited proximal humerus, tuberoplasty, and then rotator cuff advancement. Although the latter technique is technically demanding, it allows preservation of the native humeral head, which is associated with a low complication rate, and avoids concerns about long-term prosthetic survival in young patients (Video).<ref name=":13">Burkhart SS, Klein JR. Arthroscopic repair of rotator cuff tears associated with large bone cysts of the proximal humerus: compaction bone grafting technique. Arthroscopy 2005;21:1149.</ref><ref name=":44">Lädermann A, Denard PJ, Burkhart SS. Arthroscopic management of proximal humerus malunion with tuberoplasty and rotator cuff retensioning. Arthroscopy 2012;28:1220-9.</ref>
[[File:1563115162982-lg.mp4|center|thumb|720x720px|Video]]
 
[[File:1563115159736-lg.mp4|center|frame|Video]]
 

====Operative Technique====

The patient was placed in a beach chair or in a lateral decubitus position. A diagnostic arthroscopy is performed with an arthroscopic pump maintaining pressure at 50 mm Hg. The joint surfaces were inspected to rule out any incongruities. The articular side of the rotator cuff is carefully assessed with a probe searching for tears. Any capsular retraction is addressed at this point. A release of the rotator interval and superior glenohumeral ligament is performed with an electrocautery introduced from an anterior portal. This was followed by a release of the posterior, inferior, and anterior capsule 5 mm away from the labrum with an electrocautery introduced from the posterior portal while the surgeon is viewing from an anterosuperolateral portal. If still present, the intra articular part of the long head of the biceps tendon undergo either tenotomy or tenodesis. After treatment of any intra-articular pathology, such as loose body removal, attention is turned to the subacromial space. The lateral and posterolateral gutters are cleared. ny previously placed metal hardware are removed. While the surgeon is viewing from a posterior glenohumeral portal, the tuberoplasty is initiated. The arthroscope is then moved to the subacromial space, and the rotator cuff, if necessary, is sharply elevated from its malunited footprint by use of an electrocautery. Elevation of the rotator cuff consisted of the supraspinatus and anterior half of the infraspinatus, which is the part that overlies the proximally migrated tuberosity (Video). After elevation of the rotator cuff attachments, a burr is used to perform a tuberoplasty. The cuff is assessed for mobility and integrity and is then retensioned by advancing the cuff laterally on the greater tuberosity and performing a rotator cuff repair. The rotator cuff is advanced and repaired. A modified acromioplasty with a lateral bevel is routinely performed if not done previously.

===A.3 Tuberosity Insufficiency===

Tuberosity insufficiency can range from contained cystic bony defects within the tuberosity to the absence of the entire tuberosity. Cystic bony defects are often encountered during primary or revision rotator cuff repair. Such defects may be idiopathic, related to a patient's rotator cuff disease, or secondary to osteolysis from breakdown of bioreabsorbable anchors. These osseous defects reduce biological healing capacity and may decrease repair fixation strength. Bone grafting techniques are needed to address these defects.<ref name=":13" />
[[File:1562471498963-lg.jpg|center|thumb|500x500px|Computed tomography (CT) scan show greater tuberosity bone loss.]] 
In such a situation, a simple tendon rotator repair is usually unsuccessful, as a large bony defect significantly lowers the prognosis for primary repair.<ref>Moore DR, Cain EL, Schwartz ML, Clancy WG, Jr. Allograft reconstruction for massive, irreparable rotator cuff tears. Am J Sports Med 2006;34:392-6.</ref> 
One explanation might be that deltoid tension and therefore function is potentiated by the greater tuberosity, also called “deltoid wrapping”.<ref>Roche CP, Diep P, Hamilton M, Crosby LA, Flurin PH, Wright TW, Zuckerman JD, Routman HD. Impact of inferior glenoid tilt, humeral retroversion, bone grafting, and design parameters on muscle length and deltoid wrapping in reverse shoulder arthroplasty. Bulletin of the Hospital for Joint Disease 2013;71:284-93.</ref> 
Therefore, reconstruction of this combined bony and tendon defect may require both tendinous and bony reconstruction. In older patients, such insufficiency is most reliably addressed with reverse shoulder arthroplasty. However, reverse shoulder arthroplasty is not ideal for young patients as multiple studies have demonstrated increased complications in this patient population.<ref>Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: results after five to fifteen years. J Shoulder Elbow Surg 2013;22:1199-208.</ref><ref>Sershon RA, Van Thiel GS, Lin EC, McGill KC, Cole BJ, Verma NN, Romeo AA, Nicholson GP. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg 2014;23:395-400.</ref> 
Recently, a fresh frozen bony-tendinous allograft of the calcaneus and Achilles tendon has been proposed to address this difficult problem (Video). Long term results and larger series need to confirm this technique.<ref name=":14">Lädermann A, Denard P, Abrassart S, Schwitzguébel A. Achilles Tendon Allograft for an Irreparable Massive Rotator Cuff Tear with Bony Deficiency of the Greater Tuberosity: A Case Report. Knee Surg Sports Traumatol Arthrosc 2016;Jan 25.</ref>

===Surgical Technique===

Allograft Reconstruction with Calcaneum and Achilles Tendon for an Irreparable Massive Rotator Cuff Tear with Bony Deficiency of the Greater Tuberosity (Video). Under general anesthesia and interscalene nerve block, the patient is placed in the beach chair position, with the operative arm draped free. An open anterosuperior incision with a deltoid split is performed in order to expose the greater tuberosity defect. The long head of the biceps was already resected. The remaining posterosuperior rotator cuff was carefully dissected and the proximal humeral head is debrided. The quality of cuff tissue is usually poor (Figure).
[[File:1563115175999-lg.mp4|center|thumb|900x900px|Video]]
[[File:1562472470428-lg.jpg|center|thumb|600x600px|Lateral view of a right shoulder. Observe the bony defect in the greater tuberosity associated with the poor rotator cuff tendon quality.]]
 The Achilles tendon allograft with attached calcaneus is then prepared (Figure and Video).
[[File:1562474028794-lg.jpg|center|thumb|600x600px|The allograft is prepared with an Achilles tendon.]]
The calcaneus is shaped to fill proximal humeral head defect. If necessary, the Achilles tendon is then split longitudinally to decrease its thickness, with the deep layer used to reinforce the rotator cuff repair. Then, the bony portion of the allograft is secured to the humeral head with a 4 mm malleolar screw under fluoroscopic control (Figure).
[[File:1562474027986-lg.jpg|center|thumb|600x600px|Lateral view of a right shoulder. A malleolar screw fixes the calcaneum in the defect. The calcaneum is ready to reinforce the rotator cuff.]]
The native rotator cuff was then repaired onto the bony graft with a combination of an anchor and bone tunnels in the graft. The deep split of Achilles tendon is then sewn into the native posterosuperior rotator cuff to reinforce the repair (Figures and Video).
[[File:1562474087899-lg.jpg|center|thumb|600x600px|Final reconstruction.]]
Two years follow-up confirm bony and tendinous integration (Figures).
[[File:1562474024175-lg.jpg|center|thumb|600x600px|Anteroposterior X-ray of a right shoulder. The bony allograft is incorporated in the proximal humerus, filling the greater tuberosity defect.]]
[[File:1562474554815-lg.jpg|center|thumb|412x412px|Long term computed tomography (CT) arthrogram confirming the repair of the rotator cuff.]]
Postoperatively, the patient wears an abduction pillow for six weeks and is allowed to perform pendulum exercises. After six weeks the abduction pillow is discontinued and passive mobilization is allowed. Full activity return and strengthening was permitted at three months, with a progressive increase of loads.

===Type B: Full Thickness Tendon Lesion===
====B1: Lateral tendinous disruption====

Full thickness disruption of the lateral tendon stump is the most frequent type of rotator cuff lesion, comprising approximately 90.1% of all surgically treated lesions (Table 1). Tendinous lesions most commonly involve the posterosuperior cuff. Subscapularis tears are nevertheless found in 59% of arthroscopic rotator cuff repairs.<ref>Barth JR, Burkhart SS, De Beer JF. The bear-hug test: a new and sensitive test for diagnosing a subscapularis tear. Arthroscopy. 2006;22:1076-84.</ref> However, such tears are only full-thickness in 8.7% of cases, and are rarely isolated (Table 1).

=====Size of Tendon Lesion=====

Classifications for tear size include measurement in centimeters or number of tendons involved. This information can be derived from arthroscopy or magnetic resonance imaging and used to offer guidance on treatment and prognosis.<ref>Cofield RH. Rotator cuff disease of the shoulder. J Bone Joint Surg Am 1985;67:974-9.</ref><ref name=":15">Davidson J, Burkhart SS. The geometric classification of rotator cuff tears: a system linking tear pattern to treatment and prognosis. Arthroscopy 2010;26:417-24.</ref><ref name=":21">Gerber C, Fuchs B, Hodler J. The results of repair of massive tears of the rotator cuff. J Bone Joint Surg Am 2000;82:505-15.</ref><ref>Harryman DT, 2nd, Mack LA, Wang KY, Jackins SE, Richardson ML, Matsen FA, 3rd. Repairs of the rotator cuff. Correlation of functional results with integrity of the cuff. J Bone Joint Surg Am 1991;73:982-9.</ref><ref name=":16">Lädermann A, Denard PJ, Collin P. Massive rotator cuff tears: definition and treatment. International orthopaedics 2015;39:2403-14.</ref>

Once size is identified and if massive, it can be further classified according to Collin et al.<ref name=":1" />

=====Tendon Retraction=====

Patte devised a method of classifying tendon coronal retraction that is often used for research purposes.<ref>Patte D. Classification of rotator cuff lesions. Clin Orthop Relat Res 1990:81-6.</ref>

The retraction is due to tendon and muscle shortening that are not synchronous after tendon tear.<ref name=":10" />

Substance loss in the later stages of musculotendinous retraction may be because of either active shortening of the tendon substance, suggesting that overreduction and lateral transposition of the tendon over the greater tuberosity may be unphysiological.

=====Tear Pattern=====

Full-thickness posterosuperior tears come in a variety of patterns. The most common categories include crescent tears, L and reverse L-shaped tears, and U-shaped tears accounting for respectively 40%, 30% and 15% of posterosuperior rotator cuff lesions.<ref name=":15" />

Recognition of these tear patterns is most useful for anatomic restoration during repair. Crescent tears have good medial to lateral mobility and are amenable to a double-row repair. Longitudinal tears (L and reverse L-shaped tears, and U-shaped tears) have greater mobility in 1 plane and typically require margin convergence to achieve complete repair. Finally, massive contracted tears have also been described. These tears have limited medial to lateral and anterior to posterior mobility and typically require advanced mobilization techniques (i.e. interval slides) to achieve repair.

=====Releases for the Rotator Cuff=====

In clinical practice, rotator cuff tears may present with a wide spectrum of size and mobility. Many massive rotator cuff tears may be reparable without releases and, in contrast, some small rotator cuff tears may require releases. Release is only required if tear may not be reduced to the footprint anatomically as it would otherwise unnecessarily increase the complexity of the procedure. Releases may be divided into bursal sided releases, articular sided releases (i.e. capsular release) and interval slides.

=====Double-Row Versus Single-Row Cuff Repair=====

Biomechanical testing has consistently demonstrated the superiority of double-row constructs.<ref>Hohmann E, König A, Kat CJ, Glatt V, Tetsworth K, Keough N. Single- versus double-row repair for full-thickness rotator cuff tears using suture anchors. A systematic review and meta-analysis of basic biomechanical studies. Eur J Orthop Surg Traumatol. 2018;28:859-868.</ref>

Within the domain of level I mid-term and short-term studies, double-row repair (Video) showed significant better UCLA score only (American Shoulder and Elbow Surgeons (ASES), Constant, WORC, and SANE scores showed no significance). This may correlate weakly with the significant lower partial-thickness retear rates of double-row repairs. In contrary, long-term level III studies showed a direct correlation of both functional outcomes and cuff structural integrity, with significant superiority of double-row over single-row repair techniques.<ref>Sobhy MH, Khater AH, Hassan MR, El Shazly O. Do functional outcomes and cuff integrity correlate after single- versus double-row rotator cuff repair? A systematic review and meta-analysis study. Eur J Orthop Surg Traumatol. 2018;28:593-605.</ref>

=====Margin Convergence=====

Margin convergence to bone can be used in L or V tears. This technique accomplishes margin convergence between the two leaves of the cuff, and at the same time it anchors the cuff to bone, providing very secure fixation. Margin convergence to bone has the mechanical strain reduction advantage of margin convergence coupled with strong fixation to bone. This provides a very secure component to the overall fixation construct.

=====Load Sharing Rip Stop Construct=====

Double-row repair is not possible in the setting of medially based tears, lateral tendon loss, or limited tendon mobility. Load sharing rip stop constructs demonstrated improved functional outcomes with reasonable healing rates in an otherwise challenging subset of rotator cuff tears.<ref name=":22">Noyes MP, Lädermann A, Denard PJ. Functional Outcome and Healing of Large and Massive Rotator Cuff Tears Repaired With a Load-Sharing Rip-Stop Construct. Arthroscopy. 2017 Sep;33(9):1654-1658.</ref>

This suture technique combines the advantages of a rip stop suture tape and load sharing properties of a double-row repair and has biomechanically superior properties compared to a single-row repair (Figure and Video).<ref>Denard PJ, Burkhart SS. A load-sharing rip-stop fixation construct for arthroscopic rotator cuff repair. Arthrosc Tech 2012;1:e37-42.</ref>
[[File:1562475768794-lg.jpg|center|thumb|700x700px|Anchor-based rip-stop rotator cuff repair for rotator cuff tear with lateral tendon loss. (A) A suture has been placed as an inverted mattress stitch in the rotator cuff. Two medial anchors have also been placed, and sutures from these anchors are passed medial to the rip-stop stitch. (B) Prior to tying of the sutures from the medial anchors, the rip-stop stitch is secured to bone with 2 lateral anchors. (C) Tying the suture limbs from the anchors completes the repair. Reproduce from Noyes et al., with permission.]]
[[File:1563115214642-lg.mp4|center|thumb|900x900px|Video]]
[[File:1563115230318-lg.mp4|center|thumb|900x900px|Video]]

=====Massive Posterosuperior Rotator Cuff Tears=====

======Prevalence======
Massive rotator cuff tears comprise approximately 20% of all cuff tears and 80% of recurrent tears.<ref name=":23">Lo IK, Burkhart SS. Arthroscopic revision of failed rotator cuff repairs: technique and results. Arthroscopy 2004;20:250-67.</ref><ref>Burkhart SS, Danaceau SM, Pearce CE, Jr. Arthroscopic rotator cuff repair: Analysis of results by tear size and by repair technique-margin convergence versus direct tendon-to-bone repair. Arthroscopy 2001;17:905-12.</ref>

=====Definition and Classification of Massive Rotator Cuff Tears=====

Historically a massive rotator cuff tear has been described as a tear with a diameter of 5 cm or more as described by Cofield or as a complete tear of two or more tendons as described by Gerber (Figure).<ref>Cofield RH. Subscapular muscle transposition for repair of chronic rotator cuff tears. Surg Gynecol Obstet 1982;154:667-72.</ref><ref name=":21" />

The former in particular is usually applied at the time of surgery. In an attempt to provide a preoperative MRI-based classification, Davidson et al. defined a massive tear as one with a coronal length and sagittal width greater than or equal to 2 cm.<ref name=":15" />

Unfortunately, these systems are vulnerable to error due to variation in patient size and arm position at the time of measurement. It is more appropriate to define the size of a tear in terms of the amount of tendon that has been detached from the tuberosities. While the Gerber definition helps account for variability in size, there are exceptions to the complete two tendons requirement and this classification does not distinguish different patterns or predict function. Additionally, in using the term “massive”, there is a connotation of difficulty and irreparability. While challenging, most massive rotator cuff tears are reparable and other factors like the tendon retraction, atrophy, arthritis, and mobilization must be considered. Thus, in addition to the number of tendons involved, some authors proposed at least one of the two tendons must be retracted beyond the top of the humeral head (i.e Patte 3 for the supraspinatus in the coronal plane).<ref name=":16" />

Such classification also takes advantage of 3-dimensional information on tear pattern, providing guidance on treatment technique.
{| class="wikitable"
|+
!Author
!Description
!Limitation(s)
|-
|Cofield
|5 cm or more
|No 3-dimensional information, variation in patient size and arm position
|-
|Gerber
|≥ 2 complete tendons
|No 3-dimensional information
|-
|Davidson
|Coronal length and sagittal width ≥ 2 cm
|Variation in patient size and arm position
|-
|Lädermann
|≥ 2 complete tendons, 1 tendon with > Patte 2 retraction
|
|}
Table 2: Different Classification of Massive Rotator Cuff Tears

 Once a massive rotator cuff tear is identified, it can be further classified according to Collin et al. In this subclassification, the rotator cuff is divided into five components: supraspinatus, superior subscapularis, inferior subscapularis, infraspinatus, and teres minor (Figure).
[[File:1562478202097-lg.jpg|center|thumb|600x600px|The rotator cuff is divided into 5 components: supraspinatus, superior subscapularis, inferior subscapularis, infraspinatus, and teres minor.]]
Rotator cuff tear patterns can then be classified into 5 types: type A, supraspinatus and superior subscapularis tears; type B, supraspinatus and entire subscapularis tears; type C, supraspinatus, superior subscapularis, and infraspinatus tears; type D, supraspinatus and infraspinatus tears; and type E, supraspinatus, infraspinatus, and teres minor tears (Figure).<ref name=":1" />
[[File:1562478202102-lg.jpg|center|thumb|600x600px|Rotator cuff tears classified by the involved components: type A, supraspinatus and superior subscapularis tears; type B, supraspinatus and entire subscapularis tears; type C, supraspinatus, superior subscapularis, and infraspinatus tears; type D, supraspinatus and infraspinatus tears; and type E, supraspinatus, infraspinatus, and teres minor tears.]]
This classification not only subclassifies massive tears but has also been linked to function, particularly the maintenance of active elevation, offering more information than the traditional six sagittal segments of Patte’s classification.

=====Rotator Cuff Incarceration in the Glenohumeral Joint=====
Case of a complete rotator cuff tendon avulsion with glenohumeral joint incarceration after significant trauma to the shoulder have been described.<ref>Dodson CC, Bedi A, Sahai A, Potter HG, Cordasco FA. Complete rotator cuff tendon avulsion and glenohumeral joint incarceration in a young patient: A case report. J Shoulder Elbow Surg. 2010;19:e9–e12.</ref>

[[File:Incarceration sup.png|thumb|Anteroposterior radiograph of the left shoulder demonstrates superior subluxation as evidenced by the decrease in the interval between the acromion and the superior aspect of the humeral head. Coronal fast-spin echo magnetic resonance image (MRI) demonstrates an avulsion of the supraspinatus tendon, which is draped over the superior labrum and extends into the glenohumeral joint. The humeral head is subluxated superolaterally.]]

=====Suprascapular Nerve Neuropathy and Massive Rotator Cuff Tear=====
Recently there has been growing interest in the relationship between suprascapular neuropathy and massive rotator cuff tears. Theoretically, medial retraction of posterosuperior rotator cuff tears can place excessive traction on the suprascapular nerve.<ref>Albritton MJ, Graham RD, Richards RS, 2nd, Basamania CJ. An anatomic study of the effects on the suprascapular nerve due to retraction of the supraspinatus muscle after a rotator cuff tear. J Shoulder Elbow Surg 2003;12:497-500.</ref>

However, clinical diagnosis is beset with uncertainties as the potential symptoms of suprascapular nerve neuropathy, namely, pain, weakness, and atrophy, are inseparable from those of massive rotator cuff tear. There is actually no support for routine suprascapular nerve release when repair is performed for several reasons. First, it is clearly demonstrated that repair of repair without release leads to satisfactory results. Moreover, the prevalence of suprascapular nerve neuropathy in case of massive rotator cuff tears in a prospective study is low (2%).<ref name=":17">Collin P, Treseder T, Lädermann A, Benkalfate T, Mourtada R, Courage O, Favard L. Neuropathy of the suprascapular nerve and massive rotator cuff tears: a prospective electromyographic study. J Shoulder Elbow Surg 2014;23:28-34.</ref>

====Treatment Options for Massive Rotator Cuffs====
It should be remembered that nonoperative treatment is successful in many cases. When surgery is indicated, the primary aim is restoration of force couples and anatomic or partial repair of the rotator cuff to its footprint. However, a number of factors (refusal of the patient, biologic factors, characteristics of the tear, etc) can make these goals difficult, impossible, or unwanted to achieve. Fatty infiltration, rotator cuff retraction, and poor tendon compliance are common in patients with massive rotator cuff tears. In these situations, other approaches have been advocated, with varying degrees of success.<ref>Berhouet J, Collin P, Benkalfate T, Le Du C, Duparc F, Courage O, Favard L; Société d'Orthopédie de l'Ouest. Massive rotator cuff tears in patients younger than 65 years. Epidemiology and characteristics. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:S13-8.</ref>

These include physical therapy,59,60 subacromial decompression and palliative biceps tenotomy (subacromial debridement),61 muscle transfer,62 and reverse shoulder arthroplasty.63 However, there are no randomized controlled trials comparing these various options and recommendations are mainly based on retrospective case series and the surgeon’s own experiences.<ref name=":24">Collin PG, Gain S, Nguyen Huu F, Lädermann A. Is rehabilitation effective in massive rotator cuff tears? Orthopaedics & traumatology, surgery & research : OTSR 2015;101:S203-5.</ref><ref name=":26">Zingg PO, Jost B, Sukthankar A, Buhler M, Pfirrmann CW, Gerber C. Clinical and structural outcomes of nonoperative management of massive rotator cuff tears. J Bone Joint Surg Am 2007;89:1928-34.</ref><ref name=":25">Walch G, Edwards TB, Boulahia A, Nove-Josserand L, Neyton L, Szabo I. Arthroscopic tenotomy of the long head of the biceps in the treatment of rotator cuff tears: clinical and radiographic results of 307 cases. J Shoulder Elbow Surg 2005;14:238-46.</ref><ref name=":27">Gerber C, Rahm SA, Catanzaro S, Farshad M, Moor BK. Latissimus dorsi tendon transfer for treatment of irreparable posterosuperior rotator cuff tears: long-term results at a minimum follow-up of ten years. J Bone Joint Surg Am 2013;95:1920-6.</ref><ref>Wall B, Nove-Josserand L, O'Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am 2007;89:1476-85.</ref>

=====Conservative Treatment=====
Many patients with massive rotator cuff tears respond favorably to nonsurgical treatment. Nevertheless, patients must be aware that despite clinical improvement, future treatment may be impacted by progression of glenohumeral osteoarthritis and fatty infiltration as well as narrowing of the acromiohumeral distance. In a series of 19 patients with massive rotator cuff tears treated nonoperatively the average Constant score was 83% at a mean follow-up of 48 months. However, 50% of “reparable” tears became “irreparable” during this period.<ref name=":26" />

The mainstay of nonoperative treatment includes nonsteroidal anti-inflammatory drugs, subacromial corticosteroid injections, and physical therapy. The protocol of rehabilitation focused habitually on global deltoid reconditioning and periscapular strengthening. Although certain authors proposed that re-education of the anterior deltoid muscle to compensate for a deficient rotator cuff is the cornerstone, we attach more importance to solicitation of stabilizing muscles of the glenohumeral joint with an approach based on exercises in high position. In this position, the deltoid, which acts synergistically with the remaining rotator muscles, has no upward component and participates in the articular coaptation.<ref name=":24" />

In general, nonoperative management is attempted for six months before considering surgery. Younger patients (<60 years of age), however, may be immediate candidates for surgery based on the high risk for progression with conservative treatment. If after six months, symptoms have not improved, the chances of success with further nonoperative treatment decreases and operative treatment may be considered for older patients. It is unclear if it is exercise alone or exercise in combination with other interventions during the recovery process that offers the greatest benefit. In a recent prospective cohort of 45 patients suffering from pseudoparalysis with a radiographically confirmed massive rotator cuff tears, Collin and al. found after a follow-up of 48 months that the mean Constant score improved from 43 to 56 points and the mean forward flexion improved from 76 degrees to more than 160 degrees after completion of the program. They also demonstrated that effectiveness of physical therapy is related to the size and location of the lesion; if the tear involved the posterosuperior rotator cuff (B type), or only two tendons or less, most patients regained active anterior elevation that persisted for 48 months. The anterior rotator cuff is the key of anterior active elevation as only 20% of patients with MRCTs, but an intact subscapularis, develop pseudoparalysis.

=====Surgical (Operative) Treatment=====
For older patients surgery is considered when nonoperative treatment fails. Additionally, we often consider surgery as first line treatment in young patients because there is a high rate of progression with conservative treatment and for tears involving the anterior rotator cable since this area is most important to maintenance of forward elevation.

======Arthroscopic Rotator Cuff Repair======
The approach is to repair all of the rotator cuff that can reasonably be brought back to the tuberosities without excessive tension, and to address all potential causes of persistent pain or factors threatening the repair. The goal of a repair, even if partial, is to restore force couples and to re-establish the “suspension bridge”. In this theory, complete closure of the defect is less important than restoration of a stable fulcrum for normal shoulder kinematics. Although shoulder strength may not improve after this intervention, function is usually enhanced because of relief from pain caused by mechanical impingement. Additionally, although complete healing of massive tears is not always achievable, we believe that partial healing of the cuff may prevent secondary extension of the tear.

======The Acromion and Biceps======
Over the last decade, arthroscopic acromioplasty has been widely performed as an adjuvant to rotator cuff repair, to increase subacromial space and thereby decrease wear of the repaired tendon.<ref name=":0">McFarland EG, Matsen FA 3rd, Sanchez-Sotelo J. Clinical Faceoff: What is the Role of Acromioplasty in the Treatment of Rotator Cuff Disease? Clin Orthop Relat Res. 2018;476(9):1707-1712</ref><ref>Neer CS 2nd. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. J Bone Joint Surg Am. 1972;54(1):41-50</ref> Acromioplasty has the potential advantages of decreasing strain on the repaired tendon by changing the vector of the deltoid muscle, improving the healing response by increasing bone-marrow derived cells, creating more working space for rotator cuff repair<ref name=":0" /> and possibly to lower the reoperation rate.<ref>MacDonald P, McRae S, Leiter J, Mascarenhas R, Lapner P. Arthroscopic rotator cuff repair with and without acromioplasty in the treatment of full-thickness rotator cuff tears: a multicenter, randomized controlled trial. J Bone Joint Surg Am. 2011;93(21):1953-60</ref> However, recent studies reported no direct clinical benefits of adjuvant acromioplasty in the short- or mid-terms,<ref>Bond EC, Maher A, Hunt L, Leigh W, Brick M, Young SW, Caughey M. The role of acromioplasty when repairing rotator cuff tears-no difference in pain or functional outcome at 24 months in a cohort of 2,441 patients. N Z Med J. 2017;130:13-20.</ref><ref>Chahal J, Mall N, MacDonald PB, Van Thiel G, Cole BJ, Romeo AA, Verma NN. The role of subacromial decompression in patients undergoing arthroscopic repair of full-thickness tears of the rotator cuff: a systematic review and meta-analysis. Arthroscopy. 2012;28:720-7.</ref><ref>Ketola S, Lehtinen J, Arnala I, Nissinen M, Westenius H, Sintonen H, Aronen P, Konttinen YT, Malmivaara A, Rousi T. Does arthroscopic acromioplasty provide any additional value in the treatment of shoulder impingement syndrome?: a two-year randomised controlled trial. J Bone Joint Surg Br. 2009;91(10):1326-34</ref><ref>Ketola S, Lehtinen JT, Arnala I. Arthroscopic decompression not recommended in the treatment of rotator cuff tendinopathy: a final review of a randomised controlled trial at a minimum follow-up of ten years. Bone Joint J. 2017;99-B(6):799-805</ref><ref>Kolk A, Thomassen BJW, Hund H, de Witte PB, Henkus HE, Wassenaar WG, van Arkel ERA, Nelissen RGHH. Does acromioplasty result in favorable clinical and radiologic outcomes in the management of chronic subacromial pain syndrome? A double-blinded randomized clinical trial with 9 to 14 years' follow-up. J Shoulder Elbow Surg. 2017;26:1407-15.</ref><ref>Mardani-Kivi M, Karimi A, Keyhani S, Hashemi-Motlagh K, Saheb-Ekhtiari K. Rotator Cuff Repair: Is there any role for acromioplasty? Phys Sportsmed. 2016;44:274-7.</ref><ref>Paloneva J, Lepola V, Karppinen J, Ylinen J, Äärimaa V, Mattila VM. Declining incidence of acromioplasty in Finland. Acta Orthop. 2015;86:220-4.</ref><ref>Saltychev M, Äärimaa V, Virolainen P, Laimi K. Conservative treatment or surgery for shoulder impingement: systematic review and meta-analysis. Disabil Rehabil. 2015;37:1-8.</ref><ref>Shin SJ, Oh JH, Chung SW, Song MH. The efficacy of acromioplasty in the arthroscopic repair of small- to medium-sized rotator cuff tears without acromial spur: prospective comparative study. Arthroscopy. 2012;28:628-35.</ref> suggesting that the procedure should be performed only in selected patients. The morphology of the scapula and of the humerus is highly variable and bone removal may not be routinely necessary. Avoiding acromioplasty and particularly detaching the coracoacromial ligament may be preferable regarding alteration of the coracoacromial arch, as it might cause significant anterosuperior translation or even escape of the humeral head,<ref>Su WR, Budoff JE, Luo ZP. The effect of coracoacromial ligament excision and acromioplasty on superior and anterosuperior glenohumeral stability. Arthroscopy. 2009;25:13-8.</ref><ref>Wiley AM. Superior humeral dislocation. A complication following decompression and debridement for rotator cuff tears. Clin Orthop Relat Res. 1991:135-41.</ref> weakening of the deltoid origin<ref>Katthagen JC, Marchetti DC, Tahal DS, Turnbull TL, Millett PJ. The Effects of Arthroscopic Lateral Acromioplasty on the Critical Shoulder Angle and the Anterolateral Deltoid Origin: An Anatomic Cadaveric Study. Arthroscopy. 2016;32:569-75.</ref> and adhesions between the raw exposed bone on the undersurface of the acromion and the underlying tendon.<ref>Liu J, Hughes RE, Smutz WP, Niebur G, Nan-An K. Roles of deltoid and rotator cuff muscles in shoulder elevation. Clin Biomech (Bristol, Avon). 1997;12:32-38.</ref><ref>Goldberg BA, Lippitt SB, Matsen FA 3rd. Improvement in comfort and function after cuff repair without acromioplasty. Clin Orthop Relat Res. 2001;142-50.</ref><ref name=":28">Romeo AA, Loutzenheiser T, Rhee YG, Sidles JA, Harryman DT 2nd, Matsen FA 3rd. The humeroscapular motion interface. Clin Orthop Relat Res. 1998;120-7.</ref> In addition, even if the role of the lateral overhanging has been recently emphasized,<ref>Moor BK, Wieser K, Slankamenac K, Gerber C, Bouaicha S. Relationship of individual scapular anatomy and degenerative rotator cuff tears. J Shoulder Elbow Surg. 2014;23:536-41.</ref><ref>Nyffeler RW, Werner CM, Sukthankar A, Schmid MR, Gerber C. Association of a large lateral extension of the acromion with rotator cuff tears. J Bone Joint Surg Am. 2006;88:800-5.</ref> it is still unknown if a lateral acromioplasty to decrease critical shoulder angle (CSA)<ref>Moor BK, Bouaicha S, Rothenfluh DA, Sukthankar A, Gerber C. Is there an association between the individual anatomy of the scapula and the development of rotator cuff tears or osteoarthritis of the glenohumeral joint?: A radiological study of the critical shoulder angle. Bone Joint J. 2013;95-B:935-41.</ref> is a safe procedure that could improve clinical outcome. Complete anterior acromioplasty is not advisable in the setting of a massive tear as it may lead to postoperative anterosuperior migration of the humeral head. The acromiohumeral arch is probably a component of human evolution used to compensate the deficiency of the superior rotator cuff.<ref name=":4" /> Consequently, when and how should acromioplasty should be performed is still debated.<ref>Voisin JL, Ropars M, Thomazeau H. The human acromion viewed from an evolutionary perspective. Orthopaedics & traumatology, surgery & research : OTSR 2014;100:S355-60.</ref> The type of acromioplasty has to be correlated to our actual practice. A recent dynamic evaluation of subacromial impingement revealed that impingement is not anterior as previously believed and that detachment of the coracoacromial ligament is not necessary.<ref>Lädermann A, Chagué S, Preissmann D, Kolo FC, Rime O, Kevelham B, Bothorel H, Charbonnier C. Guided versus freehand acromioplasty during rotator cuff repair. A randomized prospective study. Orthop Traumatol Surg Res. 2020:;106(4):651-659</ref> Moreover, it has been shown that acromioplasty significantly reduces dynamic subacromial impingement compared to preoperative situation.<ref>Lädermann A, Chagué S, Preissmann D, Kolo FC, Zbinden O, Kevelham B, Bothorel H, Charbonnier C. Acromioplasty during repair of rotator cuff tears removes only half of the impinging acromial bone. JSES Int. 2020:29;4:592-600.</ref> Furthermore, Gerber et al. advocated that adjuvant acromioplasty is necessary in shoulders with high critical shoulder angle (preoperative CSA≥34 degrees), and found that insufficient acromial resection (postoperative CSA≥35 degrees) is associated with significantly worse abductor strength and higher retear rate.<ref>Gerber C, Catanzaro S, Betz M, Ernstbrunner L. Arthroscopic Correction of the Critical Shoulder Angle Through Lateral Acromioplasty: A Safe Adjunct to Rotator Cuff Repair. Arthroscopy. 2018;34:771-780.</ref>

A tenotomy or tenodesis of the long head of the biceps should be performed in the setting of a massive rotator cuff tear. There is evidence suggesting that the long head of the biceps tendon may be a source of pain and contributes to the discomfort. In a large series, Walch et al. observed an increase in the Constant score from 48.4 preoperatively to 67.6 after arthroscopic biceps tenotomy. At last follow-up, 87% of patients were satisfied or very satisfied with the result. However, the acromiohumeral interval decreased by a mean of 1.3 mm during the follow-up period.<ref name=":25" />

======Repair Techniques======

Unfortunately, even if reinsertion of the tendon on the bone is achievable, it is often difficult to reliably achieve long-term healing with a structurally intact repair.<ref>Zumstein MA, Jost B, Hempel J, Hodler J, Gerber C. The clinical and structural long-term results of open repair of massive tears of the rotator cuff. J Bone Joint Surg Am 2008;90:2423-31.</ref>

In the setting of a massive tear, a double-row repair improves long-term functional outcome.<ref>Carbonel I, Martinez AA, Calvo A, Ripalda J, Herrera A. Single-row versus double-row arthroscopic repair in the treatment of rotator cuff tears: a prospective randomized clinical study. Int Orthop 2012;36:1877-83.</ref><ref>Connelly TM, Shaw A, O'Grady P. Outcome of open massive rotator cuff repairs with double-row suture knotless anchors: case series. Inter Orthop 2015;39:1109-14.</ref><ref name=":29">Denard PJ, Jiwani AZ, Lädermann A, Burkhart SS. Long-term outcome of arthroscopic massive rotator cuff repair: the importance of double-row fixation. Arthroscopy 2012;28:909-15.</ref>

However, this should not be performed at the expense of over-tensioning as application of a double-row repair to a tendon with poor tendon length and excursion may lead to medial failure.<ref name=":10" />

======Augmentation======

Graft augmentation may improve healing in massive rotator cuff tears, but add significant cost and time to the procedure.<ref>Barber FA, Burns JP, Deutsch A, Labbe MR, Litchfield RB. A prospective, randomized evaluation of acellular human dermal matrix augmentation for arthroscopic rotator cuff repair. Arthroscopy 2012;28:8-15.</ref>

The choice of graft is influenced by several factors including mechanical properties, host response and potential for ingrowth. Scaffolds provide mechanical support and have biological properties that may favorably influence cell proliferation and differentiation, hopefully improving tendon-to-bone healing. Currently, scaffolds derived from dermis, small intestinal submucosa, skin, fascia lata, and pericardium have been processed and marketed for augmentation in the repair of massive tears. Biological grafts are preferred, when compared to synthetic grafts, due to the unknown host response to synthetic grafts. An important factor in the longevity and strength of a graft is the amount of ingrowth.

======Results of Primary Repairs======

Results following arthroscopic repair of massive rotator cuffs have previously been reported.<ref name=":30">Denard PJ, Lädermann A, Jiwani AZ, Burkhart SS. Functional outcome after arthroscopic repair of massive rotator cuff tears in individuals with pseudoparalysis. Arthroscopy 2012;28:1214-9.</ref><ref name=":31">Lädermann A, Denard PJ, Burkhart SS. Midterm outcome of arthroscopic revision repair of massive and nonmassive rotator cuff tears. Arthroscopy 2011;27:1620-7.</ref>

For primary repair, improvements are observed in forward flexion (132 degrees vs 168 degrees), pain (6.3 v 1.3), UCLA score, (15.7 v 30.7) and American Shoulder and Elbow Surgeons score (41.7 v 85.7) (P<.001). A good or excellent outcome is obtained in 78% of cases. Similar results are noticed after repair of type A, B and C massive rotator cuff tears.<ref name=":29" />

After revision repair, mean active forward elevation improves by 15 degrees, from 136.0 degrees ± 51.9 degrees (range, 30 to 180 degrees) at baseline to 151.4 degrees ± 41.5 degrees (range, 30 to 180 degrees) at final follow-up (P=.019). The mean pain score improves by 3.1 points, from 5.0 ± 2.4 points at baseline to 1.9 ± 2.3 points at final follow-up (p<.001). The mean American Shoulder and Elbow Surgeons (ASES) score improves from 45.7 ± 17.8 at baseline to 75.5 ± 20.3 at final follow-up (P<.001). The mean UCLA score also improves, from 16.7 ±4.9 at baseline to 26.4 ± 6.9 at final follow-up (P<.001). According to the UCLA score, functional results are excellent in 15% of cases, good in 35%, fair in 25%, and poor in 25%. Seventy-nine percent of the patients are satisfied, and 32 patients (60%) returned to their previous activities.<ref name=":31" />

======Revision Rotator Cuff Repair======
'''Introduction'''

Failure of tendon healing after rotator cuff repair is common, reported in approximately 20% of cases depending on tear size.<ref>Collin P, Abdullah A, Kherad O, Gain S, Denard PJ, Lädermann A. Prospective evaluation of clinical and radiologic factors predicting return to activity within 6 months after arthroscopic rotator cuff repair. J Shoulder Elbow Surg 2015;24:439-45.</ref>

Tear recurrence can be related to various factors such as: 1) inadequate strength of the initial repair construct, 2) biological failure to heal despite strong initial fixation, and 3) inappropriate post-operative rehabilitation causing structural failure of the repair.<ref>Boileau P, Brassart N, Watkinson DJ, Carles M, Hatzidakis AM, Krishnan SG. Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? J Bone Joint Surg Am 2005;87:1229-40.</ref><ref>Cho NS, Moon SC, Jeon JW, Rhee YG. The influence of diabetes mellitus on clinical and structural outcomes after arthroscopic rotator cuff repair. Am J Sports Med 2015;43:991-7.</ref><ref>Chung SW, Oh JH, Gong HS, Kim JY, Kim SH. Factors affecting rotator cuff healing after arthroscopic repair: osteoporosis as one of the independent risk factors. Am J Sports Med 2011;39:2099-107.</ref><ref>Clement ND, Hallett A, MacDonald D, Howie C, McBirnie J. Does diabetes affect outcome after arthroscopic repair of the rotator cuff? J Bone Joint Surg Br 2010;92:1112-7.</ref>

While functional outcome has been correlated with postoperative rotator cuff integrity many patients maintain a satisfactory outcome despite structural failure.<ref name=":32">Jost B, Zumstein M, Pfirrmann CW, Gerber C. Long-Term Outcome After Structural Failure of Rotator Cuff Repairs. J Bone Joint Surg Am 2006;88:472-9.</ref>

The ideal treatment for a recurrent tear is thus not completely defined.

'''Initial Radiological Findings'''

The goal of imaging studies is to confirm the site of the recurrent tear. Trantalis et al. reported five patients with retearing of the cuff after double-row rotator cuff repair. All five patients had retearing medial to the medial row if sutures were placed near the musculotendinous junction of the supraspinatus.<ref name=":33">Trantalis JN, Boorman RS, Pletsch K, Lo IK. Medial rotator cuff failure after arthroscopic double-row rotator cuff repair. Arthroscopy 2008;24:727-31.</ref>

Hayashida et al. observed that the prevalence of complete retearing of the tendon after a double-row rotator cuff repair is similar around the medial anchors with a well-preserved footprint.<ref name=":35">Hayashida K, Tanaka M, Koizumi K, Kakiuchi M. Characteristic retear patterns assessed by magnetic resonance imaging after arthroscopic double-row rotator cuff repair. Arthroscopy 2012;28:458-64.</ref>

Another point of interest is the quality of the tendon.<ref>Denard PJ, Burkhart SS. Techniques for managing poor quality tissue and bone during arthroscopic rotator cuff repair. Arthroscopy 2011;27:1409-21.</ref>

A significant and growing number of rotator cuff repairs are performed in individuals with poor rotator cuff tissue quality. Djurasovic reported an incidence of 30% (24 on 80) of poor rotator cuff tissue quality (graded subjectively at the time of surgery).<ref name=":36">Djurasovic M, Marra G, Arroyo JS, Pollock RG, Flatow EL, Bigliani LU. Revision rotator cuff repair: factors influencing results. J Bone Joint Surg Am 2001;83-A:1849-55.</ref>

At the same time, the muscle undergoes intrinsic degeneration. After a retear, Deniz et al. found that fatty infiltration and atrophy continued to worsen significantly.<ref name=":18">Deniz G, Kose O, Tugay A, Guler F, Turan A. Fatty degeneration and atrophy of the rotator cuff muscles after arthroscopic repair: does it improve, halt or deteriorate? Arch Orthop Trauma Surg 2014;134:985-90.</ref>

However, fatty infiltration of the supraspinatus does not seem to be a determinant factor in tendon healing. Park et al. did not find significant relationship between preoperative supraspinatus fatty infiltration and postoperative tendon healing. Contrarily, it seems that fatty infiltration of infraspinatus and subscapularis are highly significant factors (P<.001).<ref name=":37">Park JS, Park HJ, Kim SH, Oh JH. Prognostic Factors Affecting Rotator Cuff Healing After Arthroscopic Repair in Small to Medium-sized Tears. Am J Sports Med 2015;43:2386-92.</ref>

Another point is the bone quality. Oh et al. demonstrated that bone mineral density within the greater tuberosity decreases in patients with rotator cuff tears. In another retrospective study that investigated the relationship between greater tuberosity osteopenia and chronicity of rotator cuff tears, Cadet et al. found that there were significantly greater osteopenic changes in the greater tuberosity in patients with chronic retracted rotator cuff tears.<ref>Cadet ER, Hsu JW, Levine WN, Bigliani LU, Ahmad CS. The relationship between greater tuberosity osteopenia and the chronicity of rotator cuff tears. J Shoulder Elbow Surg 2008;17:73-7.</ref>

However, this localized osteoporosis may not influence tendon healing. In a recent study, Park et al. did not observe after primary repair that bone mineral density influenced final results.<ref name=":37" />

Nevertheless, the greater tuberosity in revision cases can also be deficient due to anchor removal or perianchor cyst formation. Kim et al. observed in a retrospective case series of two hundred and nine patients bone cyst formation in 97 instances (46.4%), and these authors questioned the utility of bioabsorbable anchors because of possible interference with revision surgery. Consequent bone lysis can be noticed after trauma. Lädermann et al. reported massive bone resorption after osteosynthesis of the greater tuberosity leading to combined tendon and bony insufficiency and pseudoparalysis/pseudoparesis.

When milestones of typical post-operative recovery are not met, analysis of rotator cuff repair should be considered and a multi-modal evaluation is required. The goal of imaging studies is to confirm the site of the recurrent tear (Figure)86,92 the type of failure (e.g. in continuity), and if possible, it’s cause.<ref name=":35" /><ref>Mellado JM, Calmet J, Olona M, Ballabriga J, Camins A, Pérez del Palomar L, Giné J. MR assessment of the repaired rotator cuff: prevalence, size, location, and clinical relevance of tendon rerupture. European radiology 2006;16:2186-96.</ref><ref>McCarron JA, Derwin KA, Bey MJ, Polster JM, Schils JP, Ricchetti ET, Iannotti JP. Failure with continuity in rotator cuff repair "healing". Am J Sports Med 2013;41:134-41.</ref>
[[File:1562480510006-lg.jpg|center|thumb|600x600px|Figure 25. Six patterns of anatomic deficiency associated with failed rotator cuff repair. (A) Failure of tendon healing; (B) poor tendon quality; (C) fatty infiltration/atrophy; (D) retear medial to the medial row of fixation; (E) bone defects in the greater tuberosity after anchor removal, or perianchor cyst formation and (F) bony and tendinous insufficiency. Reproduced from Lädermann et al., with permission.]]
Other points of interest are the quality of the bone (tuberosity deficiency), tendon, and muscle, and whether further surgery is feasible.<ref name=":14" /><ref name=":18" />

Standard shoulder radiographs, including anteroposterior, axillary lateral and scapular Y (outlet) views, may demonstrate decreased acromiohumeral distance, glenohumeral arthritis, subacromial spurs, acetabularization of the acromion, femoralization of the humeral head, and implant or anchor migration.<ref name=":38">Hartzler RU, Sperling JW, Schleck CD, Cofield RH. Clinical and radiographic factors influencing the results of revision rotator cuff repair. International journal of shoulder surgery 2013;7:41-5.</ref><ref name=":7" />

It can also be used to rule out chondrolysis, anchor migration or prominence, and acromial fracture. Among evaluation techniques, the most widely accepted reference standard is magnetic resonance imaging which allows visualization of the tendons and does not involve radiation exposure. Intra-articular contrast may be used in association with magnetic resonance imaging to increase the sensitivity for detecting a recurrent tear.<ref>de Jesus JO, Parker L, Frangos AJ, Nazarian LN. Accuracy of MRI, MR arthrography, and ultrasound in the diagnosis of rotator cuff tears: a meta-analysis. AJR American journal of roentgenology 2009;192:1701-7.</ref>

Postoperative magnetic resonance imaging images are difficult to interpret; inadequate coverage of the greater or lesser tuberosity may indicate partial healing and not a recurrent full-thickness tear.<ref name=":39">Khazzam M, Kuhn JE, Mulligan E, Abboud JA, Baumgarten KM, Brophy RH, Jones GL, Miller B, Smith M, Wright RW. Magnetic resonance imaging identification of rotator cuff retears after repair: interobserver and intraobserver agreement. Am J Sports Med 2012;40:1722-7.</ref><ref>Saccomanno MF, Cazzato G, Fodale M, Sircana G, Milano G. Magnetic resonance imaging criteria for the assessment of the rotator cuff after repair: a systematic review. Knee Surg Sports Traumatol Arthrosc 2015;23:423-42.</ref><ref>Motamedi AR, Urrea LH, Hancock RE, Hawkins RJ, Ho C. Accuracy of magnetic resonance imaging in determining the presence and size of recurrent rotator cuff tears. J Shoulder Elbow Surg 2002;11:6-10.</ref>

Furthermore, only 10% of re-attached tendons generate a normal magnetic resonance imaging signal. Thus, a common finding is the presence of an intermediate signal within the tendon indicating granulation tissue or of a low-intensity signal produced by fibrous tissue.<ref name=":39" /><ref>Zanetti M, Hodler J. MR imaging of the shoulder after surgery. Radiologic clinics of North America 2006;44:537-51, viii.</ref>

These signal changes may persist for longer than six months, due to tissue remodeling, and seem to have no clinical implications.<ref>Tudisco C, Bisicchia S, Savarese E, Fiori F, Bartolucci DA, Masala S, Simonetti G. Single-row vs. double-row arthroscopic rotator cuff repair: clinical and 3 Tesla MR arthrography results. BMC musculoskeletal disorders 2013;14:43.</ref><ref>Gerber C, Schneeberger AG, Perren SM, Nyffeler RW. Experimental rotator cuff repair. A preliminary study. J Bone Joint Surg Am 1999;81:1281-90.</ref>

Finally, the evaluation of magnetic resonance imaging scans is made difficult by the normal leakage of fluid into the subacromial space after the opening of the rotator interval and passage of instruments through the tendon, which may contain artifacts generated, for instance, by metal anchors or high-strength sutures. These factors, together with the high cost of magnetic resonance imaging, lend considerable appeal to ultrasound as a method for evaluating rotator cuff repair, even if its effectiveness is operator-dependent.<ref>Ok JH, Kim YS, Kim JM, Yoo TW. Learning curve of office-based ultrasonography for rotator cuff tendons tears. Knee Surg Sports Traumatol Arthrosc 2013;21:1593-7.</ref>

Computed tomography arthrogram can also be used to aid in the identification of recurrent rotator cuff tears when neither ultrasound or magnetic resonance imaging are options.<ref>Nazarian LN, Jacobson JA, Benson CB, Bancroft LW, Bedi A, McShane JM, Miller TT, Parker L, Smith J, Steinbach LS, Teefey SA, Thiele RG, Tuite MJ, Wise JN, Yamaguchi K. Imaging algorithms for evaluating suspected rotator cuff disease: Society of Radiologists in Ultrasound consensus conference statement. Radiology 2013;267:589-95.</ref>

Failure after rotator cuff repair was previously believed to occur during the first three months.<ref>Kluger R, Bock P, Mittlbock M, Krampla W, Engel A. Long-term survivorship of rotator cuff repairs using ultrasound and magnetic resonance imaging analysis. Am J Sports Med 2011;39:2071-81.</ref><ref>Miller BS, Downie BK, Kohen RB, Kijek T, Lesniak B, Jacobson JA, Hughes RE, Carpenter JE. When do rotator cuff repairs fail? Serial ultrasound examination after arthroscopic repair of large and massive rotator cuff tears. Am J Sports Med 2011;39:2064-70.</ref>

While the majority of retears do occur within the first three months, it has now been demonstrated retears can occur up to six months after repair.<ref>Barth J, Fotiadis E, Barthelemy R, Genna S, Saffarini M. Ultrasonic evaluation of the repair integrity can predict functional outcomes after arthroscopic double-row rotator cuff repair. Knee Surg Sports Traumatol Arthrosc 2015;23:376-85.</ref><ref>Iannotti JP, Deutsch A, Green A, Rudicel S, Christensen J, Marraffino S, Rodeo S. Time to failure after rotator cuff repair: a prospective imaging study. J Bone Joint Surg Am 2013;95:965-71.</ref><ref>Kim JH, Hong IT, Ryu KJ, Bong ST, Lee YS, Kim JH. Retear rate in the late postoperative period after arthroscopic rotator cuff repair. Am J Sports Med 2014;42:2606-13.</ref>

Recent prospective studies have confirmed that ultrasound has a high sensitivity and specificity for detecting a recurrent rotator cuff tear compared to magnetic resonance imaging.In a study comparing magnetic resonance imaging and ultrasound after rotator cuff repair, Codsi et al. found 92% agreement with a coefficient of 0.70.<ref>Codsi MJ, Rodeo SA, Scalise JJ, Moorehead TM, Ma CB. Assessment of rotator cuff repair integrity using ultrasound and magnetic resonance imaging in a multicenter study. J Shoulder Elbow Surg 2014;23:1468-72.</ref>

Similarly, Collin et al. reported that ultrasound had 80% sensitivity and 98% specificity compared to magnetic resonance imaging.<ref>Collin P, Yoshida M, Delarue A, Lucas C, Jossaume T, Lädermann A; French Society for Shoulder and Elbow (SOFEC). Evaluating postoperative rotator cuff healing: Prospective comparison of MRI and ultrasound. Orthopaedics & traumatology, surgery & research : OTSR 2015;101:S265-8.</ref>

=====Treatment=====

======Non Surgical (Conservative) Treatment of Failed Rotator Cuff Repair======
Jost et al. evaluated 20 patients with a failed rotator cuff repair at a mean follow-up of 38 months and reported that the adjusted Constant score and shoulder simple value averaged 83% and 75%, respectively.<ref name=":32" />

Namdari et al. demonstrated a successful outcome in 54% of patients (defined by an American Shoulder and Elbow Surgeons score of more than 80 points) and a mean 15 point improvement in the American Shoulder and Elbow Surgeons score at a mean of 52 months postoperative. Finally, the same group compared the two and ten year results for patients with known structural failures of rotator cuff repair. The average long-term American Shoulder and Elbow Surgeons score was 79 points (range, 50 to 95 points) and the average visual analog scale pain score was 2.2 points (range, 1 to 4 points); both scores were unchanged from those at two years. The average simple shoulder test score was 9.2 points (range, 6 to 12 points), and the average age-adjusted Constant score was 73 points (range, 59 to 90 points).<ref>Paxton ES, Teefey SA, Dahiya N, Keener JD, Yamaguchi K, Galatz LM. Clinical and radiographic outcomes of failed repairs of large or massive rotator cuff tears: minimum ten-year follow-up. J Bone Joint Surg Am 2013;95:627-32.</ref>

======Surgical (Operative) Treatment Revision Rotator Cuff Repair======
'''Surgical Technique'''

The alarming retear rate indicates that several surgical options can be considered which must be individualized to the patient. For example, in the setting of an acute traumatic retear in a physiologically young, healthy, active and non-pseudoparalytic patient, arthroscopic revision surgery is generally recommended. Techniques to enhance mechanical fixation, such as linked load-sharing rip-stop constructs should be considered.<ref name=":22" />

Augmented repair using scaffold devices derived from autografts,46,119,120 allograft,121 xenograft extracellular matrix122 or synthetic matrices such as poly-l-lactide grafts123 have been used to offer a structural support of the repair during the crucial healing period and to improve healing rates. The scientific literature does not contain enough data to justify any systematic associated augmentation techniques. Tendon transfers may be used in patients without advanced glenohumeral arthritis who have significant loss of external rotation strength and maintain anterior active elevation.62,124 If the patient is young, pseudoparalytic and suffers from a combined bony and tendinous rotator cuff insufficiency, calcaneum and Achilles tendon allograft could be considered.40

Finally, whereas primary pseudoparalysis responds well to arthroscopic rotator cuff repair, persistent pseudoparalysis after a previous attempt at rotator cuff repair may be more predictably managed with reverse shoulder arthroplasty. Denard et al. reported that pseudoparalysis/pseudoparesis was reversed in the revision setting in only 43% of patients with a low rate (54%) of satisfaction.<ref name=":2" />

In contrast, Boileau et al. found that anterior elevation was reliably restored with reverse shoulder arthroplasty after failed rotator cuff repair and 73% of patients were satisfied.<ref>Boileau P, Gonzalez JF, Chuinard C, Bicknell R, Walch G. Reverse total shoulder arthroplasty after failed rotator cuff surgery. J Shoulder Elbow Surg 2009;18:600-6.</ref>

'''Clinical and Radiological Results After Revision Rotator Cuff Repair'''

The clinical results of are summarized in Table 3. Overall, range of motion improved, except in one series of open rotator cuff repair.94 Functional outcome improved in all series and 70% or more of patients were satisfied or very satisfied.<ref name=":38" />

'''''Table 3: Clinical Results of Revision RCR'''''
[[File:1562481228568-lg.jpg|alt=|none|thumb|720x720px]]
 '''Complication'''

The short- to intermediate-term incidence of complications, including subsequent revision surgery, after revision rotator cuff repair is relatively low, around ten percent in this review (Table). However, most studies primarily considered reoperation a complication and did not examine complications such as hematoma, hardware failure, and postoperative stiffness. The prevalence of postoperative complications is therefore probably higher than reported. The prevalence of non-healing or retear was around 40% (range, 0 to 62%) in the four studies with postoperative imaging.<ref>Agrawal V. Healing rates for challenging rotator cuff tears utilizing an acellular human dermal reinforcement graft. International journal of shoulder surgery 2012;6:36-44.</ref><ref>Lenart BA, Martens KA, Kearns KA, Gillespie RJ, Zoga AC, Williams GR. Treatment of massive and recurrent rotator cuff tears augmented with a poly-l-lactide graft, a preliminary study. J Shoulder Elbow Surg 2015;24:915-21.</ref><ref>Keener JD, Wei AS, Kim HM, Paxton ES, Teefey SA, Galatz LM, Yamaguchi K. Revision arthroscopic rotator cuff repair: repair integrity and clinical outcome. J Bone Joint Surg Am 2010;92:590-8.</ref><ref name=":40">Shamsudin A, Lam PH, Peters K, Rubenis I, Hackett L, Murrell GA. Revision versus primary arthroscopic rotator cuff repair: a 2-year analysis of outcomes in 360 patients. Am J Sports Med 2015;43:557-64.</ref>

Furthermore, these tears may progress with time; Shamsudin et al. reported a prevalence of defect of 28% at six months and of 40% at two years. If revision is planned, patients have to be aware of the high prevalence of persistent structural defect. Moreover, retear rate after reoperation continues to deteriorate with time.<ref name=":40" /><ref>Vastamaki M, Lohman M, Borgmastars N. Rotator cuff integrity correlates with clinical and functional results at a minimum 16 years after open repair. Clin Orthop Relat Res 2013;471:554-61.</ref>

Structural failure does not always result in clinical failure. Many patients with partial healing of the cuff and a residual defect will be much improved after surgery. Characteristics associated with successful and unsuccessful results after structural failure of rotator cuff repair are poorly understood. Retear or non-healing of tendons is rather frequent and surgery is rarely proposed because this condition is often well tolerated with marked clinical improvement in comparison with the preoperative state.<ref>Namdari S, Donegan RP, Chamberlain AM, Galatz LM, Yamaguchi K, Keener JD. Factors affecting outcome after structural failure of repaired rotator cuff tears. J Bone Joint Surg Am 2014;96:99-105.</ref>

One reason for clinical failure is probably the non-restoration of balanced force couples and the suspension bridge system of force transmission in the shoulder. The location (involvement of the subscapularis on which the rotator cable is attached) and the size (more than two tendons) are the primary determinant of rotator cuff function.

'''Risk Factors for Postoperative Poorer Results'''

Several patient-related factors appear to be associated with poorer results. The most important factor seems to be poor preoperative range of motion. Female sex and, in one study, if the surgery was performed on the dominant arm, were negatively associated with postoperative outcome.<ref name=":34">Chuang MJ, Jancosko J, Nottage WM. Clinical outcomes of single-row arthroscopic revision rotator cuff repair. Orthopedics 2014;37:e692-8.</ref><ref name=":41">Piasecki DP, Verma NN, Nho SJ, Bhatia S, Boniquit N, Cole BJ, Nicholson GP, Romeo AA. Outcomes after arthroscopic revision rotator cuff repair. Am J Sports Med 2010;38:40-6.</ref><ref name=":31" />

There is still controversy about certain risk factors such as age of patients. Disease-related factors included patients with a recurrent tear after the revision repair, preoperative visual analogue scale pain score greater than five, and poor preoperative range of motion. The range vary from less than 90 degrees in the studies from Denard et al. and Piasecki et al. to 140 degrees in the study of Chuang et al.<ref name=":30" /><ref name=":34" /><ref name=":41" />

The latter factor has been reported in almost all series and is probably the most important preoperative indicator. In addition, acromiohumeral distance (less than seven mm) can be associated with a satisfactory outcome.<ref name=":38" />

There is controversy about patients with more than one prior surgery, with one study reporting that this negatively impacted results and another study reporting that it did not.<ref name=":31" /><ref name=":41" />

Operative-related factors like poor tendon quality is associated with poorer results.<ref name=":36" /><ref name=":23" />

One study compared outcomes between massive and non-massive tears and did not find any significant difference in terms of post-operative anterior elevation, pain, or functional outcome.<ref name=":31" />

'''Post-revision Rehabilitation'''

In all studies, subjects took part in standardized rehabilitation protocols. Most studies did not allow immediate overhead passive motion. Most studies recommend sling during 6 weeks. Strengthening is delayed until six to sixteen weeks post-operatively. Full return to activity was not allowed until four to twelve months.

====B2: Medial Tendinous Disruption====
Disruption of the tendon medial to an intact lateral tendon stump has been reported in primary chronic and acute cases or postoperatively as a failure medial to the medial row.<ref name=":33" /><ref>Loew M, Magosch P, Lichtenberg S, Habermeyer P, Porschke F. How to discriminate between acute traumatic and chronic degenerative rotator cuff lesions: an analysis of specific criteria on radiography and magnetic resonance imaging. J Shoulder Elbow Surg 2015;24:1685-93.</ref>

Regarding the former, it is now understood that the infraspinatus insertion is quite broad and wraps around from posterior to anterior to occupy much of the lateral greater tuberosity. Therefore, such descriptions of a lateral tendon stump remaining may, in fact, represent a torn supraspinatus with an intact infraspinatus.

Full thickness defects medial to an intact footprint of the rotator cuff can be seen following a rotator cuff repair (Figure). Trantalis et al. described 5 patients with medial failure following a double-row rotator cuff repair. Such failure results from overtensioning during repair and is very difficult to manage with revision repair. These lesions do not produce muscular edema, except in traumatic cases with important and acute retraction of the muscle and the remnant of the tendon (Figure); its origin is then either retraction (which may appear in some hours) or neurological lesions (noted after some weeks).<ref>Fleckenstein JL, Watumull D, Conner KE, Ezaki M, Greenlee RG Jr, Bryan WW, Chason DP, Parkey RW, Peshock RM, Purdy PD. Denervated human skeletal muscle: MR imaging evaluation. Radiology 1993;187:213-8.</ref>

===B3: Tendon to Tendon Adhesion: “Fosbury Flop Tear”===

The Fosbury flop tear occurs from a full thickness tear that has flipped upon itself and adhered medially (Figure 26).<ref name=":42">Lädermann A, Denard PJ, Kolo FC. A new tear pattern of the rotator cuff and its treatment: Fosbury flop tears. International journal of shoulder surgery 2015;9:9-12.</ref>
[[File:1562482685626-lg.jpg|center|thumb|600x600px|Figure 26. Figure: Illustration of a “Fosbury flop tear” development. Reproduced from Lädermann et al., with permission.]]

=====Prevalence=====
In a prospective study spanning one-year, Lädermann et al. reported five patients with full or partial-thickness rotator cuff lesions in a series of 97 (5 % incidence rate). Radiologically, these lesions showed a thicker than normal tendon stump on the bursal-side of the retracted supraspinatus tendon in a superomedial orientation.<ref name=":42" />
[[File:1562482680697-lg.jpg|center|thumb|600x600px|Figure 27. Coronal T1 weighted image of a right shoulder that demonstrates (black arrow) an abnormally thickened supraspinatus (9.5 mm). Reproduced from Lädermann et al., with permission.]]
[[File:1562483248519-lg.jpg|center|thumb|600x600px|Figure 28. Coronal T1 weighted MRA image with fat saturation of a right shoulder demonstrates adhesions between the bursal side of the tendon and the wall of the subacromial bursa (red arrow), and abnormal orientation of the fibers stump (yellow arrow). Reproduced from Lädermann et al., with permission.]]
Additionally, patients with this lesion were also found to have an accumulation of fluid in the superomedial part of the subacromial bursa as well as adhesions between the wall of the subacromial bursa and the tendon of the supraspinatus. Since the original description, another group verified the same entity.<ref>Nakamizo H. Arthroscopic repair for subacromial incarceration of a torn rotator cuff. AP-SMART 2015;2:90-4.</ref>

=====Surgical Technique=====
A diagnostic arthroscopy is performed with an arthroscopic pump maintaining pressure at 50 mm Hg. The biceps is tenotomized or tenodesed. Attention is then turned to the posterosuperior rotator cuff (supraspinatus and infraspinatus tendons). The appearances of the tears are unusual with ulcerations on the bursal surface (anemone like) and what initially appeared to be a thickened lateral tendon stump (Figure and Video).
[[File:1562483266291-lg.jpg|center|thumb|600x600px|Figure 29. Arthroscopic view of a right shoulder through lateral portal after bursectomy and creation of a bone socket for medial row anchor placement. The supraspinatus tendon is unusually thick and has the appearance of ulcerations and flanges of the bursal side (sea anemone appearance, black arrow). H, hole of the tap; HH, humeral head; SS, supraspinatus tendon. Reproduced from Lädermann et al., with permission.]]
[[File:1563115158292-lg.mp4|center|thumb|600x600px|Video 13.]]
 After a progressive dissection, however, medial adhesions of the bursal layer is found. A complete excavation of the rotator cuff must be performed by skeletonizing the scapular spine medially, removing any bursal leaders (false insertions into the internal deltoid fascia) laterally, and debriding the fibrofatty bursa overlying the rotator cuff. These steps allow identification of the lateral tendon stump which is reversed upon itself and scarred medially. Once identified the tendon stump is unfolded (Video) and subsequently repaired to the lateral bone bed.

====B4: Tendon to Acromion Adhesion====
Disruption of the lateral tendon stump can be followed by adhesion under the acromion, the coracoid process or the coracoacromial arch (Figure). These adhesions are most pronounced in revision situations, but may also be observed in primary cases, particularly in the setting of a massive contracted rotator cuff tear.<ref name=":28" />
[[File:1562484138603-lg.jpg|center|thumb|700x700px|Figure 30. A) A coronal view of a right shoulder computed tomography (CT) arthrogram shows a probable B2 rotator cuff lesion with a Patte 3 retraction. b) The arthroscopic view through lateral portal revealed after partial debridement that the tendon was not retracted but actually had adhered under the acromion. Reproduced from Lädermann et al., with permission.]]

===Type C: Musculotendinous Junction Lesion===
Isolated ruptures of the musculotendinous junction are rare in the rotator cuff, but have a dramatic impact on functional outcome. Such lesions have been observed in all muscles of the rotator cuff, affecting the infraspinatus muscle in half of cases, followed by the supraspinatus in 31% of cases, the subscapularis in 25%, and the teres minor in 19% of cases (more than one muscle is occasionally involved).<ref>Taneja AK, Kattapuram SV, Chang CY, Simeone FJ, Bredella MA, Torriani M. MRI findings of rotator cuff myotendinous junction injury. AJR American journal of roentgenology 2014;203:406-11.</ref>

These lesions can been classified into 3 stages. Grade I injuries are a muscular strain that heals without adverse sequelae. Grade II injuries are partial ruptures without tendon retraction. Grade III injuries are complete ruptures at the musculotendinous junction. The acute phase of these injuries are associated with severe inflammation, leading to a highly characteristic bright signal on T2 weighted magnetic resonance imaging (Figure 31).<ref>Zarins B, Ciullo JV. ACute muscle and tendon injuries in athletes. Clinics in sports medicine 1983;2:167-82.</ref>
[[File:1562484142491-lg.jpg|center|thumb|700x700px|Figure 31. Axial and sagittal T2-weighted FATSAT magnetic resonance imaging (MRI) images demonstrating a type C rotator cuff lesion with an intact tendon, a stage 3 rupture of the musculotendinous junction, and huge edema of the muscle. Reproduced from Lädermann et al., with permission.]]
Edema of rotator cuff muscle with an intact tendon-bone insertion is infrequent. It has been described in cases of denervation, such as compression of the suprascapular nerve, Parsonage Turner syndrome, in other rare and non-specific conditions.<ref>Ludig T, Walter F, Chapuis D, Mole D, Roland J, Blum A. MR imaging evaluation of suprascapular nerve entrapment. European radiology 2001;11:2161-9.</ref><ref>Bredella MA, Tirman PF, Fritz RC, Wischer TK, Stork A, Genant HK. Denervation syndromes of the shoulder girdle: MR imaging with electrophysiologic correlation. Skeletal radiology 1999;28:567-72.</ref>

Complete musculotendinous junction ruptures have only been described in the infraspinatus and the supraspinatus.<ref>Walch G, Nove-Josserand L, Liotard JP, Noel E. Musculotendinous infraspinatus ruptures: an overview. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:463-70.</ref><ref>Hertel R, Lambert SM. Supraspinatus rupture at the musculotendinous junction. J Shoulder Elbow Surg 1998;7:432-5.</ref><ref>Lädermann A, Christophe FK, Denard PJ, Walch G. Supraspinatus rupture at the musclotendinous junction: an uncommonly recognized phenomenon. J Shoulder Elbow Surg 2012;21:72-6.</ref>

Possible causes for musculotendinous junction infraspinatus lesion are calcific tendinitis or previous cortisone injection. On the other hand, rupture of the other muscles seem to be due to trauma or inlet impingement syndrome. There is little information about the clinical results of grade 3 musculotendinous junction lesions.

====Type C with Reverse Fosbury Flop Tear====
Exceptionally, a lesion of the musculotendinous junction can develop a Fosbury pattern and heals, for its tendon part, on the humerus or even coracoid process.<ref>Tirefort J, Cunningham G, Lädermann A. Reverse Fosbury Flop Tear of the Rotator Cuff. Case Reports in Orthopedics 2017;2017:3635897.</ref>
[[File:1562484351328-lg.jpg|center|thumb|600x600px|Figure 32. Coronal T2 weighted image with fat saturation of a right shoulder. A tear at the musculotendinous junction (green arrow) as well as a muscular edema (white arrows in the frame) are observed. Reproduced from Tirefort et al., with permission.]]
[[File:1562484588402-lg.jpg|center|thumb|600x600px|Figure 33. Coronal T1-weighted (A) and axial T2-weighted (B) with fat saturation of a right shoulder. The supraspinatus flopped on itself (white dotted line) and healed on the anterior humerus (white arrows). Reproduced from Tirefort et al., with permission.]]
[[File:1562484589524-lg.jpg|center|thumb|600x600px|Figure 34. Arthroscopic view of a right shoulder viewed from posterior portal. A) The supraspinatus tendon had the appearance of ulcerations and flanges of the bursal side (sea anemone appearance, black arrows) and, B) after debridement of the flanges, the tendon that flopped on itself and the long head of the biceps and healed on the anterior humerus had an unusual orientation (HH, humeral head; LHB, long head of the biceps; SS, supraspinatus tendon). Reproduced from Tirefort et al., with permission.]]
[[File:1562484592294-lg.png|center|thumb|600x600px|Figure 35. Illustration of a "Fosbury flop tear" (A) and of a "reverse Forsbury flop tear" (B). Reproduced from Tirefort et al., with permission.]]
 

===Type D: Muscle Insufficiency===

====D1: Fatty Infiltration and Muscle Atrophy====
One of the most important prognostic factor for rotator cuff repair is nonfunctional muscle bellies. Muscle quality is most commonly classified according to Goutallier et al. to determine the extent of injuries based upon the degree in which fat is present in the muscle. They proposed a 5 stage classification system of fatty infiltration. Additionally, they demonstrated that multiple muscles develop fatty degeneration, even if they were not directly impacted by the original lesion.<ref name=":9" />

With the advent of MRI, however, the classification was extrapolated to the most lateral parasagittal image on which the scapular spine was in contact with the scapular body (Y view).<ref>Fuchs B, Weishaupt D, Zanetti M, Hodler J, Gerber C. Fatty degeneration of the muscles of the rotator cuff: assessment by computed tomography versus magnetic resonance imaging. J Shoulder Elbow Surg 1999;8:599-605.</ref>

The mean time to tendon rupture observed for stage 2 fatty infiltration is 3 years for the supraspinatus and 2.5 years for the infraspinatus and the subscapularis when their tendons ruptured. The mean time observed to grade 3 and 4 fatty infiltration is 5, 4, and 3 years for the supraspinatus, the infraspinatus, and the subscapularis, respectively.<ref>Melis B, Nemoz C, Walch G. Muscle fatty infiltration in rotator cuff tears: descriptive analysis of 1688 cases. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:319-24.</ref>

Zanetti et al. described a radiographic tangent sign to quickly and reliably assess the presence or absence of supraspinatus atrophy on MRI. This sign is a reliable method for evaluating the presence or absence of muscle atrophy using the sagittal plane and is moreover significantly related to the level of fatty infiltration within the supraspinatus muscle.<ref name=":11" />

It has been reported to be a predictor of whether a rotator cuff tear will be repairable.<ref name=":12" />

Thomazeau et al. proposed calculating the occupation ratio of the supraspinatus muscle belly using MRI. This was calculating by comparing the supraspinatus fossa volume to total supraspinatus muscle belly volume and computing the ratio. This ratio was found to be significantly decreased in patients with repairable rotator cuff tears.<ref name=":20" />

Inability to obtain a complete repair of the supraspinatus was associated with a positive tangent sign (30% irreparable) versus a negative tangent sign (6.3% irreparable, OR = 6,3, P =0.0102) and with Goutallier grade 3-4 fatty infiltration of the supraspinatus (42.9% irreparable) versus grade 0-2 fatty infiltration (5.7% irreparable, OR = 11.8, P =0.001).<ref name=":8" />

Rotator cuff repair should thus be performed before the appearance of fatty infiltration (Stage 2) and atrophy (positive tangent sign) and as soon as possible in older patients when the tear involves multiple tendons.<ref>Melis B, DeFranco MJ, Chuinard C, Walch G. Natural history of fatty infiltration and atrophy of the supraspinatus muscle in rotator cuff tears. Clin Orthop Relat Res 2010;468:1498-505.</ref>

====D2: Neurological impairment====
Isolated suprascapular nerve neuropathy is a condition associated with acute and chronic shoulder girdle traction injuries, compressive lesions such as paralabral cysts and compressive ligaments, as well as large or massive rotator cuff tears (Figure 36). In the latter situation, the proposed mechanism involves traction of the nerve caused by retraction of the supraspinatus against its fixed points on the suprascapular and spinoglenoid notches. However, clinical diagnosis is beset with uncertainties as the potential symptoms of suprascapular nerve neuropathy, namely, pain, weakness, and atrophy, are inseparable from those of rotator cuff tear. Currently, there is no support for routine suprascapular nerve release as the prevalence of suprascapular nerve neuropathy in the setting of a massive rotator cuff tear was very low (2%) in a recent prospective study.<ref name=":17" />
[[File:1562485382488-lg.jpg|center|thumb|600x600px|Figure 36. Sagittal view of a patient suffering from suprascapular neuropathy. A) T1 sequences reveal fatty infiltration and B) T2 FATSAT sequences demonstrate muscle edema.]]

====D3: Tumors====
Numerous tumors, such as an arthrosynovial cyst, intramuscular lipoma, or a calcified hematoma, can developed at the expense of the muscular tissue and cause muscular insufficiency (Figure 37).<ref>Lädermann A, Genevay M, Abrassart S, Schwitzguebel AJ. Supraspinatus Intramuscular Calcified Hematoma or Necrosis Associated with Tendon Tear. Case Rep Orthop 2015;2015:496313.</ref>
[[File:1562485402714-lg.jpg|center|thumb|600x600px|Figure 37. A) Schema of a D rotator cuff insufficiency.
B) Coronal T2-weighted SPAIR magnetic resonance imaging (MRI) image of a right shoulder showing a B2D3 lesion with an intramuscular arthrosynovial cyst. 
C) Coronal T2-weighted PD
D) sagittal T1-weighted image demonstrating D3 rotator cuff lesion with a calcified hematoma in the supraspinatus and an intramuscular lipoma of the subscapularis, respectively. Reproduced from Lädermann et al., with permission.]]
These impairments can be as isolated or be associated with other rotator cuff lesions. Management may require treatment of the associated mechanical stress in addition to rotator cuff repair.

==Irreparable Rotator Cuff Tears==

===Introduction===
One of the most challenging issues in shoulder surgery is the management of symptomatic irreparable rotator cuff tears. The literature reports that 12% of posterosuperior rotator cuff tear are not repairable.<ref name=":8" />

The latter condition when symptomatic can be managed with several approaches without clear evidence based guidelines. For example, the same patient with a D type irreparable rotator cuff tears according to Collin et al. may be offered physiotherapy, partial repair, tendon transfer, superior capsular reconstruction, subacromial spacer (balloon), or even a reverse shoulder arthroplasty (RSA) depending on multiple factors, including, geography, surgeon experience, implants costs, etc. Moreover, even if it is reported that these surgical procedures have different indications, they are often applied to patients with similar problems indiscriminately.

===Definition of an Irreparable Rotator Cuff Tears & Clinical and Imaging Findings===
The definition of an irreparable rotator cuff varies widely. Furthermore, with advances in anchors, suture strength, techniques of release and repair with load-sharing rip-stop fixation, etc, the definition continues to evolve. Two situations can be faced; the first one consists of a patient who has a contra-indication to cuff repair, and the second scenario is intra-operative when a complete repair is not physically possible. While most rotator cuff tears can be repaired, some lesions are not reparable or should not be repaired. Imaging studies play a critical role in preoperative assessment, evaluation of the defects and selection of the correct treatment for an irreparable rotator cuff tears. The following clinical and radiological preoperative factors that have been clearly associated with postoperative clinical or radiological failure should be considered before attempting repair.

===Clinical Examination===
Pseudoparalysis was defined as a chronic inability to actively elevate the arm beyond 90 degrees with full passive forward flexion.<ref>Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-86.</ref>

It is nevertheless important to note that this correspond to functional limitation associated or not with an antero-superior escape and not just to pain inhibition. Several studies purport to reverse pseudoparalysis although it represents mainly pseudoparesis cases. When pain inhibition or slight stiffness limits the patient from elevating the shoulder, the limited motion is not secondary to complete cuff deficiency.<ref>Tokish JM, Alexander TC, Kissenberth MJ, Hawkins RJ. Pseudoparalysis: a systematic review of term definitions, treatment approaches, and outcomes of management techniques. J Shoulder Elbow Surg 2017;26:e177-e87.</ref>

Anatomically, pseudoparalysis requires the disruption of at least of rotator cable attachment which in the study of Collin et al. was found in only 2.9% of massive D-type cases. This means that pseudoparalysis of the posterosuperior rotator cuff cases involved usually the whole posterior cuff (33.3% of pseudoparalysis found in E-type irreparable rotator cuff tears).<ref name=":1" />

In addition to pseudoparalysis, the presence of lag signs (external rotation lag, drop, dropping, hornblower signs) is also associated with non-reparability.<ref>Axe JM. Tendon transfers for irreparable rotator cuff tears: An update. EFORT Open Rev 2016;1:18-24.</ref>

===Treatment===

====Non-Surgical (Conservative) Treatment====
As patients with posterosuperior irreparable rotator cuff tears do not have anterosuperior escape, many respond favorably to nonsurgical treatment which should be attempted for six months before considering surgery. If after this adequate period of time symptoms have not improved, the chances of success with further non-operative treatment decreases and operative treatment may be considered. The mainstay of non-operative treatment includes nonsteroidal anti-inflammatory drugs, subacromial corticosteroid injections, and physical therapy. Levy et al. prospectively assessed 17 patients with clinically and radiographically diagnosed irreparable rotator cuff tears that underwent an anterior deltoid training program.<ref name=":19">Levy O, Mullett H, Roberts S, Copeland S. The role of anterior deltoid reeducation in patients with massive irreparable degenerative rotator cuff tears. J Shoulder Elbow Surg 2008;17:863-70.</ref>

By 9 months, the mean Constant score improved from 26 to 63, and the forward flexion improved from 40° to 160°. In another prospective cohort of 45 patients suffering from pseudoparalysis with a radiographically confirmed D-type rotator cuff tear, Collin et al. found after a follow-up of 48 months that 14 of 15 patients had substantial improvement in active forward elevation to above 90 degrees.<ref name=":24" />

The protocol of rehabilitation focused habitually on a multimodal physical therapy program with global deltoid reconditioning and periscapular strengthening.<ref>Ainsworth R. Physiotherapy rehabilitation in patients with massive, irreparable rotator cuff tears. Musculoskeletal care 2006;4:140-51.</ref>

Certain authors propose that reeducation of the anterior deltoid muscle to compensate for a deficient rotator cuff is the cornerstone of successful non-operative treatment.<ref name=":19" />

The promising results has nevertheless not been confirmed.<ref>Yian EH, Sodl JF, Dionysian E, Schneeberger AG. Anterior deltoid reeducation for irreparable rotator cuff tears revisited. J Shoulder Elbow Surg 2017;26:1562-5.</ref><ref name=":24" />

====Surgical (Operative) Treatment====
In the absence of a gold standard surgical solution, treatment of irreparable rotator cuff tears has proven to be quite challenging, adding to the surgeon’s dilemma regarding the choice of patient and treatment option. Younger active patients (<60 years of age) with traumatic tears, may be immediate candidates for surgery based on the high risk for progression with conservative treatment. Surgical approaches have been advocated, with varying degrees of success. The surgical options include arthroscopic debridement, partial repair, biceps procedure, superior capsular reconstruction, muscle transfers, biodegradable subacromial spacer interposition, biological augmentation and reverse shoulder arthroplasty. Despite all these options, irreparable rotator cuff tears are difficult to manage and treat effectively. There are no high levels of evidence prospective trials comparing these various options and therefore recommendations are mainly based on retrospective case series, surgeon experiences, and expert opinions.

=====Long Head of the Biceps Tenotomy or Tenodesis +/- Partial Repair=====
This procedure includes biceps tenotomy or tenodesis, partial repair if evaluation has deemed the remaining tendon to be of good quality, and associated procedures such as distal clavicle resection if necessary. Tenotomy or tenodesis of the long head of the biceps should consistently be performed, as biceps tendinopathy is observed in 92% of rotator cuff lesions.<ref>Boileau P, Maynou C, Balestro JC, Karataglis D, Papadopoulos P. [Long head of the biceps pathology]. Rev Chir Orthop Reparatrice Appar Mot 2007;93:5S19-53.</ref>

There is evidence suggesting that this structure is a source of pain and contributes to the symptomatology of patients with irreparable rotator cuff tears. Walch et al. reported statistically significant improvements in the Constant score with an isolated biceps tenotomy (Constant score 48 points preoperatively to 68 points at follow-up (P < .0001)) which has been confirmed by numerous authors.<ref name=":25" />

The aim of this procedure is to repair all of the rotator cuff tendon that can reasonably be brought back to the tuberosities without excessive tension, and to address all potential causes of persistent pain or factors threatening the repair. The goal of a partial repair is to restore force couples, to re-establish the “suspension bridge”, and to prevent secondary extension of the tear. In this theory, complete closure of the defect is less important than restoration of a stable fulcrum for normal shoulder kinematics. Although having little effect on improvement in shoulder strength after this intervention, eliminating various pain generators usually enhances function. Although a partial cuff repair is conducted, the role of the biceps tenotomy should not be overlooked in the patient improvements observed.<ref>Boileau P, Baque F, Valerio L, Ahrens P, Chuinard C, Trojani C. Isolated arthroscopic biceps tenotomy or tenodesis improves symptoms in patients with massive irreparable rotator cuff tears. J Bone Joint Surg Am 2007;89:747-57.</ref>

Acromioplasty is not advisable in the setting of an irreparable rotator cuff tears as it may lead to postoperative antero-superior migration of the humeral head. Tuberoplasty has been proposed as an alternative to classic subacromial decompression in order to preserve the integrity of the coracoacromial arch.<ref>Scheibel M, Lichtenberg S, Habermeyer P. Reversed arthroscopic subacromial decompression for massive rotator cuff tears. J Shoulder Elbow Surg 2004;13:272-8.</ref>

Although the results in compensated tears and low-demand patients are promising,176 it is currently unknown if the positive effect with regards to pain relief is due to the tuberoplasty or to the concomitant performed bursectomy, synovectomy and biceps treatment. Partial repair provides good clinical outcomes, comparable to those reported with biceps sacrifice and subacromial decompression. The main purported benefit of repairing part of the cuff is its potential to slow or halt further tear progression and to increase the strength of the shoulder. All series of partial repair reported a significant improvement in functional scores, while reporting a rate of radiological repair failure around 50% (Table 4).<ref>Berth A, Neumann W, Awiszus F, Pap G. Massive rotator cuff tears: functional outcome after debridement or arthroscopic partial repair. J Orthop Traumatol 2010;11:13-20.</ref><ref>Chen KH, Chiang ER, Wang HY, Ma HL. Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Factors Related to Greater Degree of Clinical Improvement at 2 Years of Follow-Up. Arthroscopy 2017;33:1949-55.</ref><ref>Cuff DJ, Pupello DR, Santoni BG. Partial rotator cuff repair and biceps tenotomy for the treatment of patients with massive cuff tears and retained overhead elevation: midterm outcomes with a minimum 5 years of follow-up. J Shoulder Elbow Surg 2016;25:1803-9.</ref><ref>Galasso O, Riccelli DA, De Gori M, De Benedetto M, Orlando N, Gasparini G, Castricini R. Quality of Life and Functional Results of Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears. Arthroscopy 2017;33:261-8.</ref><ref>Godeneche A, Freychet B, Lanzetti RM, Clechet J, Carrillon Y, Saffarini M. Should massive rotator cuff tears be reconstructed even when only partially repairable? Knee Surg Sports Traumatol Arthrosc 2017;25:2164-73.</ref><ref>Henry P, Wasserstein D, Park S, Dwyer T, Chahal J, Slobogean G, Schemitsch E. Arthroscopic Repair for Chronic Massive Rotator Cuff Tears: A Systematic Review. Arthroscopy 2015;31:2472-80.</ref><ref>Shon MS, Koh KH, Lim TK, Kim WJ, Kim KC, Yoo JC. Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Preoperative Factors Associated With Outcome Deterioration Over 2 Years. Am J Sports Med 2015;43:1965-75.</ref><ref>Yoo JC, Ahn JH, Koh KH, Lim KS. Rotator cuff integrity after arthroscopic repair for large tears with less-than-optimal footprint coverage. Arthroscopy 2009;25:1093-100.</ref>

Long-term benefit in prevention of head migration has not been demonstrated.

'''''Table 4: Results of partial repair of irreparable rotator cuff tear.'''''
[[File:1562487859066-lg.jpg|thumb|720x720px|†: Constant score, ‡: American Shoulder and Elbow Surgeons (ASES) score, NA: non available.|alt=|none]]

=====Tendon Transfer=====
Tendon transfers have been described in the management of an irreparable rotator cuff tears, however, the outcomes reported have been inconsistent. The results of new transfers involving the lower trapezius transfers have not been well described with mainly anatomical or biomechanical data and will not be described in this review article. L'Episcopo and latissimus dorsi transfer are reported to reconstitute the posterior force couple. L’Episcopo first described the technique of transfer of the latissimus dorsi and teres major tendons in children with obstetric palsy.<ref>L’Episcopo J. Tendon transplantation in obstetrical paralysis. Am J Surg 1934;25:122-5.</ref>

The procedure involves transferring both tendons laterally and posteriorly on the humerus, such that the function of the transfer changes from internal to external rotation. Boileau et al. analyzed recently 26 patients (2 with glenohumeral arthritis) and found a gain in active external rotation of 26 degrees and an improvement in adjusted Constant score from 63.6% to 86.9% (P < .001).<ref>Boileau P, Baba M, McClelland WB, Jr., Thelu CE, Trojani C, Bronsard N. Isolated loss of active external rotation: a distinct entity and results of L'Episcopo tendon transfer. J Shoulder Elbow Surg 2017.</ref>

The integrity of the remaining internal rotators are of utmost importance as patients after a L’Episcopo transfer loose significant internal rotation and may not reach the back anymore. Latissimus dorsi transfer has been initially proposed for irreparable rotator cuff tears as an open procedure to improve control of external rotation in young and high demand patients with an intact subscapularis.<ref>Gerber C. Latissimus dorsi transfer for the treatment of irreparable tears of the rotator cuff. Clin Orthop Relat Res 1992:152-60.</ref>

Namdari et al. in a review found that patients followed for mean of 46 months had a mean adjusted Constant score of 46 preoperatively compared with 73 postoperatively (p < 0.001). The mean active external rotation improved from 17 degrees to 27 degrees which is statistically significant (p < 0.001) but not clinically significant. As proposed by Gerber, isolated latissimus dorsi transfer with or without reverse shoulder arthroplasty is mainly to "restore control of external rotation in selected patients" rather than active external rotation itself.<ref>Gerber C, Pennington SD, Lingenfelter EJ, Sukthankar A. Reverse Delta-III total shoulder replacement combined with latissimus dorsi transfer. A preliminary report. J Bone Joint Surg Am 2007;89:940-7.</ref>

It is also important to keep in mind that the results of the open technique are superior in case of an intact or repairable subscapularis and a hypertrophic teres minor.<ref>Costouros JG, Espinosa N, Schmid MR, Gerber C. Teres minor integrity predicts outcome of latissimus dorsi tendon transfer for irreparable rotator cuff tears. J Shoulder Elbow Surg 2007;16:727-34.</ref><ref>Namdari S, Voleti P, Baldwin K, Glaser D, Huffman GR. Latissimus dorsi tendon transfer for irreparable rotator cuff tears: a systematic review. J Bone Joint Surg Am 2012;94:891-8.</ref>

In other words, latissimus dorsi transfer in D-types irreparable rotator cuff tears is efficient but only indicated in selected patients having an isolated loss of external rotation, a preserved forward elevation above 90°, an intact or repairable subscapularis an ideally a hypertrophic teres minor. Conversely, latissimus dorsi transfer gives unpredictable results in E-type latissimus dorsi transfer and potentially a L’Episcopo transfer is superior in those cases. Recently, indications and techniques have evolved and arthroscopic procedures have been proposed to hopefully limit humeral head upper migration and to restore anterior active elevation.<ref>Grimberg J, Kany J, Valenti P, Amaravathi R, Ramalingam AT. Arthroscopic-assisted latissimus dorsi tendon transfer for irreparable posterosuperior cuff tears. Arthroscopy 2015;31:599-607 e1.</ref>

The same group has observed in a prospective series of 25 patients with a follow-up of 12 months an improvement in mean Constant score from 44 points preoperatively to 65 postoperatively, a slight improvement (10 degrees) in external rotation but a radiological failure rate of 43%.<ref>Bonnevialle N, Joudet T. [Massive Rotator Cuff Lesions]. Société Francophone d'Arthroscopie. Marseille2017.</ref>

=====Posterior rotator cuff insufficiency=====
Currently, the most commonly used transfer for an irreparable type D or E massive rotator cuff tears is latissimus dorsi transfer. The ideal candidate is a patient who has maintained active anterior elevation, but lacks control of the arm in space in external rotation (simple weakness in external rotation is not a sufficient indication for surgery), and who also has an intact subscapularis and no glenohumeral arthritis. Results are disappointing in patients with subscapularis insufficiency. In addition, results have been disappointing in the setting of preoperative teres minor tears or atrophy. Gerber et al. reported long-term results at a mean of 147 months. The mean simple shoulder value (SSV) in 46 shoulders increased from 29% preoperatively to 70%, the relative Constant score improved from 56% to 80%, and the pain score improved from 7 to 13 points (p < 0.0001 for all).<ref name=":27" />

However, there is no proof that latissimus dorsi transfer gives better long-term results than a simple partial rotator cuff repair. Effectively, 60% of type E massive rotator cuff tears do not lose control of the arm in external rotation. Consequently and despite large series recently published, indications for this type of surgery are rare.<ref name=":1" />

=====Superior Capsular Reconstruction=====
Superior capsular reconstruction with either fascia lata autograft, dermal allograft patch or long head of the biceps is a solution that could prevent superior humeral head migration and restore the shoulder muscle force couples (Video of Superior Capsular Reconstruction with Long Head of the Biceps "The Chinese Way").<ref name=":3">Mihata T, Lee TQ, Watanabe C, Fukunishi K, Ohue M, Tsujimura T, Kinoshita M. Clinical results of arthroscopic superior capsule reconstruction for irreparable rotator cuff tears. Arthroscopy 2013;29:459-70.</ref><ref>Burkhart SS, Denard PJ, Adams CR, Brady PC, Hartzler RU. Arthroscopic Superior Capsular Reconstruction for Massive Irreparable Rotator Cuff Repair. Arthrosc Tech 2016;5:e1407-e18.</ref><ref>Boutsiadis A, Chen S, Jiang C, Lenoir H, Delsol P, Barth J. Long Head of the Biceps as a Suitable Available Local Tissue Autograft for Superior Capsular Reconstruction: “The Chinese Way”. Arthroscopy Techniques 2017.</ref>
[[File:1563115166796-lg.mp4|center|thumb|650x650px|Video 14.]]
The superior capsule is believed to be important in maintaining humeral head depression and compensating for the dynamic effect of the rotator cuff muscles. However, the superior capsule is an inconsistent structure constituted by a confluence a various ligaments, that is in continuity in only 27% of the cases (Video that shows an L-shape left rotator cuff lesion with an intact superior capsule).<ref>Pouliart N, Somers K, Eid S, Gagey O. Variations in the superior capsuloligamentous complex and description of a new ligament. J Shoulder Elbow Surg 2007;16:821-36.</ref>
[[File:1563119074281-lg.mp4|center|thumb|677x677px|Video 15.]]
No articles reported on the mid- or longer-term clinical and radiological results. Mihata et al. in a small series of 23 patients using fascia lata autograft found at a mean follow-up of 34 months an increased in forward flexion from 84° to 148° (P < .001) and external rotation increased from 26° to 40° (P < .01). Twenty patients (83%) at most recent follow-up had an intact graft without retear.<ref name=":3" />

Denard et al. reported in a series of 59 patients using a dermal allograft with a minimum follow-up of 1 year an increase in forward flexion from 130 degrees preoperative to 158 degrees postoperative, an improvement in American Shoulder and Elbow Surgeons (ASES) score from 44 to 78 and a 55% failure rate. In all cases, a biceps tenotomy or tenodesis was performed.<ref>Denard PJ, Brady PC, Adams CR, Tokish JM, Burkhart SS. Preliminary Results of Arthroscopic Superior Capsule Reconstruction with Dermal Allograft. Arthroscopy 2018;34:93-9.</ref>

=====Subacromial Balloon Interposition=====
The biodegradable spacer (balloon shape) is arthroscopically implanted between the acromion and the humeral head. The subacromial spacer has been designed to create a physical barrier between tissues in the subacromial space and keep the humeral head depressed when the rotator cuff is not efficient to facilitate deltoid action, thus permitting improvement in glenohumeral joint motion with significant pain reduction. At 5 years follow-up, a recent study on the subacromial spacer with an associated biceps tenotomy reported that 85% of the patients showed a clinically significant improvement of at least 15 points in Constant score, while 62% showed at least 25 points of improvement.<ref>Senekovic V, Poberaj B, Kovacic L, Mikek M, Adar E, Markovitz E, Maman E, Dekel A. The biodegradable spacer as a novel treatment modality for massive rotator cuff tears: a prospective study with 5-year follow-up. Arch Orthop Trauma Surg 2017;137:95-103.</ref>

Deranlot et al. described in a series of 37 patients (39 shoulders) a significant improvement of the Constant score from 45 preoperatively to 76 at a mean of 33 months follow-up. In their study, 92% of the shoulders also underwent a long head of biceps tenotomy.<ref>Deranlot J, Herisson O, Nourissat G, Zbili D, Werthel JD, Vigan M, Bruchou F. Arthroscopic Subacromial Spacer Implantation in Patients With Massive Irreparable Rotator Cuff Tears: Clinical and Radiographic Results of 39 Retrospectives Cases. Arthroscopy 2017;33:1639-44.</ref>

====marche pas=====

=====Biological Augmentation=====
These techniques involve using a graft (allo, auto, or xeno) or synthetic patch to bridge the defect in the rotator cuff and improve connection of the tendon remnant at least at the border of the original footprint. During this procedure, the torn rotator cuff tendons are released, mobilized, and undergo a partial repair. The graft is then sutured on top of the residual defect between the lateral margin of the medial fixed rotator cuff tendon and its native insertion site on the lateral footprint and humerus. A systematic review confirm that this approach improved function with a high rate of structural integrity rates on MRI at 12-month minimum follow-up.<ref>Lewington MR, Ferguson DP, Smith TD, Burks R, Coady C, Wong IH. Graft Utilization in the Bridging Reconstruction of Irreparable Rotator Cuff Tears: A Systematic Review. Am J Sports Med 2017;45:3149-57.</ref>

=====Achilles Tendon-Bone Block Allograft for Massive Rotator Cuff Tears With Bony Deficiency of the Greater Tuberosity=====
In patients aged >60 years, reverse shoulder arthroplasty is an acceptable solution. However, because of longevity concerns, reverse shoulder arthroplasty is not an ideal option for young patients. Achilles tendon–bone block allograft has been described as an alternative to reverse shoulder arthroplasty in a young patient with greater tuberosity and rotator cuff deficiency. There has also been growing interest in utilizing the Achilles tendon allograft for superior capsular reconstruction.

=====Reverse Shoulder Arthroplasty=====
Reverse shoulder arthroplasty has emerged as a treatment for irreparable rotator cuff tears. Two recent systematic reviews confirmed that this is a reliable procedure to improve mobility and strength, producing an improvement in pain and postoperative outcome scores.<ref>Petrillo S, Longo UG, Papalia R, Denaro V. Reverse shoulder arthroplasty for massive irreparable rotator cuff tears and cuff tear arthropathy: a systematic review. Musculoskelet Surg 2017;101:105-12.</ref><ref>Sevivas N, Ferreira N, Andrade R, Moreira P, Portugal R, Alves D, Vieira da Silva M, Sousa N, Salgado AJ, Espregueira-Mendes J. Reverse shoulder .arthroplasty for irreparable massive rotator cuff tears: a systematic review with meta-analysis and meta-regression. J Shoulder Elbow Surg 2017;26:e265-e77.</ref>

Moreover, reverse shoulder arthroplasty yielded benefits considered cost-effective when compared with other treatments, especially in elderly patients with irreparable rotator cuff tears.<ref>Kang JR, Sin AT, Cheung EV. Treatment of Massive Irreparable Rotator Cuff Tears: A Cost-effectiveness Analysis. Orthopedics 2017;40:e65-e76.</ref>

Reverse shoulder arthroplasty should be considered in older patients for whom long period of immobilization and rehabilitation is undesirable.<ref>Lädermann A, Denard PJ, Tirefort J, Collin P, Nowak A, Schwitzguebel AJ. Subscapularis- and deltoid-sparing vs traditional deltopectoral approach in reverse shoulder arthroplasty: a prospective case-control study. Journal of orthopaedic surgery and research 2017;12:112.</ref>

Even if the rate of complications was high in the two above mentioned systematic reviews, a dramatic decrease has been observed with new designs and better techniques.<ref>Lädermann A, Lo EY, Schwitzguebel AJ, Yates E. Subscapularis and deltoid preserving anterior approach for reverse shoulder arthroplasty. Orthopaedics & traumatology, surgery & research : OTSR 2016;102:905-8.</ref>

Recently, the complication rate has been reported to be lower. However, caution should still be exercised when offering reverse shoulder arthroplasty to young patient that are often disappointed by the results.<ref>Ernstbrunner L, Suter A, Catanzaro S, Rahm S, Gerber C. Reverse Total Shoulder Arthroplasty for Massive, Irreparable Rotator Cuff Tears Before the Age of 60 Years: Long-Term Results. J Bone Joint Surg Am 2017;99:1721-9.</ref><ref>Virk MS, Nicholson GP, Romeo AA. Irreparable Rotator Cuff Tears Without Arthritis Treated With Reverse Total Shoulder Arthroplasty. Open Orthop J 2016;10:296-308.</ref>

====Conclusion====
Various surgeries are proposed for similar posterosuperior irreparable rotator cuff tears and preoperative patient' clinical evaluation. There is no panacea for primary treatment and patients must be aware, in case of palliative or non-prosthetic option, of an alarming rate of structural failure (around 50%) in the short term (Table 5).

'''''Table 5: Results of the different techniques of irreparable rotator cuff tear treatment from representative series'''''
[[File:1562520882562-lg.jpg|center|thumb|720x720px|†: Constant score, ‡: American Shoulder and Elbow Surgeons (ASES) score, NA: non available.|alt=]]
The initial use of complex and expensive techniques in management of posterosuperior irreparable rotator cuff tears is actually not supported. Further prospective and comparative studies with large cohort populations and long-term follow-up are necessary to establish effectiveness of expensive or complicated procedures such as SCR, biological augmentation or subacromial spacer as reliable and useful alternative treatment for irreparable rotator cuff tears. 

==What would Codman have thought about this?==

Rupture of the supraspinatus tendon

CHAPTER V

Now that we have considered the shoulder from the anatomic and pathologic points of view, we come to the clinical study of the lesions which may be identified by special groups of symptoms as definite entities. It seems to me that the practice of medicine might be greatly simplified if an official list of clinical entities was constantly maintained by some great medical association. Our literature and our methods of medical education are greatly hampered by synonyms. McCarthy has recently pointed out in Surg. Gyn. and Obst., February, 1932, that there is great need for such a list of malignant conditions. Pathologic entities and clinical entities are not the same. Clinical entities are the practical working diagnoses on which rational treatment may be based. I feel that the Registry of Bone Sarcoma has served such a purpose so far as the nomenclature of bone tumors is concerned, and that this fact alone has done much to crystallize our working knowledge of the diagnoses and treatment of bone lesions.
I shall try in this book to make a. similar list of the lesions of the shoulder which have such distinctive characters that they may be recognized clinically and given appropriate treatment. For instance, I recognize as significant clinical entities, complete rupture of the supraspinatus tendon, partial rupture of the supraspinatus tendon, calcified deposits in the tendons of the short rotators, and tendinitis of the short rotators; and I do not recognize muscular rheumatism, neuritis, or idiopathic monarticular arthritis of the shoulder, as entities of sufficient clinical frequency or importance to make them demand special forms of treatment, although these terms are much more frequently used as diagnoses on which physicians base their therapeutics. If an official list existed I would ask to have my new entities added and the old ones at least put in small type. The reader is referred to the Index.

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CHART I

Excluding obvious diagnoses such as tumors, fractures and dislocations, most painful shoulders may be classed under the four diagnoses indicated in large type, although each entity merges into the two which adjoin it. For example, calcified deposits are probably a product of tendinitis, but if large in amount, they alter the clinical picture, both in prognosis and in the character of treatment required. If the deposits are very small, they may be negligible, and the clinical picture be that of a "frozen shoulder" due to tendinitis, lendinitis may also be confused with its other neighbor, because a "rim rent" may precipitate the inflammation which results in the frozen shoulder. In a similar way the line between partial and complete ruptures is difficult to draw; e.g., some cases of partial ruptures do not show much restriction of motion. Even complete ruptures may be confused with calcified deposits, as in Case 76, where the tendon was torn through a partially calcified area. Pathologically, too, there is some reason to believe that calcified deposits may be caused originally by small ruptures, and that the defects left after the deposits have disappeared may later lead to rupture. Nevertheless, although these entities are difficult to separate in borderline cases, typical instances are very clearly distinguished for purposes of treatment as well as in prognosis. There are also suggestive variations in sex, age, and occupation among the patients subject to these conditions.

This chapter discusses the most serious of these entities. As far as I know, I was the first writer to call attention to this lesion, and it seems to me that I can best introduce the rest of the book by reprinting here my first article, so that we may thus start at the beginning, so far as the history of this particular entity is concerned.

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Reprinted from the Boston Medical and Surgical Journal, Vol. clxiv, No. 20, pp. 708-710, May 18, 1911

COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON. OPERATIVE TREATMENT WITH REPORT OF TWO SUCCESSFUL CASES

In a paper on "Stiff and Painful Shoulders," published in the Boston Medical and Surgical Journal for May 31, 1906, in speaking of rupture of the supraspinatus tendon in connection with subacromial bursitis, I presupposed, on anatomic grounds, the probable symptoms of such rupture as follows:

"One theoretical symptom (since the supraspinatus is put out of action) should be the persistence of passive and loss of active abduction. I am not ready to say this as yet, however, because in most cases the pain is so great that spasm prevents even passive motion, and later adhesion takes the place of spasm. When rupture of the tendon does take place, it probably is only partial and a Y-shaped attachment still remains to perform part of the function. In a similar way, the quadriceps may extend the femur when the patella is broken if the lateral expansions of its tendon are not torn. Nevertheless, I believe that the active function of the supraspinatus is important in elevation of the arm."

Since this paragraph was written I have had two cases of complete rupture of the supraspinatus tendon on which I have operated, and in both of which I was able not only to demonstrate the existence of the anatomical lesion in conjunction with the above symptoms, but succeeded by suturing the tendon to the tuberosity in bringing about complete restoration of the function of abduction. I have also, in a number of cases, verified the clinical diagnosis of a partial rupture such as depicted in the accompanying figure, which was produced in the other articles which I have written on this subject. (The reader is referred to the articles appearing in the Boston Medical and Surgical Journal for Oct. 22 and 29, Nov. 5,12,19 and 26, and Dec. 3, 1908. The figure alluded to is not repeated here.)
This partial rupture is the common lesion, and, as I have explained, the remaining portion of the tendon is competent to take up the function when the sensitiveness due to the reparative process about the point of rupture has disappeared. The curious deposits of lime salts sometimes shown in the X-ray, and spoken of by Painter and Baer, are, I believe, faulty attempts at repair of these tiny ruptures of the tendon.
The following two cases are quite definite because they present complete rupture of the tendon of the supraspinatus. Therefore, the function of active abduction was almost entirely lost.

CASE 1.—Mrs. J. A. Aged fifty-two. Born in Scotland. Referred by Dr. Kent, of Dorchester, March 7, 1909.
Patient had always been a healthy, hard-working woman and had practically never been sick. On Oct. 3 of the previous year, i.e., five months before I saw her, while she was hanging recently washed clothes on the line in her yard, she endeavored to toss over a heavy blanket and felt something snap in her shoulder as she threw her arm up. She felt an intense pain and her arm fell and "hung by her side for a while." She was examined later by Dr. Kent, who found no thickening or ecchymosis. An X-ray was negative. Since then she had not been able to abduct the arm and had suffered much pain at night and somewhat during the day. The symptoms were in general those which I have described as the symptoms of adherent subacromial bursitis. The following points were, however, noticeably different.
(1) There was little atrophy of the deltoid, and it even appeared hypertrophied on account of the apparent swelling of the joint beneath. (2) Under the fibers of the deltoid, beneath the acromion and over the joint, there was a distinct deep fluctuation as if the whole bursa were full of fluid. (3) The ability to start abduction was absent, but when the arm was passively abducted to about 140°, the patient, by a strong contraction of the deltoid, could prevent the arm from falling for an instant, but the slightest downward pressure made it drop to the side. External rotation was about one-half the normal.
Operation.—March 11, 1909. Usual incision between fibers of deltoid. Roof of bursa abnormally thick with granulation-like bodies on its under surface. Escape of straw-colored fluid, about one-half ounce. The floor of the bursa was found communicating with the joint, because practically the whole supraspinatus was torn from its insertion and retracted inwards. The biceps tendon was exposed over the articular surface, but was apparently uninjured. For about one-half inch on the lower visible portion it was bright pink; the rest of it was normal in appearance. By holding the bursa wide open,
pulling down on the arm and raising the elbow from the table, the retracted end of the supraspinatus could be seen. This was caught with a tenaculum and pulled down enough to suture with four heavy silk threads to the remaining portion still attached to the tuberosity. This could not be done exactly, but was done nearly enough so that it seemed possible for repair to take place along the silk sutures. A little gap was also left on each side, which was not covered with tendon substances. It was in a sense a suture a-distance. When the operation was completed it seemed as if there was a fair possibility of the supraspinatus obtaining enough attachment to enable it to perform its function, although the base of the bursa would necessarily remain a rough instead of a smooth surface. Dr. Kent gave ether, Dr. Vincent assisting. Dr. J. J. Putnam and Dr. M. P. Smith-wick present.
June 9, 1909. Looks very strong and well. Sleeps well. Arm aches at times but not much. Pain in stormy weather (after use). Gets good use out of arm and does her own work. Can button back of dress and do her own hair. Real free abduction to 135°. Fair rotation. Muscles developing well and deltoid is strong. Very much pleased with result.
This patient was demonstrated to the Interurban Orthopedic Club, March 25, 1911. The arm is perfectly well and the function is perfect. The only abnormal sign is that the deltoid is unusually prominent due to the presence of joint fluid in the bursa.

CASE 2.—Mr. D. R. Aged forty. Hostler. Referred by Dr. John Homans, Dec. 21, 1910.
Patient is a strong, wiry Irishman. He has always been well. About three and one-half months previously, he had been saddling a horse in the stable and while tightening the girth he felt something in his shoulder give way and he fell to the floor. There was immediate loss of power in the arm, but lie managed to finish saddling the horse without raising that arm. That night he consulted Dr. Luce, of Canton, who found no ccchymosis, but thought there was slight crepitus. An X-ray a little later was negative. The hip was also hurt by his fall, so that for some time he was more bothered by that than he was by his shoulder and he was obliged to use crutches for several weeks. At the time he presented himself to me for examination the symptoms were at first sight those of the adherent type of subacromial bursitis, but on more careful examination the same signs that were present in the previous case were demonstrable, that is, (1) Relatively slight atrophy of the deltoid and an appearance of hypertrophy. (2) Fluctuation over the region of the bursa beneath the deltoid producing a "verwblbung" of the latter. (3) The persistence of nearly normal passive abduction with no active abduction. When the arm was passively abducted, the patient by a strenuous exertion of the deltoid could hold the head of the bone on the glenoid and thus prevent the arm from falling immediately. (4) In this case a distinct depression could be felt just above the tuberosity at the point where the tendon was torn away from the latter. A definite diagnosis was made and the members of the Boston Orthopedic Club invited to examine the case and witness the operation.
Operation.—Jan. 10, 1911, at the Massachusetts General Hospital.
As in the previous case, when the fibers of the deltoid.and the thickened roof of the bursa were incised, there was an escape of straw-colored fluid and the bursa was found to be in communication with the true joint. The supraspinatus had retracted so far that at first it could not be seen, and one looked directly at the articular surface of the bone with the uninjured biceps tendon lying across it. With some difficulty the supraspinatus tendon was caught with a tenaculum, freed and pulled forward. It was then sutured "a-dis-tance" to the tuberosity with heavy silk prepared with paraffine after the manner of Lange. As in the previous case, the retracted tendon could not be entirely united, but enough strands of silk were put in to make it possible for the function of the tendon to be replaced.
Convalescence was normal and the patient was not allowed to use the arm in abduction for three weeks, but since then has been using it with more or less freedom. He was shown to the Interurban Orthopedic Club on March 25, and the following condition noted at that time:
Patient is working every day—can chop wood and do other "chores" without pain. He can easily place his hand on top of his head or behind his back. Full abduction of the humerus on the scapula is, however, weak, and although he can elevate his arm, he cannot hold it in an abducted position against a downward pull of even moderate force. The strength of the arm in other respects is excellent and the patient is well satisfied. The function of the supraspinatus is fully as good as it was in Case 1, at the same length of time after the operation.
I have seen only one other case in which I have made a diagnosis of complete rupture of the supraspinatus, and as I have not been able to persuade this patient to allow me to operate, his present condition is very instructive as compared to the two cases mentioned above.
In spite of the fact that the patient is a powerful man with an extremely well-developed deltoid, he is now, four years after the injury, still unable to start abduction. As in the other cases, however, when the arm is passively abducted so that the patient's deltoid acts in the same line of force as the axis of the humerus and the remaining short rotators {i.e., subscapularis, teres minor, infraspinatus), the head of the humerus obtains a fairly firm contact with the glenoid so that the weight of the arm can be held by a great effort of will on the part of the patient. The slightest pull downward on the arm, however, will overcome what little power he has, and as soon as the fulcrum on the glenoid is lost, the arm drops to the side.
It will be necessary for those readers who are interested in this subj ect to refer to the articles mentioned above to thoroughly understand this one, but, best of all, they should look for themselves at dissecting-room subjects, because injuries to this tendon are so common that I have never had any difficulty in finding examples of it in a single set (20) of dissecting-room subjects.
The injury, as I have explained, is usually confined to a partial rupture of not more than one-quarter to one-half inch in breadth. Such complete cases as these three which I have reported are exceptional. The smaller ruptures, which are not of sufficient mechanical importance to interfere greatly with the function of the arm, are best considered with the subacromial bursitis which they cause. It must be understood that these ruptures are beneath the serous base of the bursa, which may or may not be torn through. If it is torn through, a communication is established between the bursa and the true joint.
In operating for subacromial bursitis, if on entering the bursa one finds straw-colored joint fluid, a careful search will usually demonstrate a small opening into the true joint at the point of rupture. In only one case has it seemed worth while to me to make an attempt to suture one of these small ruptures. Usually these heal satisfactorily if the inflamed portion of the bursa over them is clipped away with scissors. I am convinced, nevertheless, that suture is necessary in long-standing complete cases such as those cited above. The one which was not sutured has a decidedly impaired function and for two years was unable to work.
I have never seen the tendons of the other short rotators ruptured except in conjunction with that of the supraspinatus. Twice I have seen a longitudinal split between the tendon of the subscapularis and that of the supraspinatus. (End of 1911 paper.)

FIGURE 38. RUPTURE OF THE SUBSCAPULARIS
Sketch by Mr. Aitkin of a specimen found and prepared in the dissecting room by my former assistant, Dr. T. W. Stevenson. It illustrates a rupture of the subscapulars without rupture of the supraspinatus, and is instructive from several points of view. This is the only instance of an exception to the statement in the last paragraph which has come to my knowledge in the twenty-two intervening years. It gives a very good idea of how the insertion of the supraspinatus, which in this specimen was intact, normally fills the sulcus at the anatomic neck, and covers the tuberosity, thus leaving a perfectly smooth exterior contour beneath the base of the bursa. In this case the bursa has been thoroughly dissected away in order to show the superficial fibers of the tendons passing over the tuberosity and becoming continuous with the periosteum below. In Chapter X it will be shown how these fibers cover up and hold together the fragments in comminuted fractures.
The figure also gives a good idea of the manner in which the supraspinatus emerges from under the coraco-acromial ligament and acromion. The lower or inner edge of the muscle has been rather sharply dissected, but in the undissected specimen this edge blended with the upper portion of the subscapularis. Below this, one sees that most of the subscapularis has been torn away from the conjoined tendinous cuff, so that the biceps tendon, running through its groove between the two tuberosities, is exposed at the left edge of the gap. Internal to the biceps tendon we see the lesser tuberosity, from most of which the subscapularis fibers have been evulsed. The knobby character of the surface of the exposed tuberosity is shown; an appearance usually found in old cases where the tuberosity is exposed by evulsion of the fibers of any of the other tendons. (See frontispiece and Fig. 40.) In other words, this knobby look is the superficial appearance of the "excrescences" or "volcanoes" spoken of on page 91, and also shown in Plate V, Fig. 1.
In the upper half of the gap above the excrescences is the exposed cartilage of the joint. If this gap extended outward from the biceps tendon, instead of inward, it would represent the condition which we usually see; i.e., rupture of the supraspinatus rather than of the subscapularis. It is not unusual to find in the dissecting room extensive tears involving both tendons, but it is very unusual to find the subscapularis involved alone, as in this case. One can readily picture how easy it would be to produce such a condition as this by forcibly performing external rotation in a case of "frozen shoulder."
This diagram also gives an excellent idea of the coracoid process, coraco-clavicular and coraco-acromial ligaments, as well as of the conjoined origin of the internal or short head of the biceps, and of the cornco-brachialis muscles. It also shows the insertion of the pectoralis minor, the tendon of which protrudes as a stub at the inner side of the coracoid process in this diagram.

Although it is over twenty years since the above paper was written, I have very little of importance to add or subtract from it. I followed the two cases for many years and the results continued to be satisfactory. Although the second case never had perfect function in his shoulder, he could do all sorts of farm and stable work without complaint. As he worked for a neighbor, I had frequent opportunity to observe him for over ten years.
There is a point in the quoted paragraph which might cause confusion. At that time, 1906, I did not realize that the stooping posture was such a great help in testing mobility in the scapulo-humeral joint. One may get the impression, when examining a patient in the upright position, that scapulo-humeral adhesions exist, and yet in the stooping posture, positive proof will be given that the joint is movable. It is important for the reader to understand at once that scapulo-humeral passive mobility is a sine qua non for the diagnosis of a complete rupture of the supraspinatus, and that in the stooping posture this mobility is much less inhibited by pain and spasm. I did not fully appreciate this point in 1906, and even in 1911 I had hardly grasped it, and did not accent it enough in the above paper. It will be discussed later in this chapter.
The only other point which I desire to correct is in the next to the last paragraph. I do not think I was justified in making such a general statement as "usually these heal satisfactorily if the inflamed portion of the bursa over them is clipped away with scissors," for I am still in doubt as to how to treat the incomplete ruptures.
I have really little more than I had in 1911 to give to the profession in this book, except that repeated experience with the same signs, symptoms, operative findings and follow-up have increased my confidence in the accuracy of my former observations and opinions. During these years I have only operated upon about forty belated cases, although I have made the diagnosis over a hundred times. My results have been good but by no means perfect, because I never see these cases in their early stages, when I am sure the operations would be easy and the results entirely satisfactory. This book aims to try to teach the practicing physicians, who see the cases soon after the injury, how to recognize this lesion immediately, and to rush the patient to a competent surgeon as promptly as if the patient had a broken arm—a much less disabling accident. As in acute appendicitis, early recognition and prompt operation are of the utmost importance. The remainder of this chapter will therefore be devoted to a more detailed discussion of the symptoms.

FIGURE 39. RUPTURE OF THE SUPRASPINATUS
A schematic posterior view of a case of ruptured supraspinatus, to show the posterior short rotators and the sulcus and eminence formed where rupture of the supraspinatus has occurred. The acromion has been sawed off at its base. The reader should study the frontispiece and the next figure in connection with this one.

The size of the rent in the tendon is an important factor since the degree of the severity of each symptom may vary with the extent of the rupture. It seems best to discuss first the symptoms of those cases where the rent is large, as in the two cases which I first reported and which I have called "complete." This means that at least that portion of the conjoined tendinous insertions supplied by the supraspinatus has been torn away, with or without portions of the adjacent tendons. These are the cases which should certainly have the benefit of immediate operation. I do not at present advocate operating upon incomplete cases, for it is likely that after a few months they may heal in whole or in part. On the other hand, there is good reason to believe that the complete ruptures which make an open communication between the joint and the bursa never do heal entirely unless sutured. In other words, the symptoms have had to be pretty pronounced in order to make me willing to operate. It is significant that almost invariably the rent in the tendon has been found to be larger than anticipated. I have perhaps been over-conservative in deciding to operate, but the reader must remember that I have taken the responsibility of doing an operation which is not generally practiced, and naturally I have been somewhat cautious. It is my sincere belief, however, that a small exploratory incision is harmless and that the practice of promptly making such an incision in acute, doubtful cases is to be encouraged, provided the operator has carefully studied the anatomy of the region.
Almost all surgical operations which are now standard procedures had similar histories. Many human sacrifices were required to teach us not to delay when the symptoms strongly suggested appendicitis, perforated duodenal ulcers or intestinal obstruction. The fact that death occurs when we procrastinate in these serious cases has made us, in the public eye, more to blame for delay than for making negative explorations. The surgeon who does explorations on these injured shoulders might be criticized today and yet a few years hence be blamed for the failure to do them. Moreover, the laboring man with a shoulder injury has not yet been educated to dread this particular lesion as he has been to fear appendicitis.

FIGURE 40. X-RAY OF SPECIMEN SHOWN IN FRONTISPIECE Owing to the fact that it had been dissected, air has entered both the joint and the bursa, somewhat after the manner indicated in the cover design. It suggests appearances which we might see if we used air or opaque fluid injections in the bursa and joint. It shows a little irregularity on the surface of the tuberosity, which in the painting gives the appearance that I have called a " volcano "; i.e., a small eminence which has a craterlike place in its center. These little eminences are found in many old cases of ruptured supraspinatus. They may represent a productive osteitis due to irritation from contact with the acromion during elevation. The figure also shows two small caverns such as those illustrated in Plate V, Fig. 1 and Fig. 2. I am not sure just what these caverns indicate.

The account of symptoms given in my 1931 paper before the American College of Surgeons was presented in a twenty-minute talk, and while I still think it accurate, I am not satisfied with its arrangement nor with the amount of detail its time limit permitted. The immediate symptoms were not separated as they should have been from those that supervene later in the course of the disability. The early signs should have been emphasized, because success in treatment must depend largely on prompt diagnosis. It is easy enough to recognize one of these cases when atrophy has developed and the lapse of time has shown the persistent character of the lesion, but to make the diagnosis on the day of, or on the day after, an injury is quite another matter.
Probably insurance records would show that 80 or 90 per cent of employees complaining of shoulder "strains," return to work within three months. Certainly we could not recommend exploratory incision of the bursa in all of these cases in order to detect perhaps 10 or even 20 per cent where the rupture would be complete. When we have learned just what to do when we find minor ruptures or tendinitis, it may become wise to make such incisions as a routine, but at present the bill for negative explorations would be far too large. I contend that it is possible to detect the severe cases.

CERTAIN CONDITIONS, SYMPTOMS AND SIGNS WHICH INDICATE COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON AND WHICH SHOULD BE PRESENT WITHIN TWENTY-FOUR HOURS AFTER THE ACCIDENT.

(1) Occupation—labor.
(2) Age—over 40.
(3) No symptoms in shoulder prior to accident.
(4) Adequate injury—usually a fall.
(5) Immediate sharp, brief pain.
(6) Severe pain on following night.
(7) Loss of power in elevation of the arm.
(8) Negative X-ray.
(9) Little, if any, restriction when stooping.
(10) Faulty scapulo-humeral rhythm.
(11) A tender point,
(12) a sulcus, and
(13) an eminence
(14) at the insertion of the supraspinatus,
(15) which cause a jog,
(16) a wince and
(17) soft crepitus as the tuberosity
(18) disappears under the acromion when the arm is elevated, and usually also, as it reappears during descent of the arm.

Here are eighteen conditions to be fulfilled—an especially exacting syndrome. If such a syndrome is present I do feel that not only is exploration indicated but that it should be strongly urged, for immediate suture should be a simple and successful operation. Delay means retraction of the tendon and a much more serious problem.

I feel confident that this syndrome must exist, although I admit that I have never seen one of these cases within twenty-four hours of an injury. My best way of knowing the immediate symptoms is from the accounts of the patients or of their physicians given weeks or months after the injuries. Moreover, since these same symptoms are found at varying periods from three weeks to many years after the accidents, and do not vary much with the lapse of time, either in quality or in degree, it is likely that they were present at first. In a case in which they were all typical I should be positive of the diagnosis, and should urge operation. If several of the conditions were not fulfilled, it would influence me against operation, but if there were doubt, a negative exploration, if correctly performed, is a trivial matter, although the patient must be hospitalized in case a rupture is found.
If suture is done he should remain in the hospital for about ten days; if the exploration is negative he might well be discharged in twenty-four hours. These eighteen points will be discussed in more detail in numerical order.

(1) Occupation. The great majority of cases must belong to the laboring classes, for I have seen only one case in a person whose occupation did not or had not required heavy work. This suggests that overuse as well as increased liability to accident may be a contributory cause. The occupations are given serially in the following paragraph because if they were tabulated the list would not give the same impression of sequence which is presented by patients as they come for examination. On looking over these occupations the reader should contrast them with those in the following three paragraphs which are the occupations of patients who have had calcified deposits, tendinitis and partial rupture.

COMPLETE RUPTURE OP THE SUPRASPINATUS (100 Cases) Women 8%

Housewife, hostler, plasterer, street cleaner, housewife, coal-heaver, waiter, paper cutter, laborer, housewife, marble worker, currier, cooper, housewife, stationary engineer, two laborers, longshoreman, wrecker, teamster, two laborers, steamfitter, three laborers, truck driver, stock fitter, cook, stableman, painter, two laborers, truck driver, laborer, lineman, lather, farmer, three laborers, harness maker, wood molder, planer, electrician, plumber, mechanic's helper, laborer, roofer, laborer, longshoreman, riveter, two laborers, porter, cooper, two laborers, steamfitter, laborer, lather, steamfitter, laborer, stationary engineer, laborer, store clerk, carpenter, laborer, night watchman, longshoreman, laborer, taxi driver, lineman, laborer, painter, coal-heaver, laborer, foreman, truck driver, laborer, construction, painter, laborer, rubber worker, laborer, painter, laborer, carpenter, meat cutter, floor layer, stitcher, two laborers, housewife, foreman, laborer, store clerk, burnisher, teamster, laborer.

CALCIFIED DEPOSIT (100 Cases) Women 34%

Housewife, two no occupation, two physicians, chemist, physician, superintendent, two physicians, business, no occupation, business, manufacturer, architect, business, three physicians, milk delivery, supervisor, ironworker, housewife, filing clerk, physician, machinist, histologist, housewife, physician, business, no occupation, physician, no occupation, pipefitter, stenographer, no occupation, physician, garage, postman, business, waitress, musician, shipper, laborer, bookkeeper, machine tender, porter, teacher, laborer, housewife, broker, housewife, business, baker's helper, two salesmen, organist, weaver, housewife, shoemaker, forewoman, box-maker, two laborers, housewife, shoe machinist, farmer, housewife, advertising, paper mill, housewife, surgeon, real estate, advertising, housewife, machinist, boxmaker, store manager, wool handler, laborer, physician, truck driver, shoe worker, teacher, knitting mills, housewife, plasterer, laborer, shoe stitcher, clerical, physician, treasurer, investments, laborer, housewife, laborer, beauty parlor, manufacturer, salesman, manufacturer.

TENDINITIS (100 Cases) Women 58%

Two housewives, two no occupation, army officer, two housewives, carpenter, tailor, nurse, no occupation, tailor, nurse, business, P. O. clerk, secretary, three housewives, no occupation, physician, maid, coppersmith, merchant, housewife, jeweler, minister, harnessmaker, housewife, hostler, tailoress, storekeeper, priest, no occupation, photographer, housewife, professor, housewife, carpenter, starter, housewife, shoe laster, housewife, two no occupation, housewife, roofer, civil engineer, two housewives, cigar maker, judge, shoe manufacturer, no occupation, nurse, three housewives, physician, housewife, laborer, two housewives, physician, two housewives, store clerk, housewife, social worker, housewife, insurance broker, factory worker, two housewives, desk work, social worker, salesman, food checker, housewife, consulting engineer, banker, physician, invalid, two housewives, nurse, laundry, writer, surgeon, two housewives, two physicians, foreman, lawyer, grocer, executive secretary, nurse, public accountant, no occupation.

PARTIAL RUPTURE (100 Cases) Women 11%

Three laborers, farmer, carpenter, eight laborers, baker, plumber, laborer, housewife, two laborers, carpenter, housewife, painter, laborer, mechanic, garage, two laborers, writer, three laborers, physician, laborer, carpenter, teamster, laborer, carpenter, laborer, machinist, laborer, housewife, teamster, cook, stone mason, bricklayer, carpenter, three laborers, store, housewife, laborer, mechanic, housewife, store clerk, cook, machine oiler, laborer, two housewives, insurance, store, business, janitor, hoisting engineer, painter, meat cutter, three laborers, florist, two laborers, ironworker, nurse, gardener, shoe factory, clerk, plasterer, lawyer, laborer, no occupation, student, bartender, manager, housewife, laborer, foreman, bricklayer, horseman, two laborers, nurse, farmer, machinist, real estate, gardener, laborer, housewife, tailor.

Both occupation and sex are of importance in the diagnosis of shoulder conditions. Men who have done heavy labor are typical subjects for complete ruptures of the supraspinatus, and women of the so-called "leisure class," for tendinitis (frozen shoulder). Calcified deposits are more characteristic of the class who have gainful but not laborious occupations (the white collar class) ; i.e., they are not usually found in inactive people. Partial ruptures are also in the main characteristic of men of the laboring group, but they may occur in the more active and athletic members of the leisured class, both in men and in women.
These observations were already made from general impressions in the course of my practice, but they are in part confirmed by the above analysis of the occupations of 400 cases. The detailed accounts which each patient has given of his or her occupation and other activities, are of even greater weight in confirming my own impressions. For instance, the term housewife may apply to a woman who does all the work and washing for a large family, or to a lady who scarcely uses her arms, or to an active wife who plays golf, sends out her washing and only occasionally uses her kitchenette. The percentage of women varies greatly in the different classes, eight per cent, eleven per cent, fifty-eight per cent and thirty-four per cent. The eight cases of complete rupture and eleven of the fifteen cases of partial rupture were women whose work was really laborious. The fifty-eight tendinitis cases were chiefly women of the leisure class and the thirty-four calcified cases were active single women or wives.

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(2) Age. The four clinical entities also affect different age groups. Young persons below twenty-five seldom have any of these conditions. Apparently in young people the tendon is stronger than the bone in which it is inserted, and stresses, which in later life would break the tendon, cause fracture of the bone or separation of the tuberosity. Chart I shows that the four entities affect, in the main, persons in the latter half of life, and that the occurrence of tendinitis both of the calcified and uncalcified forms precedes the peaks of incidence of the ruptures, partial and complete, by about five to ten years. The curves of the two forms of tendinitis, calcified and uncalcified, have their peaks at the same period, but the rise of the curve is distinctly earlier in the calcified form. These facts suggest that injuries of the tendon prior to the thirtieth year either are rare or that the tendons are capable of normal repair. Then follows a period when repair is uncertain and is apt to be complicated by the deposit of calcium. Later even this incomplete repair fails.

WOMEN—CHART III

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If we chart separately the male and female cases there is a marked contrast. The curve of the female cases suggests that tendinitis, both calcified and uncalcified, may be related to the menopause or to the age when the teeth begin to loosen. By comparison of the two charts we find that calcified deposits apparently occur somewhat earlier in males than in females, and their occurrence tends to diminish at the period when they are highest in the female. The contrast of Chart II and Chart III makes it very clear that the more serious forms of rupture of the supraspinatus are characteristic of the male toward the end of his laboring days. The period of life shown in all the curves is that in which the teeth are usually in decay. If these charts are made without separating the cases in four entities the contrast between the ages of males and females is even greater, so that the coincidence with the menopause is more striking.

MEN—CHART IV

Click for large image

(3) The history of a previously painless and useful arm is unreliable for two main reasons. First,—previous troubles may have been forgotten. Men of the laboring classes put up with a great deal of soreness and pain and forget it easily. Such a matter as an attack of bursitis years before, may readily be forgotten. I would rather
have the history of previous troubles from a man's wife than from the man himself. I am inclined to think that in many cases where complete rupture has occurred, there may have been previous minor troubles, which might have indicated either partial rupture of a few fibers, or a "calcined deposit." However, my records do not show this, for in only nine of a hundred cases could a history of previous trouble be obtained.
The second reason is that men may lie as well as forget. The statements of employer and fellow workmen are sometimes more accurate than the patient's own. Patients may conceal previous trouble to avoid losing compensation.
The other shoulder should always be examined in these cases, for occasionally one finds signs of a partially ruptured tendon or of chronic bursitis there, although no complaint is made of symptoms. This would, of course, be very suggestive of preexisting disease in the injured shoulder. However, we must not forget that a rupture may occur as a bona fide injury in degenerated or diseased tendon.
(4) Adequate injury seems pretty well illustrated by the following brief accounts of the accidents in twenty-one successive cases which were proved by operation, and in seventy-nine others in which the diagnosis was made but not proved.

ACCIDENTS (Operated Supraspinatus Cases)

57. "Fell taking down an old gallery."
75. "On this date (Aug. 25, 1922) he was engaged with others in hoisting lumber, when a plank slipped off the hoist and struck him in the side knocking him down."
83. "On Jan. 17th, 1923, he fell downstairs and injured his left shoulder."
88. "On Feb. 1st, 1926, while at work he was pulling a heavy case along the floor with a hook. The hook slipped and as he caught his balance he felt something snap in his shoulder accompanied and followed by intense pain."
89. " When getting off truck caught his hand in fly wheel. Cuts of hand."
96. "On April 4th, 1927, he slipped on a concrete floor and injured his left shoulder."
97. "On Nov. 8th, 1926, he was pushing a freight car with another man, using bars. His bar slipped and he fell down wrenching his left shoulder."
98. "Six weeks ago he had slipped on the ice while at work and had injured his right shoulder. He fell on his back striking his elbow, but had no bruise on the elbow. (It is probable he threw up his arm to get his balance.)"
102. "On Nov. 2nd, 1927, he was piling some 100-lb. sacks of beans with another man who stood above him and received the sacks as he threw them up. On one throw the other man failed to connect with the sack and the entire weight came on the patient's right arm. He felt something in his shoulder snap with a sharp pain."
106. "On January 20th, 1928, he was cranking his truck, which he uses to deliver cans of ice cream. The engine backfired and he felt a sharp pain in his right shoulder."
107. "On Jan. 18th, 1928, she fell on the floor of the kitchen where she works and dislocated her left shoulder."
108. "At some time in July (date uncertain) while at work he was turning a board and felt something snap in his right upper arm about the middle, in the region of the long head of the biceps. There was a sharp pain which went away in a few minutes."
112. "On March 10, 1928, he was wheeling a barrow up into a barn when he slipped and fell forward on the barrow, but did not let go of the handles."
115. "On August 21st, 1928, about 1.30 P.M., slipped and fell from piazza roof, striking the edge of the piazza floor with his right arm in abduction. Had immediate pain in shoulder and arm."
119. "Day before Thanksgiving, Nov., 1928, fell off staging three feet high. Walked backwards off."
123. "On Jan. 14th, 1929, he slipped on an icy platform and hit on his left elbow."
127. "On Oct. 17, 1929, was handling 2x4 lumber and stepped in a hole. Fell against left shoulder on pile of lumber, hitting on elbow."
128. "He slipped on the ice near a building and fell, striking the side of his right shoulder against a low step. This is what he says, but such a fall as that would probably be impossible. It is more likely that he threw his arm up as he fell."
129. "On October 24th, while piling some pipe, he was standing on a pile of pipe which rolled under his feet and he fell between two piles of pipes."
185. "He slipped on the ice and fell. After he got up, he found that he could not raise the left arm."
137. "On May 13, 1930, he had a fracture near the left elbow which healed satisfactorily and he went back to work about September 1st. On October 7th, in Andover, he fell and dislocated his left shoulder."

ACCIDENTS (Unoperated Supraspinatus Cases)

". . . he was doing some overhead work standing on a support twelve or fifteen inches high. The support slipped and he fell on his right hand and elbow, and then forward on his shoulder." ". . . he was pulling on a rope which suddenly gave way. He fell to the ground with his right arm below and behind him. He felt a sharp pain in the shoulder as if a bone had broken." ". . . he fell about ten feet while at work and injured his shoulder." ". . . he had been hit by an automobile, knocked down and taken to the Boston City Hospital. His shoulder had been injured." ". . . he was cranking his truck, and had a kick back. He thinks the handle struck him on the lower part of his upper right arm, but his shoulder was w.renched." "... when walking in a dark passageway, he stepped over some steps and in trying to save himself caught with his left arm on the wall, but kept his feet. He had a violent pain in his left shoulder but pulled himself together and went to his next job." ". .. he was struck on the left shoulder by a falling bale of hemp while at work. He was knocked down and much shaken up, but pulled himself together and continued to work the rest of the afternoon with his right hand." "Fell off wagon when unloading barrels. Hurt badly at time and went to Camb. Relief Hosp." ". . . he was lifting a barrel and something snapped in his shoulder, since which he has been unable to work." ". . . he tripped on a rolling log and fell injuring his left shoulder." ". . . he fell down some stairs and injured his right shoulder." ". . . the employee slipped on a loose plank and injured his left shoulder and right foot." ". . . he was pulling on a chain fall and something slipped in the right shoulder." ". . . he was jammed between a moving truck and the side of a building. Fortunately, he was near the corner of the building and the moving truck carried him around the corner, squeezing him from side to side as it did so. His left arm immediately became powerless." ". . . he fell from a staging and injured his right shoulder and has not yet recovered the use of it for anything requiring the function of abduction." ". . . he was filling a wagon with coal when the horses started and he fell in between the wagon and the side of the coal-pocket." ". . . he fell forward at the top of a flight of stairs and injured his shoulder as he supposed by hitting some beams." "A frame which he was moving dropped and to prevent it striking his feet stepped aside, losing his balance and falling to the floor." ". . . she felt something snap in her shoulder (left) when raising some wet clothes on a pole to put them in a laundry machine." ". . . while raking grass on a steep bank, he slipped and injured his left shoulder." ". . . as he was stepping out of a tip cart on the hub of the wheel, he slipped and fell heavily to the ground injuring his left shoulder and also his right shoulder to some extent." ". . . the employee was carrying a plank with another man, when one of the planks on which he was walking gave way, letting part of his body through the pier so that he sustained injuries to his left shoulder, arm and leg." ". . . she fell over a bag of soles and injured her right shoulder." ". . . he slipped off a plank and fell headlong to the floor, about four feet." ". . . large heavy car six or eight feet on the side. On this occasion the car skipped the track in spite of his efforts to prevent it, striking him on the left arm." ". . . he says that he was using his truck to load heavy rubber bales weighing about 350 lbs. each. He had put the edge of his truck under one such bale and reached forward with his right hand to pull the bale toward him on to the truck. As he pulled, he felt something give in his right shoulder." ". . . he was helping with other men, to pull a heavy truck, when he felt something give way in his right shoulder." "He was carrying a roll of leather and fell on the floor in the room where he usually worked." ". . . he fell from his truck and injured his left shoulder." ". . . he fell thirty feet from a staging and was badly bruised all over." ". . . he was on a lumber pile helping to load a truck. He was using a pick to drag the lumber. The pick slipped and he felt a sudden pain and something snapped in his arm at the right shoulder. His arm fell limp at his side." ". . . he slipped on some stairs and injured his left shoulder. . . ." ". . . fell among some barrels in the hold of a vessel and struck his right shoulder again." Had had previous similar accident six years ago, and never full use of arm since. ". . . while working in a meat market in Nantucket, he slipped on going out of the ice chest and injured his right shoulder." ". . . while carrying rubbish on an incline in the factory where he works, he fell and injured his right shoulder. As he says, 'it went dead immediately.'" "He was piling wool at the time, lost his balance and fell from one bale to some other bales not far below. As he fell he felt something snap in his shoulder which did not hurt him very badly at the time. . . ." ". . . slipped on ice in street." ". . . while working on a flat-car he fell and struck his right shoulder on the side of the car." "While at work in the factory in Lawrence ... he was in an elevator holding a heavy plank in both hands to steady it. One end of the plank was on the floor of the elevator and it stood vertically. Some one below started the elevator downward and then upward. As it went up it thrust the top of the plank violently against the top of the well. This shattered the heavy plank just above his hands with extreme violence and he was thrown into the corner of the car in a heap." ". . . he fell off the back of a load of straw and injured his shoulder." ". . . he again fell downstairs—only a few steps—and again injured his right shoulder." " Slipped and fell, and a box or case fell over on him." ". . . while directing some work where a floor was being replaced and the boards were up, he tripped on a beam and fell on his right side against another beam, probably breaking some ribs." ". . . he received an injury to his left shoulder when trying to move a large rock with a pitchfork. He felt something snap in his shoulder joint and suffered a sharp, severe pain at the same time." "He injured his right shoulder by falling from a truck." ". . . he was pulling some lumber off a truck and when it slid off quicker than he expected he fell backward and injured his left shoulder." ". . . he fell four feet, striking on the pavement, and inj ured his left shoulder." "... he slipped on an oily floor, and hurt his right shoulder and left shin." ". . . he fell from a staging about six feet to the floor below, and injured his right shoulder." ". . . he fell from a ladder and sustained injuries to the left shoulder and ribs." ". . . he was on a roof sawing a plank, and was standing on an extension ladder, which fell with him thirty-one feet to the ground. His right shoulder was injured, and his nose was cut" "Strap from machine fell off wheel and hit patient on right shoulder." ". . . he was working with others on a bridge in Rumford, Maine, helping to receive some cement in a frame from a bucket. In some manner, the bucket swung in the wrong direction and the patient fell from the bridge a distance of fifty feet." ". . . he was lifting a concrete block and felt something give in his left shoulder." ". . . he fell injuring his left shoulder." ". . . he had started to crank a hoisting truck when the starter began to work and the crank flew round and struck him on the right shoulder." "Slipped on ice." "Fell yesterday and sustained a contusion over outer end of right clavicle." ". . . while helping to unload a truck, a derrick knocked down a platform above him, and something, probably a heavy plank, fell on him and others working with him. He was knocked out by the blow, and cannot describe exactly the manner in which the plank struck him, but he knows it injured his shoulder and elbow and there was blood streaming down his arm." "He was pulling hard on a gunny sack, which gave way, and he fell over and thinks he struck his right shoulder." ". . . she tripped and fell on the floor at her work. She dislocated her right shoulder, bruised her knees severely and cut her face." "He was standing on stony ground swinging a sledge hammer, when he had to step back quickly. As he did so, he lost his footing and the sledge hammer, which he was swinging, carried on around his body so that his left shoulder was in an awkward position. He felt something snap in the left shoulder."

One may interpret the mechanism which produces this injury in several ways, but a sudden character is common to all of the accidents, which are generally falls. It is my belief that the rupture usually takes place from sudden elevation of the arm in attempting to regain balance, particularly if the hand is at the same time grasping a heavy object. Under these conditions a tremendous strain must be suddenly thrown on this little tendon as it attempts to quickly overcome the inertia of the arm, and perhaps, in addition, that of some heavy object held in the hand. In my first case, the woman attempted to throw a heavy, wet blanket over a clothes-line. It seems to me that this case, like a "slowed down movie," typifies the kind of strain which occurred in most of the other accidents. I believe that the even more sudden effort to regain balance during a fall caused the damage, probably before the patients struck the ground. For anatomic reasons one cannot, in falling, strike on the supraspinatus, because it is protected by the acromion.
Undoubtedly, however, in some cases, the tendon may have been torn in conjunction with dislocations, because of the leverage of the humerus on the fulcrum of the acromion. This mechanism will be explained in Chapter IX.

(5) A sharp pain in the shoulder at the time of the accident is almost always spoken of, although occasionally complaint of it is not volunteered. Sometimes patients say that they have felt something actually snap and think that they have broken a bone. Sometimes they feel that something has struck them on the shoulder. It has been explained on page 9 in the chapter on anatomy that histories of striking on the head of the humerus are unreliable because the acromion intervenes, and on page 144 that in falling, the arm is usually raised before the top of the shoulder can strike the ground. Consequently it seems to me that these tendons must usually be ruptured by indirect violence or sudden efforts of the muscles to overcome the inertia of the dependent arm, especially if there is a weight as a pick or shovel in the hand at the time, or the hand grasps something to save the man a fall. Often the fall is so sudden and the man so confused that the only thing he can understand is that he has hurt his shoulder and attributes the pain to having hit something as he fell.

(6) So far as I can judge from histories, there is then usually an interim of a few hours after the acute, immediate pain has somewhat subsided before the more severe pain comes on. Often the employee does not even consult a doctor at once, but tries to work the day out, favoring his arm. Perhaps he does not report the accident to his foreman. In the evening the pain becomes worse, and later in the night intolerable. He calls the doctor, or sits up in a chair, or "walks the floor." Next day he is pretty sure to report that he cannot work, but may persuade an accommodating foreman to let him "hang around" for a day or two until he gets better. These patients usually think the injury of no great consequence and expect "to have it wear off." This hopefulness is generally confirmed by the doctor's opinion, who perhaps may never have heard that such lesions occur. This attitude of mind of both patient and doctor is the main cause of delay in diagnosis and appropriate treatment.
It seems to me that the following theory is the probable explanation of the interim between the sharp pain when rupture occurs and the intense pain which appears some hours later. These tendons are not very vascular, and when they tear, there is probably very little bleeding; what there is, would come from the tissue between the bursa and the tendon. The interim spoken of would come during the period it would take this slight hemorrhage to distend the joint and bursa somewhat, i.e., enough to start a tension pain. This would create some spasm, and the tension caused by this would stop the slight bleeding. It would take several nights or perhaps a week for tension and spasm to subside and the hemorrhage to absorb. During this period the acute pain would continue.

(7) Inability to raise the arm is a constant symptom, but one must be on guard not to mistake unwillingness for inability. After almost any shoulder injury there may be pain when attempt is made to raise the arm, owing to the fact that the head of the humerus has to be forced upward to gain its fulcrum on the glenoid. The mere fact that the muscles have to exert tension to do this, causes pain in whatever structure about the shoulder may be injured. Therefore, the examiner must be sure that an honest effort is made to ignore the pain and elevate the humerus. It takes experience to tell whether such an effort is made, and one judges it by the degree of tension palpable in the deltoid. Even in the case of trivial injuries, such as ruptures of a few fibers of the supra- or infraspinatus, the symptom of inability to raise the arm may be pronounced, simply from the fact that the power to exert the appropriate muscles is inhibited by sensitiveness to pain. As explained on page 59, the deltoid needs the assistance of the supraspinatus and of the short rotators to hold the head of the bone on its fulcrum in order to have proper direction for its power; If the supraspinatus is torn, contraction of the deltoid brings the arm upward on the vertical axis of the humerus, and the amount the shoulder is raised will depend on the amount that the scapula, moving via the. sterno-clavicular joint and at the acromio-clavicular joint, can rise and rotate on the chest wall.
Formerly I thought that it was necessary to have this symptom of inability to raise the arm absolutely demonstrable in order to make the diagnosis of rupture of the supraspinatus, but experience has shown that, even when the supraspinatus is torn across its full width, the other short rotators can sometimes hold the head of the humerus on its fulcrum sufficiently to permit the patient to weakly perform elevation. However, as will be explained under No. 10, this elevation is never accomplished with a normal scapulo-humeral rhythm.

(8) A negative X-ray is almost always reported after these in juries. I believe that in the near future we shall be able to make the X-ray of more use in this diagnosis, either by using injections into the joint of non-radiable fluid, or by developing a soft tissue technique which will show the rupture. However, at present, negative X-rays are the rule, for ruptures which do not involve the bony facet of insertion are not shown in the film. A negative X-ray is of some positive importance, however, for it rules out the two conditions which are likely to make confusion in the diagnosis, that is, fracture of the
greater tuberosity and the presence of calcified material in the tendon. In long-standing cases changes in the structure of the trabec-ulae of the tuberosity which may be shown by the X-ray do take place. These are described on page 92.

(9) In the symptom complex of this condition, lack of restriction of motion takes a very important part, and this lack of restriction can be best determined when the patient is stooping from the hips with the knees extended. The patient should stoop (Fig. 47) to the horizontal position, letting the arms hang loosely toward the floor. In this position the deltoid is relaxed and there is no fulcrum needed in order to have the arm passively raised, i.e.-, brought forward into complete elevation (quadruped extension) ; in fact, even if this is not passively done, the patient has to exert but little muscular power
to swing the arm forward into this position. This he is usually able to do without much pain. The examiner may then hold one hand on the scapula and with the other raise the lower end of the humerus, so that he takes the full weight of the arm and permits the patient to stand upright with the arm still in complete elevation. Such a procedure eifectually rules out restriction from adhesions. Even if the supraspinatus is torn, the patient can retain the arm in this up right position. If he stoops again he can lower it without much pain, and then if he rises to the upright position with the arm relaxed,
the humerus will, by gravity alone, come into its normal position at the side of the body.
When I say that lack of restriction is an essential symptom, I must not be taken too literally, for there is often, in fact usually, in these cases, a very little restriction in extreme elevation and in rotation, probably due to the presence of fluid.

(10) Faulty scapulo-humeral rhythm is a sine qua non for this diagnosis. When one sees a patient who in raising the arm lets it ascend to the horizontal while maintaining (quadruped) flexion of the scapulo-humeral joint, and then slowly and painfully (perhaps with a little help) proceeds to complete elevation by motion in the scapulo-humeral joint, and finds that when the patient 'allows the arm to descend, he keeps the scapula and humerus fixed in (quadruped) extension until he reaches the horizontal, and then quickly flexes it, a presumptive diagnosis oi rupture of the supraspinatus
can be made. Ascent in flexion, descent in extension, might be a slogan for students to learn in this connection. To express this lack of scapulo-humeral rhythm in other words, we may say that the normal ratios of the movements of the joints in elevating the arm, explained on page 59, disappear. Instead, in the first part of the movement only the motions of the scapula on the chest wall are concerned; then the relations of the humerus and scapula change, wholly above the horizontal. In the descent of the arm the reverse is the case—no scapulohumeral motion takes place above the horizontal, but all below it. While the symptom is a sine qua non to the diagnosis of complete rupture of the supraspinatus, it is also present in most cases of minor ruptures and in many cases of calcified deposits. It therefore is an indispensable but not a pathognomonic sign.

(11) The tender or sensitive point is not complained of by the patient as a rule, and in fact he is unconscious of its exact location until the examiner finds it, when he usually says: "You have your finger right on it." Without your aid in locating it he will perhaps know that there is a tender point, but locate it deep under the acromion or even in the spasmodic deltoid muscle down near its point of insertion. In fact, the lower portion of the deltoid is usually also tender. Examination of this part of this muscle in all these patients nearly always shows that there is some thickening and sensitiveness, as compared to the normal side. In the old, chronic cases the sensitiveness at the point of rupture may not be very noticeable, and even when the exact point is pressed the patient will hardly admit that it is tender. Presumably in fresh cases it would be especially sensitive.

FIGURE 41. POSITION OF HANDS FOR EXAMINATION OF SHOULDER

The left thumb lies along the depression below the spine of the scapula and the tip of the forefinger is just anterior to the acromion. The other three fingers cross and hold the clavicle. Thus the shoulder girdle is firmly held and any motion of the scapulo-humeral joint is at once detected.

In speaking of the 11th, one is necessarily obliged to consider the remaining symptoms, since the tender point is at the gap between the ends of the torn tendon, and this gap is the reason for the sulcus and eminence, which may be felt just anterior to the edge of the acromion, when the arm is in dorsal flexion. If the examiner remembers his anatomy, the tender point, sulcus and eminence will be found to be at or near the insertion of the tendon of the supraspinatus. It is the passing of this irregular sulcus and eminence under the acromion and acromio-clavicular ligament which causes a jog, a wince, and a soft crepitus, as the sensitive, irregular base of the bursa disappears under the acromion when the arm is brought forward by the examiner. The two figures (41 and 42) present the condition, it seems to me, more vividly than could any description. However, I will give a few brief additional points under each one of the remaining headings.

FIGURE 42. TIP OF FINGER PRESSING ON EMINENCE AND ON SULCUS
The plane of this diagram is halfway between the coronal and sagittal.It is, perhaps, the most important diagram in the book for the reader entirely to understand, for it is the ability to put the finger in this position which enables one to make the clinical diagnosis of rupture of the supraspinatus tendon. The dotted line represents the contour of the bursa. Compare this with Figure 44, which shows the contour of the bursa when filled with the calcified material, and also with Plate II, Fig.3, which shows a large calcified deposit in exactly the situation in which the rupture lies in this diagram. In this one the sulcus is immediately under the tip of the finger and the' eminence just external to it, but in Figure 3 the eminence would be just under the finger. Therefore, as explained on page 148, the tender point in a case of rupture is represented by a depression, but in cases of calcified deposit, by an eminence at the corresponding position.

(12) The sulcus is just about big enough to be filled by the tip of the finger, as indicated in the diagram. It is nearly always found to be larger at operation than one would guess from palpation before incision.

(13) The eminence is an eminence only by contrast with the sulcus. It consists of normal tuberosity with perhaps a remnant of the tendon attached to it. In elderly men without injury to the shoulder one can often feel the tuberosity because the tendon is more or less atrophied, so that at times it is hard to be sure whether the tendon is torn or merely atrophic. However, in most cases of ruptured supraspinatus the eminence is conspicuously large and one is quite sure of its existence. It is well to say here that the eminence which is found in cases of calcified deposit is not on the tuberosity itself, but proximal to the tuberosity in the tendon at just the point where ruptures so often occur. Furthermore, the tenderness is usually greater on the eminence in cases of calcified deposit than it is on the eminence in the cases we are speaking of.

(14) As may be seen under Pathology, the supraspinatus is nearly always torn if any of the other short rotators are, but it is very common to have portions of the adjacent tendons torn, so that the tenderness, eminence and sulcus may be a little internal or external to the mid-point of the insertion of the supraspinatus itself. This latter may be determined pretty accurately by placing the forearm in flexion and drawing a line from the mid-point of the flexure of the elbow to the mid-point of the head of the humerus. The bicipital groove lies about its own width external to this line, and the supraspinatus is on the top of this line and to the outer side of it for about three-quarters of an inch. The insertion of the infraspinatus is just external and also partly in front of that of the supraspinatus, for, as explained in Fig. 6, the two insertions nearly cross each other. The insertion of the teres will be found nearly exactly on the mid-point of the head of the humerus on its outer aspect. Be careful, in determining this, that the forearm is flexed at. the elbow and held straight forward. The insertion of the subscapu-laris can be determined by putting the arm in the anatomic position and placing the examiner's forefinger just external to the tip of the coracoid process, which is always palpable, as shown in Fig. 6.

(15) The jog is noticeable to the patient himself, and sometimes is visible as well as palpable to the examiner.

(16) The patient nearly always winces as the jog occurs, but in long-standing cases he may not do so.

(17) The soft crepitus is not like the crepitus in fractures. It is of a more velvety, gristly character. When one has become familiar with it, it is easily distinguished from the kind of crepitus often found in the shoulders of old working men, which resembles the crepitus one frequently feels over the prepatclla and olecranon bursas and about the other joints.

(18) When the sulcus, eminence and tender point have once passed beneath the acromion as the arm is elevated, there is a sense of relief on the part of the patient which is usually apparent in his countenance. When the arm is almost fully elevated (there is often so much fluid in the joint and bursa that absolutely complete elevation is not attained), the patient is relatively comfortable. His pain will appear again when flexion occurs at the level of the shoulder, after the arm has descended with humerus and scapula locked, to a horizontal position. At this time the jog and crepitus are usually again palpable. As this occurs the patient leans toward the affected side and lowers the whole arm quite suddenly.
These eighteen symptoms must be present soon after the accident, but the difficulty is to estimate the degree of the rupture at this time. Partial ruptures must give much the same symptoms as complete ones at this stage, and the degree of spasm must vary, as well as the courage of the patient as he makes a voluntary effort to raise the arm. Immediate diagnosis cannot be easy at this stage. However, the progress of the case makes the diagnosis easier and easier, although valuable time elapses. If exploration is not done these symptoms remain the same and the following points in the course of the case will tend to confirm the diagnosis.

Character of Pain. Practically every patient whom I have seen has given the history that during the first few nights after the accident the pain was severe or intense. Gradually this severe pain changes to a nagging, annoying one, sufficient to greatly interfere with the night's rest, but bearable without drugs. It is usually located near the deltoid insertion far below the actual lesion. Pain of this character continues week after week and with but little change for many months. It is aggravated by the attempt to work, and the patient's resistance to it is gradually lowered as he becomes more and more worn out by restless, painful nights. I am convinced that this pain is very severe as well as prolonged, for I have heard many strong laboring men state that they have never suffered such pain in their lives. It is more the persistence of it than the pain at any one time which wears them out. They often say: "If I could only get a good night's rest I could work during the day." Practically they find that working during the day gives them bad nights, and therefore nearly all of them, in spite of their courage, give up work after a time. Of the series of a hundred cases, only eighteen stated that they had worked for even a brief period. They say that they may go to sleep for a while, but wake with pain in the shoulder or in the region of the insertion of the deltoid, and that they have great difficulty in getting the arm into a comfortable position again. When they do, they go to sleep only to wake up in a few hours for another change of position. Sometimes they get up and walk about or apply hot water bags or other household remedies. It is very characteristic of these cases to have complaint of pain out of proportion to the physical signs, and therefore they receive little sympathy.

Atrophy of the spinati, as shown by prominence of the spine of the scapula, always occurs after these injuries, but does not appear for about three weeks. After it has once appeared it persists, and is apparent for a long time even in the operated cases.
In very few of the cases that I have seen years after the injury was it absent. The atrophy may be more conspicuous in the infraspinatus, which is the larger muscle. Whether the fact that the infraspinatus is always also atrophied, is due to the crossing of its fibers of insertion with those of the supraspinatus so that they are always also torn to some degree, or is due to the fact that the two muscles are supplied by the same nerve, i.e., the suprascapular, I do not know, but it is a fact that atrophy of both is a constant sign. Of course atrophy of these muscles occurs in any chronic condition of real severity affecting a shoulder joint, so that the presence of atrophy does not necessarily indicate this diagnosis, but its absence would he strong evidence against it. In a few long-standing cases I have seen only a small amount of atrophy. It is usually very pronounced. As a rule the deltoid is not much atrophied and may even be hypertrophied.
The general condition of the patient is a factor in diagnosis, for he gets into a vicious circle. He is out of work so that all the muscles of his body become enfeebled. He often cannot afford good food, and he may, therefore, be ill-nourished. Add to this the constant depletion of his energy from restless, painful nights, and we may readily account for the fact that while previously he was a strong, healthy man, he now appears haggard and unhappy.
The mental condition also is poor, for worry on account of inability to work, and that he may never be able to work again, is enhanced by the fact that the physician he consults is unable to tell him the cause of his trouble, and all attempts to relieve him by ordinary remedies absolutely fail. Seeing these cases months after their accident, I am frequently told, "Nothing they have done has done it any good."
The actual physical deterioration from worry is still further aggravated by the doubt that is thrown on their veracity by the physicians employed by the insurer. Usually by the time they are sent to see me some months later, their attitude of mind is defensive, and they at once begin to express their disgust with being told that they ought to go to work and think less about the pain.
This attitude of mind becomes still worse when they are actually accused of hysteria or malingering. They say they want to work. "Do you think I would lie around like this if I could earn $24.00 a week?" They become embittered at their treatment by society in general in spite of the fact that they may still be receiving their compensation.
At length they may lose their self-respect, and brooding over their hard luck take to drink. My second patient was such a case. He had had a good job which he enjoyed; after his injury became discouraged, and evidently decided to let things go and to use up what money he had saved, in drinking as much as he had a mind to. The person for whom he formerly worked, instead of losing sight of him, looked him up, and, realizing that he must have some real trouble with the shoulder, sent him to a doctor who referred him to me. The result of the repair of his tendon was not only that he was able to work, but that he refrained from drinking and worked for ten or more years for the same people who formerly employed him.
Unfortunately the attitude of the relatives of such an old man with a disabled shoulder is apt to become somewhat like that of the doctors who have been unable to diagnose and relieve him. His own family after a while get to think of him as a burden, and since they can see nothing the matter, such as a limp or a deformity, are inclined also to think that he has "laid down" before his time. In recent years, however, we see more signs of sympathy, for the compensation such patients may receive will perhaps be the chief support of the family.
Undoubtedly many such cases eventually turn up as recipients of charity and eventually die in state institutions. It is not surprising to me that the material reported in this book, which was accumulated by Dr. Akerson at a hospital for the indigent, shows such a high percentage of instances of these lesions.
I would venture to predict that if one should see the patients who are chronic nuisances to industrial insurance boards, and the physicians connected with the administration of compensation for industrial injuries, most of those complaining of shoulder disability would have this particular lesion.

Some patients may continue to work. There are rare individuals who, in spite of the disability, have the courage and otherwise sound health to continue to work in spite of the soreness, awkwardness, loss of power, and painful and restless nights. About one-fifth of my series attempted to work for a time before they gave in and sought compensation. I have no doubt that there are others who have never given in.
This is a lesion which tries a man's character, and, since it usually occurs in later life, is often the cause of permanent incapacity, for even if the use of the arm returns in good measure at the end of a year, the patient's habit of work has been destroyed, his muscles have become soft. If he has the courage to go to work again, he will find it difficult to get a job. Those courageous men who do work in spite of the lesion, become more or less free of serious symptoms in from two to five years. As has been explained under Pathology, compensatory changes take place so that the eminence absorbs, the sulcus partially fills, and an excess of fluid allays friction. After several years even the night discomfort disappears, and weakness in abduction, atrophy of the spinati, friction rubs, the fluid sign and occasional pain in certain positions may be the only aftermaths of the injury.

Hypertrophy of the Deltoid. Perhaps it would be better to make this heading "well-developed deltoid as contrasted to the spinati," for the hypertrophy is not striking except when compared to the condition of the spinati. It is a fact that, in the long-standing cases, the deltoid itself is as well developed, or even more so, than that of the other side. I explain this because it has to do most of the abducting work of the arm unaided by the supraspinatus. It not only misses its help, but acts at a disadvantage as explained in Fig. 3. Hence it retains its development or even hypertrophies. My third case had a deltoid like a ham, but at the end of five years he could only feebly perform abduction and could not raise even a slight weight in that hand above his head. He had refused operation.

The Fluid Sign. Among the auxiliary signs and symptoms I find some help from what I call "the fluid sign." I had studied shoulders for many years before I realized how fluid in the true shoulder joint behaves. When the arm is by the side, the fluid sags in the relaxed axillary portion of the capsule. When the arm is elevated the axillary portion of the capsule is stretched tightly below the rounded head of the bone, and the fluid is driven upward where the capsule is now relaxed. In case there is a rupture of the supra-spinatus tendon, the fluid is forced through the gap and distends the bursa in the subdeltoid portion beneath the upper fibers of the deltoid.
Stand behind one of these patients, who is holding both arms as straight as he can toward the ceiling, and you will see that the contours of the two shoulders are quite different. When there is a considerable amount of synovial secretion, absolute complete elevation of the arm is prevented by the mass of fluid. Another interesting point is that when there is fluid the friction is largely prevented as the arm is elevated. When it subsides pain reappears. This phantom improvement by the formation of fluid is not uncommon.
Patients who continue to work in spite of their pain develop fluid, as do people with various affections of the knee. The fluid continually pumping in and out of the bursa dilates it and a true hydrops may result (p. 478). One finds in long-standing cases that the bursa is very large. (See case Fig. 44.) Some fluid, from a dram to an ounce, is a constant operative finding in these cases. It may not be noticed when the bursa is first opened, but if one elevates the arm and puts the axillary portion of the capsule on the stretch, the thick, straw-colored fluid runs out of the wound. Sometimes there is enough to distend the bursa even in the anatomic position, and when the first incision into the bursa is made, it obscures the field and has to be sponged out.
This behavior of the fluid was forced on my attention when I used to put the arm in abduction after suture. This caused the weeping wounds described on p. 248, and this serious and annoying complication led me to reason out the facts.

INCOMPLETE RUPTURE

Although there is no sharp anatomic distinction between complete and incomplete rupture, there is the practical one that cases of the former will not recover completely unless the tendon is sutured, while cases of the latter may heal in a natural manner. One which is typically complete involves the whole supraspinatus tendon, with perhaps parts of the adj acent tendons. One which is typical of the incomplete form need neither involve the whole width nor run through the whole thickness of the tendon. In its minimum phase it may be only an evulsion of a few fibers from the tuberosity; in its maximum phase it would be a borderline case of complete rupture. In its acute phase it may be definitely due to trauma; in its chronic phase the tendinitis overshadows the traumatic history.
The reader who has the patience to finish this book will inevitably remain confused about the lines of distinction which I have attempted to draw among the six most common clinical entities which affect the shoulder, i.e., complete and incomplete tendon ruptures, rim rents, calcified deposits, tendinitis and arthritis. In fact, I must leave the reader puzzled, for I am still puzzled myself. I can only confront him with the puzzle—show him that there is a puzzle. Personally, I believe that these rim rents and incomplete ruptures are the cause of the great majority of sore shoulders, and yet I believe they usually occur in degenerated tendons. For example, a man might have degenerative changes in both shoulders without symptoms and then, after trauma to one tendon, have severe local symptoms without any signs of trouble in the other shoulder.
One cannot even divide complete and incomplete lesions by the criterion of whether or not there is a direct communication from the bursa to the joint through the rupture, for the size of the opening is important also. Yet splitting hairs on a definition is not worth while. Practically, it is convenient to say that when one opens the roof of the bursa and finds the cartilage of the joint exposed to view through a rent in the floor of the bursa, we are dealing with a complete rupture. If there is no communication at all or only a small hole in the base of the bursa, we would class the case as incomplete. Of course the persistence of a direct communication between the joint and the bursa, even if small, is a most important point, because it alters the mechanics, as indicated on the cover of this book. Yet the size of the hole is also important if it is large enough to permit erosion of the joint cartilage (Plate VII, Fig. 8) by friction on the acromion.
It seems to me highly probable that incomplete rupture is much more common than complete. Since I have only operated upon cases where very pronounced symptoms existed, I have naturally found many more instances of the complete form, but in my observations on the cadaver, or on living cases in the clinic, I have much more often found incomplete lesions. I have not kept a numerical account and therefore cannot give the exact number or even the proportion.
Dr. Akerson's statistics give the best measure we have, but are subject to the criticisms on page 65. Similar observations may be made by any one having access to autopsy material. Moreover, when the economic importance of this lesion is appreciated, and the principles of efficiency become applied to the practice of medicine, such observations must be made.
I am inclined to think the table on page 469 also gives a low proportion of the incomplete ruptures, because so many cases in the other classes probably had this lesion besides the lesion which caused their classification. For instance, rupture of the supraspinatus is a not uncommon complication of dislocation and of circumflex paralysis, and many of the minor unclassified cases may have also been instances of this lesion. On the other hand, I have usually found at operation that the rupture was more extensive than I had previously thought, so that a good proportion of the supposed incomplete type may have been complete.
Referring to the chapter on Pathology, it will be seen that incomplete ruptures of four kinds are described:
(a) A few of the lower fibers on the joint side, together with the synovial reflection, may be torn out; these I call "rim rents."
(b) Some of the central fibers may be parted without tearing either the joint side or the bursal side of the tendon.
(c) The rupture may extend vertically through the whole tendon, making a communication between the joint and the bursa, without involving the whole breadth of the tendon.
(d) The fibers on the bursal side may be eroded without complete communication with the joint.
I believe that type (a) is synonymous with the cases so frequently found at autopsy where the sulcus is bare and eburnated, i.e., the condition I speak of as "rim rents." I think that type (b) may be the precursor of calcified deposits. Types (c) and (d) may be among the cases which give "tendinitis" symptoms out of proportion to the traumatic history.
Since I do not intentionally operate on incomplete ruptures, what I have to say in regard to these minor lesions is more theoretic than what has been stated concerning the complete ruptures.
All four varieties should be distinguished from the complete form by the persistence of considerable power in elevation, because the mechanics of the pull of the supraspinatus are not greatly altered. I have not operated unless there was decided loss of power.
The other cardinal symptoms, jog, crepitus, atrophy, sulcus, eminence and local tenderness, will be present, although any one of them or all of them may be found in less pronounced degree than in the complete cases. Type (c) might be recognizable, as the fluid sign should be present because joint and bursa communicate.
The diagnosis of the incomplete type is therefore made chiefly by the persistence of a considerable amount of power in the elevated or abducted arm and some doubt about the presence of some of the other symptoms and signs. Complete cases are usually so absolutely typical that no doubt remains. Complete cases do not form adhesions, while many incomplete cases do.
If the surgeon is sufficiently informed about the anatomy, pathology and surgery of this particular region, I believe that when in doubt he should explore the bursa through a half-inch incision. If he finds a communication through into the joint, let him close it, but if no opening exists, let him back out, for we do not yet know what to do to these incomplete ruptures.
Before closing this chapter, I may say that I believe these lesions to be the most common form of shoulder injury. My slogan has been that complete rupture of the supraspinatus is the most common cause of prolonged disability from industrial accidents to the shoulder. I feel that I have proved this at least to my own satisfaction. I may now add that the incomplete form accounts for the majority of minor shoulder disabilities. This I have not proved, for I do not operate on these cases, but the frequent presence of broadened sulci found in any .series of autopsies in elderly people is convincing to me. The clinical examination of employees with sore shoulders often shows symptoms suggestive of this lesion. Possibly opaque fluid injected in the joints might confirm the diagnosis. I have not felt justified in doing this, for exploration seems to me quite as free from danger. I certainly should try this experiment on patients now if I had in mind some definite plan for relieving them, if I did find broadened sulci indicative of incomplete ruptures, but I do not yet conceive of a plan by which to promptly cure them.
The appearance that I think opaque fluid in the joint would show in cases of complete rupture is indicated in the cover design.

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FREQUENCY OF COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON

There are certain reasons for believing that this is a far more common lesion than is generally appreciated.
1. The writer's personal experience.
2. The statistics of Dr. Akerson.
3. The lack of attention paid to lesions of the shoulder in general; i.e., of end result studies of large series of shoulder injuries.

1. Personal Experience. The above chart shows that the writer's experience in operating upon these lesions was confined to two periods of about three years each, when attentive study was given to relatively large groups of shoulder cases. In the first period (1911 to 1913 inclusive) an intensive study was made of the shoulder cases at the Massachusetts General Hospital. The author resigned from that hospital in 1914 and was not reappointed until 1929. Other activities and a period in the army during the war intervened, without opportunity to operate on such cases, although I continued to make occasional impartial examinations for the Industrial Accident Board. In 1926, owing to the interest of Dr. Henry C. Marble and Dr. W. A. Bishop, who are directors of Insurance Clinics, I again gave intensive study to a group of shoulder cases, and the chart again ran to a peak. This led to increased interest in other clinics, so that other surgeons (e.g., Dr. Wilson) began doing these operations, which accounts for the decline at the end of my chart, although the rate of frequency, if we included other surgeons' cases, would not show this decline.
In other words, the chart shows that whenever I gave intensive study to a group of shoulder injuries, I was able to diagnose some of these cases and to demonstrate them by operation. My work received little attention after the first period but since the second, largely owing to the changes brought about by the Workmen's Compensation Laws, the importance of the lesion is becoming recognized by industrial surgeons in this state. I do not know just how many cases were seen during these two periods, and therefore cannot give the exact percentage of the cases examined which were instances of this lesion, although the limits may be stated pretty positively. For instance, the first fifteen cases were found among less than 200 patients, and the second fifteen cases were from an uncertain number, but probably less than 100. This means that the frequency of occurrence was about 7%% to 15% of all shoulder lesions that came under my observation.
By referring to my records for the twenty years since I recognized the first case, I find that I have seen in all about one thousand shoulder cases. Of these more than one hundred have been positively diagnosed as instances of complete rupture and many more as incomplete. This would justify an estimate of between 10% and 20%. It would require an amount of labor disproportionate to the present object to go over these records to apportion the exact percentage, since it is sufficiently clear that I have made this diagnosis in not less than 10% and perhaps more than 20% of all shoulder cases. If cases of partial rupture were included the percentage would be at least doubled.
The figures in the annual Reports of the Industrial Accident Board help us only in a negative way, for this diagnosis is not classified. Their tabulations of the durations of disability are not carried over from year to year, so that we cannot obtain a list of the cases in which disability is protracted. This is unfortunate, for this list would probably be largely composed of cases of rupture of the supraspinatus.
The report of the Industrial Accident Board for the year 1928, Table 7, gives the following figures in regard to shoulder injuries. It is supposed to cover every accident occurring in industry in this state.

The last two columns, "Sprains and Strains," and "All Other," are the ones which would probably contain most of these ruptures, although a large number must be included under dislocations and fractures. If we double the figures where both shoulders were injured, the total of the two columns would be 748, five per cent of which would be thirty-seven. During the same period, July 1, 1927, to June 30, 1928, I personally made the diagnosis in seventeen cases which were referred to me by Insurance Clinics or by the Board for "Impartial Examination." Since I probably see but a small fraction of these shoulder injuries of doubtful diagnoses which occur annually in this state, the estimate of thirty-seven is surely a minimum one. The maximum reasonable estimate would double this and also include twenty-five per cent of the 125 dislocations. It seems to me pretty well proved that not less than thirty-seven and very likely more than one hundred injuries of this type occur annually among Massachusetts employees.
At first sight thirty-seven, or even a hundred, neglected shoulder injuries in a state of 4,200,000 inhabitants does not seem a very serious matter, but as each insured case may cost the state $4,000 for compensation (aside from the pain endured and the economic loss of productive effort in labor), the amount of money involved is considerable (37 X $4,000 = $148,000). This fact mates this obscure injury more interesting, and, if we multiply by 100, still more so. My opinion is that the larger figure is a more accurate estimate. If we included partial ruptures which heal after a few months, but which cause a large total of lost time, the annual expense to the state for injuries of this small tendon can be reasonably estimated to be over half a million. Furthermore, there must be many such injuries which are not industrial.
In addition to the above reasons for believing that this lesion is not rare, I may say that in a single set of twenty dissecting room subjects I have always been able to demonstrate one or more instances. When I have been asked to speak to small groups of doctors or students, I have usually been able to find a subject on whom to demonstrate the diagnostic signs of this lesion, by asking at adj acent clinics for cases complaining of inability to raise their arms. I feel quite confident that I can demonstrate (recognized or unrecognized) instances of this lesion by examination of the cases under treatment in the out-patient departments of any large general hospital in any city of the United States, and, in fact, probably in most parts in the world, where there are many persons over forty doing laboring work. This does not necessarily mean that there are large numbers, for each case is apt to be a patient for several years, meanwhile going from one hospital to another in search of relief.
2. Dr. Akerson's statistics, already given on page 67, give us a maximum estimate, because nearly all the observations were made on elderly subjects of the laboring class, in whom a previous injury could only be assumed, for there were no histories negative or positive of accidents. There is a splendid chance for a clinical research at the Long Island Hospital, in future, to correlate autopsy findings with retrospective histories of shoulder injury, taken from patients before death comes. It would be a time-consuming job, but it would help us to decide the important question of whether these lesions can occur without injury, and it might lead to the saving of many thousands of dollars, not only in compensation, cost of medical care and economic loss, but in maintenance of the indigent. Dr. Akerson's work might in this way lead to a saving of more than the cost of his entire department. Similar opportunities exist in like institutions from one end of the country to the other.
3. The Lack of Attention to Shoulder Injuries. There is a voluminous literature on fractures and dislocations (especially on habitual dislocations) of the shoulder, but, with the exception of Dr. Meyer's work (loc. cit.) and an investigation now being undertaken by Dr. Fowler of Evanston, 111., I know of no systematic observations from autopsy findings in this part of the body. Nor are there any serious studies of similar clinical cases. If the End Result system of organization existed in our hospitals and insurance clinics, these cases of prolonged disabilities would be automatically revealed, studied and eventually prevented by early operation.
Thus my confidence that these lesions are common is enhanced because no one has evidence to. contradict me, and a few support me. It is clear that Dr. Meyer finds similar lesions, although he explains them as the results of attrition. Dr. Fowler will, I believe, as he has already told me, confirm some of my findings and give support to those of Dr. Akerson.

ARGUMENT

This book is not written to show that I have had good results in this class of cases. My argument is merely that this lesion exists; is not uncommon; has characteristic symptoms which permit accurate diagnosis; and, since I have been able by suture of the tendons to greatly relieve a few cases, even though the diagnosis was belated, it is highly probable that the prolonged and trying symptoms from which these patients suffer, when not operated upon, might be prevented by early diagnosis and the prompt use of a minor surgical operation, which should not be difficult, if promptly done.
If I can offer reasonable evidence for the clauses italicized, it seems to me that the conclusions in the last clause of the above paragraph would be sustained sufficiently to justify prompt exploratory operation when the symptoms suggest this diagnosis.

POSSIBLE ACCURACY OF DIAGNOSIS

I have already established the existence of this lesion, endeavored to estimate its frequency and have described the characteristic symptoms. Evidence is now offered to sustain the statement that accurate diagnosis is possible. The following extracts, taken verbatim from my pre- and post-operative reports to insurance companies, show that a'positive diagnosis of this lesion may be made. Every case operated upon during the last sixteen years, in which I have demonstrated a complete rupture of the supraspinatus, is given. Even in the cases operated upon prior to 1916, one may find that my definite pre-opera-tive diagnoses in the records of the Massachusetts Hospital are correct, in all but five cases in which the diagnosis was simply " subacromial bursitis." With each of the abstracts given below the case number is stated. The reader will find further information about each of these cases by referring to these numbers in the Table on pages 255 to 260 in Chapter VIII.

CASE No. 57.
Preop. Diag. "The injury which he sustained two years ago, I believe to have been a rupture of the supraspinatus tendon and the upper portion of the capsule of the shoulder joint."
Op. Findings. "As soon as the bursa was opened it was apparent that the entire supraspinatus tendon had been torn away, for the cartilage of the bone showed where the supraspinatus tendon should be. A small stub of the tendon still remained attached to the tuberosity. Further exploration showed not only that the supraspinatus tendon, but the upper portion of the infraspinatus tendon was also torn, but the subscapularis was intact. The long tendon of the biceps could be seen crossing the field just at the edge of the subscapularis. The proximal portion of the supraspinatus had retracted so far into the subacromial space that only a rather unsatisfactory portion of it could be pulled upward and attached to the stub on the tuberosity. It was evident that the atrophy which had taken place in the two years left practically no hope of the restoration of the complete function of the muscle or tendon."

CASE NO. 75.
Preop. Diag. " I have no hesitation in making a diagnosis of rupture of the supraspinatus tendon, nor in advising an operation to suture it and clean off the ragged vegetations at the edges of the old rupture."
Op. Findings. " Showed supraspinatus entirely torn off and retracted far under acromion. Biceps tendon lying at inner edge of rupture."

CASE NO. 88.
Preop. Diag. "I feel that the diagnosis of subacromial bursitis is correct, but that the underlying cause of the bursitis was a ruptured supraspinatus tendon. This has now partially healed—enough to renew the power of abduction but not enough to make the point of rupture smooth. The result is an irregularity on the base of the bursa which in abduction impinges on the acromion and acromio-clavicular ligament."
Op. Findings. "On opening the bursa the ruptured supraspinatus tendon was beautifully demonstrated, the tendon having been torn from the tuberosity, leaving none of the original attachment on the bone. It had retracted about a half inch and the torn end could be seized with a tenaculum."

CASE NO. 88.
Preop. Drag. " He has the following signs indicating that his trouble is a ruptured supraspinatus tendon and his history is typical of this lesion.
"1. There is an acutely tender spot on the greater tuberosity at the normal point of insertion of this tendon.
"2. I can, I believe, feel at this point a sulcus where the tendon is torn.
"3. There is a painful jog in the motion as he raises his arm.
"4. There is velvety crepitus as he does this.
"5. After the arm has been elevated one can easily pull it down, although the deltoid muscle can be felt strongly contracted.
"6. There is a feeling of fullness under the upper part of the deltoid as if there was fluid in the bursa."
Op. Findings. "Free straw-colored fluid. Cartilage of head of humerus and the greatly swollen and injected biceps tendon visible on retracting the margins of wound in deltoid. The tear of the supraspinatus tendon was complete and the tendon of the infraspinatus was also almost completely torn. The proximal ends had retracted so as to be barely reached by Allis forceps to enable passing a suture."

CASE NO. 89.
Preop. Diag. "Patient presents to me typical symptoms of supraspinatus. He can abduct his arm slowly and with a hitch which gives an obvious sudden change in the relative position of the humerus and the scapula. He cannot maintain his arm extended against any considerable pressure."
Op. Findings. "Routine bursal incision disclosed a very extensive tear of the supraspinatus tendon. The biceps tendon had disappeared and could not be located except possibly as a few fibers in the anterior part of the joint."

CASE NO. 96.
Preop. Diag. "Examination shows pretty typical signs of a ruptured supraspinatus tendon, except that the friction rub is masked by the presence of joint fluid in the bursa. The outlines of the bursa are visible through a heavy deltoid as evidence of this fluid. It is well shown when the patient attempts to abduct the arm. The arc of abduction cannot be performed without a typical jog in the motion. The patient himself feels this and complains of pain during it. There is tenderness over the bursa."
Op. Findings. "Routine bursal incision showed a typical rupture of the supraspinatus tendon which did not involve either the subscapularis or the infraspinatus; making a gap pulled away from the tuberosity of about one-half inch width. Through this, on opening the bursa, the cartilage of the head of the humerus was visible. By retracting a little, the biceps tendon could be seen to the inner side, greatly congested."

CASE No. 97.
Preop. Diag. "Diagnosis. Rupture of supraspinatus tendon (left) complete and of severe grade. The same on right but incomplete and partially repaired. Probably rupture of the long heads of both biceps tendons."
Op. Findings. "The supraspinatus tendon was completely ruptured -and the upper portion of the subscapularis also. The biceps tendon had disappeared, evidently having been torn off the glenoid and retracted into its groove."

CASE No. 98.
Preop. Diag. "Examination shows very typical tenderness, crepitus, abduction weakness and the jog in motion typical of a ruptured supraspi-natus tendon in the right shoulder."
Op. Findings. "Routine bursal incision showed the supraspinatus was completely ruptured and also a part of the tendon of the subscapularis over the biceps tendon, and also a portion of the infraspinatus. The joint cartilage was exposed for about a half inch to the outer side of the bicipital groove and there was a tag of tendon still attached to the tuberosity just external to the groove."

CASE No. 102.
Preop. Diag. "Examination shows a decided atrophy of the muscles about the right shoulder, tenderness and irregularity of the tissue over the greater tuberosity, a painful jog in the motion of abduction, free external rotation, persistence of passive and loss of active complete abduction. These signs and the history are characteristic of rupture of the supraspinatus tendon. He also has' a rupture of the long head of the biceps, if one may judge by the contour of the belly of the muscle."
Op. Findings. "Free joint fluid found in bursa, which was large. The supraspinatus tendon was about half torn away from the tuberosity and the torn tendon retracted only about one-half inch, exposing a small extent (about) one-quarter inch of the edge of the joint cartilage. The opening was not large enough to view the tendon of the biceps, so I made an incision about one-half inch long into the bicipital groove and identified the biceps tendon. It was large and normal in appearance, so that it is likely that the apparent atrophy of the outer belly of the muscle in this case was due to simple disuse from reflex pain."

CASE NO. 106.
Preop. Diag. "Examination of the right shoulder shows typical signs of a rupture of the supraspinatus of considerable degree. One can feel the sulcus on the facet of insertion from which the tendon has been evulsed. There is fluid in the bursa."
Op. Findings. "The roof of the bursa was thickened. When incised, free straw-colored fluid escaped, about one dram. The supraspinatus was found torn from its attachment and retracted far under the acromion. About one-half of the insertion had evulsed from the facet. The other half was torn about one-half inch from the facet, leaving a thickened, irregular, whitish mass about the size of a large lima bean attached to the tuberosity."

CASE No. 107. Reported in text.

CASE No. 108.
Preop. Diag. "The diagnosis is fairly certain of a partial rupture of the supraspinatus, and also a rupture of the long head of the biceps."
Op. Findings. "The complete supraspinatus tendon had been torn close to the tuberosity and was retracted about an inch and a half. The infraspinatus and subscapularis were intact, but the biceps tendon had been torn completely off the glenoid and had retracted part way, instead of wholly into the sheath, leaving a frayed end protruding at the edge of the articular surface. In repairing I used this by sewing the supraspinatus to it and the subscapularis, anchoring the biceps tendon in its groove as I did so."

CASE No. 112.
Preop. Diag. "Examination shows the following: A slight atrophy of the intrinsic muscles of the shoulder, a soft crepitus which occurs with a snap just as the tuberosity passes under the acromion in abduction, a tender point on the greater tuberosity at the insertion of the supraspinatus tendon, a tendency of the scapula to follow the motions of the humerus, a flaccid condition of the outer head of the biceps muscle. These signs indicate that he has torn the supraspinatus tendon from its attachment on the tuberosity, and probably has also torn the biceps tendon from its adjustment on the glenoid."
Op. Findings. "This displayed a perfectly typical complete rupture of the supraspinatus tendon without rupture of either the subscapularis or infraspinatus. The biceps tendon was slightly frayed at its inner edge where there were two small papilloma-Iike, whitish excrescences, the size of one-quarter of a pea. The stub of the ruptured tendon was still attached to the tuberosity, but had worn down to a falciform edge; similar falciform edges showed on the lateral aspect of the tear; i.e., the unruptured edges of the subscapularis and infraspinatus. By lifting the edge towards the subscapularis, a pinkish, inflamed biceps tendon was demonstrated. A few fibers of the outer portion of this had been ruptured as spoken of before. There was only a moderate amount of joint fluid seen at any time. The edges of the torn surfaces were refreshed, and the parts sutured in place with three heavy braided silk sutures."

CASE No. 115. See history on page 389

CASE No. 119.
Preop. Diag. "Typical ruptured supraspinatus tendon. Atrophy, crepitus, jog, fluid, loss of power very great. Biceps O. K. Rotation free, tender sulcus."
Op. Findings. " The tendon was much thicker than usual and less retracted, so that the triangular gap was longer transversely than vertically. . . . There was quite a stub on the tuberosity, enough to suture. The biceps tendon was so badly damaged that there were but a few strands of it left and these were adherent to the roof of the joint. Most of the tendon had retracted into the groove and become adherent there. None was left crossing the joint surface and none was seen in the joint, although it might have been imbedded there behind the head."

CASE No. 123.
Preop. Diag. " This patient has the typical symptoms of a rupture of the supraspinatus tendon of considerable extent, but not enough to prevent his having a fair amount of power in abduction—although with pain. He has atrophy of the spinati, scapulo-humeral spasm, a j og in the motion of abduction, the fluid sign with limitation in complete abduction, a tender, palpable defect on the greater tuberosity where the tendon should be attached."
Op. Findings. "An exploratory incision a half inch long was first made and it was at once apparent that the supraspinatus and the infraspinatus tendons were evulsed from their facets, leaving no stubs of tendon. The biceps tendon, which was double at this point, was greatly swollen and inflamed and presented as soon as the roof of the bursa was opened. To its inner side the subscapularis and the inner portion of the tendinous expansion of all the tendons lay intact, and to its outer side was bare joint cartilage and the top and posterior portion of the greater tuberosity from which the tendons had been torn. The facets were smooth and the superficial parts of them had not been carried away by the tendons. The incision was enlarged to an inch and a half and a good view of the field obtained. It was found that the teres minor had also been evulsed. The whole posterior part of the capsule and conjoined tendon of the above muscles was retracted downward and outward. It was impossible to draw this back and to suture it in place."

CASE No. 127.
Preop. Diag. "At my first examination I did not make the diagnosis in this case, although it had been suggested by Dr. Marble, but on my second
examination, seventeen days later, I wrote, 'H--- is better, but I have
changed my opinion about the diagnosis. I am now quite confident that he has a ruptured tendon and should be operated upon. I think Dr. Marble was correct in his original diagnosis.' "
Op. Findings. "A small exploratory incision was first made over the point of tenderness. As soon as the roof of the bursa was incised, an irregular, whitish mass of tendon about as large as a thumb nail popped out of the incision. It proved to be the proximal portion of the torn tendon and was about one-quarter inch thick. It evidently turned on itself as the arm was abducted and caused the catch which the patient himself could accurately localize, There was about a tablespoonful of straw-colored fluid in the bursa. The incision was then enlarged to about two inches and a good view of the lesion obtained. This case differed from others on which I have operated in that the tear did not involve the whole thickness of the tendon, but left a very thin layer toward the joint surface so that there was not a demonstrable communication with the true joint. However, the layer was so thin that the cartilage could be seen through it. The ruptured portion formed a little flap about a square inch in extent, attached only to the proximal end and evulsed on the distal end from the facet of insertion. I have seen similar cases in the cadaver where the distal end had not evulsed. It is a fact that lamination of the tendon is found in many cases, but this is the first one on which I have operated where the laminated portion evulsed without the lower surface also tearing. The free portion seemed rather necrotic but was clearly rather recently ruptured. The torn surface was rather bulbous, as if partially healed. Near the lesion and to its inner side was a streaked, red area which was excessively tender when touched, but the torn end itself had no sensation and was not so made by the novo-caine. It is to be assumed, therefore, that the pain in these cases is not due to the tissue pinched but to the uninjured tissue on the tuberosity which does the pinching."

CASE No. 128.
Preop. Diag. " My opinion is very strong that he has a ruptured supraspinatus, but I am a little uncertain as to whether it is not a renewed injury in an old lesion. X-ray is very strong evidence of this. Clinically, I should not suspect it. In either case I should advise immediate operation as soon as arrangements can be made."
Op. Findings. "On opening the bursa there was found to be evidence of old inflammation in the bursa, as well as recent light adhesions. The supraspinatus was torn away from the tuberosity to the extent of about one-half inch, and little of the bursal floor remained untorn, but there was a gap directly into the joint through which the cartilage could be seen. This gap was about one-quarter of an inch in extent. The tendon had retracted very little and I was able to close it with four silk sutures, two of heavy silk and two of light silk."

CASE No. 129.
Preop. Diag. "Signs of ruptured supraspinatus tendon were present at my previous examination, but they are much more prominent now than they were at that time. He has a very distinct crepitus, sulcus, eminence, scapulo-humeral spasm, tenderness at the border of the tuberosity; localized tenderness, atrophy of the supraspinatus, sign of fluid when both arms are elevated. I agree with Dr. Marble in the diagnosis and would advise operation in this man's case."
Op. Findings. "The bursa was first opened by a half-inch exploratory incision. A small amount of free fluid escaped and it was readily seen that the supraspinatus tendon was ruptured and greatly retracted. . . . The tendon was partly evulsed and partly ruptured at the 'palisade junction.' The complete tendon was involved with possibly some of the infraspinatus. As in another recent case (H--- ) there was still some tissue remaining
on the joint side so that the cartilage was partly covered with a turgid, deep-red, softish tissue containing a few obvious whitish tendinous bands. One of these was especially noteworthy because it was very sensitive, and the patient winced when it was touched. I excised it because it did not seem to be of sufficient strength to make up for its sensitiveness. The biceps tendon lay to the inner side of the rupture buried in inflamed synovial folds, but not injured, unless the strand of tendon above alluded to had been stripped off it. The bulk of the proximal end of the supraspinatus tendon had retracted far under the acromion and could barely be drawn into the field."

CASE NO. 135.
Preop. Diag. " I feel very confident that he has a rupture of the supraspinatus tendon. I am not sure that there was not a previous rupture and that this latter accident merely increased the trouble. However, there is no question in my mind but that his chances will be much better if his bursa is explored and suture is done, if the tendon is ruptured."
Op. Findings. "No blood or fluid on opening bursa. A complete rupture of the supraspinatus, with extension across the bicipital groove, about one-half inch into the subscapularis. Definite indications that the rupture was fairly recent; i.e., very little separation between the distal and proximal portions. Stub of tendon still attached to the tuberosity over most of its extent. No new-formed falciform edge. Biceps tendon flattened and superficially reddened in portions beneath rupture. Parts satisfactorily sutured together with pedicle silk; five stitches. In my opinion, the condition found indicated a recent rupture of a tendon which had already been partially ruptured."

CASE No. 137.
Preop. Diag. "Examination shows that this patient has a symptomless, chronic bursitis, with crepitus in the right shoulder. The left shoulder shows the typical signs and symptoms of a rupture of the supraspinatus tendon. Since he has considerable power in abduction—although the abduction is painful, and accompanied with a jog and crepitus—I am inclined to think that the rupture is not extensive enough to involve the adjoining tendons. Even though this man is sixty-two, and it is four months since the injury, I would advise him to have the tendon sutured to the tuberosity."
Op. Findings. "A one-half inch exploratory incision was made and the bursa opened. Rupture of the supraspinatus throughout its whole extent was disclosed. The rupture extended also, to a slight extent, into the insertion of the infraspinatus. The sulcus and tuberosity were bare, except for a very slight amount of tag of tendon near the edge of the bicipital groove. The incision was enlarged to two and one-half inches to permit suture."

ERRORS IN DIAGNOSIS

But a skeptical reader may now ask for a statement of how many cases I have operated upon under this diagnosis and have failed to find a complete rupture of the tendon. I give below a similar set of verbatim extracts from the records of nine cases during the same sixteen years, the only ones in which I have made a positive diagnosis and have not been confirmed by the operative findings.

CASE No. 76.
Preop. Diag. "I believe this patient has a ruptured supraspinatus tendon, at the point of the insertion of the tendon in the tuberosity. This diagnosis is consistent with the X-ray appearances seen in the films taken by Dr. George. These films show an irregular opacity in the area of the bursa, which may be due to extravasated blood or to crumbs of bone torn off the tuberosity."
Op. Findings. The operative notes in this case have been lost, but I clearly remember that the condition proved to be a case of calcified deposit which had recently ruptured into the bursa, leaving a defect in the tendon very similar to a true rupture, but containing blood and calcified material.

CASE NO. 80.
Preop. Diag. "This is unquestionably a case of ruptured supraspinatus tendon of considerable extent, but the main symptoms are due to a tuft of synovial granulations from the remnant of the supraspinatus tendon still attached to the tuberosity."
Op. Findings. " The walls were much thickened and there were synovial tags in the region, over the tuberosity, showing more or less chronic inflammation. The tender point, which could be felt prior to the operation and was thought to be a tag of tendon remaining on the tuberosity, proved to be a rounded elevation, markedly circumscribed and about one-half inch in diameter, slightly longer in the axial direction than the transverse. This was acutely tender when pressed on. It was incised and found to be the insertion of the tendon of the supraspinatus attached to an osteophyte at the edge of the joint cartilage. There was no direct evidence of a rupture of the supraspinatus tendon. If there had been one, it must have healed. No communication with the joint was demonstrated. The essential pathology was probably the hypertrophic arthritis which was evident in other joints. (Patient's age was 77.)"

CASE NO. 91.
Preop. Diag. "The history and symptoms are typical of a ruptured supraspinatus tendon in the right shoulder, with some adhesions of the bursa, or blocking of the motion by the remains of the torn tendon impinging on the acromion. I think the latter."
Op. Findings. "The base of the bursa was deeply congested and swollen, but there was no demonstrable tear of the tendon of the supraspinatus. There were light adhesions in the bursa which were broken up with the finger. The short rotators and capsule were greatly contracted and were slowly stretched until full external rotation and abduction could be attained, and the wound closed."

CASE No. 105.
Preop. Diag. " I have little doubt that this patient has a rupture of the supraspinatus tendon of considerable extent."
Op. Findings. " Incision through the roof of bursa with the escape of about one dram of clear, straw-colored fluid. Exploration revealed an intensely inflamed zone on the greater tuberosity, approximately the size of a half dollar with red periphery and white center, resembling the condition seen in calcified cases. An inflamed fold moved back and forth over this as the patient's arm was moved. This fold was excised. The point of the knife was used to puncture the tendon in several places in the inflamed area with the purpose of allowing a new blood supply by attaching the scar to the inflamed base. There was no indication that the supraspinatus tendon had been ruptured."

CASE No. 110.
Preop. Diag. "The whole tuberosity is tender and it is hard to find a definite spot from which one can say the tendon has been torn. With the exception of this, his symptoms are fairly characteristic of a ruptured supraspinatus. From the relaxed condition of the biceps muscle and particularly of its outer head, I am inclined to feel that the biceps tendon is torn from its attachment on the glenoid. Indeed this may be the main lesion.
"I should advise inspection of his bursa under local anaesthesia and suture of the tendons if they are found torn. If there is no tear in the base of the bursa, I should advise opening the joint between the supraspinatus and the subscapularis and inspecting the tendon of the biceps.
"Remarks. This case is atypical in the age of the patient (17). Ruptured supraspinatus lesions are usually in elderly men. The character of the accident is unusual; sudden abduction efforts are more common as causes. There has been comparatively little pain, especially in the first week, and usually one has a history of swelling over the bursa in the first few days. Palpation over the tuberosity is a little atypical. For these reasons I cannot be as positive as I sometimes am, but I am sufficiently certain of a rupture to feel that in the boy's place I would want to have an exploration. Little harm would be done if this is negative, which I am confident it will not be."
Op. Findings. "The exploratory instrument was first introduced into the bursa, which was found to be full of adhesions and consisted of a series of pockets of walled synovia. Through the exploratory instrument it could be definitely determined that the bursa had been subacutely inflamed, but that there was no tear in the supraspinatus tendon. There was no fluid in the bursa. As both Dr. Baker and I thought that the biceps tendon was probably torn, the incision was enlarged to about one and a half inches, and the bicipital groove was incised. It did not contain the tendon, which evidently had retracted downward. The arm was put through the accustomed motions of rotation and abduction while a finger was introduced into the bursa to break up all the adhesions existing there. When the adhesions had been broken, which was easily done, the motion of the arm was normal. No steps were taken to repair the biceps tendon."

CASE No. 111.
Preop. Diag. "The shoulder presents typical signs of a ruptured supraspinatus tendon of a considerable degree. He has my fluid sign— characteristic velvety crepitus, a jog in motion, a tender irregularity on the greater tuberosity and weakness in abduction. He is able, however, with a little coaxing, to abduct the arm, but has very irregular action of the humerus on the scapula as he does this. There is still some ecchymosis in the anterior portion of the arm over the bicipital region, as if after the injury blood may have escaped down the tendon sheath; the tendon, however, appears to be intact."
Op. Findings. "Exploration of the bursa showed no fluid. No communication was found between the bursa and the joint. The bursa was adherent over about half the extent of the lower portion. On separating the adhesions it was evident that the supraspinatus had been torn, but had spontaneously healed; the tissues were red and swollen with white patches here and there. I therefore closed the wound in the usual manner without doing anything in the way of an operation."

CASE No. 120.
Preop. Diag. "The left shoulder presents very typical signs of an extensive rupture of the supraspinatus and possibly of the long head of the biceps. There is slight but decided atrophy—consistent with a history of two weeks. There is a very tender point on the tuberosity, scapulo-humeral spasm, a j og in motion and the fluid sign. In the stooping position the patient can abduct and hold the arm abducted as he straightens up."
Op. Findings. "Routine bursal incision. Adhesions prevented easy access, for roof was stuck to base over an area as large as a quarter over the greater tuberosity. These were separated and showed that the tendon of the supraspinatus was bright red, swollen, and covered with tags of vascular adhesions. The line of demarcation of the affected area was very sharp on the outer side, so that the contrast between the yellowish white to the right and the turgid red at the left was very decided. It suggested an infarction. Although there was some free fluid in the bursa there was no communication through the inflamed area to the joint. The supraspinatus tendon, if ruptured at all, must have been torn beneath the base of the bursa without communicating with the bursa. Several small incisions were made with the point of the knife to relieve tension in the tendon. Through one of these a tiny bit of white nondescript tissue protruded. This was saved for pathologic examination j I am pretty sure it was necrotic tendinous substance. The wound was closed as usual without endeavoring to suture the roof of the bursa. The pathology found at this operation may be explained in two ways, or as a combination of both ways. There was certainly an acute bursitis with recent adhesions, but it was impossible for me to say positively that this localized acute inflammation over the site of the supraspinatus tendon was due to a rupture of the tendon beneath the base of the bursa. It might have been due, as suggested by the evidence of osteitis shown in the X-ray, to a chronic necrotic process in the tendon. The extrusion of the bit of necrosed tendon from the incision also supports this. So does the symptomless condition in the well shoulder. It seems to me that if we accept the man's history that the condition of the shoulder was O. K. before he helped lift the case, that the whole picture can be explained by the supposition that there was a necrotic process going on in the tendon which had weakened it so that it partially evulsed without tearing into the bursa. This would explain all which was found at the operation, and my opinion is that this theory truly does account for the facts. I have had several other similar cases and have frequently seen evidence of such lesions in the cadaver."

CASE No. 126.
Preop. Diag. August 12, 1929. "I have little doubt that this patient has a mild rupture of the supraspinatus, but as the power in abduction is good, operation need not be considered. It is probably not an extensive rent. I suspect both from the clinical signs and from the X-ray that he has had an old lesion here for some years. It seems to me that the best plan of treatment would be to let him rest a few weeks and to have him attend your clinic three times a week for massage. If he does not feel able to go to work again in a month, let me see him again." Sept. 22, 1929. "Examination is as on August 19th. My opinion that he has a small rupture of the supraspinatus is somewhat strengthened by the fact that the symptoms have not improved. As he is only forty-two, I am inclined to advise an exploratory incision under novoeaine to confirm the diagnosis and, if necessary, to suture the tendon. The spot at which he complains of tenderness is so localized that it seems likely we shall find some lesion at this region."
Op. Findings. Oct. 23, 1929. "Under local ansesthesia no rupture of the tendon was demonstrated. The walls of the subacromial bursa were thickened and the bursa contained a little fluid. There was nothing found which indicated any recent injury other than the presence of this chronic bursitis. The wound was closed after taking out a small specimen of the synovial lining for pathologic examination." (This showed chronic inflammation.)

CASE NO. 181.
Preop. Diag. "In my opinion, he has a chronic subacromial bursitis in consequence of a rupture of the tendon of the supraspinatus."
Op. Findings. "A half-inch exploratory incision showed that the roof of the bursa was thickened and adherent to the floor beneath. The wound was enlarged to about one and one-half inches and the adhesions freed, partly by cutting and partly by tearing with the finger. Several small bursal sacs had replaced the usual large one. These sacs lay beneath the adhesions which permitted a certain amount of motion. The adhesions were red and inflamed looking. There were one or two small calcified deposits which were wiped out. The periphery of the bursa outward and backward under the acromion was more normal in appearance and not adherent. The total area involved by the adhesions was about the size and shape of a fifty-cent piece over the greater tuberosity and insertion of the supraspinatus tendon. The most acute tenderness was felt at this point, although there was a little sensitiveness over the bicipital groove. Two or three tags of inflamed serosa were removed for examination and a very small bit of tendon at the point where the adhesions centered was clipped out for examination."

In most of these nine cases, although there was not a complete rupture, there was some evidence of partial rupture beneath the base of the bursa. However, I did not confirm this supposition by cutting through the base, for it seemed to me that its tissue formed a bridge over the gap which would assist in healing the tendon. I am inclined now to think that I have been too conservative, for several of these cases had long convalescences, and it might have been wiser to explore beneath the base of the bursa.
At the danger of repetition, I wish to state that I do not intentionally operate, unless I think the ruptures are complete, because I feel confident that where the rupture is complete, healing will not take place unless suture is done. I am not sure enough of what the treatment of partial ruptures should be, to make me urge operation, even if I were sure of the diagnosis. Therefore, the above nine cases may be considered to be errors in diagnosis, although by no means as negative explorations. The difficulty is to tell beforehand whether or not there is actually a complete rupture which needs suture. I think the fact that during a period of sixteen years I made the diagnosis correctly twenty-one times, and incorrectly in only nine cases, shows that the diagnosis is not difficult. When in doubt, such a trivial operation as exploration would be justified, even if the proportion of errors was three to one.
In several of the nine cases it is to be noted that the mistake could have been avoided by more reliance on the fact that if there are decided restricting adhesions the diagnosis is not established. In the first case the X-ray indicated the presence of a calcified deposit and should have warned me not to make the mistake, although I should have operated at any rate. In several of the other cases where a mistake was made, the notes indicate that I was in decided doubt about the diagnosis before the operation, and, therefore, the incision as a matter of fact was "exploratory."

END RESULTS IN OPERATED CASES

We next come to the clause "since I have been able to relieve a few cases even though the diagnosis was belated." By referring to pp. 255-260, the reader may see that, excluding cases where there was a coincident fracture of considerable extent, I have operated on thirty-seven cases. In four of these the tendon was retracted to such a degree that I could not even attempt a suture. I have been unable to trace two patients operated upon about twenty years ago. Deducting these six cases we have thirty-one in which an attempt was made to suture the tendon. The results have been as follows: poor, four; fair, seven; good, twenty. That is, two out of every three operations were successful in that the results enabled the patients to return to work, although in most cases only after the elapse of months.
A very few, but not many, of my results have been perfect in the sense that the arm was just as useful and just as painless as before the injury; but many of them have been good in the sense that the arms have been relatively painless and quite, if not completely, useful. When I have written "good" I mean that the operation was well worth doing. When I have written "fair" it should convey that, in my opinion, there was some improvement from the operation, but that it was hardly worth doing. "Poor" means that the sum total of relief of the suffering of the patient was not sufficient to compensate for the pain and trouble which were incident to the recovery. There have been no bad results in the sense that any joint was made worse by the operation, but in at least two of the "fair" cases (Cases 83 and 112, see p. 175) the patient's point of view would have been that the result was poor, because his symptoms were not improved in spite of his post-operative pain.
There are many factors to account for the lack of perfection in the results, such as the age, the length of time the operation has been delayed, coincident disease, and above all, the desire of the patient to get well. The non-industrial patient is more readily pleased by improvement which lacks perfection than is the employee, who prefers compensation and no work, to double the pay plus work which would undoubtedly cause some pain and discomfort.
This compensation factor always causes some delay in the convalescence. Hard times have the same effect.
However, my argument does not need to show that all results should be perfect. I could give many excuses for the failures, but will be contented to present the following table.

In three of the four poor results, the tear was very extensive and the repair unsatisfactory; three had weeping wounds from excessive fluid drainage without frank sepsis (see p. 248), and all four had secondary operations. The seven cases of fair results were all improved to a considerable extent but have not actually gone to work again permanently.
There was one death which might possibly be attributed to the operation. This patient, Case No. 123, was drowned while in bathing at one of the beaches three weeks after I did an exploratory operation. The operation had shown that the tendons were too badly injured to admit of any attempt at repair. The wound healed by first intention, and as the patient enjoyed going in bathing I permitted him to do so about ten days after the operation. On the twenty-first day he was drowned. He was known to have had a heart lesion. The medical examiner reported "Death by drowning," and did no autopsy. I myself can see no connection between the operation and the drowning, but two doctors offered testimony at the Industrial Accident Board that the patient had had pulmonary embolism from the operative wound. The Board, however, did not accept their testimony, because there was no autopsy or other reason to support their diagnosis.
I feel that the proportion of good results is a sufficient reason for advising this operation, even in late cases. With greater experience and improved technique it is likely that the percentage of good results will be increased, but, as in many other surgical conditions, prompt recognition and treatment will be of greater importance than the difference in surgical skill between experienced and inexperienced operators, provided the pathologic condition is thoroughly understood.

END RESULTS IN UNOPERATED CASES

As most of my cases have been "industrial" the question of compensation becomes an important factor in estimating the period of disability. Cases who have no prospect of compensation will unquestionably go to work sooner; for instance, Case 119, a painter who had his own shop, began doing some work within a month after his operation. On the other hand in some cases, the compensation becomes equivalent to an old age pension. I have spent much time and money in tracing the unoperatcd cases of both partial and complete rupture, and have obtained enough information to venture the estimates on page 124 as to the probable costs of each. My estimate of $300,000.00 for 100 cases of complete rupture is also sustained by figures on ten patients on whom I did operate and therefore established the diagnosis. In five of these (delayed) cases the operation was a practical failure, but the patients were no worse off in consequence, and therefore were in a similar status to those in which no operation was done. In the other five the operation was essentially successful.

(The law limits total compensation to $1,000 so that these figures do not cover the period the patient is still disabled after his compensation ceases. The figures also include all medical and surgical charges.)

Case 96 in the first group had a delayed convalescence but eventually was able to go to work again as a steamfitter. Case 127 in the second group was a similar one. The reader may shift either case to the other group if he is disposed to exaggerate either average figure. Although it would not be fair to use the second group at all in computing the cost of 100 unoperated cases, by using it we may obtain an average minimum figure — $2,143.00. Therefore, the figure for 100 cases must be somewherebetween$200,000.00and$4-00,000.00.
Pain and disability are difficult to estimate in figures; these estimates are presented to impress on the reader that this lesion is important.

REFERENCES

BTTCHOLZ, C. H., Der Abriss der Supraspinatusshue, Arch. f. klin. Chir., Berlin, 1922, cxxi, 255-264.
CODMAN, E. A., Abduction of the Shoulder. An interesting observation in connection with Subacromial Bursitis and Rupture of the Supraspinatus, Boston Med. and Surg. Jour., 1912, clxvi, no. 24, 890-891; Also: Complete Rupture of the Supraspinatus Tendon. Operative Treatment with Report of Two Successful Cases, Boston Med. and Surg. Jour., 1911, clxiv, no. 20, 708-710; On Stiff and Painful Shoulders, As Explained by Subacromial Bursitis and Partial Rupture of the Tendon of the Supraspinatus, Boston Med. and Surg. Jour., 1911, clxv, no. 4, 115-120; The Pathology and Treatment of Lesions in and about the Shoulder Joint. The Industrial Doctor, 1926, iv, No. 8,121-131; Obscure Lesions of the Shoulder; Rupture of the Supraspinatus Tendon, Boston Med. and Surg. Jour., 1927, cxcvi, no. 10, 381-387.
FOWLER, E. B., Rupture of Spinati Tendons and Capsule repaired by new operation, Illinois M. J., 1932, lxi, 332-334.
KITCHEN, A. S., Surgery of the Supraspinatus Muscle, Journ. Michigan M. Soc,
1920, xix, 64-67.
METER, A. W., Absence of the Tendon of the Long Head of the Biceps. Jour. Anat. and Phys., 1913-1914, xlviii; Also: Anatomical Specimens of Unusual Clinical Interest, Am. J. Orthop. Surg., 1915, xiii, 86; Unrecognized Occupational Destruction of the Tendon of the Long Head of the Biceps Brachii, Arch. Surg.,
1921, ii, p. 130; Further Observations Upon Use-Destruction in Joints, Jour. Bone and Joint Surg., 1922, iv, p. 491; Evidences of Attrition in the Human Body, Proc. Am. Assn. Anatomists, Anat. Rec, 1923, xxv, 142; Further Evidences of Attrition in the Human Body, Proc, Am. Assn. Anatomists, Anat. Rec, xxvii, 211, 1924; Further Evidences of Attrition in the Human Body, Am. Jour. Anat., 1924, xxxiv, 241; Spontaneous Dislocation of the Tendon of the Long Head of the Biceps Brachii, Arch, of Surg., 1926, xiii, 109; Spon
taneous Dislocation and Destruction of Tendon of Long Head of Biceps Brachii j Fifty-nine Instances, Arch, of Surg., 1928, xvii, no. 3, 493-506; The Minuter Anatomy of Attrition Lesions, Jour. Bone and Joint Surg., xiii, 841, 1931.
WARNER, F., Injury to Tendons and Joints, Intn. J. Surg., N. Y., 1918, xxxi, 196. WILSON, P. D., Complete Rupture of Supraspinatus Muscle. J. A. M. A., 1931, 483.

So far as I know there is at present no literature on the subject of this chapter which deserves serious study, except that comprised in the above references. I have no doubt that Doctor Meyer and I refer to the same lesions which were studied by Doctor Akerson and can be found by any one who wishes to look for them in similar material. Doctor Meyer's attention has been focused on the long head of the biceps; mine has been focused on the supraspinatus. Probably both of us are in a measure right, and in great measure wrong, but at least we have opened up the field for future students who wish to relieve persons incapacitated by lesions in this region of the body.

NON-OPERATIVE TREATMENT OF RUPTURE OF THE SUPRASPINATUS
TENDON

I think every general surgeon who could see one of the complete cases at operation would agree that no form of physiotherapy could influence beneficially one of these lesions, except in a subjective way. The subjective symptoms might possibly be alleviated to a certain degree by massage or by diathermy, but as a matter of fact, nearly all patients say that these agents are of little help. From the very nature of the lesion, manipulations and forced exercises can do no good and might do some harm. If it is determined that a patient is not to have an operation, there are two rational plans of treatment: (1) Fixation in elevation to relax the tendon, improve the blood supply and approximate the torn ends; (2) Gentle "stooping exercises" to help nature smooth off the irregular surface of the lesion. This is merely an aid to nature's own partially successful method.
Fixation in elevation, to be effective, would necessarily have to be instituted soon after the injury, and would require at least three weeks. It would be useless in old cases, yet even in the old cases one can see, when the bursa is open on the operating table, that there is a tendency toward approximation of the torn ends of the tendon as the arm is abducted. Of course, in these old cases the proximal end is retracted and cicatrized in its retracted position. Even prolonged fixation in such cases could accomplish little except in possibly diminishing the size of the defect. This tendency to approximation observed at operation in old cases, when the arm is abducted, shows that it is probable that if the rupture were small, this treatment, if immediately instituted, would be worth while. If I were the patient, I would prefer incision and suture to this problematical and uncomfortable, even if reasonable, plan.

The "stooping exercise" method is founded on the pathologic findings described in Chapter III. Clearly nature has developed this method of absorption of the tuberosity to restore function after this accident, for as these patients, after a year or two of misery, improve somewhat, it is fairly clear that this method of smoothing off the eminence and sulcus which caused the jog is the best she can do. Nature's plan is the combination of this slow smoothing-off of the tuberosity and meanwhile increasing the supply of fluid, which, as the lower portion of the capsule becomes tense in any action, is forced up to the site of friction.
The idea of the stooping exercises is to begin this process with the weight taken off the arm so that the irregular surface is not forced up under the acromion by muscular tension. If the patient stands and elevates the arm, the very point which is sore becomes the fulcrum on the acromion for the deltoid to exert its power. When the patient stoops with the arm relaxed, the scapula can be abducted on the humerus without the need of the fulcrum either on the glenoid or acromion. Gravity takes the place of the power of the deltoid.
It is clear that until a patient can swing his arms freely in the stooping position without pain, he is not ready to use the arm when standing.
To patients who refuse operation I explain these mechanics and impress on them what I have said in the last paragraph. I also try to teach them to sleep with the arm abducted, with the hand behind the head. Palliatives in the form of drugs or physiotherapy are not often required in these cases. The pain is always bearable, if they do not increase it with work or exercise which make a fulcrum of the sore point. I think I can accomplish more with these patients by explanation of the mechanics of their trouble than I can with any palliative measures. Show a workman the normal function of the joint, the necessity of the supraspinatus to maintain the fulcrum on the glenoid, the tendency, without it, for the fulcrum to ride on the sore spot where it touches the acromion, the changed action of the weight of the arm when stooping or lying with the hand behind the head, and, as a rule, he will get your drift. He knows about levers and weights. When he understands his condition, he will get rid of the fear element and realize that though his arm is impaired, he has not really lost the use of it. He has learned that he has lost the use of certain motions unless he is willing to stand the pain. This education has more therapeutic value than drugs or electrical treatment. Massage, of course, may do good in stimulating the nutrition of the tissues, but it cannot unite the tendon.

It has seemed to me best to present my operations on the shoulder tabulated in this way, rather than to give complete case histories of each patient. Many of the cases have been used in the text to illustrate different points, sometimes only the occupation being used and perhaps in another place the preoperative diagnosis given to compare with the operative findings, etc. Under the comments at the right of this table the page numbers are given when the individual cases are referred to in the text. Should any one desire to do so, he could, by referring to these pages, make up brief individual case histories. As a rule, the cases which have been spoken of in the text are those in which the result was poor or fair. Those which I have considered good, lack detail. On the whole, compared with the results of the cases in the rest of the table, the outcome in the cases of complete rupture has been relatively poor. The reader is urged to bear in mind that in all the cases on which I have operated my attempts were more or less delayed, for only cases 18, 27, 42, 49,106,115,127, 128, 129 and 135 were done within two months of the accident. In cases 49 and 115 suture was impossible, and cases 27 and 42 could not be traced over a period of years, although the immediate results were good. I probably should not have written this book at all had the results all been good, for one of my chief objects is to urge prompt diagnosis and immediate operation.
Some of the cases marked "poor" actually did obtain some improvement. For instance, Case 88 worked over a year after the operation and then had another accident, so that his total compensation was the maximum allowed by law. Case 89 has worked steadily as a watchman after he had made a settlement with the insurer. I feel that I have certainly not exaggerated the benefits of surgery in these delayed cases, for I am sure something was accomplished in all of them, even in cases such as number 115 where no suture was attempted, for at least a definite diagnosis was made, as a basis for a settlement. If, as I hope, eventually the profession comes to realize the importance and frequency of this lesion, and the laboring class becomes educated to take it seriously, exploration through a small incision will be the rule in doubtful cases. When the insurance companies become interested in the problem, I shall be glad to cooperate in making a more extensive survey of the economic side than that which is presented on page 176.

REFERENCE

Wilson and Fowler have modified my operative methods. References to their articles will be found at the end of Chapter V.

OPERATIVE TREATMENT OF RUPTURE OF THE SUPRASPINATUS
TENDON

The best time to operate would be immediately after the injury. When in doubt of the diagnosis, exploratory incision of the bursa should be done. The technique of this incision is the same as that which has just been described for use in cases of calcified deposits. Practically the whole base of the bursa can be inspected through this incision and the exact extent of the rupture determined. The incision is then enlarged inward or outward at either end for a half-inch, depending on the direction of the tear. On account of the herringbone structure of the deltoid it makes little difference whether or not the enlargement of the incision is at an angle with the first one. A good exposure can be obtained with an incision one and one- half to two inches in length. Do not enlarge upward farther than the coraco-acromial ligament.
Assuming that the operation is done soon after the accident, it would seem that no special directions would be needed. The surgeon knowing the normal relations would restore them by appropriate sutures and close the wound in his favorite manner. It seems to me that this immediate operation would be very easy, but I have not been able to operate on one of these cases in an early stage.
In general the operation has two main objects: the repair of the tendon to give power to the arm, and the making of a frictionless lower bursal surface to relieve inflammation and pain. Perhaps the latter is more important, for even a powerful arm, if painful, is not as useful as an arm which is rather weak in the power of abduction but not painful. It is important to keep these two objects in mind, for although in some cases both can be attained, it is sometimes necessary to take a choice between them, because the tissues may be so damaged and retracted that good approximation is impossible. In such a case we may wish to discard all hope of restoring power and devote our whole effort to trying to allay friction. For instance, the tuberosity could be excised wherever it is free from tendinous attachment, and hence is useless. This might diminish the pain by removing the eminence.
One must not feel too discouraged, however, about his repair work, for on several occasions I have opened a bursa a second time and found a smooth base and no visible sign of my suture, which, at the end of my previous operation, had appeared rough and clumsy with the ends of the tendons not even approximated but held "a distance." (See p. 245.) Even in a certain number of the delayed cases which I have operated upon, there has been little difficulty in making a satisfactory suture aiming for both objectives, but in other cases, there was little or no hope of making a smooth, even suture which would leave no rough eminence or sulcus. The latter is particularly likely to be the case where the tendon is evulsed from the tuberosity, leaving no stub to hold the stitches. In a few cases the retraction was so great that no suture could be attempted at all.

Special Points and Special Difficulties

I have found that in the old cases on which I have operated, it is seldom easy, often difficult and sometimes impossible to repair the tendon. It seems best to list the difficulties and then to discuss each.

Position on table
Mobilizing the tendons
The long head of the biceps.
Drilling the tuberosity or removing it.
Suturing the rent.
Formation of a new sulcus.
Frictionless surface
Material of suture.
Shape of needles.
Closure of bursa. Disposal of fluid.
Postoperative treatment.
1. The arrangement of the position of the patient on the table to permit proper mobilization of the arm during the operation, is an important factor in technique. The point of the shouldeT is a difficult region on which to work, for both the surgeon and the assistants. It slinks away and the patient's head and neck seem to wish to take its place. (See Fig. 50.) I should like to stress the importance of so placing a heavy sand bag under the shoulder and another under the corresponding hip that the patient is half turned on his side, while the head, with the face turned away, is at a lower level than the point of the shoulder. The shoulder should be slightly over the edge of the table toward the operator, so that the arm may be allowed to hang down in a position of dorsal flexion when desired. This position throws the distal portion of the supraspinatus tendon forward for the maximum distance from under the acromion.
The operator and assistant stand on the same side of the table, while the anaesthetist and nurse with the instrument table are on the other side. A second assistant is welcome, and often almost necessary, because the first assistant must at times give his entire attention to holding the arm and the nurse may be occupied with retractors. Much of the facility with which the operation is conducted depends on the assistant who holds the arm, for his ability to rotate just at the right time will enable the operator to put his needle at just the right point in the somewhat small field. Since the lips of the incision do not move appreciably, the operative field is really controlled by the assistant as he rotates the humerus, bringing this side of the rent or that into a position which the operator desires.
The maneuver already described, of letting air into the joint and bursa, is often a great help. The position in which to place the sutures is best illustrated by a diagram. (Fig. 52.) While this is the ideal, it is seldom possible to carry it out exactly, for too often the retracted, stiffened tissues cannot be worked into nice apposition.

FIGURE 52. METHODS OF PLACING SUTURES
a illustrates the writer's suggestion that the biceps tendon may be sutured to the supraspinatus in some cases when the former has been already torn from the edge of the glenoid, b, c, and d suggest the method of placing the sutures in the ruptured supraspinatus and in the tuberosity. The ideal is c, for in this case the lines of incision have been carried up on each side of the supraspinatus to mobilize it. d illustrates Dr. Wilson's method of cutting a slot to receive the supraspinatus tendon, e and / offer a suggestion for operation in a case where the short rotators have been entirely evulsed from the head of the humerus. Fascia lata might be passed through a drill hole and through a slot over the tuberosity to form an anchorage for the tendons.

2. Mobilizing the tendons. When one considers that each one of the short rotators is separated from the other by a definite bony partition through most of its extent, and it is only the last three-quarter inch which is welded with the others into the terminal conjoined tendon or cuff (Fig. 10), it would seem easy to isolate any one tendon so that the more or less elastic muscle belly could be stretched enough to bring the tendon down again to the tuberosity and suture it there. However, if you try this on a normal shoulder at autopsy, you will find it is not easy, and when you try it on a ruptured tendon in which operation has been delayed for many months, you will find it impossible.
In the first place, you are cramped for room by the acromion and coraco-acromial ligament so that you cannot see the muscle bellies even in the normal shoulder. In the second place, if you dissect back more than an inch on either the supraspinatus or infraspinatus, you run the risk of wounding the suprascapular nerve, and if you do, you may lose your power in those muscles forever.
In order to get at these tendons more effectively, I used to use the "sabre-cut incision," which gave a perfect exposure and every possible opportunity. (Plate VIII.) Even then the mobilization was only a little more satisfactory, so I have given up this incision. Practice has given me a little more confidence, and I believe now I can do almost as well through the simple routine incision. Dr. William Rogers has suggested removing the deltoid attachment with the periosteum from the acromion and suturing them back at the end of the operation." This seems rational, but I have not tried it and do not know whether one may rely on having the deltoid origin anchor again satisfactorily. I have sometimes thought that a subcutaneous osteotomy of the base of the acromion might mobilize it enough even without division of the coraco-acromial and acromioclavicular ligaments to allow easy access. The trouble with any incision which mobilizes the acromion is the long period which one must wait for union to occur before moving the joint. I am inclined at present to do all the mobilizing I can through the routine incision, and I find that I am constantly improving in my ability to do this.
It is probably best to remove the falciform edge of new tissue and to refresh the edges of the tendon itself. I attribute some of my imperfect results to my failure to do this. One learns by experience to put the suture back of the falciform edge, for the latter has no strength and the stitch at once tears out. One is tempted not to remove the edge because it is obviously difficult to close the rent without using it, and it seems folly not to save all the tissue one can. It might be contended that the falciform edge may have more tendency to unite than the real tendon substance, which has very little blood supply, so that perhaps I may be wrong in recommending the removal of this new tissue with which nature is attempting to repair the damage. The method of closure which seems to me the best is illustrated in Fig. 52.

3. The long head of the biceps. The problems connected with how to deal with the long head of the biceps when it is found exposed, owing to the retraction of the ruptured tendons, are not a few. I can only discuss them and do not pretend to solve them. Although I am not in agreement with some of Meyers' views on the importance of the role of the biceps tendon in shoulder injuries, I feel that his observations ought to be known to every one who operates on these cases. To my mind, the rupture of the supraspinatus is the primary and important lesion which uncovers the biceps tendon, makes it slip a little at the top of the bicipital groove and to tend to be caught between the tuberosity and the acromion. At any rate, one often finds it a conspicuous, pink, inflamed-looking, swollen band lying across the j oint cartilage at the bottom of the rent. ( Plate VIII.) The portions exposed in the rent look inflamed; those covered by the remaining intact part of the capsule are white, glistening and normal. It is pretty obvious that our suture should cover up the biceps tendon without interfering with it otherwise. It usually lies just under the inner edge of the rent, but if any of the subscapularis fibers are involved, it lies entirely exposed. Sometimes it is not found at all, for it has been torn away from its glenoid attachment and has retracted down the bicipital groove. Sometimes it is split in two, longitudinally. Often it is flattened and frayed at the edges. Varying proportions of it may be ruptured. It may be composed of indefinitely separated longitudinal strands, some of which have become welded into the capsule. It may have little, rice-like tags on its edge. However, almost always the parts which do not become exposed in the gap left by the supraspinatus are normal in appearance.
When it has ruptured from the glenoid, it may be held high in the groove by a few remaining bands, and we can capture it and pull it up. What shall we do with it? We might try to suture it back on the glenoid, or rather on the fibrocartilage which surrounds the glenoid. Or we might attach it to the proximal portion of the supraspinatus, or to the capsule, or anchor it in the groove, or excise a part of it and use it to repair the supraspinatus. We might even take a relatively normal biceps tendon, clip its attachment off the glenoid, anchor the tendon in the groove, and then use the redundant portion to fill the gap in the supraspinatus. (Fig. 52a.) This would give the biceps muscle a fixed origin, and we would at the same time obtain a firm attachment for our supraspinatus. We should only have lost whatever function the long head of the biceps has from having its attachment on the glenoid rather than on the humeral head; i.e., the outer head of the biceps would no longer be of use in motions of the humerus on the scapula, but could still apply its power in flexing the forearm on the humerus. What then is this function which we should lose so far as scapulo-humeral motion is concerned?
The function of the biceps muscle is fourfold. First, it is a flexor of the forearm on the humerus. Second, it is one of the flexors (or extensors?) of the whole arm on the scapula; in a sense, therefore, it is a weak abductor or elevator of the arm. Third, the external insertion on the tubercle of the radius enables it to act as a supinator of the radius and hand. Fourth, the long head of the biceps passing through the intertubercular groove helps to retain the head of the bone on the glenoid, and stabilizes the head in the various degrees of rotation, as the arm is elevated. This function is well illustrated by the findings in two of my cases, which at operation showed that except for the subscapularis, the whole of the capsule with the tendons of the supraspinatus, infraspinatus and teres minor had been evulsed, yet the head did not tend to dislocate; apparently it was held in the joint'by the long head of the biceps, and by that only. We lose nothing in the first function, little in the second, none in the third and but a problematic amount in the fourth, by using it in the way suggested in Fig. 52a.
So far as the action of the shoulder joint is concerned, particularly with reference to the functions of flexion of the arm on the scapula and of the forearm on the humerus, the origin of the short head of the biceps from the coracoid process is more important than that of the long head from the edge of the glenoid. The coracoid origin is sufficient to give power in these motions; the long head is chiefly a stabilizer and one of secondary use so far as the application of power is concerned. For instance, in cases in which the long head of the biceps is ruptured and no other lesion has occurred, the function of the shoulder remains almost normal.
The short rotators are sufficient to maintain the fulcrum on the glenoid in most positions of the arm, but where these short rotators are damaged, I am confident that the long head serves a very useful purpose in guiding the head of the humerus and restraining it from forging upward and getting its fulcrum on the acromion. I therefore regard it as important to keep the long head of the biceps intact if possible.
I have notes that in some of my operated cases, the biceps was torn away from its glenoid attachment. In such cases in future I intend to search for the distal end of the tendon and to anchor it with stitches in the bicipital groove, and also to the supraspinatus tendon, thus abandoning any idea of retaining its stabilizing function and being content with retaining its power as a flexor of the forearm. At present I see no good mechanical way of re-attaching it to the glenoid so as to make it function in guiding the head of the humerus as the latter is abducted. One is apt to think of the long head of the biceps moving up and down in the intertubercular groove, but this is not what actually happens. The humerus moves up and down on the tendon; it is not the tendon which moves through the groove. (See Fig. 52.) On the whole, I should say that if the operator finds that the biceps is so damaged that he thinks it will not in future form a smooth cord on which the humerus can ride up and down, he had better use it, as described above, to replace the lost substance in the supraspinatus.

4. What shall we do if we find there is no stub of supraspinatus tendon left on the tuberosity to which we may suture the proximal portion? In long-standing cases we find a tuberosity completely bare of tendinous substance, and perhaps somewhat eroded. Since this tuberosity is useless unless we can suture the tendon to it, it might as well be removed. I have not hitherto excised the tuberosity in cases in which I could not suture, but it might be well to do so. Such an excision would make the surface which must ride under the acromion less apt to cause friction. Nature does exactly this by causing recession of the tuberosity. As a rule I have drilled two holes in the tuberosity with an ordinary shoemaker's awl, and passed a heavy silk suture through these holes and the tendon so as to draw the tendon as nearly as possible to the facet of insertion of the supraspinatus. This can usually be accomplished, but occasionally the supraspinatus is so retracted that I cannot quite draw it down to the bone.
I have on several occasions made a sort of plastic so that I covered the suture with part of the roof of the bursa, believing that the repair of the tendon comes not from the tendon itself, but from the adj acent synovial membrane which is much richer in vascular supply.

5. Another operative problem is how to repair the rent. As explained in the chapter on pathology, these rents are in a general way triangular, with the base on the humerus and the apex retracted, the apex being usually the center of the supraspinatus, and the sides the lateral expansions which are united to the neighboring tendons. The ideal way to close would be to bring the center of the apex to the center of the base, but if the retraction is great and the base is small, the triangle is so prolonged upwards that one is tempted to close the gap from side to side until very near the base, and then to make
the last suture a triangular stitch. This method is easier, but it does not bring back the normal relations. However, it is a feasible method to use where there is much retraction. The exact way in which to put the sutures does not seem important, that is, whether they are mattress sutures or interrupted or continuous.

6. Formation of a new sulcus. If the reader will refer to Chapter IV, and especially to Plate VI, Figs. 3-4, and their legends concerning the remarkably effective method which nature has devised to attach the supraspinatus tendon to its facet, he will feel great doubt as to whether the surgeon will ever be able to imitate it with any degree of success. We need much study and experimental work before we can rely on being able to create a line of living cement such as the "blue line," with its pores for the finger-like processes. At present, from what we know of histology, it seems doubtful
whether in adult life such a method of union of tendon to bone can ever be achieved. However, we know that tendon can form a fairly firm cicatricial attachment to raw bone. What is the best practical way to secure this ?

If it were possible, we should wish to have the new tendon form on the raw surfaces of the sulcus and of the tuberosity down to the actual edge of the joint cartilage. When I drill the tuberosity I try to drill it as far as the cartilage edge, and I usually erode the bone of the sulcus with the point of a knife or curette, so that the tendon will have a little better chance to become attached by granulation. Dr. Philip Wilson has improved on my operation by cutting a slot around the cartilage edge and drilling through the base of the tuberosity. He then passes a slip of fascia lata through the drill holes to be attached above to the supraspinatus. He thus makes a more ideal suture, so that the tendon fills the entire sulcus and thus gains a firm hold on the tuberosity. It remains to be seen whether nature will tolerate such attachments indefinitely.

7. A frictionless surface for the base of the bursa is a most important point. Dr. Wilson's method has this advantage. It would be repetition to discuss this further, but I should like to repeat that even in those cases where the suture at the end of the operation has seemed rough, it may nevertheless be so changed by the healing process that a surface is produced which at a later operation appears smooth and normal.

8. I use silk sutures because I want them to endure long enough for new, strong, scar tissue or tendinous substance to form over them. I use a fairly heavy pedicle silk for the main suture, which passes through the holes in the tuberosity or between the proximal and distal portions of the tendon. I have on four occasions reopened the bursa later to remove these silk stitches because the patient complained of pain. The following are the findings in these four cases:

CASE 18
Mr. R. H. S. Age 60. M. G. H. No. 181765 E. S., Mar. 26, 1912. A typical case of complete rupture of the supraspinatus, one and one-quarter inches wide. Although much retracted, the tendon was caught and sutured in place with three mattress sutures. The functional result was good, but he continued to have more or less pain, apparently from the formation of a considerable amount of dense inflammatory tissue about the site of suture. On Feb. 13,1913, under novocaine, the bursa was again opened and the tendon was found not only completely repaired, but there was a large amount of dense hypertrophic, callous-like tissue about the sutures. This mass impinged on the acromion in abduction; most of it was removed with the scissors and a new opening made through the supraspinatus into the joint, so that some of the synovial fluid could flow into the bursa and lubricate it. The result of this operation has been satisfactory. Twelve years later, on June 9, 1925, he called to see me because of a slight injury to his left shoulder. The right, on which I had operated, had given him no trouble in the intervening years, although he had worked steadily as a coachman.

CASE 29
Mr. M. M. W. Age 39. M. G. H. No. 184216 W. S., Aug. 5, 1912. A clear case of badly ruptured supraspinatus tendon. The tendon was sutured with heavy silk and function was restored. During the following year he had much pain on use of the arm in his work as a laborer. The bursa was again explored and the silk sutures and some of the chronic inflammatory tissues lying about them were removed. I also made a new opening into the true joint to permit the fluid to flow into the bursa. This was followed by improvement but not by complete relief. No late report. Note that entire repair of the rupture had taken place.

CASE 88
Mr. T. M. Age 50+. Operated on at Faulkner Hospital, July 24, 1926, six months after his injury. The supraspinatus, infraspinatus and part of the subscapularis were found to be torn away, exposing the biceps tendon, which was greatly inflamed. There was much fluid in the joint. A very unsatisfactory suture was made, and the tuberosity had to be drilled. The arm was put up in abduction. Mild sepsis occurred and there was much fluid drainage, so that the wound took several weeks to heal. Some of the deep sutures were taken out. In spite of this the result at first was good, and he returned to his work after five months. He worked for a year and three months, although in some pain, and then had another slight injury. On July 2, 1928,1 again explored the bursa and found that most of the sutures had pulled away, leaving the condition practically as bad as at the first operation. This was as bad a result as I have ever had. The patient was for a time benefited, but in the end gained nothing by the operation, for I did not attempt a second suture.

CASE 112
Mr. A. C. Age 62. Operated on at the Trumbull Hospital on June 11, 1928, three months after his injury. A typical complete rupture of the supraspinatus was found and satisfactorily sutured. The immediate result appeared to be good. However, the patient would not go to work again, complained bitterly of pain on use of the arm and became very neurasthenic. On Feb. 7, 1929, I again explored the bursa, thinking that if I took out the deep sutures some of the irritation might be relieved. My notes say:
"I operated on him yesterday under novocaine ansesthesia. Dr. B. E. Wood was present and Dr. Stevenson assisted. Incision was made just inside the old scar and the bursa was opened. It was clearly shown that the former suture had been effective in restoring the insertion of the tendon. Moreover, the floor of the bursa was smooth and shiny, and there did not appear to be any cause for friction over the site of the suture. One heavy silk suture could be seen just below the transparent synovial lining of the base of the bursa; this was easily pulled out, but the other two sutures were buried deeply in the new-formed tendon and were found and removed with difficulty, as I was anxious not to weaken the tendon in so doing. In two of the sutures the knots were apparently untied; in one the knot was still present, but almost untied. At first I thought that the knots of the two untied ones had been left behind, but on reflection I think it is more reasonable to suppose that they had become untied as the tissues increased in amount and grew into the knots, which were cut very short. Yet it is possible that they broke off and remained in, although the total amount of silk in the untied ones appears greater than in the tied one by more than double. At any rate, very little silk could have been left behind.
"I did not feel satisfied that the silk was causing any trouble, for there appeared to be no inflammation about it, and the tender point of which the patient complained was nearly a half-inch away from the sutures, on the edge of the greater tuberosity close to the bicipital groove. That there was some inflammation at this point was made clear by finding a little crumbly, soft, cheesy tissue close to the synovial sheath of the biceps tendon, which in certain positions bulged slightly. The repair of the tendon was weakest at this point, and I fear that my search for the sutures weakened it still more, although not to an extent sufficient to interfere with function, and recompensed by the finding of this suspicious tissue. Two tiny bits of this tissue were saved for pathologic examination. (Plate V, Fig. 5.) The patient still claimed to be unable to work in January, 1931.
Since three out of four cases, which were explored a year or so after the first operation, showed not only firm tendons but hyper-trophied ones, it seems to me that it is proved that suture may be effective. In each case I was surprised to see how well nature had restored the even convexity of the floors of the bursae, which at the completions of the operations had been quite irregular and rough at the suture lines. All four cases, if operated on immediately after their injuries, might have had excellent results; as it was, although two of the four cases had good results, little was gained by the other two patients, unless they may take some satisfaction as demonstrators of the fact that these tendons even when badly broken may be repaired.

9. The shape of the needles is dictated by the shape of the field of operation and by the fact that a tremendous strain is put on them. They must be either fully curved or half curved, not over a half-inch long and with very strong shank and eye. One has to
work between the acromion and the tuberosity, where there is very little room, so that even a curved needle such as is used in ordinary operations is too large to be turned about in this space.

10. Shall we close the roof of the bursa or shall we merely close the muscle, leaving the roof of the bursa free to allow the synovial secretions to seep into the areolar tissue?
As I have previously stated, there is usually in these cases a considerable synovitis with a large amount of fluid. If the bursa is closed tight, this fluid forms under tension and causes pain. Closure also tends to keep blood in the bursa which would otherwise be washed out by the fluid itself. I prefer the idea of leaving the roof of the bursa unsutured to allow this fluid to escape, but I am not prepared to say positively that it is not better to suture the bursa and allow free motion after the operation to pump fluid out between the stitches. The fact is, in cases where there is much fluid (and these cases are usually those that have continued to work in spite of the friction and pain), the fluid seeps into the soft tissues to an extent which causes marked swelling and sometimes induces an edema and suggestion of sepsis. This used to be a frequent complication when I put the arm in elevation, permitting the lower side of the capsule to be held tense and therefore driving the fluid up toward the wound. Now that I treat them without restraint, I do not have this complication

11. The postoperative treatment. I find that my tendency has been, as the years go by, to allow more motion and to allow it sooner. I usually pad the axilla with a small pillow and then let the arm lie on it in a position a little more abducted than that in which the arm rests in a sling, contriving as best I can to keep the hand away from the front of the abdomen, because the tendency of the patient after these operations is to get the arm in a strongly internally rotated position, and therefore the recovery of the power of external rotation is slow. After the first night is over, I remove the dressing and let the patient put the arm in any comfortable position which he can find. Each day I exercise it in a way which is difficult to describe, but which is a matter of personal touch. The general purpose of the exercises is to let the patient bend his body from the hips with the arm relaxed, as described under the stooping exercises (Fig. 47). As in treating fractures near joints, I try to make the patient do as much active and passive motion of the arm as I believe I can without displacing the fragments. It is impossible to lay down more definite directions, but I may say that by the end of the first week I expect the patient to be able to bend his body at the hips to a right angle, and to let both the injured and well arm fall in a relaxed position at right angles to his body. By twisting his body from side to side so as to make one shoulder higher than the other, alternately, he can also move the joint without contracting the shoulder muscles. During the second week he is encouraged to swing the arms a little in both directions in this stooping position. The wound should be soundly and completely healed and the patient discharged from the hospital in from ten days to two weeks. After that he is encouraged to take the stooping exercises.
If the patient is cooperative and understands the mechanics of the operation and can use common sense in taking his exercises, he gets on fairly smoothly, but there is pain of an annoying although not of a serious degree, not only for weeks but for months. I do not think this would be the case where the operation was done immediately after the accident. In convalescence it is a good rule to restrain the patient from exercising his arm in the erect position until he has learned to abduct it freely and strongly in the stooping position. (See Fig. 47.) In long-standing cases the nerves of the region have already become sensitized and are slow in returning to a normal condition. Much of this postoperative soreness in the delayed cases is due to the sensitiveness and synovitis acquired between the date of the injury and that of the operation.

THE SABRE-CUT INCISION

Reprinted from the Bos. Med. & Surg. Jour., Mar. 10, 1927. It does not differ greatly from Kocher's posterior incision, but is more appropriate after a preliminary exploratory cut anterior to the joint.

FIGURE 1

"Sabre-cut" seemed an appropriate name for this incision, for it might well be made by the downward cut of a sabre on top of the shoulder. An incision is made through the acromio-clavicular joint and continued with a saw through the base of the acromion. The anterior point of the incision would be continuous with a previous routine bursal exploratory incision. When the acromion has been sawed through, an epulet of tissue, consisting of the deltoid muscle and the acromion process from which it arises, is formed to be pulled outward and downward. This step is accomplished' with ease, for it is only held by a little areolar tissue and a few fibers of the trapezius attached to the upper margin of the detached portion of the acromion. The upper posterior fibers of the deltoid must be separated a little to gain mobility. In sawing the base of the acromion one must bear in mind the suprascapular nerve which supplies the supra- and infra-spinatus muscles and lies between them, a little below the saw-cut. It is deep enough to be out of the way of the saw but not of gross carelessness.

FIGURE 2

The second diagram shows the structures exposed when this epulet is pulled downward and outward. Even without dissection one can identify the subscapularis, supraspinatus and infraspinatus as they emerge to join together their tendinous expansions beneath the base of the bursa. To one unfamiliar with this dissection the smooth convex surface of this base appears to be the articular surface of the humerus. The subacromial and subcoracoid or coraco-humeral bursse are nicely shown. As explained in previous papers, they are often intercommunicating and are always functionally one bursa although frequently, as in this instance, separated by one of the diaphanous nictitating folds. Notice the separated portion of the acromion and see how easily it will fit back into place.

FIGURE 3

The third diagram is identical with the last except that the supraspinatus and capsule have been cut across into the true joint and the ends of the supraspinatus depicted as retracted. The stub of the tendon is still attached to the tuberosity beneath the base of the bursa, while the muscular belly is retracting into the supraspinatus fossa. The glenoid and the articular surface of the humerus are exposed, with the long head of the biceps arising from the superior edge of the glenoid lying across the cartilaginous surface of the head of the humerus.
This is exactly the condition I have found at operation again and again in the living, except that there is seldom so much of a stub of tendon still attached to the tuberosity. Quite frequently it is entirely evulsed from the latter, requiring drilling of the tuberosity to resuture it. I have always found the base of the bursa to be torn across with the tendon. The point of least resistance appears to be about the subbursal portion of the tendon. In fact the tendon itself is very short, the muscle fibers beginning within a half-inch of the attachment.
In the long-standing cases on which I have operated the biceps tendon is found inflamed, swollen and bright pink in color, forming a striking contrast with the white articular surface of the humerus. Sometimes it is apparently absent entirely, having been evulsed and then retracted downward into its sheath.
To close this incision the parts are sutured back into place in the reverse order of these diagrams. It is probably safer to wire the acromion process, although catgut in the soft parts holds it well. I do not advise attempting to close the bursa even in the exploratory operation; a stitch or two in the muscle holds the edges in sufficient apposition and excess fluid may drain into the areolar tissue.

The pendulum will probably swing in future toward postoperative treatment in abduction and back again to adduction. Dr. Wilson now uses abduction after the sabre-cut incision and complete repair of the insertion into the bone by the use of fascia lata. It is possible that this method has the advantage of creating a larger gap between the head of the humerus and the acromion and the coraco-acromial ligament, because reunion of the mobilized acromion process would take place at a higher level, since it is pressed upward by the abducted humerus.

The Sabre-Cut Incision. Although I have personally given up the sabre-cut incision for cases of rupture of the supraspinatus, it is still used by others, especially by Dr. Wilson. It gives a splendid opportunity to repair the tendon or any other structure in the shoulder joint, but it is really a major operation, while the one I use is a minor one. The main reasons why I seldom use it are three. In the first place, I have learned to work through the routine incision in such a way that I can do the operation without cutting any ligaments or bone. This improvement has come about not only from doing the operation in dorsal flexion, but by using the method of rotating the humerus so that each desired point is placed in the middle of the small incision at the appropriate moment for a stitch. One assistant has to manipulate the arm in unison with the wishes of the surgeon. In the second place, I have found that after division and suture the acromio-clavicular joint may remain somewhat unstable.
A third reason is less technical and more in the domain of human nature. In Industrial Surgery there is not a frank understanding between surgeon and patient as in their ordinary professional relation. The patient is apt to have the element of compensation too strongly in mind, as compared to a cooperative tendency to make the best of the surgeon's attempt to better an injured limb, although both know it may never again be "as good as new." The extent of the sabre-cut incision exaggerates in the patient's mind the degree of the injury and the scar would certainly be impressive to a commission or jury.

Frontispiece

RUPTURE OF THE SUPRASPINATUS TENDON

FRONTISPIECE

THANKS to Dr. F. B. Mallory I was able to obtain the autopsy specimen of a case of a completely ruptured supraspinatus, from which this painting was made by Mr. Aitkin.
The skin and subcutaneous tissues were removed; then the fibers of the deltoid separated and held apart by retractors as in the usual routine incision. The diamond-shaped area between the two retractors is the floor of a rather large bursa. Nearly the whole right half of this floor retains its normal, smooth, whitish appearance, but in the left-hand portion of the base or floor is a roughly triangular area which represents the gap formed by the retracted supraspinatus tendon. At the right of this triangular gap, the long head of the biceps appears just beneath the falciform edge of the portion of the musculo-tendi-nous cuff formed by the subscapularis. In the left angle of the triangular area is seen a falciform edge formed by some of the superficial fibers of the infraspinatus. Just superior to this are a few vertical fibers of the deep posterior part of the supraspinatus which have not been evulsed. This was a. very thin, tenuous bit of tissue. The remaining central portion is roughly divided into three parts. The upper, bluish third is the exposed cartilage of the true joint. On its shiny surface near the very edge of the true joint cartilage, we see the high light of the reflection of the window. The lower third of this central space shows a typical "volcano" on the tip of the tuberosity, such as those depicted in Plate V, Figure 1, and in Figures 36 and 40. Between this "volcano" and the cartilage, and also occupying about one-third of the central area and bounded on the right by the margin of the biceps tendon, and on the left by the film-like, untorn edges of the infraspinatus and supraspinatus, we see a red, granulation-like irregular surface. This is the pathologically changed facet of insertion of the supraspinatus tendon and of a portion of that of the infraspinatus from which the tendons have been torn. Compare Figure 40, which is the Rontgen picture of the same specimen.
It must be understood that this picture represents the result of an injury experienced, in all probability, many years before; the tuberosity is in the recessing stage, and the edges of the torn tendons have become smooth by becoming falciform. The distal stub of the supraspinatus tendon, which was probably present in the first few months after the injury, being functionless, has disappeared. The proximal end of the tendon has retracted upward and could only be demonstrated if the newly formed falciform edge of the whole rent were removed. Even in this old case it could be isolated, pulled down and attached to the tuberosity, although with difficulty. One can readily imagine the pain which this patient endured during the first few years after his injury from the mere mechanical irritation from the tuberosity striking on the edge of the acromion during efforts at elevation of the arm, although nature has gradually nearly smoothed off the former prominent tuberosity, and, by partial healing of the edges of the torn structures, has made a new base of approximately spherical surface to pass under the acromion. The writer's operative efforts have mostly been concerned with relieving the results of such conditions. When the general practitioner has learned to recognize the symptoms of these lesions within a few days of their occurrence, suture of such torn tendons will be easily and successfully accomplished.

==References==
<references />

Shoulder:Rotator Cuff Pathology/Thickness Rotator Cuff Tears/Posterosuperior Rotator Cuff Tears and Associated Pathologies

2023-02-23T09:02:24Z

Alexandre.laedermann: /* Surgical (Operative) Treatment */

==Bullet Points==
*The rotator cable explains why patients with most rotator cuff tears can maintain active forward flexion, and also why even after only a partial rotator cuff repair, good functional results can be achieved.
*The most important negative prognostic factor is high-grade fatty infiltration of the rotator cuff muscle bellies (grade 3 or 4 fatty infiltration).
*The tangent sign is an indicator of advanced fatty infiltration and is a predictor of whether a rotator cuff tear will be reparable.
*Full thickness disruption of the lateral tendon stump (B1) is the most frequent type of rotator cuff lesion, comprising approximately 90% of all surgically treated lesions.
*Musculotendinous junction lesions (C-type) or rare and characterized by an edema of the muscle belly. They are associated to calcific deposit (infraspinatus) or trauma (supraspinatus). Unrepaired, grade III lesions lead rapidly to grade 4 fatty infiltration of the muscle.
*Tendon retraction is classified according to Patte. Overreduction and lateral transposition of the tendon over the greater tuberosity may be unphysiological.
*Massive rotator cuff has different definitions in the literature, each having potential benefits or drawbacks.
*Massive rotator cuff tears comprise approximately 20% of all cuff tears and 80% of recurrent tears.
*The classification of Collin not only subclassifies massive tears but has also been linked to function, particularly the maintenance of active elevation.
*Non-surgical treatment is effective in patient with massive rotator cuff if the tear involves less than three tendons and do not involves the subscapularis (D-type).
*Biomechanical testing has consistently demonstrated the superiority of double-row constructs over single-row. However, there is no obvious difference clinically.
*There is actually no support for routine suprascapular nerve release when massive rotator cuff repair is performed.
*Functional outcome improved after revision rotator cuff repair and 70% or more of patients were satisfied or very satisfied. However, the prevalence of persistent defect (retear or non-healing) is 28% at six months and 40% at two years.
*Rotator cuff are irreparable when associated to true pseudoparalysis with the presence of lag signs (external rotation lag, drop, dropping, hornblower signs), femoralization of the humerus or acetabulization of the acromion, grade 3 or 4 fatty infiltration and tangent sign.
*The current literature does not support the initial use of complex and expensive techniques in the management of posterosuperior irreparable rotator cuff tears.

==Key Words==
Shoulder arthroscopy; Rotator cuff lesion; Partial repair; Tear pattern; Classification; Massive; Reparable and non-repairable; Irreparable; Imaging; Recurrent; Failed; Revision surgery; Open and arthroscopic approach; Conservative or non-operative treatment; Physiotherapy; Functional outcomes; Prognostic factors; Latissimus dorsi transfer; Subacromial spacer interposition; Balloon; Biceps tenotomy; Superior capsular reconstruction; Reverse arthroplasty; Magnetic resonance imaging (MRI) arthrography (MRA); Fosbury flop tear; New tear pattern; FUSSI; SAM.

==Anecdote==
===How double-row was born===
When Ian Lo was my Fellow in 2001-2002, he and I wrote 2 papers on my technique of arthroscopic non-linked double-row rotator cuff repairs. As far as I can tell, these were the first 2 published articles on arthroscopic double-row cuff repair. These were published in 2003 in The American Journal of Sports Medicine<ref>Lo IKY, Burkhart SS. Current concepts in arthroscopic rotator cuff repair. Am J Sports Med 2002;31(2):308-324</ref> and The Arthroscopy Journal.<ref>Lo IKY, Burkhart SS. Double row arthroscopic rotator cuff repair: Re-establishing the footprint of the rotator cuff. Arthroscopy 2002;19(9):1035-1042</ref> The technique was a non-linked double row repair that I had first done 8 years earlier, in 1995. However, the reason that I did my first arthroscopic double-row repair was not what you might think.......

My index double row repair patient was a 55-year-old female who had fallen and sustained a traumatic non-retracted tear of the supra- and infraspinatus. After I had done an arthroscopic acromioplasty and subacromial bursectomy, I still had trouble visualizing the greater tuberosity footprint because the torn tendon was quite redundant and extended far laterally. It seemed as if the redundant, unstable cuff tissue filled the entire subacromial space, making visualization very difficult. So, in order to stabilize the cuff and see the greater tuberosity well enough to properly prepare the bone, I placed a single anchor medially on the tuberosity and then passed the sutures from the anchor through the medial part of the cuff; then I tied the knot as a mattress stitch. This single fixation point on the medial part of the greater tuberosity controlled the "unstable" redundant tendon so that I could then see well enough to prepare the greater tuberosity bone bed. But it also allowed me to see that I would have enough tendon length to completely cover the greater tuberosity with the repair. So I placed 2 more medial anchors and completed the medial fixation of the tendon. Then I placed 2 lateral anchors to tack down the lateral flap of the tendon so that there was firm contact of the tendon to the bone between the two rows of anchors. At that point, the repair looked completely anatomic. In fact, it looked so good, that I resolved to start doing double-row repairs on torn cuffs whose tendons had enough redundancy to cover the greater tuberosity without undue tension. So, in retrospect, I did my first double row repair to control an unstable tendon so that I could visualize the operative field better, rather than intentionally trying to create a broader anatomic footprint with my repair. But this opened the door for further biomechanical research on double-row versus single-row repairs, and soon the biomechanical superiority of double row was apparent.

Steve Burkhart

==Biomechanics of the Posterosuperior Rotator Cuff==
A primary function of the rotator cuff is to work synergistically with the deltoid to maintain a balanced force couple about the glenohumeral joint. A force couple is a pair of forces that act on an object and tend to cause it to rotate. For any object to be in equilibrium, the forces must create moments about a center of rotation that are equal in magnitude and opposite in direction. Coronal and transverse plane force couples exist between the subscapularis anteriorly and infraspinatus and teres minor posteriorly. The rotator cuff force across the glenoid provides concavity compression, which creates a stable fulcrum and allows the periscapular muscles to move the humerus around the glenoid.

The rotator cable is a thickening of the rotator cuff that has been likened to a suspension bridge in which force is distributed through cables that are supported by pillars (the anterior and posterior attachments). The anterior rotator cable attachment bifurcates to attach to bone just anterior and posterior to the proximal aspect of the bicipital groove. The posterior attachment comprises the inferior 50% of the infraspinatus. With small central tears the cable attachments often stay intact and forces are transmitted along the rotator cable. The rotator cable also explains why patients with most rotator cuff tears can maintain active forward flexion, and also why even after only a partial rotator cuff repair, good functional results can be achieved.<ref>Burkhart SS, Nottage WM, Ogilvie-Harris DJ, Kohn HS, Pachelli A. Partial repair of irreparable rotator cuff tears. Arthroscopy 1994;10:363-70.</ref> 

However, in the setting of massive rotator cuff with rotator cable disruption and non-compensation by other humeral head stabilizers (i.e pectoralis major and latissimus dorsi), the moments created by the opposing muscular forces are insufficient to maintain equilibrium in the coronal plane, resulting in altered kinematics, instability, and ultimately in pseudoparalysis. Interestingly, only few patients with an irreparable rotator cuff tears developed pseudoparalysis and arthritis.This finding has at least two potential explanations. First, the subscapularis that may not be involved in these tears is the key factor of active forward flexion.<ref name=":1">Collin P, Matsumura N, Lädermann A, Denard PJ, Walch G. Relationship between massive chronic rotator cuff tear pattern and loss of active shoulder range of motion. J Shoulder Elbow Surg 2014;23:1195-202.</ref> 

Second, the rotator cable, has still an intact anterior attachment which is important for elevation. This may explain why patients can maintain active mobility, and also why even after only a partial rotator cuff repair, good functional results can be achieved.<ref name=":2">Denard PJ, Lädermann A, Brady PC, Narbona P, Adams CR, Arrigoni P, Huberty D, Zlatkin MB, Sanders TG, Burkhart SS. Pseudoparalysis From a Massive Rotator Cuff Tear Is Reliably Reversed With an Arthroscopic Rotator Cuff Repair in Patients Without Preoperative Glenohumeral Arthritis. Am J Sports Med 2015;43:2373-8.</ref>

Consequently, all the conditions for an imbalance in the force couples are not always met and subsequently loss of function is only occasionally seen.

==Clinical examination==
===Inspection===
Inspection has to rule out deformation, swelling (i.e Milwaukee shoulder syndrome, Figure) or hematoma (Video).

[[File:Milwalkee.png|thumb|Milwaukee shoulder syndrome is associated with intra-articular deposition of hydroxyapatite crystals and disruption of the rotator cuff. The Figure illustrates a patient with involvement of the left shoulder]]
[[File:Bossy épaule sénile hémorragique.mov|thumb|Hematoma related to massive rotator cuff tear.]]

===Palpation===
This subsection does not exist. You can ask for it to be created, but consider checking the search results below to see whether the topic is already covered.

===Range of Motion===
The patient must be examined not only in the standing position, but also supine on a table in order to block scapulothoracic movements, and look for all amplitudes (anterior elevation, abduction, internal rotation and external rotation elbow at the side and at 90 degrees of abduction).

===Tests for posterosuperieur rotator cuff lesions===
====Supraspinatus====
Supraspinatus is an external rotator.<ref name=":4">Inman VT, Saunders M, Abbott, MC. Observations on the function of the shoulder joint. J Bone Joint Surg Br. 1944;1:1-30.</ref> It also initiates abduction in conjunction with deltoid, serrates anterior and infraspinatus. The following tests are consequently not specific for the supraspinatus but are sensitive due to antalgique reflex. Superior rotator cuff insufficiency, present in complete tears, is usually associated with a positive Jobe manoeuver (empty can) (Video) and decreased strength in external resistance elbow at the side (Figure).<ref>Jobe FW, Moynes DR. Delineation of diagnostic criteria and a rehabilitation program for rotator cuff injuries. Am J Sports Med 1982;10:336-9.</ref>

[[File:Jobe test.mov|thumb|The Jobe test is performed by placing the patient's arms at 90 degrees of abduction within the scapular plane, maximally internally rotating the arms and resisting further abduction by the patient. A positive test occurs with localized pain to the affected arm.]]

[[File:cuff104_2.jpg|thumb|Testing of the strength in external resistance elbow at the side.]]

Testing of abduction strength in the champagne toast position, i.e., 30 degrees of abduction, mild external rotation, and 30 degrees of flexion, better isolates the activity of the supraspinatus from the deltoid than Jobe's “empty can” position (Figure 3).<ref>Chalmers PN, Cvetanovich GL, Kupfer N, Wimmer MA, Verma NN, Cole BJ, Romeo AA, Nicholson GP. The champagne toast position isolates the supraspinatus better than the Jobe test: an electromyographic study of shoulder physical examination tests. J Shoulder Elbow Surg 2016;25:322-9.</ref>
[[File:1562464235806-lg.jpg|center|thumb|900x900px|Testing at 30 degrees of abduction, 30 degrees of forward elevation, 90 degrees of elbow flexion, and mild external rotation replicates a “toast” position.]]
 

====Infraspinatus and Teres Minor====
=====Strength in External Rotation Elbow at the Side=====

Strength in external rotation elbow at the side of the supraspinatus, infraspinatus and teres minor represents approximately 10%, 70% and 20% of total external rotation strength, respectively.<ref>Gerber C, Blumenthal S, Curt A, Werner CM. Effect of selective experimental suprascapular nerve block on abduction and external rotation strength of the shoulder. J Shoulder Elbow Surg 2007;16:815-20.</ref> 

However, the function of the teres minor may become more important in the setting of a chronic infraspinatus tear, as its hypertrophy is commonly observed in these cases and probably compensates for external rotation weakness.

=====External Rotation Lag Sign=====
The external rotation lag sign (Figure and Video), described by Hertel, was designed to test the integrity of infraspinatus and supraspinatus tendons.<ref>Hertel R, Ballmer FT, Lombert SM, Gerber C. Lag signs in the diagnosis of rotator cuff rupture. J Shoulder Elbow Surg 1996;5:307-13</ref>

The extent of internal rotation is recorded to the nearest 10 degrees degrees (10, 20, 30 and 40 degrees or above). An external rotation lag sign > 40 degrees seems to be the most reliable test for the teres minor.<ref name=":5">Collin P, Treseder T, Denard PJ, Neyton L, Walch G, Lädermann A. What is the Best Clinical Test for Assessment of the Teres Minor in Massive Rotator Cuff Tears? Clin Orthop Relat Res 2015;473:2959-66</ref>
[[File:1562464228129-lg.jpg|center|frame|A) The external rotation lag sign is performed seated with the elbow flexed to 90 degrees and the shoulder elevated 20 degrees in the scapular plane. The arm is passively taken to maximal external rotation minus 5 degrees to allow for elastic recoil. B) The patient was asked to maintain that position as the clinician released the wrist. A positive test is defined as any internal rotation of more than 10 degrees. Reproduced from Collin et al., with permission.]]

[[File:ERLS 2 N25 (converti).mov|thumb|External rotation lag sign.]]

=====Drop Sign=====
The drop sign (Figure and Video), also described by Hertel, is designed to assess the function of the infraspinatus.
[[File:1562464890613-lg.jpg|center|frame|A) The drop sign is a lag sign beginning from 90 degrees of abduction in the scapular plane, with elbow flexion of 90 degrees, and external rotation of the shoulder to 90 degrees. From this position, the patient is asked to maintain the position against gravity (MRC Grade 3). B) Failure to resist gravity and internal rotation of the arm is considered a positive drop sign. Reproduced from Collin et al., with permission.]]
[[File:1563115163992-lg.mp4|center|frame|Drop sign]]

=====Hornblower sign=====
The patient is asked to bring both hands to his mouth, but is unable to do so without abducting the affected arm (Video 5).
[[File:1562465141586-lg.mp4|center|thumb|Hornblower sign]]
 

=====Patte Test=====
The Patte test (Figure and Video ) is the only test that allowed to analyze the muscular strength of the teres minor in case of deficient infraspinatus.<ref>Patte D, Goutallier D. [Grande libération antérieure dans l'épaule douloureuse par conflit antérieur]. Rev Chir Orthop Reparatrice Appar Mot 1988;74:306-11.</ref> Walch et al. reported a 100% sensitivity and 93% specificity with the Patte test and teres minor fatty atrophy Grade 3 or greater.<ref name=":6">Walch G, Boulahia A, Calderone S, Robinson AH. The 'dropping' and 'hornblower's' signs in evaluation of rotator-cuff tears. J Bone Joint Surg Br 1998;80:624-8</ref>

[[File:1562465387058-lg.jpg|center|frame|A) The Patte test is performed by passively taking from a starting point of 90 degrees of abduction in the scapular plane, an elbow flexion of 90 degrees without external rotation. B) The patient is asked to perform external rotation of the shoulder from this position against resistance. A positive Patte test is defined as external rotation power less than MRC Grade 4. Reproduce from <ref name=":5" />, with permission.]]

[[File:2 Patte.mov|thumb|Patte test]]

=====Dropping Sign=====
The dropping sign of Neer had a 100% sensitivity and 66% specificity for teres minor involvement.<ref>Neer C. Cuff tears, biceps lesions, and impingement. In: Neer C, ed. Shoulder reconstruction. Philadelphia: W. B. Saunders Company; 1990:41-142.</ref><ref name=":6" />

[[File:Dropping Walch.mov|thumb|Dropping sign]]

==Imaging==
#REDIRECT [[https://wiki.beemed.com/view/Shoulder:Radiographic_Evaluation_of_Shoulder_Problems#Rotator_Cuff_Evaluation]<nowiki>]</nowiki>

==Classification==
The rotator cuff lesions are categorized into four major groups based on involvement of the bone (Type A), tendon (Type B), musculotendinous junction (Type C) or muscle insufficiency (Type D).

[[File:1562468648674-lg.png|thumb|600x600px|alt=|center|Classification of full-thickness rotator cuff lesions in the coronal plane. Reproduced from Lädermann et al.,<ref>Lädermann A, Burkhart SS, Hoffmeyer P, Neyton L, Collin P, Yates E, Denard PJ. Classification of full-thickness rotator cuff lesions: a review. EFORT Open Rev. 2017;1:420-430.</ref> with permission]]

===Type A: Bony Involvement===
While the majority of rotator cuff lesions involve the tendinous insertion, bony involvement is an important consideration. Bony involvement includes acute fractures, malunion/nonunion, and chronic bony insufficiency.

====A1. Acute Bony Involvement (Fractures and Avulsions)====
Isolated greater tuberosity fractures are considered uncommon, representing less than 5% of all operatively treated proximal humeral fractures.<ref>Court-Brown CM, Garg A, McQueen MM. The epidemiology of proximal humeral fractures. Acta Orthop Scand 2001;72:365-71.</ref> 

Isolated lesser tuberosity fractures are generally considered rare. Type A lesion of the greater or lesser tuberosity represent approximately 3.2% and 1.1% respectively of surgically treated rotator cuff lesions (Table). Tuberosity fractures are included in the accepted classification for proximal humeral fractures by Neer, in itself a modification of Codman’s original description. Because the greater and lesser tuberosity are the insertion site of the rotator cuff, even small tuberosity fractures or avulsions can represent substantial disruption of the rotator cuff and lead to functional impairment if displaced and left untreated. Historically, Neer proposed 10 mm of displacement as a threshold for operative intervention.<ref>Neer CS, 2nd. Displaced proximal humeral fractures. I. Classification and evaluation. J Bone Joint Surg Am 1970;52:1077-89.</ref> 

However, more recent investigation has recommended that a threshold of 5 mm should be used.<ref>Bono CM, Renard R, Levine RG, Levy AS. Effect of displacement of fractures of the greater tuberosity on the mechanics of the shoulder. J Bone Joint Surg Br 2001;83:1056-62.</ref> 

Displacement of greater than 5 mm can lead to bony impingement with loss of range of motion as well as loss of strength from compromise in the normal length–tension relationship of the rotator cuff. A traumatic mechanism is typical such as violent muscular contraction, impaction of the greater tuberosity beneath the acromion, or shearing against the anterior glenoid rim during a glenohumeral dislocation event. Thorough patient evaluation is required to make an appropriate treatment recommendation. Conservative therapy is limited to non- or minimally-displaced fractures. The ongoing development of arthroscopic techniques has led to multiple reports about arthroscopically assisted or total arthroscopic techniques in the treatment of these injuries.<ref>Greiner S, Scheibel M. [Bony avulsions of the rotator cuff : Arthroscopic concepts]. Der Orthopade 2011;40:21-4, 6-30.</ref>

====A.2 Tuberosity Malunion/Nonunion====
Tuberosity malunion or nonunion can be a sequela of either conservative treatment or surgical treatment of acute injuries. As noted previously, displacement effectively shortens the muscle-tendon unit such that the rotator cuff cannot function properly (Figures).
[[File:1562470234366-lg.jpg|center|thumb|750x750px|Schema of tuberoplasty for varus malunion of a surgical neck fracture. (A) Intact proximal humerus. (B) Varus malunion results in a medialized greater tuberosity and effectively decreases the resting tension in the rotator cuff. As a result, force generation is compromised. (C) The rotator cuff is detached, and a tuberoplasty is performed with a burr. (D) Reattachment of the rotator cuff laterally results in restoration of the rotator cuff length–tension relation. Reproduce from Lädermann et al.,<ref name=":44" /> with permission.]]
[[File:1562470238482-lg.jpg|center|thumb|750x750px|Schema of tuberoplasty for valgus malunion of 3-part proximal humeral fracture. (A) Intact proximal humerus. (B) Valgus impaction results in superior displacement of the greater tuberosity and effectively decreases the resting tension in the rotator cuff. As a result, force generation is compromised. (C) The rotator cuff is detached, and a tuberoplasty is performed with a burr. (D) Reattachment of the rotator cuff laterally results in restoration of the rotator cuff length-tension relation. Reproduce from Lädermann et al.,<ref name=":44" /> with permission.]]Various open techniques have been described for the management of the malunion of proximal humeral fractures, including prosthetic reconstruction, open corrective osteotomy, or arthroscopic capsular release followed by takedown of the rotator cuff from the malunited proximal humerus, tuberoplasty, and then rotator cuff advancement. Although the latter technique is technically demanding, it allows preservation of the native humeral head, which is associated with a low complication rate, and avoids concerns about long-term prosthetic survival in young patients (Video).<ref name=":13">Burkhart SS, Klein JR. Arthroscopic repair of rotator cuff tears associated with large bone cysts of the proximal humerus: compaction bone grafting technique. Arthroscopy 2005;21:1149.</ref><ref name=":44">Lädermann A, Denard PJ, Burkhart SS. Arthroscopic management of proximal humerus malunion with tuberoplasty and rotator cuff retensioning. Arthroscopy 2012;28:1220-9.</ref>
[[File:1563115162982-lg.mp4|center|thumb|720x720px|Video]]
 
[[File:1563115159736-lg.mp4|center|frame|Video]]
 

====Operative Technique====

The patient was placed in a beach chair or in a lateral decubitus position. A diagnostic arthroscopy is performed with an arthroscopic pump maintaining pressure at 50 mm Hg. The joint surfaces were inspected to rule out any incongruities. The articular side of the rotator cuff is carefully assessed with a probe searching for tears. Any capsular retraction is addressed at this point. A release of the rotator interval and superior glenohumeral ligament is performed with an electrocautery introduced from an anterior portal. This was followed by a release of the posterior, inferior, and anterior capsule 5 mm away from the labrum with an electrocautery introduced from the posterior portal while the surgeon is viewing from an anterosuperolateral portal. If still present, the intra articular part of the long head of the biceps tendon undergo either tenotomy or tenodesis. After treatment of any intra-articular pathology, such as loose body removal, attention is turned to the subacromial space. The lateral and posterolateral gutters are cleared. ny previously placed metal hardware are removed. While the surgeon is viewing from a posterior glenohumeral portal, the tuberoplasty is initiated. The arthroscope is then moved to the subacromial space, and the rotator cuff, if necessary, is sharply elevated from its malunited footprint by use of an electrocautery. Elevation of the rotator cuff consisted of the supraspinatus and anterior half of the infraspinatus, which is the part that overlies the proximally migrated tuberosity (Video). After elevation of the rotator cuff attachments, a burr is used to perform a tuberoplasty. The cuff is assessed for mobility and integrity and is then retensioned by advancing the cuff laterally on the greater tuberosity and performing a rotator cuff repair. The rotator cuff is advanced and repaired. A modified acromioplasty with a lateral bevel is routinely performed if not done previously.

===A.3 Tuberosity Insufficiency===

Tuberosity insufficiency can range from contained cystic bony defects within the tuberosity to the absence of the entire tuberosity. Cystic bony defects are often encountered during primary or revision rotator cuff repair. Such defects may be idiopathic, related to a patient's rotator cuff disease, or secondary to osteolysis from breakdown of bioreabsorbable anchors. These osseous defects reduce biological healing capacity and may decrease repair fixation strength. Bone grafting techniques are needed to address these defects.<ref name=":13" />
[[File:1562471498963-lg.jpg|center|thumb|500x500px|Computed tomography (CT) scan show greater tuberosity bone loss.]] 
In such a situation, a simple tendon rotator repair is usually unsuccessful, as a large bony defect significantly lowers the prognosis for primary repair.<ref>Moore DR, Cain EL, Schwartz ML, Clancy WG, Jr. Allograft reconstruction for massive, irreparable rotator cuff tears. Am J Sports Med 2006;34:392-6.</ref> 
One explanation might be that deltoid tension and therefore function is potentiated by the greater tuberosity, also called “deltoid wrapping”.<ref>Roche CP, Diep P, Hamilton M, Crosby LA, Flurin PH, Wright TW, Zuckerman JD, Routman HD. Impact of inferior glenoid tilt, humeral retroversion, bone grafting, and design parameters on muscle length and deltoid wrapping in reverse shoulder arthroplasty. Bulletin of the Hospital for Joint Disease 2013;71:284-93.</ref> 
Therefore, reconstruction of this combined bony and tendon defect may require both tendinous and bony reconstruction. In older patients, such insufficiency is most reliably addressed with reverse shoulder arthroplasty. However, reverse shoulder arthroplasty is not ideal for young patients as multiple studies have demonstrated increased complications in this patient population.<ref>Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: results after five to fifteen years. J Shoulder Elbow Surg 2013;22:1199-208.</ref><ref>Sershon RA, Van Thiel GS, Lin EC, McGill KC, Cole BJ, Verma NN, Romeo AA, Nicholson GP. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg 2014;23:395-400.</ref> 
Recently, a fresh frozen bony-tendinous allograft of the calcaneus and Achilles tendon has been proposed to address this difficult problem (Video). Long term results and larger series need to confirm this technique.<ref name=":14">Lädermann A, Denard P, Abrassart S, Schwitzguébel A. Achilles Tendon Allograft for an Irreparable Massive Rotator Cuff Tear with Bony Deficiency of the Greater Tuberosity: A Case Report. Knee Surg Sports Traumatol Arthrosc 2016;Jan 25.</ref>

===Surgical Technique===

Allograft Reconstruction with Calcaneum and Achilles Tendon for an Irreparable Massive Rotator Cuff Tear with Bony Deficiency of the Greater Tuberosity (Video). Under general anesthesia and interscalene nerve block, the patient is placed in the beach chair position, with the operative arm draped free. An open anterosuperior incision with a deltoid split is performed in order to expose the greater tuberosity defect. The long head of the biceps was already resected. The remaining posterosuperior rotator cuff was carefully dissected and the proximal humeral head is debrided. The quality of cuff tissue is usually poor (Figure).
[[File:1563115175999-lg.mp4|center|thumb|900x900px|Video]]
[[File:1562472470428-lg.jpg|center|thumb|600x600px|Lateral view of a right shoulder. Observe the bony defect in the greater tuberosity associated with the poor rotator cuff tendon quality.]]
 The Achilles tendon allograft with attached calcaneus is then prepared (Figure and Video).
[[File:1562474028794-lg.jpg|center|thumb|600x600px|The allograft is prepared with an Achilles tendon.]]
The calcaneus is shaped to fill proximal humeral head defect. If necessary, the Achilles tendon is then split longitudinally to decrease its thickness, with the deep layer used to reinforce the rotator cuff repair. Then, the bony portion of the allograft is secured to the humeral head with a 4 mm malleolar screw under fluoroscopic control (Figure).
[[File:1562474027986-lg.jpg|center|thumb|600x600px|Lateral view of a right shoulder. A malleolar screw fixes the calcaneum in the defect. The calcaneum is ready to reinforce the rotator cuff.]]
The native rotator cuff was then repaired onto the bony graft with a combination of an anchor and bone tunnels in the graft. The deep split of Achilles tendon is then sewn into the native posterosuperior rotator cuff to reinforce the repair (Figures and Video).
[[File:1562474087899-lg.jpg|center|thumb|600x600px|Final reconstruction.]]
Two years follow-up confirm bony and tendinous integration (Figures).
[[File:1562474024175-lg.jpg|center|thumb|600x600px|Anteroposterior X-ray of a right shoulder. The bony allograft is incorporated in the proximal humerus, filling the greater tuberosity defect.]]
[[File:1562474554815-lg.jpg|center|thumb|412x412px|Long term computed tomography (CT) arthrogram confirming the repair of the rotator cuff.]]
Postoperatively, the patient wears an abduction pillow for six weeks and is allowed to perform pendulum exercises. After six weeks the abduction pillow is discontinued and passive mobilization is allowed. Full activity return and strengthening was permitted at three months, with a progressive increase of loads.

===Type B: Full Thickness Tendon Lesion===
====B1: Lateral tendinous disruption====

Full thickness disruption of the lateral tendon stump is the most frequent type of rotator cuff lesion, comprising approximately 90.1% of all surgically treated lesions (Table 1). Tendinous lesions most commonly involve the posterosuperior cuff. Subscapularis tears are nevertheless found in 59% of arthroscopic rotator cuff repairs.<ref>Barth JR, Burkhart SS, De Beer JF. The bear-hug test: a new and sensitive test for diagnosing a subscapularis tear. Arthroscopy. 2006;22:1076-84.</ref> However, such tears are only full-thickness in 8.7% of cases, and are rarely isolated (Table 1).

=====Size of Tendon Lesion=====

Classifications for tear size include measurement in centimeters or number of tendons involved. This information can be derived from arthroscopy or magnetic resonance imaging and used to offer guidance on treatment and prognosis.<ref>Cofield RH. Rotator cuff disease of the shoulder. J Bone Joint Surg Am 1985;67:974-9.</ref><ref name=":15">Davidson J, Burkhart SS. The geometric classification of rotator cuff tears: a system linking tear pattern to treatment and prognosis. Arthroscopy 2010;26:417-24.</ref><ref name=":21">Gerber C, Fuchs B, Hodler J. The results of repair of massive tears of the rotator cuff. J Bone Joint Surg Am 2000;82:505-15.</ref><ref>Harryman DT, 2nd, Mack LA, Wang KY, Jackins SE, Richardson ML, Matsen FA, 3rd. Repairs of the rotator cuff. Correlation of functional results with integrity of the cuff. J Bone Joint Surg Am 1991;73:982-9.</ref><ref name=":16">Lädermann A, Denard PJ, Collin P. Massive rotator cuff tears: definition and treatment. International orthopaedics 2015;39:2403-14.</ref>

Once size is identified and if massive, it can be further classified according to Collin et al.<ref name=":1" />

=====Tendon Retraction=====

Patte devised a method of classifying tendon coronal retraction that is often used for research purposes.<ref>Patte D. Classification of rotator cuff lesions. Clin Orthop Relat Res 1990:81-6.</ref>

The retraction is due to tendon and muscle shortening that are not synchronous after tendon tear.<ref name=":10" />

Substance loss in the later stages of musculotendinous retraction may be because of either active shortening of the tendon substance, suggesting that overreduction and lateral transposition of the tendon over the greater tuberosity may be unphysiological.

=====Tear Pattern=====

Full-thickness posterosuperior tears come in a variety of patterns. The most common categories include crescent tears, L and reverse L-shaped tears, and U-shaped tears accounting for respectively 40%, 30% and 15% of posterosuperior rotator cuff lesions.<ref name=":15" />

Recognition of these tear patterns is most useful for anatomic restoration during repair. Crescent tears have good medial to lateral mobility and are amenable to a double-row repair. Longitudinal tears (L and reverse L-shaped tears, and U-shaped tears) have greater mobility in 1 plane and typically require margin convergence to achieve complete repair. Finally, massive contracted tears have also been described. These tears have limited medial to lateral and anterior to posterior mobility and typically require advanced mobilization techniques (i.e. interval slides) to achieve repair.

=====Releases for the Rotator Cuff=====

In clinical practice, rotator cuff tears may present with a wide spectrum of size and mobility. Many massive rotator cuff tears may be reparable without releases and, in contrast, some small rotator cuff tears may require releases. Release is only required if tear may not be reduced to the footprint anatomically as it would otherwise unnecessarily increase the complexity of the procedure. Releases may be divided into bursal sided releases, articular sided releases (i.e. capsular release) and interval slides.

=====Double-Row Versus Single-Row Cuff Repair=====

Biomechanical testing has consistently demonstrated the superiority of double-row constructs.<ref>Hohmann E, König A, Kat CJ, Glatt V, Tetsworth K, Keough N. Single- versus double-row repair for full-thickness rotator cuff tears using suture anchors. A systematic review and meta-analysis of basic biomechanical studies. Eur J Orthop Surg Traumatol. 2018;28:859-868.</ref>

Within the domain of level I mid-term and short-term studies, double-row repair (Video) showed significant better UCLA score only (American Shoulder and Elbow Surgeons (ASES), Constant, WORC, and SANE scores showed no significance). This may correlate weakly with the significant lower partial-thickness retear rates of double-row repairs. In contrary, long-term level III studies showed a direct correlation of both functional outcomes and cuff structural integrity, with significant superiority of double-row over single-row repair techniques.<ref>Sobhy MH, Khater AH, Hassan MR, El Shazly O. Do functional outcomes and cuff integrity correlate after single- versus double-row rotator cuff repair? A systematic review and meta-analysis study. Eur J Orthop Surg Traumatol. 2018;28:593-605.</ref>

=====Margin Convergence=====

Margin convergence to bone can be used in L or V tears. This technique accomplishes margin convergence between the two leaves of the cuff, and at the same time it anchors the cuff to bone, providing very secure fixation. Margin convergence to bone has the mechanical strain reduction advantage of margin convergence coupled with strong fixation to bone. This provides a very secure component to the overall fixation construct.

=====Load Sharing Rip Stop Construct=====

Double-row repair is not possible in the setting of medially based tears, lateral tendon loss, or limited tendon mobility. Load sharing rip stop constructs demonstrated improved functional outcomes with reasonable healing rates in an otherwise challenging subset of rotator cuff tears.<ref name=":22">Noyes MP, Lädermann A, Denard PJ. Functional Outcome and Healing of Large and Massive Rotator Cuff Tears Repaired With a Load-Sharing Rip-Stop Construct. Arthroscopy. 2017 Sep;33(9):1654-1658.</ref>

This suture technique combines the advantages of a rip stop suture tape and load sharing properties of a double-row repair and has biomechanically superior properties compared to a single-row repair (Figure and Video).<ref>Denard PJ, Burkhart SS. A load-sharing rip-stop fixation construct for arthroscopic rotator cuff repair. Arthrosc Tech 2012;1:e37-42.</ref>
[[File:1562475768794-lg.jpg|center|thumb|700x700px|Anchor-based rip-stop rotator cuff repair for rotator cuff tear with lateral tendon loss. (A) A suture has been placed as an inverted mattress stitch in the rotator cuff. Two medial anchors have also been placed, and sutures from these anchors are passed medial to the rip-stop stitch. (B) Prior to tying of the sutures from the medial anchors, the rip-stop stitch is secured to bone with 2 lateral anchors. (C) Tying the suture limbs from the anchors completes the repair. Reproduce from Noyes et al., with permission.]]
[[File:1563115214642-lg.mp4|center|thumb|900x900px|Video]]
[[File:1563115230318-lg.mp4|center|thumb|900x900px|Video]]

=====Massive Posterosuperior Rotator Cuff Tears=====

======Prevalence======
Massive rotator cuff tears comprise approximately 20% of all cuff tears and 80% of recurrent tears.<ref name=":23">Lo IK, Burkhart SS. Arthroscopic revision of failed rotator cuff repairs: technique and results. Arthroscopy 2004;20:250-67.</ref><ref>Burkhart SS, Danaceau SM, Pearce CE, Jr. Arthroscopic rotator cuff repair: Analysis of results by tear size and by repair technique-margin convergence versus direct tendon-to-bone repair. Arthroscopy 2001;17:905-12.</ref>

=====Definition and Classification of Massive Rotator Cuff Tears=====

Historically a massive rotator cuff tear has been described as a tear with a diameter of 5 cm or more as described by Cofield or as a complete tear of two or more tendons as described by Gerber (Figure).<ref>Cofield RH. Subscapular muscle transposition for repair of chronic rotator cuff tears. Surg Gynecol Obstet 1982;154:667-72.</ref><ref name=":21" />

The former in particular is usually applied at the time of surgery. In an attempt to provide a preoperative MRI-based classification, Davidson et al. defined a massive tear as one with a coronal length and sagittal width greater than or equal to 2 cm.<ref name=":15" />

Unfortunately, these systems are vulnerable to error due to variation in patient size and arm position at the time of measurement. It is more appropriate to define the size of a tear in terms of the amount of tendon that has been detached from the tuberosities. While the Gerber definition helps account for variability in size, there are exceptions to the complete two tendons requirement and this classification does not distinguish different patterns or predict function. Additionally, in using the term “massive”, there is a connotation of difficulty and irreparability. While challenging, most massive rotator cuff tears are reparable and other factors like the tendon retraction, atrophy, arthritis, and mobilization must be considered. Thus, in addition to the number of tendons involved, some authors proposed at least one of the two tendons must be retracted beyond the top of the humeral head (i.e Patte 3 for the supraspinatus in the coronal plane).<ref name=":16" />

Such classification also takes advantage of 3-dimensional information on tear pattern, providing guidance on treatment technique.
{| class="wikitable"
|+
!Author
!Description
!Limitation(s)
|-
|Cofield
|5 cm or more
|No 3-dimensional information, variation in patient size and arm position
|-
|Gerber
|≥ 2 complete tendons
|No 3-dimensional information
|-
|Davidson
|Coronal length and sagittal width ≥ 2 cm
|Variation in patient size and arm position
|-
|Lädermann
|≥ 2 complete tendons, 1 tendon with > Patte 2 retraction
|
|}
Table 2: Different Classification of Massive Rotator Cuff Tears

 Once a massive rotator cuff tear is identified, it can be further classified according to Collin et al. In this subclassification, the rotator cuff is divided into five components: supraspinatus, superior subscapularis, inferior subscapularis, infraspinatus, and teres minor (Figure).
[[File:1562478202097-lg.jpg|center|thumb|600x600px|The rotator cuff is divided into 5 components: supraspinatus, superior subscapularis, inferior subscapularis, infraspinatus, and teres minor.]]
Rotator cuff tear patterns can then be classified into 5 types: type A, supraspinatus and superior subscapularis tears; type B, supraspinatus and entire subscapularis tears; type C, supraspinatus, superior subscapularis, and infraspinatus tears; type D, supraspinatus and infraspinatus tears; and type E, supraspinatus, infraspinatus, and teres minor tears (Figure).<ref name=":1" />
[[File:1562478202102-lg.jpg|center|thumb|600x600px|Rotator cuff tears classified by the involved components: type A, supraspinatus and superior subscapularis tears; type B, supraspinatus and entire subscapularis tears; type C, supraspinatus, superior subscapularis, and infraspinatus tears; type D, supraspinatus and infraspinatus tears; and type E, supraspinatus, infraspinatus, and teres minor tears.]]
This classification not only subclassifies massive tears but has also been linked to function, particularly the maintenance of active elevation, offering more information than the traditional six sagittal segments of Patte’s classification.

=====Rotator Cuff Incarceration in the Glenohumeral Joint=====
Case of a complete rotator cuff tendon avulsion with glenohumeral joint incarceration after significant trauma to the shoulder have been described.<ref>Dodson CC, Bedi A, Sahai A, Potter HG, Cordasco FA. Complete rotator cuff tendon avulsion and glenohumeral joint incarceration in a young patient: A case report. J Shoulder Elbow Surg. 2010;19:e9–e12.</ref>

[[File:Incarceration sup.png|thumb|Anteroposterior radiograph of the left shoulder demonstrates superior subluxation as evidenced by the decrease in the interval between the acromion and the superior aspect of the humeral head. Coronal fast-spin echo magnetic resonance image (MRI) demonstrates an avulsion of the supraspinatus tendon, which is draped over the superior labrum and extends into the glenohumeral joint. The humeral head is subluxated superolaterally.]]

=====Suprascapular Nerve Neuropathy and Massive Rotator Cuff Tear=====
Recently there has been growing interest in the relationship between suprascapular neuropathy and massive rotator cuff tears. Theoretically, medial retraction of posterosuperior rotator cuff tears can place excessive traction on the suprascapular nerve.<ref>Albritton MJ, Graham RD, Richards RS, 2nd, Basamania CJ. An anatomic study of the effects on the suprascapular nerve due to retraction of the supraspinatus muscle after a rotator cuff tear. J Shoulder Elbow Surg 2003;12:497-500.</ref>

However, clinical diagnosis is beset with uncertainties as the potential symptoms of suprascapular nerve neuropathy, namely, pain, weakness, and atrophy, are inseparable from those of massive rotator cuff tear. There is actually no support for routine suprascapular nerve release when repair is performed for several reasons. First, it is clearly demonstrated that repair of repair without release leads to satisfactory results. Moreover, the prevalence of suprascapular nerve neuropathy in case of massive rotator cuff tears in a prospective study is low (2%).<ref name=":17">Collin P, Treseder T, Lädermann A, Benkalfate T, Mourtada R, Courage O, Favard L. Neuropathy of the suprascapular nerve and massive rotator cuff tears: a prospective electromyographic study. J Shoulder Elbow Surg 2014;23:28-34.</ref>

====Treatment Options for Massive Rotator Cuffs====
It should be remembered that nonoperative treatment is successful in many cases. When surgery is indicated, the primary aim is restoration of force couples and anatomic or partial repair of the rotator cuff to its footprint. However, a number of factors (refusal of the patient, biologic factors, characteristics of the tear, etc) can make these goals difficult, impossible, or unwanted to achieve. Fatty infiltration, rotator cuff retraction, and poor tendon compliance are common in patients with massive rotator cuff tears. In these situations, other approaches have been advocated, with varying degrees of success.<ref>Berhouet J, Collin P, Benkalfate T, Le Du C, Duparc F, Courage O, Favard L; Société d'Orthopédie de l'Ouest. Massive rotator cuff tears in patients younger than 65 years. Epidemiology and characteristics. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:S13-8.</ref>

These include physical therapy,59,60 subacromial decompression and palliative biceps tenotomy (subacromial debridement),61 muscle transfer,62 and reverse shoulder arthroplasty.63 However, there are no randomized controlled trials comparing these various options and recommendations are mainly based on retrospective case series and the surgeon’s own experiences.<ref name=":24">Collin PG, Gain S, Nguyen Huu F, Lädermann A. Is rehabilitation effective in massive rotator cuff tears? Orthopaedics & traumatology, surgery & research : OTSR 2015;101:S203-5.</ref><ref name=":26">Zingg PO, Jost B, Sukthankar A, Buhler M, Pfirrmann CW, Gerber C. Clinical and structural outcomes of nonoperative management of massive rotator cuff tears. J Bone Joint Surg Am 2007;89:1928-34.</ref><ref name=":25">Walch G, Edwards TB, Boulahia A, Nove-Josserand L, Neyton L, Szabo I. Arthroscopic tenotomy of the long head of the biceps in the treatment of rotator cuff tears: clinical and radiographic results of 307 cases. J Shoulder Elbow Surg 2005;14:238-46.</ref><ref name=":27">Gerber C, Rahm SA, Catanzaro S, Farshad M, Moor BK. Latissimus dorsi tendon transfer for treatment of irreparable posterosuperior rotator cuff tears: long-term results at a minimum follow-up of ten years. J Bone Joint Surg Am 2013;95:1920-6.</ref><ref>Wall B, Nove-Josserand L, O'Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am 2007;89:1476-85.</ref>

=====Conservative Treatment=====
Many patients with massive rotator cuff tears respond favorably to nonsurgical treatment. Nevertheless, patients must be aware that despite clinical improvement, future treatment may be impacted by progression of glenohumeral osteoarthritis and fatty infiltration as well as narrowing of the acromiohumeral distance. In a series of 19 patients with massive rotator cuff tears treated nonoperatively the average Constant score was 83% at a mean follow-up of 48 months. However, 50% of “reparable” tears became “irreparable” during this period.<ref name=":26" />

The mainstay of nonoperative treatment includes nonsteroidal anti-inflammatory drugs, subacromial corticosteroid injections, and physical therapy. The protocol of rehabilitation focused habitually on global deltoid reconditioning and periscapular strengthening. Although certain authors proposed that re-education of the anterior deltoid muscle to compensate for a deficient rotator cuff is the cornerstone, we attach more importance to solicitation of stabilizing muscles of the glenohumeral joint with an approach based on exercises in high position. In this position, the deltoid, which acts synergistically with the remaining rotator muscles, has no upward component and participates in the articular coaptation.<ref name=":24" />

In general, nonoperative management is attempted for six months before considering surgery. Younger patients (<60 years of age), however, may be immediate candidates for surgery based on the high risk for progression with conservative treatment. If after six months, symptoms have not improved, the chances of success with further nonoperative treatment decreases and operative treatment may be considered for older patients. It is unclear if it is exercise alone or exercise in combination with other interventions during the recovery process that offers the greatest benefit. In a recent prospective cohort of 45 patients suffering from pseudoparalysis with a radiographically confirmed massive rotator cuff tears, Collin and al. found after a follow-up of 48 months that the mean Constant score improved from 43 to 56 points and the mean forward flexion improved from 76 degrees to more than 160 degrees after completion of the program. They also demonstrated that effectiveness of physical therapy is related to the size and location of the lesion; if the tear involved the posterosuperior rotator cuff (B type), or only two tendons or less, most patients regained active anterior elevation that persisted for 48 months. The anterior rotator cuff is the key of anterior active elevation as only 20% of patients with MRCTs, but an intact subscapularis, develop pseudoparalysis.

=====Surgical (Operative) Treatment=====
For older patients surgery is considered when nonoperative treatment fails. Additionally, we often consider surgery as first line treatment in young patients because there is a high rate of progression with conservative treatment and for tears involving the anterior rotator cable since this area is most important to maintenance of forward elevation.

======Arthroscopic Rotator Cuff Repair======
The approach is to repair all of the rotator cuff that can reasonably be brought back to the tuberosities without excessive tension, and to address all potential causes of persistent pain or factors threatening the repair. The goal of a repair, even if partial, is to restore force couples and to re-establish the “suspension bridge”. In this theory, complete closure of the defect is less important than restoration of a stable fulcrum for normal shoulder kinematics. Although shoulder strength may not improve after this intervention, function is usually enhanced because of relief from pain caused by mechanical impingement. Additionally, although complete healing of massive tears is not always achievable, we believe that partial healing of the cuff may prevent secondary extension of the tear.

======The Acromion and Biceps======
Over the last decade, arthroscopic acromioplasty has been widely performed as an adjuvant to rotator cuff repair, to increase subacromial space and thereby decrease wear of the repaired tendon.<ref name=":0">McFarland EG, Matsen FA 3rd, Sanchez-Sotelo J. Clinical Faceoff: What is the Role of Acromioplasty in the Treatment of Rotator Cuff Disease? Clin Orthop Relat Res. 2018;476(9):1707-1712</ref><ref>Neer CS 2nd. Anterior acromioplasty for the chronic impingement syndrome in the shoulder: a preliminary report. J Bone Joint Surg Am. 1972;54(1):41-50</ref> Acromioplasty has the potential advantages of decreasing strain on the repaired tendon by changing the vector of the deltoid muscle, improving the healing response by increasing bone-marrow derived cells, creating more working space for rotator cuff repair<ref name=":0" /> and possibly to lower the reoperation rate.<ref>MacDonald P, McRae S, Leiter J, Mascarenhas R, Lapner P. Arthroscopic rotator cuff repair with and without acromioplasty in the treatment of full-thickness rotator cuff tears: a multicenter, randomized controlled trial. J Bone Joint Surg Am. 2011;93(21):1953-60</ref> However, recent studies reported no direct clinical benefits of adjuvant acromioplasty in the short- or mid-terms,<ref>Bond EC, Maher A, Hunt L, Leigh W, Brick M, Young SW, Caughey M. The role of acromioplasty when repairing rotator cuff tears-no difference in pain or functional outcome at 24 months in a cohort of 2,441 patients. N Z Med J. 2017;130:13-20.</ref><ref>Chahal J, Mall N, MacDonald PB, Van Thiel G, Cole BJ, Romeo AA, Verma NN. The role of subacromial decompression in patients undergoing arthroscopic repair of full-thickness tears of the rotator cuff: a systematic review and meta-analysis. Arthroscopy. 2012;28:720-7.</ref><ref>Ketola S, Lehtinen J, Arnala I, Nissinen M, Westenius H, Sintonen H, Aronen P, Konttinen YT, Malmivaara A, Rousi T. Does arthroscopic acromioplasty provide any additional value in the treatment of shoulder impingement syndrome?: a two-year randomised controlled trial. J Bone Joint Surg Br. 2009;91(10):1326-34</ref><ref>Ketola S, Lehtinen JT, Arnala I. Arthroscopic decompression not recommended in the treatment of rotator cuff tendinopathy: a final review of a randomised controlled trial at a minimum follow-up of ten years. Bone Joint J. 2017;99-B(6):799-805</ref><ref>Kolk A, Thomassen BJW, Hund H, de Witte PB, Henkus HE, Wassenaar WG, van Arkel ERA, Nelissen RGHH. Does acromioplasty result in favorable clinical and radiologic outcomes in the management of chronic subacromial pain syndrome? A double-blinded randomized clinical trial with 9 to 14 years' follow-up. J Shoulder Elbow Surg. 2017;26:1407-15.</ref><ref>Mardani-Kivi M, Karimi A, Keyhani S, Hashemi-Motlagh K, Saheb-Ekhtiari K. Rotator Cuff Repair: Is there any role for acromioplasty? Phys Sportsmed. 2016;44:274-7.</ref><ref>Paloneva J, Lepola V, Karppinen J, Ylinen J, Äärimaa V, Mattila VM. Declining incidence of acromioplasty in Finland. Acta Orthop. 2015;86:220-4.</ref><ref>Saltychev M, Äärimaa V, Virolainen P, Laimi K. Conservative treatment or surgery for shoulder impingement: systematic review and meta-analysis. Disabil Rehabil. 2015;37:1-8.</ref><ref>Shin SJ, Oh JH, Chung SW, Song MH. The efficacy of acromioplasty in the arthroscopic repair of small- to medium-sized rotator cuff tears without acromial spur: prospective comparative study. Arthroscopy. 2012;28:628-35.</ref> suggesting that the procedure should be performed only in selected patients. The morphology of the scapula and of the humerus is highly variable and bone removal may not be routinely necessary. Avoiding acromioplasty and particularly detaching the coracoacromial ligament may be preferable regarding alteration of the coracoacromial arch, as it might cause significant anterosuperior translation or even escape of the humeral head,<ref>Su WR, Budoff JE, Luo ZP. The effect of coracoacromial ligament excision and acromioplasty on superior and anterosuperior glenohumeral stability. Arthroscopy. 2009;25:13-8.</ref><ref>Wiley AM. Superior humeral dislocation. A complication following decompression and debridement for rotator cuff tears. Clin Orthop Relat Res. 1991:135-41.</ref> weakening of the deltoid origin<ref>Katthagen JC, Marchetti DC, Tahal DS, Turnbull TL, Millett PJ. The Effects of Arthroscopic Lateral Acromioplasty on the Critical Shoulder Angle and the Anterolateral Deltoid Origin: An Anatomic Cadaveric Study. Arthroscopy. 2016;32:569-75.</ref> and adhesions between the raw exposed bone on the undersurface of the acromion and the underlying tendon.<ref>Liu J, Hughes RE, Smutz WP, Niebur G, Nan-An K. Roles of deltoid and rotator cuff muscles in shoulder elevation. Clin Biomech (Bristol, Avon). 1997;12:32-38.</ref><ref>Goldberg BA, Lippitt SB, Matsen FA 3rd. Improvement in comfort and function after cuff repair without acromioplasty. Clin Orthop Relat Res. 2001;142-50.</ref><ref name=":28">Romeo AA, Loutzenheiser T, Rhee YG, Sidles JA, Harryman DT 2nd, Matsen FA 3rd. The humeroscapular motion interface. Clin Orthop Relat Res. 1998;120-7.</ref> In addition, even if the role of the lateral overhanging has been recently emphasized,<ref>Moor BK, Wieser K, Slankamenac K, Gerber C, Bouaicha S. Relationship of individual scapular anatomy and degenerative rotator cuff tears. J Shoulder Elbow Surg. 2014;23:536-41.</ref><ref>Nyffeler RW, Werner CM, Sukthankar A, Schmid MR, Gerber C. Association of a large lateral extension of the acromion with rotator cuff tears. J Bone Joint Surg Am. 2006;88:800-5.</ref> it is still unknown if a lateral acromioplasty to decrease critical shoulder angle (CSA)<ref>Moor BK, Bouaicha S, Rothenfluh DA, Sukthankar A, Gerber C. Is there an association between the individual anatomy of the scapula and the development of rotator cuff tears or osteoarthritis of the glenohumeral joint?: A radiological study of the critical shoulder angle. Bone Joint J. 2013;95-B:935-41.</ref> is a safe procedure that could improve clinical outcome. Complete anterior acromioplasty is not advisable in the setting of a massive tear as it may lead to postoperative anterosuperior migration of the humeral head. The acromiohumeral arch is probably a component of human evolution used to compensate the deficiency of the superior rotator cuff.<ref name=":4" /> Consequently, when and how should acromioplasty should be performed is still debated.<ref>Voisin JL, Ropars M, Thomazeau H. The human acromion viewed from an evolutionary perspective. Orthopaedics & traumatology, surgery & research : OTSR 2014;100:S355-60.</ref> The type of acromioplasty has to be correlated to our actual practice. A recent dynamic evaluation of subacromial impingement revealed that impingement is not anterior as previously believed and that detachment of the coracoacromial ligament is not necessary.<ref>Lädermann A, Chagué S, Preissmann D, Kolo FC, Rime O, Kevelham B, Bothorel H, Charbonnier C. Guided versus freehand acromioplasty during rotator cuff repair. A randomized prospective study. Orthop Traumatol Surg Res. 2020:;106(4):651-659</ref> Moreover, it has been shown that acromioplasty significantly reduces dynamic subacromial impingement compared to preoperative situation.<ref>Lädermann A, Chagué S, Preissmann D, Kolo FC, Zbinden O, Kevelham B, Bothorel H, Charbonnier C. Acromioplasty during repair of rotator cuff tears removes only half of the impinging acromial bone. JSES Int. 2020:29;4:592-600.</ref> Furthermore, Gerber et al. advocated that adjuvant acromioplasty is necessary in shoulders with high critical shoulder angle (preoperative CSA≥34 degrees), and found that insufficient acromial resection (postoperative CSA≥35 degrees) is associated with significantly worse abductor strength and higher retear rate.<ref>Gerber C, Catanzaro S, Betz M, Ernstbrunner L. Arthroscopic Correction of the Critical Shoulder Angle Through Lateral Acromioplasty: A Safe Adjunct to Rotator Cuff Repair. Arthroscopy. 2018;34:771-780.</ref>

A tenotomy or tenodesis of the long head of the biceps should be performed in the setting of a massive rotator cuff tear. There is evidence suggesting that the long head of the biceps tendon may be a source of pain and contributes to the discomfort. In a large series, Walch et al. observed an increase in the Constant score from 48.4 preoperatively to 67.6 after arthroscopic biceps tenotomy. At last follow-up, 87% of patients were satisfied or very satisfied with the result. However, the acromiohumeral interval decreased by a mean of 1.3 mm during the follow-up period.<ref name=":25" />

======Repair Techniques======

Unfortunately, even if reinsertion of the tendon on the bone is achievable, it is often difficult to reliably achieve long-term healing with a structurally intact repair.<ref>Zumstein MA, Jost B, Hempel J, Hodler J, Gerber C. The clinical and structural long-term results of open repair of massive tears of the rotator cuff. J Bone Joint Surg Am 2008;90:2423-31.</ref>

In the setting of a massive tear, a double-row repair improves long-term functional outcome.<ref>Carbonel I, Martinez AA, Calvo A, Ripalda J, Herrera A. Single-row versus double-row arthroscopic repair in the treatment of rotator cuff tears: a prospective randomized clinical study. Int Orthop 2012;36:1877-83.</ref><ref>Connelly TM, Shaw A, O'Grady P. Outcome of open massive rotator cuff repairs with double-row suture knotless anchors: case series. Inter Orthop 2015;39:1109-14.</ref><ref name=":29">Denard PJ, Jiwani AZ, Lädermann A, Burkhart SS. Long-term outcome of arthroscopic massive rotator cuff repair: the importance of double-row fixation. Arthroscopy 2012;28:909-15.</ref>

However, this should not be performed at the expense of over-tensioning as application of a double-row repair to a tendon with poor tendon length and excursion may lead to medial failure.<ref name=":10" />

======Augmentation======

Graft augmentation may improve healing in massive rotator cuff tears, but add significant cost and time to the procedure.<ref>Barber FA, Burns JP, Deutsch A, Labbe MR, Litchfield RB. A prospective, randomized evaluation of acellular human dermal matrix augmentation for arthroscopic rotator cuff repair. Arthroscopy 2012;28:8-15.</ref>

The choice of graft is influenced by several factors including mechanical properties, host response and potential for ingrowth. Scaffolds provide mechanical support and have biological properties that may favorably influence cell proliferation and differentiation, hopefully improving tendon-to-bone healing. Currently, scaffolds derived from dermis, small intestinal submucosa, skin, fascia lata, and pericardium have been processed and marketed for augmentation in the repair of massive tears. Biological grafts are preferred, when compared to synthetic grafts, due to the unknown host response to synthetic grafts. An important factor in the longevity and strength of a graft is the amount of ingrowth.

======Results of Primary Repairs======

Results following arthroscopic repair of massive rotator cuffs have previously been reported.<ref name=":30">Denard PJ, Lädermann A, Jiwani AZ, Burkhart SS. Functional outcome after arthroscopic repair of massive rotator cuff tears in individuals with pseudoparalysis. Arthroscopy 2012;28:1214-9.</ref><ref name=":31">Lädermann A, Denard PJ, Burkhart SS. Midterm outcome of arthroscopic revision repair of massive and nonmassive rotator cuff tears. Arthroscopy 2011;27:1620-7.</ref>

For primary repair, improvements are observed in forward flexion (132 degrees vs 168 degrees), pain (6.3 v 1.3), UCLA score, (15.7 v 30.7) and American Shoulder and Elbow Surgeons score (41.7 v 85.7) (P<.001). A good or excellent outcome is obtained in 78% of cases. Similar results are noticed after repair of type A, B and C massive rotator cuff tears.<ref name=":29" />

After revision repair, mean active forward elevation improves by 15 degrees, from 136.0 degrees ± 51.9 degrees (range, 30 to 180 degrees) at baseline to 151.4 degrees ± 41.5 degrees (range, 30 to 180 degrees) at final follow-up (P=.019). The mean pain score improves by 3.1 points, from 5.0 ± 2.4 points at baseline to 1.9 ± 2.3 points at final follow-up (p<.001). The mean American Shoulder and Elbow Surgeons (ASES) score improves from 45.7 ± 17.8 at baseline to 75.5 ± 20.3 at final follow-up (P<.001). The mean UCLA score also improves, from 16.7 ±4.9 at baseline to 26.4 ± 6.9 at final follow-up (P<.001). According to the UCLA score, functional results are excellent in 15% of cases, good in 35%, fair in 25%, and poor in 25%. Seventy-nine percent of the patients are satisfied, and 32 patients (60%) returned to their previous activities.<ref name=":31" />

======Revision Rotator Cuff Repair======
'''Introduction'''

Failure of tendon healing after rotator cuff repair is common, reported in approximately 20% of cases depending on tear size.<ref>Collin P, Abdullah A, Kherad O, Gain S, Denard PJ, Lädermann A. Prospective evaluation of clinical and radiologic factors predicting return to activity within 6 months after arthroscopic rotator cuff repair. J Shoulder Elbow Surg 2015;24:439-45.</ref>

Tear recurrence can be related to various factors such as: 1) inadequate strength of the initial repair construct, 2) biological failure to heal despite strong initial fixation, and 3) inappropriate post-operative rehabilitation causing structural failure of the repair.<ref>Boileau P, Brassart N, Watkinson DJ, Carles M, Hatzidakis AM, Krishnan SG. Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? J Bone Joint Surg Am 2005;87:1229-40.</ref><ref>Cho NS, Moon SC, Jeon JW, Rhee YG. The influence of diabetes mellitus on clinical and structural outcomes after arthroscopic rotator cuff repair. Am J Sports Med 2015;43:991-7.</ref><ref>Chung SW, Oh JH, Gong HS, Kim JY, Kim SH. Factors affecting rotator cuff healing after arthroscopic repair: osteoporosis as one of the independent risk factors. Am J Sports Med 2011;39:2099-107.</ref><ref>Clement ND, Hallett A, MacDonald D, Howie C, McBirnie J. Does diabetes affect outcome after arthroscopic repair of the rotator cuff? J Bone Joint Surg Br 2010;92:1112-7.</ref>

While functional outcome has been correlated with postoperative rotator cuff integrity many patients maintain a satisfactory outcome despite structural failure.<ref name=":32">Jost B, Zumstein M, Pfirrmann CW, Gerber C. Long-Term Outcome After Structural Failure of Rotator Cuff Repairs. J Bone Joint Surg Am 2006;88:472-9.</ref>

The ideal treatment for a recurrent tear is thus not completely defined.

'''Initial Radiological Findings'''

The goal of imaging studies is to confirm the site of the recurrent tear. Trantalis et al. reported five patients with retearing of the cuff after double-row rotator cuff repair. All five patients had retearing medial to the medial row if sutures were placed near the musculotendinous junction of the supraspinatus.<ref name=":33">Trantalis JN, Boorman RS, Pletsch K, Lo IK. Medial rotator cuff failure after arthroscopic double-row rotator cuff repair. Arthroscopy 2008;24:727-31.</ref>

Hayashida et al. observed that the prevalence of complete retearing of the tendon after a double-row rotator cuff repair is similar around the medial anchors with a well-preserved footprint.<ref name=":35">Hayashida K, Tanaka M, Koizumi K, Kakiuchi M. Characteristic retear patterns assessed by magnetic resonance imaging after arthroscopic double-row rotator cuff repair. Arthroscopy 2012;28:458-64.</ref>

Another point of interest is the quality of the tendon.<ref>Denard PJ, Burkhart SS. Techniques for managing poor quality tissue and bone during arthroscopic rotator cuff repair. Arthroscopy 2011;27:1409-21.</ref>

A significant and growing number of rotator cuff repairs are performed in individuals with poor rotator cuff tissue quality. Djurasovic reported an incidence of 30% (24 on 80) of poor rotator cuff tissue quality (graded subjectively at the time of surgery).<ref name=":36">Djurasovic M, Marra G, Arroyo JS, Pollock RG, Flatow EL, Bigliani LU. Revision rotator cuff repair: factors influencing results. J Bone Joint Surg Am 2001;83-A:1849-55.</ref>

At the same time, the muscle undergoes intrinsic degeneration. After a retear, Deniz et al. found that fatty infiltration and atrophy continued to worsen significantly.<ref name=":18">Deniz G, Kose O, Tugay A, Guler F, Turan A. Fatty degeneration and atrophy of the rotator cuff muscles after arthroscopic repair: does it improve, halt or deteriorate? Arch Orthop Trauma Surg 2014;134:985-90.</ref>

However, fatty infiltration of the supraspinatus does not seem to be a determinant factor in tendon healing. Park et al. did not find significant relationship between preoperative supraspinatus fatty infiltration and postoperative tendon healing. Contrarily, it seems that fatty infiltration of infraspinatus and subscapularis are highly significant factors (P<.001).<ref name=":37">Park JS, Park HJ, Kim SH, Oh JH. Prognostic Factors Affecting Rotator Cuff Healing After Arthroscopic Repair in Small to Medium-sized Tears. Am J Sports Med 2015;43:2386-92.</ref>

Another point is the bone quality. Oh et al. demonstrated that bone mineral density within the greater tuberosity decreases in patients with rotator cuff tears. In another retrospective study that investigated the relationship between greater tuberosity osteopenia and chronicity of rotator cuff tears, Cadet et al. found that there were significantly greater osteopenic changes in the greater tuberosity in patients with chronic retracted rotator cuff tears.<ref>Cadet ER, Hsu JW, Levine WN, Bigliani LU, Ahmad CS. The relationship between greater tuberosity osteopenia and the chronicity of rotator cuff tears. J Shoulder Elbow Surg 2008;17:73-7.</ref>

However, this localized osteoporosis may not influence tendon healing. In a recent study, Park et al. did not observe after primary repair that bone mineral density influenced final results.<ref name=":37" />

Nevertheless, the greater tuberosity in revision cases can also be deficient due to anchor removal or perianchor cyst formation. Kim et al. observed in a retrospective case series of two hundred and nine patients bone cyst formation in 97 instances (46.4%), and these authors questioned the utility of bioabsorbable anchors because of possible interference with revision surgery. Consequent bone lysis can be noticed after trauma. Lädermann et al. reported massive bone resorption after osteosynthesis of the greater tuberosity leading to combined tendon and bony insufficiency and pseudoparalysis/pseudoparesis.

When milestones of typical post-operative recovery are not met, analysis of rotator cuff repair should be considered and a multi-modal evaluation is required. The goal of imaging studies is to confirm the site of the recurrent tear (Figure)86,92 the type of failure (e.g. in continuity), and if possible, it’s cause.<ref name=":35" /><ref>Mellado JM, Calmet J, Olona M, Ballabriga J, Camins A, Pérez del Palomar L, Giné J. MR assessment of the repaired rotator cuff: prevalence, size, location, and clinical relevance of tendon rerupture. European radiology 2006;16:2186-96.</ref><ref>McCarron JA, Derwin KA, Bey MJ, Polster JM, Schils JP, Ricchetti ET, Iannotti JP. Failure with continuity in rotator cuff repair "healing". Am J Sports Med 2013;41:134-41.</ref>
[[File:1562480510006-lg.jpg|center|thumb|600x600px|Figure 25. Six patterns of anatomic deficiency associated with failed rotator cuff repair. (A) Failure of tendon healing; (B) poor tendon quality; (C) fatty infiltration/atrophy; (D) retear medial to the medial row of fixation; (E) bone defects in the greater tuberosity after anchor removal, or perianchor cyst formation and (F) bony and tendinous insufficiency. Reproduced from Lädermann et al., with permission.]]
Other points of interest are the quality of the bone (tuberosity deficiency), tendon, and muscle, and whether further surgery is feasible.<ref name=":14" /><ref name=":18" />

Standard shoulder radiographs, including anteroposterior, axillary lateral and scapular Y (outlet) views, may demonstrate decreased acromiohumeral distance, glenohumeral arthritis, subacromial spurs, acetabularization of the acromion, femoralization of the humeral head, and implant or anchor migration.<ref name=":38">Hartzler RU, Sperling JW, Schleck CD, Cofield RH. Clinical and radiographic factors influencing the results of revision rotator cuff repair. International journal of shoulder surgery 2013;7:41-5.</ref><ref name=":7" />

It can also be used to rule out chondrolysis, anchor migration or prominence, and acromial fracture. Among evaluation techniques, the most widely accepted reference standard is magnetic resonance imaging which allows visualization of the tendons and does not involve radiation exposure. Intra-articular contrast may be used in association with magnetic resonance imaging to increase the sensitivity for detecting a recurrent tear.<ref>de Jesus JO, Parker L, Frangos AJ, Nazarian LN. Accuracy of MRI, MR arthrography, and ultrasound in the diagnosis of rotator cuff tears: a meta-analysis. AJR American journal of roentgenology 2009;192:1701-7.</ref>

Postoperative magnetic resonance imaging images are difficult to interpret; inadequate coverage of the greater or lesser tuberosity may indicate partial healing and not a recurrent full-thickness tear.<ref name=":39">Khazzam M, Kuhn JE, Mulligan E, Abboud JA, Baumgarten KM, Brophy RH, Jones GL, Miller B, Smith M, Wright RW. Magnetic resonance imaging identification of rotator cuff retears after repair: interobserver and intraobserver agreement. Am J Sports Med 2012;40:1722-7.</ref><ref>Saccomanno MF, Cazzato G, Fodale M, Sircana G, Milano G. Magnetic resonance imaging criteria for the assessment of the rotator cuff after repair: a systematic review. Knee Surg Sports Traumatol Arthrosc 2015;23:423-42.</ref><ref>Motamedi AR, Urrea LH, Hancock RE, Hawkins RJ, Ho C. Accuracy of magnetic resonance imaging in determining the presence and size of recurrent rotator cuff tears. J Shoulder Elbow Surg 2002;11:6-10.</ref>

Furthermore, only 10% of re-attached tendons generate a normal magnetic resonance imaging signal. Thus, a common finding is the presence of an intermediate signal within the tendon indicating granulation tissue or of a low-intensity signal produced by fibrous tissue.<ref name=":39" /><ref>Zanetti M, Hodler J. MR imaging of the shoulder after surgery. Radiologic clinics of North America 2006;44:537-51, viii.</ref>

These signal changes may persist for longer than six months, due to tissue remodeling, and seem to have no clinical implications.<ref>Tudisco C, Bisicchia S, Savarese E, Fiori F, Bartolucci DA, Masala S, Simonetti G. Single-row vs. double-row arthroscopic rotator cuff repair: clinical and 3 Tesla MR arthrography results. BMC musculoskeletal disorders 2013;14:43.</ref><ref>Gerber C, Schneeberger AG, Perren SM, Nyffeler RW. Experimental rotator cuff repair. A preliminary study. J Bone Joint Surg Am 1999;81:1281-90.</ref>

Finally, the evaluation of magnetic resonance imaging scans is made difficult by the normal leakage of fluid into the subacromial space after the opening of the rotator interval and passage of instruments through the tendon, which may contain artifacts generated, for instance, by metal anchors or high-strength sutures. These factors, together with the high cost of magnetic resonance imaging, lend considerable appeal to ultrasound as a method for evaluating rotator cuff repair, even if its effectiveness is operator-dependent.<ref>Ok JH, Kim YS, Kim JM, Yoo TW. Learning curve of office-based ultrasonography for rotator cuff tendons tears. Knee Surg Sports Traumatol Arthrosc 2013;21:1593-7.</ref>

Computed tomography arthrogram can also be used to aid in the identification of recurrent rotator cuff tears when neither ultrasound or magnetic resonance imaging are options.<ref>Nazarian LN, Jacobson JA, Benson CB, Bancroft LW, Bedi A, McShane JM, Miller TT, Parker L, Smith J, Steinbach LS, Teefey SA, Thiele RG, Tuite MJ, Wise JN, Yamaguchi K. Imaging algorithms for evaluating suspected rotator cuff disease: Society of Radiologists in Ultrasound consensus conference statement. Radiology 2013;267:589-95.</ref>

Failure after rotator cuff repair was previously believed to occur during the first three months.<ref>Kluger R, Bock P, Mittlbock M, Krampla W, Engel A. Long-term survivorship of rotator cuff repairs using ultrasound and magnetic resonance imaging analysis. Am J Sports Med 2011;39:2071-81.</ref><ref>Miller BS, Downie BK, Kohen RB, Kijek T, Lesniak B, Jacobson JA, Hughes RE, Carpenter JE. When do rotator cuff repairs fail? Serial ultrasound examination after arthroscopic repair of large and massive rotator cuff tears. Am J Sports Med 2011;39:2064-70.</ref>

While the majority of retears do occur within the first three months, it has now been demonstrated retears can occur up to six months after repair.<ref>Barth J, Fotiadis E, Barthelemy R, Genna S, Saffarini M. Ultrasonic evaluation of the repair integrity can predict functional outcomes after arthroscopic double-row rotator cuff repair. Knee Surg Sports Traumatol Arthrosc 2015;23:376-85.</ref><ref>Iannotti JP, Deutsch A, Green A, Rudicel S, Christensen J, Marraffino S, Rodeo S. Time to failure after rotator cuff repair: a prospective imaging study. J Bone Joint Surg Am 2013;95:965-71.</ref><ref>Kim JH, Hong IT, Ryu KJ, Bong ST, Lee YS, Kim JH. Retear rate in the late postoperative period after arthroscopic rotator cuff repair. Am J Sports Med 2014;42:2606-13.</ref>

Recent prospective studies have confirmed that ultrasound has a high sensitivity and specificity for detecting a recurrent rotator cuff tear compared to magnetic resonance imaging.In a study comparing magnetic resonance imaging and ultrasound after rotator cuff repair, Codsi et al. found 92% agreement with a coefficient of 0.70.<ref>Codsi MJ, Rodeo SA, Scalise JJ, Moorehead TM, Ma CB. Assessment of rotator cuff repair integrity using ultrasound and magnetic resonance imaging in a multicenter study. J Shoulder Elbow Surg 2014;23:1468-72.</ref>

Similarly, Collin et al. reported that ultrasound had 80% sensitivity and 98% specificity compared to magnetic resonance imaging.<ref>Collin P, Yoshida M, Delarue A, Lucas C, Jossaume T, Lädermann A; French Society for Shoulder and Elbow (SOFEC). Evaluating postoperative rotator cuff healing: Prospective comparison of MRI and ultrasound. Orthopaedics & traumatology, surgery & research : OTSR 2015;101:S265-8.</ref>

=====Treatment=====

======Non Surgical (Conservative) Treatment of Failed Rotator Cuff Repair======
Jost et al. evaluated 20 patients with a failed rotator cuff repair at a mean follow-up of 38 months and reported that the adjusted Constant score and shoulder simple value averaged 83% and 75%, respectively.<ref name=":32" />

Namdari et al. demonstrated a successful outcome in 54% of patients (defined by an American Shoulder and Elbow Surgeons score of more than 80 points) and a mean 15 point improvement in the American Shoulder and Elbow Surgeons score at a mean of 52 months postoperative. Finally, the same group compared the two and ten year results for patients with known structural failures of rotator cuff repair. The average long-term American Shoulder and Elbow Surgeons score was 79 points (range, 50 to 95 points) and the average visual analog scale pain score was 2.2 points (range, 1 to 4 points); both scores were unchanged from those at two years. The average simple shoulder test score was 9.2 points (range, 6 to 12 points), and the average age-adjusted Constant score was 73 points (range, 59 to 90 points).<ref>Paxton ES, Teefey SA, Dahiya N, Keener JD, Yamaguchi K, Galatz LM. Clinical and radiographic outcomes of failed repairs of large or massive rotator cuff tears: minimum ten-year follow-up. J Bone Joint Surg Am 2013;95:627-32.</ref>

======Surgical (Operative) Treatment Revision Rotator Cuff Repair======
'''Surgical Technique'''

The alarming retear rate indicates that several surgical options can be considered which must be individualized to the patient. For example, in the setting of an acute traumatic retear in a physiologically young, healthy, active and non-pseudoparalytic patient, arthroscopic revision surgery is generally recommended. Techniques to enhance mechanical fixation, such as linked load-sharing rip-stop constructs should be considered.<ref name=":22" />

Augmented repair using scaffold devices derived from autografts,46,119,120 allograft,121 xenograft extracellular matrix122 or synthetic matrices such as poly-l-lactide grafts123 have been used to offer a structural support of the repair during the crucial healing period and to improve healing rates. The scientific literature does not contain enough data to justify any systematic associated augmentation techniques. Tendon transfers may be used in patients without advanced glenohumeral arthritis who have significant loss of external rotation strength and maintain anterior active elevation.62,124 If the patient is young, pseudoparalytic and suffers from a combined bony and tendinous rotator cuff insufficiency, calcaneum and Achilles tendon allograft could be considered.40

Finally, whereas primary pseudoparalysis responds well to arthroscopic rotator cuff repair, persistent pseudoparalysis after a previous attempt at rotator cuff repair may be more predictably managed with reverse shoulder arthroplasty. Denard et al. reported that pseudoparalysis/pseudoparesis was reversed in the revision setting in only 43% of patients with a low rate (54%) of satisfaction.<ref name=":2" />

In contrast, Boileau et al. found that anterior elevation was reliably restored with reverse shoulder arthroplasty after failed rotator cuff repair and 73% of patients were satisfied.<ref>Boileau P, Gonzalez JF, Chuinard C, Bicknell R, Walch G. Reverse total shoulder arthroplasty after failed rotator cuff surgery. J Shoulder Elbow Surg 2009;18:600-6.</ref>

'''Clinical and Radiological Results After Revision Rotator Cuff Repair'''

The clinical results of are summarized in Table 3. Overall, range of motion improved, except in one series of open rotator cuff repair.94 Functional outcome improved in all series and 70% or more of patients were satisfied or very satisfied.<ref name=":38" />

'''''Table 3: Clinical Results of Revision RCR'''''
[[File:1562481228568-lg.jpg|alt=|none|thumb|720x720px]]
 '''Complication'''

The short- to intermediate-term incidence of complications, including subsequent revision surgery, after revision rotator cuff repair is relatively low, around ten percent in this review (Table). However, most studies primarily considered reoperation a complication and did not examine complications such as hematoma, hardware failure, and postoperative stiffness. The prevalence of postoperative complications is therefore probably higher than reported. The prevalence of non-healing or retear was around 40% (range, 0 to 62%) in the four studies with postoperative imaging.<ref>Agrawal V. Healing rates for challenging rotator cuff tears utilizing an acellular human dermal reinforcement graft. International journal of shoulder surgery 2012;6:36-44.</ref><ref>Lenart BA, Martens KA, Kearns KA, Gillespie RJ, Zoga AC, Williams GR. Treatment of massive and recurrent rotator cuff tears augmented with a poly-l-lactide graft, a preliminary study. J Shoulder Elbow Surg 2015;24:915-21.</ref><ref>Keener JD, Wei AS, Kim HM, Paxton ES, Teefey SA, Galatz LM, Yamaguchi K. Revision arthroscopic rotator cuff repair: repair integrity and clinical outcome. J Bone Joint Surg Am 2010;92:590-8.</ref><ref name=":40">Shamsudin A, Lam PH, Peters K, Rubenis I, Hackett L, Murrell GA. Revision versus primary arthroscopic rotator cuff repair: a 2-year analysis of outcomes in 360 patients. Am J Sports Med 2015;43:557-64.</ref>

Furthermore, these tears may progress with time; Shamsudin et al. reported a prevalence of defect of 28% at six months and of 40% at two years. If revision is planned, patients have to be aware of the high prevalence of persistent structural defect. Moreover, retear rate after reoperation continues to deteriorate with time.<ref name=":40" /><ref>Vastamaki M, Lohman M, Borgmastars N. Rotator cuff integrity correlates with clinical and functional results at a minimum 16 years after open repair. Clin Orthop Relat Res 2013;471:554-61.</ref>

Structural failure does not always result in clinical failure. Many patients with partial healing of the cuff and a residual defect will be much improved after surgery. Characteristics associated with successful and unsuccessful results after structural failure of rotator cuff repair are poorly understood. Retear or non-healing of tendons is rather frequent and surgery is rarely proposed because this condition is often well tolerated with marked clinical improvement in comparison with the preoperative state.<ref>Namdari S, Donegan RP, Chamberlain AM, Galatz LM, Yamaguchi K, Keener JD. Factors affecting outcome after structural failure of repaired rotator cuff tears. J Bone Joint Surg Am 2014;96:99-105.</ref>

One reason for clinical failure is probably the non-restoration of balanced force couples and the suspension bridge system of force transmission in the shoulder. The location (involvement of the subscapularis on which the rotator cable is attached) and the size (more than two tendons) are the primary determinant of rotator cuff function.

'''Risk Factors for Postoperative Poorer Results'''

Several patient-related factors appear to be associated with poorer results. The most important factor seems to be poor preoperative range of motion. Female sex and, in one study, if the surgery was performed on the dominant arm, were negatively associated with postoperative outcome.<ref name=":34">Chuang MJ, Jancosko J, Nottage WM. Clinical outcomes of single-row arthroscopic revision rotator cuff repair. Orthopedics 2014;37:e692-8.</ref><ref name=":41">Piasecki DP, Verma NN, Nho SJ, Bhatia S, Boniquit N, Cole BJ, Nicholson GP, Romeo AA. Outcomes after arthroscopic revision rotator cuff repair. Am J Sports Med 2010;38:40-6.</ref><ref name=":31" />

There is still controversy about certain risk factors such as age of patients. Disease-related factors included patients with a recurrent tear after the revision repair, preoperative visual analogue scale pain score greater than five, and poor preoperative range of motion. The range vary from less than 90 degrees in the studies from Denard et al. and Piasecki et al. to 140 degrees in the study of Chuang et al.<ref name=":30" /><ref name=":34" /><ref name=":41" />

The latter factor has been reported in almost all series and is probably the most important preoperative indicator. In addition, acromiohumeral distance (less than seven mm) can be associated with a satisfactory outcome.<ref name=":38" />

There is controversy about patients with more than one prior surgery, with one study reporting that this negatively impacted results and another study reporting that it did not.<ref name=":31" /><ref name=":41" />

Operative-related factors like poor tendon quality is associated with poorer results.<ref name=":36" /><ref name=":23" />

One study compared outcomes between massive and non-massive tears and did not find any significant difference in terms of post-operative anterior elevation, pain, or functional outcome.<ref name=":31" />

'''Post-revision Rehabilitation'''

In all studies, subjects took part in standardized rehabilitation protocols. Most studies did not allow immediate overhead passive motion. Most studies recommend sling during 6 weeks. Strengthening is delayed until six to sixteen weeks post-operatively. Full return to activity was not allowed until four to twelve months.

====B2: Medial Tendinous Disruption====
Disruption of the tendon medial to an intact lateral tendon stump has been reported in primary chronic and acute cases or postoperatively as a failure medial to the medial row.<ref name=":33" /><ref>Loew M, Magosch P, Lichtenberg S, Habermeyer P, Porschke F. How to discriminate between acute traumatic and chronic degenerative rotator cuff lesions: an analysis of specific criteria on radiography and magnetic resonance imaging. J Shoulder Elbow Surg 2015;24:1685-93.</ref>

Regarding the former, it is now understood that the infraspinatus insertion is quite broad and wraps around from posterior to anterior to occupy much of the lateral greater tuberosity. Therefore, such descriptions of a lateral tendon stump remaining may, in fact, represent a torn supraspinatus with an intact infraspinatus.

Full thickness defects medial to an intact footprint of the rotator cuff can be seen following a rotator cuff repair (Figure). Trantalis et al. described 5 patients with medial failure following a double-row rotator cuff repair. Such failure results from overtensioning during repair and is very difficult to manage with revision repair. These lesions do not produce muscular edema, except in traumatic cases with important and acute retraction of the muscle and the remnant of the tendon (Figure); its origin is then either retraction (which may appear in some hours) or neurological lesions (noted after some weeks).<ref>Fleckenstein JL, Watumull D, Conner KE, Ezaki M, Greenlee RG Jr, Bryan WW, Chason DP, Parkey RW, Peshock RM, Purdy PD. Denervated human skeletal muscle: MR imaging evaluation. Radiology 1993;187:213-8.</ref>

===B3: Tendon to Tendon Adhesion: “Fosbury Flop Tear”===

The Fosbury flop tear occurs from a full thickness tear that has flipped upon itself and adhered medially (Figure 26).<ref name=":42">Lädermann A, Denard PJ, Kolo FC. A new tear pattern of the rotator cuff and its treatment: Fosbury flop tears. International journal of shoulder surgery 2015;9:9-12.</ref>
[[File:1562482685626-lg.jpg|center|thumb|600x600px|Figure 26. Figure: Illustration of a “Fosbury flop tear” development. Reproduced from Lädermann et al., with permission.]]

=====Prevalence=====
In a prospective study spanning one-year, Lädermann et al. reported five patients with full or partial-thickness rotator cuff lesions in a series of 97 (5 % incidence rate). Radiologically, these lesions showed a thicker than normal tendon stump on the bursal-side of the retracted supraspinatus tendon in a superomedial orientation.<ref name=":42" />
[[File:1562482680697-lg.jpg|center|thumb|600x600px|Figure 27. Coronal T1 weighted image of a right shoulder that demonstrates (black arrow) an abnormally thickened supraspinatus (9.5 mm). Reproduced from Lädermann et al., with permission.]]
[[File:1562483248519-lg.jpg|center|thumb|600x600px|Figure 28. Coronal T1 weighted MRA image with fat saturation of a right shoulder demonstrates adhesions between the bursal side of the tendon and the wall of the subacromial bursa (red arrow), and abnormal orientation of the fibers stump (yellow arrow). Reproduced from Lädermann et al., with permission.]]
Additionally, patients with this lesion were also found to have an accumulation of fluid in the superomedial part of the subacromial bursa as well as adhesions between the wall of the subacromial bursa and the tendon of the supraspinatus. Since the original description, another group verified the same entity.<ref>Nakamizo H. Arthroscopic repair for subacromial incarceration of a torn rotator cuff. AP-SMART 2015;2:90-4.</ref>

=====Surgical Technique=====
A diagnostic arthroscopy is performed with an arthroscopic pump maintaining pressure at 50 mm Hg. The biceps is tenotomized or tenodesed. Attention is then turned to the posterosuperior rotator cuff (supraspinatus and infraspinatus tendons). The appearances of the tears are unusual with ulcerations on the bursal surface (anemone like) and what initially appeared to be a thickened lateral tendon stump (Figure and Video).
[[File:1562483266291-lg.jpg|center|thumb|600x600px|Figure 29. Arthroscopic view of a right shoulder through lateral portal after bursectomy and creation of a bone socket for medial row anchor placement. The supraspinatus tendon is unusually thick and has the appearance of ulcerations and flanges of the bursal side (sea anemone appearance, black arrow). H, hole of the tap; HH, humeral head; SS, supraspinatus tendon. Reproduced from Lädermann et al., with permission.]]
[[File:1563115158292-lg.mp4|center|thumb|600x600px|Video 13.]]
 After a progressive dissection, however, medial adhesions of the bursal layer is found. A complete excavation of the rotator cuff must be performed by skeletonizing the scapular spine medially, removing any bursal leaders (false insertions into the internal deltoid fascia) laterally, and debriding the fibrofatty bursa overlying the rotator cuff. These steps allow identification of the lateral tendon stump which is reversed upon itself and scarred medially. Once identified the tendon stump is unfolded (Video) and subsequently repaired to the lateral bone bed.

====B4: Tendon to Acromion Adhesion====
Disruption of the lateral tendon stump can be followed by adhesion under the acromion, the coracoid process or the coracoacromial arch (Figure). These adhesions are most pronounced in revision situations, but may also be observed in primary cases, particularly in the setting of a massive contracted rotator cuff tear.<ref name=":28" />
[[File:1562484138603-lg.jpg|center|thumb|700x700px|Figure 30. A) A coronal view of a right shoulder computed tomography (CT) arthrogram shows a probable B2 rotator cuff lesion with a Patte 3 retraction. b) The arthroscopic view through lateral portal revealed after partial debridement that the tendon was not retracted but actually had adhered under the acromion. Reproduced from Lädermann et al., with permission.]]

===Type C: Musculotendinous Junction Lesion===
Isolated ruptures of the musculotendinous junction are rare in the rotator cuff, but have a dramatic impact on functional outcome. Such lesions have been observed in all muscles of the rotator cuff, affecting the infraspinatus muscle in half of cases, followed by the supraspinatus in 31% of cases, the subscapularis in 25%, and the teres minor in 19% of cases (more than one muscle is occasionally involved).<ref>Taneja AK, Kattapuram SV, Chang CY, Simeone FJ, Bredella MA, Torriani M. MRI findings of rotator cuff myotendinous junction injury. AJR American journal of roentgenology 2014;203:406-11.</ref>

These lesions can been classified into 3 stages. Grade I injuries are a muscular strain that heals without adverse sequelae. Grade II injuries are partial ruptures without tendon retraction. Grade III injuries are complete ruptures at the musculotendinous junction. The acute phase of these injuries are associated with severe inflammation, leading to a highly characteristic bright signal on T2 weighted magnetic resonance imaging (Figure 31).<ref>Zarins B, Ciullo JV. ACute muscle and tendon injuries in athletes. Clinics in sports medicine 1983;2:167-82.</ref>
[[File:1562484142491-lg.jpg|center|thumb|700x700px|Figure 31. Axial and sagittal T2-weighted FATSAT magnetic resonance imaging (MRI) images demonstrating a type C rotator cuff lesion with an intact tendon, a stage 3 rupture of the musculotendinous junction, and huge edema of the muscle. Reproduced from Lädermann et al., with permission.]]
Edema of rotator cuff muscle with an intact tendon-bone insertion is infrequent. It has been described in cases of denervation, such as compression of the suprascapular nerve, Parsonage Turner syndrome, in other rare and non-specific conditions.<ref>Ludig T, Walter F, Chapuis D, Mole D, Roland J, Blum A. MR imaging evaluation of suprascapular nerve entrapment. European radiology 2001;11:2161-9.</ref><ref>Bredella MA, Tirman PF, Fritz RC, Wischer TK, Stork A, Genant HK. Denervation syndromes of the shoulder girdle: MR imaging with electrophysiologic correlation. Skeletal radiology 1999;28:567-72.</ref>

Complete musculotendinous junction ruptures have only been described in the infraspinatus and the supraspinatus.<ref>Walch G, Nove-Josserand L, Liotard JP, Noel E. Musculotendinous infraspinatus ruptures: an overview. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:463-70.</ref><ref>Hertel R, Lambert SM. Supraspinatus rupture at the musculotendinous junction. J Shoulder Elbow Surg 1998;7:432-5.</ref><ref>Lädermann A, Christophe FK, Denard PJ, Walch G. Supraspinatus rupture at the musclotendinous junction: an uncommonly recognized phenomenon. J Shoulder Elbow Surg 2012;21:72-6.</ref>

Possible causes for musculotendinous junction infraspinatus lesion are calcific tendinitis or previous cortisone injection. On the other hand, rupture of the other muscles seem to be due to trauma or inlet impingement syndrome. There is little information about the clinical results of grade 3 musculotendinous junction lesions.

====Type C with Reverse Fosbury Flop Tear====
Exceptionally, a lesion of the musculotendinous junction can develop a Fosbury pattern and heals, for its tendon part, on the humerus or even coracoid process.<ref>Tirefort J, Cunningham G, Lädermann A. Reverse Fosbury Flop Tear of the Rotator Cuff. Case Reports in Orthopedics 2017;2017:3635897.</ref>
[[File:1562484351328-lg.jpg|center|thumb|600x600px|Figure 32. Coronal T2 weighted image with fat saturation of a right shoulder. A tear at the musculotendinous junction (green arrow) as well as a muscular edema (white arrows in the frame) are observed. Reproduced from Tirefort et al., with permission.]]
[[File:1562484588402-lg.jpg|center|thumb|600x600px|Figure 33. Coronal T1-weighted (A) and axial T2-weighted (B) with fat saturation of a right shoulder. The supraspinatus flopped on itself (white dotted line) and healed on the anterior humerus (white arrows). Reproduced from Tirefort et al., with permission.]]
[[File:1562484589524-lg.jpg|center|thumb|600x600px|Figure 34. Arthroscopic view of a right shoulder viewed from posterior portal. A) The supraspinatus tendon had the appearance of ulcerations and flanges of the bursal side (sea anemone appearance, black arrows) and, B) after debridement of the flanges, the tendon that flopped on itself and the long head of the biceps and healed on the anterior humerus had an unusual orientation (HH, humeral head; LHB, long head of the biceps; SS, supraspinatus tendon). Reproduced from Tirefort et al., with permission.]]
[[File:1562484592294-lg.png|center|thumb|600x600px|Figure 35. Illustration of a "Fosbury flop tear" (A) and of a "reverse Forsbury flop tear" (B). Reproduced from Tirefort et al., with permission.]]
 

===Type D: Muscle Insufficiency===

====D1: Fatty Infiltration and Muscle Atrophy====
One of the most important prognostic factor for rotator cuff repair is nonfunctional muscle bellies. Muscle quality is most commonly classified according to Goutallier et al. to determine the extent of injuries based upon the degree in which fat is present in the muscle. They proposed a 5 stage classification system of fatty infiltration. Additionally, they demonstrated that multiple muscles develop fatty degeneration, even if they were not directly impacted by the original lesion.<ref name=":9" />

With the advent of MRI, however, the classification was extrapolated to the most lateral parasagittal image on which the scapular spine was in contact with the scapular body (Y view).<ref>Fuchs B, Weishaupt D, Zanetti M, Hodler J, Gerber C. Fatty degeneration of the muscles of the rotator cuff: assessment by computed tomography versus magnetic resonance imaging. J Shoulder Elbow Surg 1999;8:599-605.</ref>

The mean time to tendon rupture observed for stage 2 fatty infiltration is 3 years for the supraspinatus and 2.5 years for the infraspinatus and the subscapularis when their tendons ruptured. The mean time observed to grade 3 and 4 fatty infiltration is 5, 4, and 3 years for the supraspinatus, the infraspinatus, and the subscapularis, respectively.<ref>Melis B, Nemoz C, Walch G. Muscle fatty infiltration in rotator cuff tears: descriptive analysis of 1688 cases. Orthopaedics & traumatology, surgery & research : OTSR 2009;95:319-24.</ref>

Zanetti et al. described a radiographic tangent sign to quickly and reliably assess the presence or absence of supraspinatus atrophy on MRI. This sign is a reliable method for evaluating the presence or absence of muscle atrophy using the sagittal plane and is moreover significantly related to the level of fatty infiltration within the supraspinatus muscle.<ref name=":11" />

It has been reported to be a predictor of whether a rotator cuff tear will be repairable.<ref name=":12" />

Thomazeau et al. proposed calculating the occupation ratio of the supraspinatus muscle belly using MRI. This was calculating by comparing the supraspinatus fossa volume to total supraspinatus muscle belly volume and computing the ratio. This ratio was found to be significantly decreased in patients with repairable rotator cuff tears.<ref name=":20" />

Inability to obtain a complete repair of the supraspinatus was associated with a positive tangent sign (30% irreparable) versus a negative tangent sign (6.3% irreparable, OR = 6,3, P =0.0102) and with Goutallier grade 3-4 fatty infiltration of the supraspinatus (42.9% irreparable) versus grade 0-2 fatty infiltration (5.7% irreparable, OR = 11.8, P =0.001).<ref name=":8" />

Rotator cuff repair should thus be performed before the appearance of fatty infiltration (Stage 2) and atrophy (positive tangent sign) and as soon as possible in older patients when the tear involves multiple tendons.<ref>Melis B, DeFranco MJ, Chuinard C, Walch G. Natural history of fatty infiltration and atrophy of the supraspinatus muscle in rotator cuff tears. Clin Orthop Relat Res 2010;468:1498-505.</ref>

====D2: Neurological impairment====
Isolated suprascapular nerve neuropathy is a condition associated with acute and chronic shoulder girdle traction injuries, compressive lesions such as paralabral cysts and compressive ligaments, as well as large or massive rotator cuff tears (Figure 36). In the latter situation, the proposed mechanism involves traction of the nerve caused by retraction of the supraspinatus against its fixed points on the suprascapular and spinoglenoid notches. However, clinical diagnosis is beset with uncertainties as the potential symptoms of suprascapular nerve neuropathy, namely, pain, weakness, and atrophy, are inseparable from those of rotator cuff tear. Currently, there is no support for routine suprascapular nerve release as the prevalence of suprascapular nerve neuropathy in the setting of a massive rotator cuff tear was very low (2%) in a recent prospective study.<ref name=":17" />
[[File:1562485382488-lg.jpg|center|thumb|600x600px|Figure 36. Sagittal view of a patient suffering from suprascapular neuropathy. A) T1 sequences reveal fatty infiltration and B) T2 FATSAT sequences demonstrate muscle edema.]]

====D3: Tumors====
Numerous tumors, such as an arthrosynovial cyst, intramuscular lipoma, or a calcified hematoma, can developed at the expense of the muscular tissue and cause muscular insufficiency (Figure 37).<ref>Lädermann A, Genevay M, Abrassart S, Schwitzguebel AJ. Supraspinatus Intramuscular Calcified Hematoma or Necrosis Associated with Tendon Tear. Case Rep Orthop 2015;2015:496313.</ref>
[[File:1562485402714-lg.jpg|center|thumb|600x600px|Figure 37. A) Schema of a D rotator cuff insufficiency.
B) Coronal T2-weighted SPAIR magnetic resonance imaging (MRI) image of a right shoulder showing a B2D3 lesion with an intramuscular arthrosynovial cyst. 
C) Coronal T2-weighted PD
D) sagittal T1-weighted image demonstrating D3 rotator cuff lesion with a calcified hematoma in the supraspinatus and an intramuscular lipoma of the subscapularis, respectively. Reproduced from Lädermann et al., with permission.]]
These impairments can be as isolated or be associated with other rotator cuff lesions. Management may require treatment of the associated mechanical stress in addition to rotator cuff repair.

==Irreparable Rotator Cuff Tears==

===Introduction===
One of the most challenging issues in shoulder surgery is the management of symptomatic irreparable rotator cuff tears. The literature reports that 12% of posterosuperior rotator cuff tear are not repairable.<ref name=":8" />

The latter condition when symptomatic can be managed with several approaches without clear evidence based guidelines. For example, the same patient with a D type irreparable rotator cuff tears according to Collin et al. may be offered physiotherapy, partial repair, tendon transfer, superior capsular reconstruction, subacromial spacer (balloon), or even a reverse shoulder arthroplasty (RSA) depending on multiple factors, including, geography, surgeon experience, implants costs, etc. Moreover, even if it is reported that these surgical procedures have different indications, they are often applied to patients with similar problems indiscriminately.

===Definition of an Irreparable Rotator Cuff Tears & Clinical and Imaging Findings===
The definition of an irreparable rotator cuff varies widely. Furthermore, with advances in anchors, suture strength, techniques of release and repair with load-sharing rip-stop fixation, etc, the definition continues to evolve. Two situations can be faced; the first one consists of a patient who has a contra-indication to cuff repair, and the second scenario is intra-operative when a complete repair is not physically possible. While most rotator cuff tears can be repaired, some lesions are not reparable or should not be repaired. Imaging studies play a critical role in preoperative assessment, evaluation of the defects and selection of the correct treatment for an irreparable rotator cuff tears. The following clinical and radiological preoperative factors that have been clearly associated with postoperative clinical or radiological failure should be considered before attempting repair.

===Clinical Examination===
Pseudoparalysis was defined as a chronic inability to actively elevate the arm beyond 90 degrees with full passive forward flexion.<ref>Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-86.</ref>

It is nevertheless important to note that this correspond to functional limitation associated or not with an antero-superior escape and not just to pain inhibition. Several studies purport to reverse pseudoparalysis although it represents mainly pseudoparesis cases. When pain inhibition or slight stiffness limits the patient from elevating the shoulder, the limited motion is not secondary to complete cuff deficiency.<ref>Tokish JM, Alexander TC, Kissenberth MJ, Hawkins RJ. Pseudoparalysis: a systematic review of term definitions, treatment approaches, and outcomes of management techniques. J Shoulder Elbow Surg 2017;26:e177-e87.</ref>

Anatomically, pseudoparalysis requires the disruption of at least of rotator cable attachment which in the study of Collin et al. was found in only 2.9% of massive D-type cases. This means that pseudoparalysis of the posterosuperior rotator cuff cases involved usually the whole posterior cuff (33.3% of pseudoparalysis found in E-type irreparable rotator cuff tears).<ref name=":1" />

In addition to pseudoparalysis, the presence of lag signs (external rotation lag, drop, dropping, hornblower signs) is also associated with non-reparability.<ref>Axe JM. Tendon transfers for irreparable rotator cuff tears: An update. EFORT Open Rev 2016;1:18-24.</ref>

===Treatment===

====Non-Surgical (Conservative) Treatment====
As patients with posterosuperior irreparable rotator cuff tears do not have anterosuperior escape, many respond favorably to nonsurgical treatment which should be attempted for six months before considering surgery. If after this adequate period of time symptoms have not improved, the chances of success with further non-operative treatment decreases and operative treatment may be considered. The mainstay of non-operative treatment includes nonsteroidal anti-inflammatory drugs, subacromial corticosteroid injections, and physical therapy. Levy et al. prospectively assessed 17 patients with clinically and radiographically diagnosed irreparable rotator cuff tears that underwent an anterior deltoid training program.<ref name=":19">Levy O, Mullett H, Roberts S, Copeland S. The role of anterior deltoid reeducation in patients with massive irreparable degenerative rotator cuff tears. J Shoulder Elbow Surg 2008;17:863-70.</ref>

By 9 months, the mean Constant score improved from 26 to 63, and the forward flexion improved from 40° to 160°. In another prospective cohort of 45 patients suffering from pseudoparalysis with a radiographically confirmed D-type rotator cuff tear, Collin et al. found after a follow-up of 48 months that 14 of 15 patients had substantial improvement in active forward elevation to above 90 degrees.<ref name=":24" />

The protocol of rehabilitation focused habitually on a multimodal physical therapy program with global deltoid reconditioning and periscapular strengthening.<ref>Ainsworth R. Physiotherapy rehabilitation in patients with massive, irreparable rotator cuff tears. Musculoskeletal care 2006;4:140-51.</ref>

Certain authors propose that reeducation of the anterior deltoid muscle to compensate for a deficient rotator cuff is the cornerstone of successful non-operative treatment.<ref name=":19" />

The promising results has nevertheless not been confirmed.<ref>Yian EH, Sodl JF, Dionysian E, Schneeberger AG. Anterior deltoid reeducation for irreparable rotator cuff tears revisited. J Shoulder Elbow Surg 2017;26:1562-5.</ref><ref name=":24" />

====Surgical (Operative) Treatment====
In the absence of a gold standard surgical solution, treatment of irreparable rotator cuff tears has proven to be quite challenging, adding to the surgeon’s dilemma regarding the choice of patient and treatment option. Younger active patients (<60 years of age) with traumatic tears, may be immediate candidates for surgery based on the high risk for progression with conservative treatment. Surgical approaches have been advocated, with varying degrees of success. The surgical options include arthroscopic debridement, partial repair, biceps procedure, superior capsular reconstruction, muscle transfers, biodegradable subacromial spacer interposition, biological augmentation and reverse shoulder arthroplasty. Despite all these options, irreparable rotator cuff tears are difficult to manage and treat effectively. There are no high levels of evidence prospective trials comparing these various options and therefore recommendations are mainly based on retrospective case series, surgeon experiences, and expert opinions.

=====Long Head of the Biceps Tenotomy or Tenodesis +/- Partial Repair=====
This procedure includes biceps tenotomy or tenodesis, partial repair if evaluation has deemed the remaining tendon to be of good quality, and associated procedures such as distal clavicle resection if necessary. Tenotomy or tenodesis of the long head of the biceps should consistently be performed, as biceps tendinopathy is observed in 92% of rotator cuff lesions.<ref>Boileau P, Maynou C, Balestro JC, Karataglis D, Papadopoulos P. [Long head of the biceps pathology]. Rev Chir Orthop Reparatrice Appar Mot 2007;93:5S19-53.</ref>

There is evidence suggesting that this structure is a source of pain and contributes to the symptomatology of patients with irreparable rotator cuff tears. Walch et al. reported statistically significant improvements in the Constant score with an isolated biceps tenotomy (Constant score 48 points preoperatively to 68 points at follow-up (P < .0001)) which has been confirmed by numerous authors.<ref name=":25" />

The aim of this procedure is to repair all of the rotator cuff tendon that can reasonably be brought back to the tuberosities without excessive tension, and to address all potential causes of persistent pain or factors threatening the repair. The goal of a partial repair is to restore force couples, to re-establish the “suspension bridge”, and to prevent secondary extension of the tear. In this theory, complete closure of the defect is less important than restoration of a stable fulcrum for normal shoulder kinematics. Although having little effect on improvement in shoulder strength after this intervention, eliminating various pain generators usually enhances function. Although a partial cuff repair is conducted, the role of the biceps tenotomy should not be overlooked in the patient improvements observed.<ref>Boileau P, Baque F, Valerio L, Ahrens P, Chuinard C, Trojani C. Isolated arthroscopic biceps tenotomy or tenodesis improves symptoms in patients with massive irreparable rotator cuff tears. J Bone Joint Surg Am 2007;89:747-57.</ref>

Acromioplasty is not advisable in the setting of an irreparable rotator cuff tears as it may lead to postoperative antero-superior migration of the humeral head. Tuberoplasty has been proposed as an alternative to classic subacromial decompression in order to preserve the integrity of the coracoacromial arch.<ref>Scheibel M, Lichtenberg S, Habermeyer P. Reversed arthroscopic subacromial decompression for massive rotator cuff tears. J Shoulder Elbow Surg 2004;13:272-8.</ref>

Although the results in compensated tears and low-demand patients are promising,176 it is currently unknown if the positive effect with regards to pain relief is due to the tuberoplasty or to the concomitant performed bursectomy, synovectomy and biceps treatment. Partial repair provides good clinical outcomes, comparable to those reported with biceps sacrifice and subacromial decompression. The main purported benefit of repairing part of the cuff is its potential to slow or halt further tear progression and to increase the strength of the shoulder. All series of partial repair reported a significant improvement in functional scores, while reporting a rate of radiological repair failure around 50% (Table 4).<ref>Berth A, Neumann W, Awiszus F, Pap G. Massive rotator cuff tears: functional outcome after debridement or arthroscopic partial repair. J Orthop Traumatol 2010;11:13-20.</ref><ref>Chen KH, Chiang ER, Wang HY, Ma HL. Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Factors Related to Greater Degree of Clinical Improvement at 2 Years of Follow-Up. Arthroscopy 2017;33:1949-55.</ref><ref>Cuff DJ, Pupello DR, Santoni BG. Partial rotator cuff repair and biceps tenotomy for the treatment of patients with massive cuff tears and retained overhead elevation: midterm outcomes with a minimum 5 years of follow-up. J Shoulder Elbow Surg 2016;25:1803-9.</ref><ref>Galasso O, Riccelli DA, De Gori M, De Benedetto M, Orlando N, Gasparini G, Castricini R. Quality of Life and Functional Results of Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears. Arthroscopy 2017;33:261-8.</ref><ref>Godeneche A, Freychet B, Lanzetti RM, Clechet J, Carrillon Y, Saffarini M. Should massive rotator cuff tears be reconstructed even when only partially repairable? Knee Surg Sports Traumatol Arthrosc 2017;25:2164-73.</ref><ref>Henry P, Wasserstein D, Park S, Dwyer T, Chahal J, Slobogean G, Schemitsch E. Arthroscopic Repair for Chronic Massive Rotator Cuff Tears: A Systematic Review. Arthroscopy 2015;31:2472-80.</ref><ref>Shon MS, Koh KH, Lim TK, Kim WJ, Kim KC, Yoo JC. Arthroscopic Partial Repair of Irreparable Rotator Cuff Tears: Preoperative Factors Associated With Outcome Deterioration Over 2 Years. Am J Sports Med 2015;43:1965-75.</ref><ref>Yoo JC, Ahn JH, Koh KH, Lim KS. Rotator cuff integrity after arthroscopic repair for large tears with less-than-optimal footprint coverage. Arthroscopy 2009;25:1093-100.</ref>

Long-term benefit in prevention of head migration has not been demonstrated.

'''''Table 4: Results of partial repair of irreparable rotator cuff tear.'''''
[[File:1562487859066-lg.jpg|thumb|720x720px|†: Constant score, ‡: American Shoulder and Elbow Surgeons (ASES) score, NA: non available.|alt=|none]]

=====Tendon Transfer=====
Tendon transfers have been described in the management of an irreparable rotator cuff tears, however, the outcomes reported have been inconsistent. The results of new transfers involving the lower trapezius transfers have not been well described with mainly anatomical or biomechanical data and will not be described in this review article. L'Episcopo and latissimus dorsi transfer are reported to reconstitute the posterior force couple. L’Episcopo first described the technique of transfer of the latissimus dorsi and teres major tendons in children with obstetric palsy.<ref>L’Episcopo J. Tendon transplantation in obstetrical paralysis. Am J Surg 1934;25:122-5.</ref>

The procedure involves transferring both tendons laterally and posteriorly on the humerus, such that the function of the transfer changes from internal to external rotation. Boileau et al. analyzed recently 26 patients (2 with glenohumeral arthritis) and found a gain in active external rotation of 26 degrees and an improvement in adjusted Constant score from 63.6% to 86.9% (P < .001).<ref>Boileau P, Baba M, McClelland WB, Jr., Thelu CE, Trojani C, Bronsard N. Isolated loss of active external rotation: a distinct entity and results of L'Episcopo tendon transfer. J Shoulder Elbow Surg 2017.</ref>

The integrity of the remaining internal rotators are of utmost importance as patients after a L’Episcopo transfer loose significant internal rotation and may not reach the back anymore. Latissimus dorsi transfer has been initially proposed for irreparable rotator cuff tears as an open procedure to improve control of external rotation in young and high demand patients with an intact subscapularis.<ref>Gerber C. Latissimus dorsi transfer for the treatment of irreparable tears of the rotator cuff. Clin Orthop Relat Res 1992:152-60.</ref>

Namdari et al. in a review found that patients followed for mean of 46 months had a mean adjusted Constant score of 46 preoperatively compared with 73 postoperatively (p < 0.001). The mean active external rotation improved from 17 degrees to 27 degrees which is statistically significant (p < 0.001) but not clinically significant. As proposed by Gerber, isolated latissimus dorsi transfer with or without reverse shoulder arthroplasty is mainly to "restore control of external rotation in selected patients" rather than active external rotation itself.<ref>Gerber C, Pennington SD, Lingenfelter EJ, Sukthankar A. Reverse Delta-III total shoulder replacement combined with latissimus dorsi transfer. A preliminary report. J Bone Joint Surg Am 2007;89:940-7.</ref>

It is also important to keep in mind that the results of the open technique are superior in case of an intact or repairable subscapularis and a hypertrophic teres minor.<ref>Costouros JG, Espinosa N, Schmid MR, Gerber C. Teres minor integrity predicts outcome of latissimus dorsi tendon transfer for irreparable rotator cuff tears. J Shoulder Elbow Surg 2007;16:727-34.</ref><ref>Namdari S, Voleti P, Baldwin K, Glaser D, Huffman GR. Latissimus dorsi tendon transfer for irreparable rotator cuff tears: a systematic review. J Bone Joint Surg Am 2012;94:891-8.</ref>

In other words, latissimus dorsi transfer in D-types irreparable rotator cuff tears is efficient but only indicated in selected patients having an isolated loss of external rotation, a preserved forward elevation above 90°, an intact or repairable subscapularis an ideally a hypertrophic teres minor. Conversely, latissimus dorsi transfer gives unpredictable results in E-type latissimus dorsi transfer and potentially a L’Episcopo transfer is superior in those cases. Recently, indications and techniques have evolved and arthroscopic procedures have been proposed to hopefully limit humeral head upper migration and to restore anterior active elevation.<ref>Grimberg J, Kany J, Valenti P, Amaravathi R, Ramalingam AT. Arthroscopic-assisted latissimus dorsi tendon transfer for irreparable posterosuperior cuff tears. Arthroscopy 2015;31:599-607 e1.</ref>

The same group has observed in a prospective series of 25 patients with a follow-up of 12 months an improvement in mean Constant score from 44 points preoperatively to 65 postoperatively, a slight improvement (10 degrees) in external rotation but a radiological failure rate of 43%.<ref>Bonnevialle N, Joudet T. [Massive Rotator Cuff Lesions]. Société Francophone d'Arthroscopie. Marseille2017.</ref>

=====Posterior rotator cuff insufficiency=====
Currently, the most commonly used transfer for an irreparable type D or E massive rotator cuff tears is latissimus dorsi transfer. The ideal candidate is a patient who has maintained active anterior elevation, but lacks control of the arm in space in external rotation (simple weakness in external rotation is not a sufficient indication for surgery), and who also has an intact subscapularis and no glenohumeral arthritis. Results are disappointing in patients with subscapularis insufficiency. In addition, results have been disappointing in the setting of preoperative teres minor tears or atrophy. Gerber et al. reported long-term results at a mean of 147 months. The mean simple shoulder value (SSV) in 46 shoulders increased from 29% preoperatively to 70%, the relative Constant score improved from 56% to 80%, and the pain score improved from 7 to 13 points (p < 0.0001 for all).<ref name=":27" />

However, there is no proof that latissimus dorsi transfer gives better long-term results than a simple partial rotator cuff repair. Effectively, 60% of type E massive rotator cuff tears do not lose control of the arm in external rotation. Consequently and despite large series recently published, indications for this type of surgery are rare.<ref name=":1" />

=====Superior Capsular Reconstruction=====
Superior capsular reconstruction with either fascia lata autograft, dermal allograft patch or long head of the biceps is a solution that could prevent superior humeral head migration and restore the shoulder muscle force couples (Video of Superior Capsular Reconstruction with Long Head of the Biceps "The Chinese Way").<ref name=":3">Mihata T, Lee TQ, Watanabe C, Fukunishi K, Ohue M, Tsujimura T, Kinoshita M. Clinical results of arthroscopic superior capsule reconstruction for irreparable rotator cuff tears. Arthroscopy 2013;29:459-70.</ref><ref>Burkhart SS, Denard PJ, Adams CR, Brady PC, Hartzler RU. Arthroscopic Superior Capsular Reconstruction for Massive Irreparable Rotator Cuff Repair. Arthrosc Tech 2016;5:e1407-e18.</ref><ref>Boutsiadis A, Chen S, Jiang C, Lenoir H, Delsol P, Barth J. Long Head of the Biceps as a Suitable Available Local Tissue Autograft for Superior Capsular Reconstruction: “The Chinese Way”. Arthroscopy Techniques 2017.</ref>
[[File:1563115166796-lg.mp4|center|thumb|650x650px|Video 14.]]
The superior capsule is believed to be important in maintaining humeral head depression and compensating for the dynamic effect of the rotator cuff muscles. However, the superior capsule is an inconsistent structure constituted by a confluence a various ligaments, that is in continuity in only 27% of the cases (Video that shows an L-shape left rotator cuff lesion with an intact superior capsule).<ref>Pouliart N, Somers K, Eid S, Gagey O. Variations in the superior capsuloligamentous complex and description of a new ligament. J Shoulder Elbow Surg 2007;16:821-36.</ref>
[[File:1563119074281-lg.mp4|center|thumb|677x677px|Video 15.]]
No articles reported on the mid- or longer-term clinical and radiological results. Mihata et al. in a small series of 23 patients using fascia lata autograft found at a mean follow-up of 34 months an increased in forward flexion from 84° to 148° (P < .001) and external rotation increased from 26° to 40° (P < .01). Twenty patients (83%) at most recent follow-up had an intact graft without retear.<ref name=":3" />

Denard et al. reported in a series of 59 patients using a dermal allograft with a minimum follow-up of 1 year an increase in forward flexion from 130 degrees preoperative to 158 degrees postoperative, an improvement in American Shoulder and Elbow Surgeons (ASES) score from 44 to 78 and a 55% failure rate. In all cases, a biceps tenotomy or tenodesis was performed.<ref>Denard PJ, Brady PC, Adams CR, Tokish JM, Burkhart SS. Preliminary Results of Arthroscopic Superior Capsule Reconstruction with Dermal Allograft. Arthroscopy 2018;34:93-9.</ref>

=====Subacromial Balloon Interposition=====
The biodegradable spacer (balloon shape) is arthroscopically implanted between the acromion and the humeral head. The subacromial spacer has been designed to create a physical barrier between tissues in the subacromial space and keep the humeral head depressed when the rotator cuff is not efficient to facilitate deltoid action, thus permitting improvement in glenohumeral joint motion with significant pain reduction. At 5 years follow-up, a recent study on the subacromial spacer with an associated biceps tenotomy reported that 85% of the patients showed a clinically significant improvement of at least 15 points in Constant score, while 62% showed at least 25 points of improvement.<ref>Senekovic V, Poberaj B, Kovacic L, Mikek M, Adar E, Markovitz E, Maman E, Dekel A. The biodegradable spacer as a novel treatment modality for massive rotator cuff tears: a prospective study with 5-year follow-up. Arch Orthop Trauma Surg 2017;137:95-103.</ref>

Deranlot et al. described in a series of 37 patients (39 shoulders) a significant improvement of the Constant score from 45 preoperatively to 76 at a mean of 33 months follow-up. In their study, 92% of the shoulders also underwent a long head of biceps tenotomy.<ref>Deranlot J, Herisson O, Nourissat G, Zbili D, Werthel JD, Vigan M, Bruchou F. Arthroscopic Subacromial Spacer Implantation in Patients With Massive Irreparable Rotator Cuff Tears: Clinical and Radiographic Results of 39 Retrospectives Cases. Arthroscopy 2017;33:1639-44.</ref>

=====Biological Augmentation=====
These techniques involve using a graft (allo, auto, or xeno) or synthetic patch to bridge the defect in the rotator cuff and improve connection of the tendon remnant at least at the border of the original footprint. During this procedure, the torn rotator cuff tendons are released, mobilized, and undergo a partial repair. The graft is then sutured on top of the residual defect between the lateral margin of the medial fixed rotator cuff tendon and its native insertion site on the lateral footprint and humerus. A systematic review confirm that this approach improved function with a high rate of structural integrity rates on MRI at 12-month minimum follow-up.<ref>Lewington MR, Ferguson DP, Smith TD, Burks R, Coady C, Wong IH. Graft Utilization in the Bridging Reconstruction of Irreparable Rotator Cuff Tears: A Systematic Review. Am J Sports Med 2017;45:3149-57.</ref>

=====Achilles Tendon-Bone Block Allograft for Massive Rotator Cuff Tears With Bony Deficiency of the Greater Tuberosity=====
In patients aged >60 years, reverse shoulder arthroplasty is an acceptable solution. However, because of longevity concerns, reverse shoulder arthroplasty is not an ideal option for young patients. Achilles tendon–bone block allograft has been described as an alternative to reverse shoulder arthroplasty in a young patient with greater tuberosity and rotator cuff deficiency. There has also been growing interest in utilizing the Achilles tendon allograft for superior capsular reconstruction.

=====Reverse Shoulder Arthroplasty=====
Reverse shoulder arthroplasty has emerged as a treatment for irreparable rotator cuff tears. Two recent systematic reviews confirmed that this is a reliable procedure to improve mobility and strength, producing an improvement in pain and postoperative outcome scores.<ref>Petrillo S, Longo UG, Papalia R, Denaro V. Reverse shoulder arthroplasty for massive irreparable rotator cuff tears and cuff tear arthropathy: a systematic review. Musculoskelet Surg 2017;101:105-12.</ref><ref>Sevivas N, Ferreira N, Andrade R, Moreira P, Portugal R, Alves D, Vieira da Silva M, Sousa N, Salgado AJ, Espregueira-Mendes J. Reverse shoulder .arthroplasty for irreparable massive rotator cuff tears: a systematic review with meta-analysis and meta-regression. J Shoulder Elbow Surg 2017;26:e265-e77.</ref>

Moreover, reverse shoulder arthroplasty yielded benefits considered cost-effective when compared with other treatments, especially in elderly patients with irreparable rotator cuff tears.<ref>Kang JR, Sin AT, Cheung EV. Treatment of Massive Irreparable Rotator Cuff Tears: A Cost-effectiveness Analysis. Orthopedics 2017;40:e65-e76.</ref>

Reverse shoulder arthroplasty should be considered in older patients for whom long period of immobilization and rehabilitation is undesirable.<ref>Lädermann A, Denard PJ, Tirefort J, Collin P, Nowak A, Schwitzguebel AJ. Subscapularis- and deltoid-sparing vs traditional deltopectoral approach in reverse shoulder arthroplasty: a prospective case-control study. Journal of orthopaedic surgery and research 2017;12:112.</ref>

Even if the rate of complications was high in the two above mentioned systematic reviews, a dramatic decrease has been observed with new designs and better techniques.<ref>Lädermann A, Lo EY, Schwitzguebel AJ, Yates E. Subscapularis and deltoid preserving anterior approach for reverse shoulder arthroplasty. Orthopaedics & traumatology, surgery & research : OTSR 2016;102:905-8.</ref>

Recently, the complication rate has been reported to be lower. However, caution should still be exercised when offering reverse shoulder arthroplasty to young patient that are often disappointed by the results.<ref>Ernstbrunner L, Suter A, Catanzaro S, Rahm S, Gerber C. Reverse Total Shoulder Arthroplasty for Massive, Irreparable Rotator Cuff Tears Before the Age of 60 Years: Long-Term Results. J Bone Joint Surg Am 2017;99:1721-9.</ref><ref>Virk MS, Nicholson GP, Romeo AA. Irreparable Rotator Cuff Tears Without Arthritis Treated With Reverse Total Shoulder Arthroplasty. Open Orthop J 2016;10:296-308.</ref>

====Conclusion====
Various surgeries are proposed for similar posterosuperior irreparable rotator cuff tears and preoperative patient' clinical evaluation. There is no panacea for primary treatment and patients must be aware, in case of palliative or non-prosthetic option, of an alarming rate of structural failure (around 50%) in the short term (Table 5).

'''''Table 5: Results of the different techniques of irreparable rotator cuff tear treatment from representative series'''''
[[File:1562520882562-lg.jpg|center|thumb|720x720px|†: Constant score, ‡: American Shoulder and Elbow Surgeons (ASES) score, NA: non available.|alt=]]
The initial use of complex and expensive techniques in management of posterosuperior irreparable rotator cuff tears is actually not supported. Further prospective and comparative studies with large cohort populations and long-term follow-up are necessary to establish effectiveness of expensive or complicated procedures such as SCR, biological augmentation or subacromial spacer as reliable and useful alternative treatment for irreparable rotator cuff tears. 

==What would Codman have thought about this?==

Rupture of the supraspinatus tendon

CHAPTER V

Now that we have considered the shoulder from the anatomic and pathologic points of view, we come to the clinical study of the lesions which may be identified by special groups of symptoms as definite entities. It seems to me that the practice of medicine might be greatly simplified if an official list of clinical entities was constantly maintained by some great medical association. Our literature and our methods of medical education are greatly hampered by synonyms. McCarthy has recently pointed out in Surg. Gyn. and Obst., February, 1932, that there is great need for such a list of malignant conditions. Pathologic entities and clinical entities are not the same. Clinical entities are the practical working diagnoses on which rational treatment may be based. I feel that the Registry of Bone Sarcoma has served such a purpose so far as the nomenclature of bone tumors is concerned, and that this fact alone has done much to crystallize our working knowledge of the diagnoses and treatment of bone lesions.
I shall try in this book to make a. similar list of the lesions of the shoulder which have such distinctive characters that they may be recognized clinically and given appropriate treatment. For instance, I recognize as significant clinical entities, complete rupture of the supraspinatus tendon, partial rupture of the supraspinatus tendon, calcified deposits in the tendons of the short rotators, and tendinitis of the short rotators; and I do not recognize muscular rheumatism, neuritis, or idiopathic monarticular arthritis of the shoulder, as entities of sufficient clinical frequency or importance to make them demand special forms of treatment, although these terms are much more frequently used as diagnoses on which physicians base their therapeutics. If an official list existed I would ask to have my new entities added and the old ones at least put in small type. The reader is referred to the Index.

Click for large image

CHART I

Excluding obvious diagnoses such as tumors, fractures and dislocations, most painful shoulders may be classed under the four diagnoses indicated in large type, although each entity merges into the two which adjoin it. For example, calcified deposits are probably a product of tendinitis, but if large in amount, they alter the clinical picture, both in prognosis and in the character of treatment required. If the deposits are very small, they may be negligible, and the clinical picture be that of a "frozen shoulder" due to tendinitis, lendinitis may also be confused with its other neighbor, because a "rim rent" may precipitate the inflammation which results in the frozen shoulder. In a similar way the line between partial and complete ruptures is difficult to draw; e.g., some cases of partial ruptures do not show much restriction of motion. Even complete ruptures may be confused with calcified deposits, as in Case 76, where the tendon was torn through a partially calcified area. Pathologically, too, there is some reason to believe that calcified deposits may be caused originally by small ruptures, and that the defects left after the deposits have disappeared may later lead to rupture. Nevertheless, although these entities are difficult to separate in borderline cases, typical instances are very clearly distinguished for purposes of treatment as well as in prognosis. There are also suggestive variations in sex, age, and occupation among the patients subject to these conditions.

This chapter discusses the most serious of these entities. As far as I know, I was the first writer to call attention to this lesion, and it seems to me that I can best introduce the rest of the book by reprinting here my first article, so that we may thus start at the beginning, so far as the history of this particular entity is concerned.

----------------------------------------------------

Reprinted from the Boston Medical and Surgical Journal, Vol. clxiv, No. 20, pp. 708-710, May 18, 1911

COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON. OPERATIVE TREATMENT WITH REPORT OF TWO SUCCESSFUL CASES

In a paper on "Stiff and Painful Shoulders," published in the Boston Medical and Surgical Journal for May 31, 1906, in speaking of rupture of the supraspinatus tendon in connection with subacromial bursitis, I presupposed, on anatomic grounds, the probable symptoms of such rupture as follows:

"One theoretical symptom (since the supraspinatus is put out of action) should be the persistence of passive and loss of active abduction. I am not ready to say this as yet, however, because in most cases the pain is so great that spasm prevents even passive motion, and later adhesion takes the place of spasm. When rupture of the tendon does take place, it probably is only partial and a Y-shaped attachment still remains to perform part of the function. In a similar way, the quadriceps may extend the femur when the patella is broken if the lateral expansions of its tendon are not torn. Nevertheless, I believe that the active function of the supraspinatus is important in elevation of the arm."

Since this paragraph was written I have had two cases of complete rupture of the supraspinatus tendon on which I have operated, and in both of which I was able not only to demonstrate the existence of the anatomical lesion in conjunction with the above symptoms, but succeeded by suturing the tendon to the tuberosity in bringing about complete restoration of the function of abduction. I have also, in a number of cases, verified the clinical diagnosis of a partial rupture such as depicted in the accompanying figure, which was produced in the other articles which I have written on this subject. (The reader is referred to the articles appearing in the Boston Medical and Surgical Journal for Oct. 22 and 29, Nov. 5,12,19 and 26, and Dec. 3, 1908. The figure alluded to is not repeated here.)
This partial rupture is the common lesion, and, as I have explained, the remaining portion of the tendon is competent to take up the function when the sensitiveness due to the reparative process about the point of rupture has disappeared. The curious deposits of lime salts sometimes shown in the X-ray, and spoken of by Painter and Baer, are, I believe, faulty attempts at repair of these tiny ruptures of the tendon.
The following two cases are quite definite because they present complete rupture of the tendon of the supraspinatus. Therefore, the function of active abduction was almost entirely lost.

CASE 1.—Mrs. J. A. Aged fifty-two. Born in Scotland. Referred by Dr. Kent, of Dorchester, March 7, 1909.
Patient had always been a healthy, hard-working woman and had practically never been sick. On Oct. 3 of the previous year, i.e., five months before I saw her, while she was hanging recently washed clothes on the line in her yard, she endeavored to toss over a heavy blanket and felt something snap in her shoulder as she threw her arm up. She felt an intense pain and her arm fell and "hung by her side for a while." She was examined later by Dr. Kent, who found no thickening or ecchymosis. An X-ray was negative. Since then she had not been able to abduct the arm and had suffered much pain at night and somewhat during the day. The symptoms were in general those which I have described as the symptoms of adherent subacromial bursitis. The following points were, however, noticeably different.
(1) There was little atrophy of the deltoid, and it even appeared hypertrophied on account of the apparent swelling of the joint beneath. (2) Under the fibers of the deltoid, beneath the acromion and over the joint, there was a distinct deep fluctuation as if the whole bursa were full of fluid. (3) The ability to start abduction was absent, but when the arm was passively abducted to about 140°, the patient, by a strong contraction of the deltoid, could prevent the arm from falling for an instant, but the slightest downward pressure made it drop to the side. External rotation was about one-half the normal.
Operation.—March 11, 1909. Usual incision between fibers of deltoid. Roof of bursa abnormally thick with granulation-like bodies on its under surface. Escape of straw-colored fluid, about one-half ounce. The floor of the bursa was found communicating with the joint, because practically the whole supraspinatus was torn from its insertion and retracted inwards. The biceps tendon was exposed over the articular surface, but was apparently uninjured. For about one-half inch on the lower visible portion it was bright pink; the rest of it was normal in appearance. By holding the bursa wide open,
pulling down on the arm and raising the elbow from the table, the retracted end of the supraspinatus could be seen. This was caught with a tenaculum and pulled down enough to suture with four heavy silk threads to the remaining portion still attached to the tuberosity. This could not be done exactly, but was done nearly enough so that it seemed possible for repair to take place along the silk sutures. A little gap was also left on each side, which was not covered with tendon substances. It was in a sense a suture a-distance. When the operation was completed it seemed as if there was a fair possibility of the supraspinatus obtaining enough attachment to enable it to perform its function, although the base of the bursa would necessarily remain a rough instead of a smooth surface. Dr. Kent gave ether, Dr. Vincent assisting. Dr. J. J. Putnam and Dr. M. P. Smith-wick present.
June 9, 1909. Looks very strong and well. Sleeps well. Arm aches at times but not much. Pain in stormy weather (after use). Gets good use out of arm and does her own work. Can button back of dress and do her own hair. Real free abduction to 135°. Fair rotation. Muscles developing well and deltoid is strong. Very much pleased with result.
This patient was demonstrated to the Interurban Orthopedic Club, March 25, 1911. The arm is perfectly well and the function is perfect. The only abnormal sign is that the deltoid is unusually prominent due to the presence of joint fluid in the bursa.

CASE 2.—Mr. D. R. Aged forty. Hostler. Referred by Dr. John Homans, Dec. 21, 1910.
Patient is a strong, wiry Irishman. He has always been well. About three and one-half months previously, he had been saddling a horse in the stable and while tightening the girth he felt something in his shoulder give way and he fell to the floor. There was immediate loss of power in the arm, but lie managed to finish saddling the horse without raising that arm. That night he consulted Dr. Luce, of Canton, who found no ccchymosis, but thought there was slight crepitus. An X-ray a little later was negative. The hip was also hurt by his fall, so that for some time he was more bothered by that than he was by his shoulder and he was obliged to use crutches for several weeks. At the time he presented himself to me for examination the symptoms were at first sight those of the adherent type of subacromial bursitis, but on more careful examination the same signs that were present in the previous case were demonstrable, that is, (1) Relatively slight atrophy of the deltoid and an appearance of hypertrophy. (2) Fluctuation over the region of the bursa beneath the deltoid producing a "verwblbung" of the latter. (3) The persistence of nearly normal passive abduction with no active abduction. When the arm was passively abducted, the patient by a strenuous exertion of the deltoid could hold the head of the bone on the glenoid and thus prevent the arm from falling immediately. (4) In this case a distinct depression could be felt just above the tuberosity at the point where the tendon was torn away from the latter. A definite diagnosis was made and the members of the Boston Orthopedic Club invited to examine the case and witness the operation.
Operation.—Jan. 10, 1911, at the Massachusetts General Hospital.
As in the previous case, when the fibers of the deltoid.and the thickened roof of the bursa were incised, there was an escape of straw-colored fluid and the bursa was found to be in communication with the true joint. The supraspinatus had retracted so far that at first it could not be seen, and one looked directly at the articular surface of the bone with the uninjured biceps tendon lying across it. With some difficulty the supraspinatus tendon was caught with a tenaculum, freed and pulled forward. It was then sutured "a-dis-tance" to the tuberosity with heavy silk prepared with paraffine after the manner of Lange. As in the previous case, the retracted tendon could not be entirely united, but enough strands of silk were put in to make it possible for the function of the tendon to be replaced.
Convalescence was normal and the patient was not allowed to use the arm in abduction for three weeks, but since then has been using it with more or less freedom. He was shown to the Interurban Orthopedic Club on March 25, and the following condition noted at that time:
Patient is working every day—can chop wood and do other "chores" without pain. He can easily place his hand on top of his head or behind his back. Full abduction of the humerus on the scapula is, however, weak, and although he can elevate his arm, he cannot hold it in an abducted position against a downward pull of even moderate force. The strength of the arm in other respects is excellent and the patient is well satisfied. The function of the supraspinatus is fully as good as it was in Case 1, at the same length of time after the operation.
I have seen only one other case in which I have made a diagnosis of complete rupture of the supraspinatus, and as I have not been able to persuade this patient to allow me to operate, his present condition is very instructive as compared to the two cases mentioned above.
In spite of the fact that the patient is a powerful man with an extremely well-developed deltoid, he is now, four years after the injury, still unable to start abduction. As in the other cases, however, when the arm is passively abducted so that the patient's deltoid acts in the same line of force as the axis of the humerus and the remaining short rotators {i.e., subscapularis, teres minor, infraspinatus), the head of the humerus obtains a fairly firm contact with the glenoid so that the weight of the arm can be held by a great effort of will on the part of the patient. The slightest pull downward on the arm, however, will overcome what little power he has, and as soon as the fulcrum on the glenoid is lost, the arm drops to the side.
It will be necessary for those readers who are interested in this subj ect to refer to the articles mentioned above to thoroughly understand this one, but, best of all, they should look for themselves at dissecting-room subjects, because injuries to this tendon are so common that I have never had any difficulty in finding examples of it in a single set (20) of dissecting-room subjects.
The injury, as I have explained, is usually confined to a partial rupture of not more than one-quarter to one-half inch in breadth. Such complete cases as these three which I have reported are exceptional. The smaller ruptures, which are not of sufficient mechanical importance to interfere greatly with the function of the arm, are best considered with the subacromial bursitis which they cause. It must be understood that these ruptures are beneath the serous base of the bursa, which may or may not be torn through. If it is torn through, a communication is established between the bursa and the true joint.
In operating for subacromial bursitis, if on entering the bursa one finds straw-colored joint fluid, a careful search will usually demonstrate a small opening into the true joint at the point of rupture. In only one case has it seemed worth while to me to make an attempt to suture one of these small ruptures. Usually these heal satisfactorily if the inflamed portion of the bursa over them is clipped away with scissors. I am convinced, nevertheless, that suture is necessary in long-standing complete cases such as those cited above. The one which was not sutured has a decidedly impaired function and for two years was unable to work.
I have never seen the tendons of the other short rotators ruptured except in conjunction with that of the supraspinatus. Twice I have seen a longitudinal split between the tendon of the subscapularis and that of the supraspinatus. (End of 1911 paper.)

FIGURE 38. RUPTURE OF THE SUBSCAPULARIS
Sketch by Mr. Aitkin of a specimen found and prepared in the dissecting room by my former assistant, Dr. T. W. Stevenson. It illustrates a rupture of the subscapulars without rupture of the supraspinatus, and is instructive from several points of view. This is the only instance of an exception to the statement in the last paragraph which has come to my knowledge in the twenty-two intervening years. It gives a very good idea of how the insertion of the supraspinatus, which in this specimen was intact, normally fills the sulcus at the anatomic neck, and covers the tuberosity, thus leaving a perfectly smooth exterior contour beneath the base of the bursa. In this case the bursa has been thoroughly dissected away in order to show the superficial fibers of the tendons passing over the tuberosity and becoming continuous with the periosteum below. In Chapter X it will be shown how these fibers cover up and hold together the fragments in comminuted fractures.
The figure also gives a good idea of the manner in which the supraspinatus emerges from under the coraco-acromial ligament and acromion. The lower or inner edge of the muscle has been rather sharply dissected, but in the undissected specimen this edge blended with the upper portion of the subscapularis. Below this, one sees that most of the subscapularis has been torn away from the conjoined tendinous cuff, so that the biceps tendon, running through its groove between the two tuberosities, is exposed at the left edge of the gap. Internal to the biceps tendon we see the lesser tuberosity, from most of which the subscapularis fibers have been evulsed. The knobby character of the surface of the exposed tuberosity is shown; an appearance usually found in old cases where the tuberosity is exposed by evulsion of the fibers of any of the other tendons. (See frontispiece and Fig. 40.) In other words, this knobby look is the superficial appearance of the "excrescences" or "volcanoes" spoken of on page 91, and also shown in Plate V, Fig. 1.
In the upper half of the gap above the excrescences is the exposed cartilage of the joint. If this gap extended outward from the biceps tendon, instead of inward, it would represent the condition which we usually see; i.e., rupture of the supraspinatus rather than of the subscapularis. It is not unusual to find in the dissecting room extensive tears involving both tendons, but it is very unusual to find the subscapularis involved alone, as in this case. One can readily picture how easy it would be to produce such a condition as this by forcibly performing external rotation in a case of "frozen shoulder."
This diagram also gives an excellent idea of the coracoid process, coraco-clavicular and coraco-acromial ligaments, as well as of the conjoined origin of the internal or short head of the biceps, and of the cornco-brachialis muscles. It also shows the insertion of the pectoralis minor, the tendon of which protrudes as a stub at the inner side of the coracoid process in this diagram.

Although it is over twenty years since the above paper was written, I have very little of importance to add or subtract from it. I followed the two cases for many years and the results continued to be satisfactory. Although the second case never had perfect function in his shoulder, he could do all sorts of farm and stable work without complaint. As he worked for a neighbor, I had frequent opportunity to observe him for over ten years.
There is a point in the quoted paragraph which might cause confusion. At that time, 1906, I did not realize that the stooping posture was such a great help in testing mobility in the scapulo-humeral joint. One may get the impression, when examining a patient in the upright position, that scapulo-humeral adhesions exist, and yet in the stooping posture, positive proof will be given that the joint is movable. It is important for the reader to understand at once that scapulo-humeral passive mobility is a sine qua non for the diagnosis of a complete rupture of the supraspinatus, and that in the stooping posture this mobility is much less inhibited by pain and spasm. I did not fully appreciate this point in 1906, and even in 1911 I had hardly grasped it, and did not accent it enough in the above paper. It will be discussed later in this chapter.
The only other point which I desire to correct is in the next to the last paragraph. I do not think I was justified in making such a general statement as "usually these heal satisfactorily if the inflamed portion of the bursa over them is clipped away with scissors," for I am still in doubt as to how to treat the incomplete ruptures.
I have really little more than I had in 1911 to give to the profession in this book, except that repeated experience with the same signs, symptoms, operative findings and follow-up have increased my confidence in the accuracy of my former observations and opinions. During these years I have only operated upon about forty belated cases, although I have made the diagnosis over a hundred times. My results have been good but by no means perfect, because I never see these cases in their early stages, when I am sure the operations would be easy and the results entirely satisfactory. This book aims to try to teach the practicing physicians, who see the cases soon after the injury, how to recognize this lesion immediately, and to rush the patient to a competent surgeon as promptly as if the patient had a broken arm—a much less disabling accident. As in acute appendicitis, early recognition and prompt operation are of the utmost importance. The remainder of this chapter will therefore be devoted to a more detailed discussion of the symptoms.

FIGURE 39. RUPTURE OF THE SUPRASPINATUS
A schematic posterior view of a case of ruptured supraspinatus, to show the posterior short rotators and the sulcus and eminence formed where rupture of the supraspinatus has occurred. The acromion has been sawed off at its base. The reader should study the frontispiece and the next figure in connection with this one.

The size of the rent in the tendon is an important factor since the degree of the severity of each symptom may vary with the extent of the rupture. It seems best to discuss first the symptoms of those cases where the rent is large, as in the two cases which I first reported and which I have called "complete." This means that at least that portion of the conjoined tendinous insertions supplied by the supraspinatus has been torn away, with or without portions of the adjacent tendons. These are the cases which should certainly have the benefit of immediate operation. I do not at present advocate operating upon incomplete cases, for it is likely that after a few months they may heal in whole or in part. On the other hand, there is good reason to believe that the complete ruptures which make an open communication between the joint and the bursa never do heal entirely unless sutured. In other words, the symptoms have had to be pretty pronounced in order to make me willing to operate. It is significant that almost invariably the rent in the tendon has been found to be larger than anticipated. I have perhaps been over-conservative in deciding to operate, but the reader must remember that I have taken the responsibility of doing an operation which is not generally practiced, and naturally I have been somewhat cautious. It is my sincere belief, however, that a small exploratory incision is harmless and that the practice of promptly making such an incision in acute, doubtful cases is to be encouraged, provided the operator has carefully studied the anatomy of the region.
Almost all surgical operations which are now standard procedures had similar histories. Many human sacrifices were required to teach us not to delay when the symptoms strongly suggested appendicitis, perforated duodenal ulcers or intestinal obstruction. The fact that death occurs when we procrastinate in these serious cases has made us, in the public eye, more to blame for delay than for making negative explorations. The surgeon who does explorations on these injured shoulders might be criticized today and yet a few years hence be blamed for the failure to do them. Moreover, the laboring man with a shoulder injury has not yet been educated to dread this particular lesion as he has been to fear appendicitis.

FIGURE 40. X-RAY OF SPECIMEN SHOWN IN FRONTISPIECE Owing to the fact that it had been dissected, air has entered both the joint and the bursa, somewhat after the manner indicated in the cover design. It suggests appearances which we might see if we used air or opaque fluid injections in the bursa and joint. It shows a little irregularity on the surface of the tuberosity, which in the painting gives the appearance that I have called a " volcano "; i.e., a small eminence which has a craterlike place in its center. These little eminences are found in many old cases of ruptured supraspinatus. They may represent a productive osteitis due to irritation from contact with the acromion during elevation. The figure also shows two small caverns such as those illustrated in Plate V, Fig. 1 and Fig. 2. I am not sure just what these caverns indicate.

The account of symptoms given in my 1931 paper before the American College of Surgeons was presented in a twenty-minute talk, and while I still think it accurate, I am not satisfied with its arrangement nor with the amount of detail its time limit permitted. The immediate symptoms were not separated as they should have been from those that supervene later in the course of the disability. The early signs should have been emphasized, because success in treatment must depend largely on prompt diagnosis. It is easy enough to recognize one of these cases when atrophy has developed and the lapse of time has shown the persistent character of the lesion, but to make the diagnosis on the day of, or on the day after, an injury is quite another matter.
Probably insurance records would show that 80 or 90 per cent of employees complaining of shoulder "strains," return to work within three months. Certainly we could not recommend exploratory incision of the bursa in all of these cases in order to detect perhaps 10 or even 20 per cent where the rupture would be complete. When we have learned just what to do when we find minor ruptures or tendinitis, it may become wise to make such incisions as a routine, but at present the bill for negative explorations would be far too large. I contend that it is possible to detect the severe cases.

CERTAIN CONDITIONS, SYMPTOMS AND SIGNS WHICH INDICATE COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON AND WHICH SHOULD BE PRESENT WITHIN TWENTY-FOUR HOURS AFTER THE ACCIDENT.

(1) Occupation—labor.
(2) Age—over 40.
(3) No symptoms in shoulder prior to accident.
(4) Adequate injury—usually a fall.
(5) Immediate sharp, brief pain.
(6) Severe pain on following night.
(7) Loss of power in elevation of the arm.
(8) Negative X-ray.
(9) Little, if any, restriction when stooping.
(10) Faulty scapulo-humeral rhythm.
(11) A tender point,
(12) a sulcus, and
(13) an eminence
(14) at the insertion of the supraspinatus,
(15) which cause a jog,
(16) a wince and
(17) soft crepitus as the tuberosity
(18) disappears under the acromion when the arm is elevated, and usually also, as it reappears during descent of the arm.

Here are eighteen conditions to be fulfilled—an especially exacting syndrome. If such a syndrome is present I do feel that not only is exploration indicated but that it should be strongly urged, for immediate suture should be a simple and successful operation. Delay means retraction of the tendon and a much more serious problem.

I feel confident that this syndrome must exist, although I admit that I have never seen one of these cases within twenty-four hours of an injury. My best way of knowing the immediate symptoms is from the accounts of the patients or of their physicians given weeks or months after the injuries. Moreover, since these same symptoms are found at varying periods from three weeks to many years after the accidents, and do not vary much with the lapse of time, either in quality or in degree, it is likely that they were present at first. In a case in which they were all typical I should be positive of the diagnosis, and should urge operation. If several of the conditions were not fulfilled, it would influence me against operation, but if there were doubt, a negative exploration, if correctly performed, is a trivial matter, although the patient must be hospitalized in case a rupture is found.
If suture is done he should remain in the hospital for about ten days; if the exploration is negative he might well be discharged in twenty-four hours. These eighteen points will be discussed in more detail in numerical order.

(1) Occupation. The great majority of cases must belong to the laboring classes, for I have seen only one case in a person whose occupation did not or had not required heavy work. This suggests that overuse as well as increased liability to accident may be a contributory cause. The occupations are given serially in the following paragraph because if they were tabulated the list would not give the same impression of sequence which is presented by patients as they come for examination. On looking over these occupations the reader should contrast them with those in the following three paragraphs which are the occupations of patients who have had calcified deposits, tendinitis and partial rupture.

COMPLETE RUPTURE OP THE SUPRASPINATUS (100 Cases) Women 8%

Housewife, hostler, plasterer, street cleaner, housewife, coal-heaver, waiter, paper cutter, laborer, housewife, marble worker, currier, cooper, housewife, stationary engineer, two laborers, longshoreman, wrecker, teamster, two laborers, steamfitter, three laborers, truck driver, stock fitter, cook, stableman, painter, two laborers, truck driver, laborer, lineman, lather, farmer, three laborers, harness maker, wood molder, planer, electrician, plumber, mechanic's helper, laborer, roofer, laborer, longshoreman, riveter, two laborers, porter, cooper, two laborers, steamfitter, laborer, lather, steamfitter, laborer, stationary engineer, laborer, store clerk, carpenter, laborer, night watchman, longshoreman, laborer, taxi driver, lineman, laborer, painter, coal-heaver, laborer, foreman, truck driver, laborer, construction, painter, laborer, rubber worker, laborer, painter, laborer, carpenter, meat cutter, floor layer, stitcher, two laborers, housewife, foreman, laborer, store clerk, burnisher, teamster, laborer.

CALCIFIED DEPOSIT (100 Cases) Women 34%

Housewife, two no occupation, two physicians, chemist, physician, superintendent, two physicians, business, no occupation, business, manufacturer, architect, business, three physicians, milk delivery, supervisor, ironworker, housewife, filing clerk, physician, machinist, histologist, housewife, physician, business, no occupation, physician, no occupation, pipefitter, stenographer, no occupation, physician, garage, postman, business, waitress, musician, shipper, laborer, bookkeeper, machine tender, porter, teacher, laborer, housewife, broker, housewife, business, baker's helper, two salesmen, organist, weaver, housewife, shoemaker, forewoman, box-maker, two laborers, housewife, shoe machinist, farmer, housewife, advertising, paper mill, housewife, surgeon, real estate, advertising, housewife, machinist, boxmaker, store manager, wool handler, laborer, physician, truck driver, shoe worker, teacher, knitting mills, housewife, plasterer, laborer, shoe stitcher, clerical, physician, treasurer, investments, laborer, housewife, laborer, beauty parlor, manufacturer, salesman, manufacturer.

TENDINITIS (100 Cases) Women 58%

Two housewives, two no occupation, army officer, two housewives, carpenter, tailor, nurse, no occupation, tailor, nurse, business, P. O. clerk, secretary, three housewives, no occupation, physician, maid, coppersmith, merchant, housewife, jeweler, minister, harnessmaker, housewife, hostler, tailoress, storekeeper, priest, no occupation, photographer, housewife, professor, housewife, carpenter, starter, housewife, shoe laster, housewife, two no occupation, housewife, roofer, civil engineer, two housewives, cigar maker, judge, shoe manufacturer, no occupation, nurse, three housewives, physician, housewife, laborer, two housewives, physician, two housewives, store clerk, housewife, social worker, housewife, insurance broker, factory worker, two housewives, desk work, social worker, salesman, food checker, housewife, consulting engineer, banker, physician, invalid, two housewives, nurse, laundry, writer, surgeon, two housewives, two physicians, foreman, lawyer, grocer, executive secretary, nurse, public accountant, no occupation.

PARTIAL RUPTURE (100 Cases) Women 11%

Three laborers, farmer, carpenter, eight laborers, baker, plumber, laborer, housewife, two laborers, carpenter, housewife, painter, laborer, mechanic, garage, two laborers, writer, three laborers, physician, laborer, carpenter, teamster, laborer, carpenter, laborer, machinist, laborer, housewife, teamster, cook, stone mason, bricklayer, carpenter, three laborers, store, housewife, laborer, mechanic, housewife, store clerk, cook, machine oiler, laborer, two housewives, insurance, store, business, janitor, hoisting engineer, painter, meat cutter, three laborers, florist, two laborers, ironworker, nurse, gardener, shoe factory, clerk, plasterer, lawyer, laborer, no occupation, student, bartender, manager, housewife, laborer, foreman, bricklayer, horseman, two laborers, nurse, farmer, machinist, real estate, gardener, laborer, housewife, tailor.

Both occupation and sex are of importance in the diagnosis of shoulder conditions. Men who have done heavy labor are typical subjects for complete ruptures of the supraspinatus, and women of the so-called "leisure class," for tendinitis (frozen shoulder). Calcified deposits are more characteristic of the class who have gainful but not laborious occupations (the white collar class) ; i.e., they are not usually found in inactive people. Partial ruptures are also in the main characteristic of men of the laboring group, but they may occur in the more active and athletic members of the leisured class, both in men and in women.
These observations were already made from general impressions in the course of my practice, but they are in part confirmed by the above analysis of the occupations of 400 cases. The detailed accounts which each patient has given of his or her occupation and other activities, are of even greater weight in confirming my own impressions. For instance, the term housewife may apply to a woman who does all the work and washing for a large family, or to a lady who scarcely uses her arms, or to an active wife who plays golf, sends out her washing and only occasionally uses her kitchenette. The percentage of women varies greatly in the different classes, eight per cent, eleven per cent, fifty-eight per cent and thirty-four per cent. The eight cases of complete rupture and eleven of the fifteen cases of partial rupture were women whose work was really laborious. The fifty-eight tendinitis cases were chiefly women of the leisure class and the thirty-four calcified cases were active single women or wives.

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(2) Age. The four clinical entities also affect different age groups. Young persons below twenty-five seldom have any of these conditions. Apparently in young people the tendon is stronger than the bone in which it is inserted, and stresses, which in later life would break the tendon, cause fracture of the bone or separation of the tuberosity. Chart I shows that the four entities affect, in the main, persons in the latter half of life, and that the occurrence of tendinitis both of the calcified and uncalcified forms precedes the peaks of incidence of the ruptures, partial and complete, by about five to ten years. The curves of the two forms of tendinitis, calcified and uncalcified, have their peaks at the same period, but the rise of the curve is distinctly earlier in the calcified form. These facts suggest that injuries of the tendon prior to the thirtieth year either are rare or that the tendons are capable of normal repair. Then follows a period when repair is uncertain and is apt to be complicated by the deposit of calcium. Later even this incomplete repair fails.

WOMEN—CHART III

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If we chart separately the male and female cases there is a marked contrast. The curve of the female cases suggests that tendinitis, both calcified and uncalcified, may be related to the menopause or to the age when the teeth begin to loosen. By comparison of the two charts we find that calcified deposits apparently occur somewhat earlier in males than in females, and their occurrence tends to diminish at the period when they are highest in the female. The contrast of Chart II and Chart III makes it very clear that the more serious forms of rupture of the supraspinatus are characteristic of the male toward the end of his laboring days. The period of life shown in all the curves is that in which the teeth are usually in decay. If these charts are made without separating the cases in four entities the contrast between the ages of males and females is even greater, so that the coincidence with the menopause is more striking.

MEN—CHART IV

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(3) The history of a previously painless and useful arm is unreliable for two main reasons. First,—previous troubles may have been forgotten. Men of the laboring classes put up with a great deal of soreness and pain and forget it easily. Such a matter as an attack of bursitis years before, may readily be forgotten. I would rather
have the history of previous troubles from a man's wife than from the man himself. I am inclined to think that in many cases where complete rupture has occurred, there may have been previous minor troubles, which might have indicated either partial rupture of a few fibers, or a "calcined deposit." However, my records do not show this, for in only nine of a hundred cases could a history of previous trouble be obtained.
The second reason is that men may lie as well as forget. The statements of employer and fellow workmen are sometimes more accurate than the patient's own. Patients may conceal previous trouble to avoid losing compensation.
The other shoulder should always be examined in these cases, for occasionally one finds signs of a partially ruptured tendon or of chronic bursitis there, although no complaint is made of symptoms. This would, of course, be very suggestive of preexisting disease in the injured shoulder. However, we must not forget that a rupture may occur as a bona fide injury in degenerated or diseased tendon.
(4) Adequate injury seems pretty well illustrated by the following brief accounts of the accidents in twenty-one successive cases which were proved by operation, and in seventy-nine others in which the diagnosis was made but not proved.

ACCIDENTS (Operated Supraspinatus Cases)

57. "Fell taking down an old gallery."
75. "On this date (Aug. 25, 1922) he was engaged with others in hoisting lumber, when a plank slipped off the hoist and struck him in the side knocking him down."
83. "On Jan. 17th, 1923, he fell downstairs and injured his left shoulder."
88. "On Feb. 1st, 1926, while at work he was pulling a heavy case along the floor with a hook. The hook slipped and as he caught his balance he felt something snap in his shoulder accompanied and followed by intense pain."
89. " When getting off truck caught his hand in fly wheel. Cuts of hand."
96. "On April 4th, 1927, he slipped on a concrete floor and injured his left shoulder."
97. "On Nov. 8th, 1926, he was pushing a freight car with another man, using bars. His bar slipped and he fell down wrenching his left shoulder."
98. "Six weeks ago he had slipped on the ice while at work and had injured his right shoulder. He fell on his back striking his elbow, but had no bruise on the elbow. (It is probable he threw up his arm to get his balance.)"
102. "On Nov. 2nd, 1927, he was piling some 100-lb. sacks of beans with another man who stood above him and received the sacks as he threw them up. On one throw the other man failed to connect with the sack and the entire weight came on the patient's right arm. He felt something in his shoulder snap with a sharp pain."
106. "On January 20th, 1928, he was cranking his truck, which he uses to deliver cans of ice cream. The engine backfired and he felt a sharp pain in his right shoulder."
107. "On Jan. 18th, 1928, she fell on the floor of the kitchen where she works and dislocated her left shoulder."
108. "At some time in July (date uncertain) while at work he was turning a board and felt something snap in his right upper arm about the middle, in the region of the long head of the biceps. There was a sharp pain which went away in a few minutes."
112. "On March 10, 1928, he was wheeling a barrow up into a barn when he slipped and fell forward on the barrow, but did not let go of the handles."
115. "On August 21st, 1928, about 1.30 P.M., slipped and fell from piazza roof, striking the edge of the piazza floor with his right arm in abduction. Had immediate pain in shoulder and arm."
119. "Day before Thanksgiving, Nov., 1928, fell off staging three feet high. Walked backwards off."
123. "On Jan. 14th, 1929, he slipped on an icy platform and hit on his left elbow."
127. "On Oct. 17, 1929, was handling 2x4 lumber and stepped in a hole. Fell against left shoulder on pile of lumber, hitting on elbow."
128. "He slipped on the ice near a building and fell, striking the side of his right shoulder against a low step. This is what he says, but such a fall as that would probably be impossible. It is more likely that he threw his arm up as he fell."
129. "On October 24th, while piling some pipe, he was standing on a pile of pipe which rolled under his feet and he fell between two piles of pipes."
185. "He slipped on the ice and fell. After he got up, he found that he could not raise the left arm."
137. "On May 13, 1930, he had a fracture near the left elbow which healed satisfactorily and he went back to work about September 1st. On October 7th, in Andover, he fell and dislocated his left shoulder."

ACCIDENTS (Unoperated Supraspinatus Cases)

". . . he was doing some overhead work standing on a support twelve or fifteen inches high. The support slipped and he fell on his right hand and elbow, and then forward on his shoulder." ". . . he was pulling on a rope which suddenly gave way. He fell to the ground with his right arm below and behind him. He felt a sharp pain in the shoulder as if a bone had broken." ". . . he fell about ten feet while at work and injured his shoulder." ". . . he had been hit by an automobile, knocked down and taken to the Boston City Hospital. His shoulder had been injured." ". . . he was cranking his truck, and had a kick back. He thinks the handle struck him on the lower part of his upper right arm, but his shoulder was w.renched." "... when walking in a dark passageway, he stepped over some steps and in trying to save himself caught with his left arm on the wall, but kept his feet. He had a violent pain in his left shoulder but pulled himself together and went to his next job." ". .. he was struck on the left shoulder by a falling bale of hemp while at work. He was knocked down and much shaken up, but pulled himself together and continued to work the rest of the afternoon with his right hand." "Fell off wagon when unloading barrels. Hurt badly at time and went to Camb. Relief Hosp." ". . . he was lifting a barrel and something snapped in his shoulder, since which he has been unable to work." ". . . he tripped on a rolling log and fell injuring his left shoulder." ". . . he fell down some stairs and injured his right shoulder." ". . . the employee slipped on a loose plank and injured his left shoulder and right foot." ". . . he was pulling on a chain fall and something slipped in the right shoulder." ". . . he was jammed between a moving truck and the side of a building. Fortunately, he was near the corner of the building and the moving truck carried him around the corner, squeezing him from side to side as it did so. His left arm immediately became powerless." ". . . he fell from a staging and injured his right shoulder and has not yet recovered the use of it for anything requiring the function of abduction." ". . . he was filling a wagon with coal when the horses started and he fell in between the wagon and the side of the coal-pocket." ". . . he fell forward at the top of a flight of stairs and injured his shoulder as he supposed by hitting some beams." "A frame which he was moving dropped and to prevent it striking his feet stepped aside, losing his balance and falling to the floor." ". . . she felt something snap in her shoulder (left) when raising some wet clothes on a pole to put them in a laundry machine." ". . . while raking grass on a steep bank, he slipped and injured his left shoulder." ". . . as he was stepping out of a tip cart on the hub of the wheel, he slipped and fell heavily to the ground injuring his left shoulder and also his right shoulder to some extent." ". . . the employee was carrying a plank with another man, when one of the planks on which he was walking gave way, letting part of his body through the pier so that he sustained injuries to his left shoulder, arm and leg." ". . . she fell over a bag of soles and injured her right shoulder." ". . . he slipped off a plank and fell headlong to the floor, about four feet." ". . . large heavy car six or eight feet on the side. On this occasion the car skipped the track in spite of his efforts to prevent it, striking him on the left arm." ". . . he says that he was using his truck to load heavy rubber bales weighing about 350 lbs. each. He had put the edge of his truck under one such bale and reached forward with his right hand to pull the bale toward him on to the truck. As he pulled, he felt something give in his right shoulder." ". . . he was helping with other men, to pull a heavy truck, when he felt something give way in his right shoulder." "He was carrying a roll of leather and fell on the floor in the room where he usually worked." ". . . he fell from his truck and injured his left shoulder." ". . . he fell thirty feet from a staging and was badly bruised all over." ". . . he was on a lumber pile helping to load a truck. He was using a pick to drag the lumber. The pick slipped and he felt a sudden pain and something snapped in his arm at the right shoulder. His arm fell limp at his side." ". . . he slipped on some stairs and injured his left shoulder. . . ." ". . . fell among some barrels in the hold of a vessel and struck his right shoulder again." Had had previous similar accident six years ago, and never full use of arm since. ". . . while working in a meat market in Nantucket, he slipped on going out of the ice chest and injured his right shoulder." ". . . while carrying rubbish on an incline in the factory where he works, he fell and injured his right shoulder. As he says, 'it went dead immediately.'" "He was piling wool at the time, lost his balance and fell from one bale to some other bales not far below. As he fell he felt something snap in his shoulder which did not hurt him very badly at the time. . . ." ". . . slipped on ice in street." ". . . while working on a flat-car he fell and struck his right shoulder on the side of the car." "While at work in the factory in Lawrence ... he was in an elevator holding a heavy plank in both hands to steady it. One end of the plank was on the floor of the elevator and it stood vertically. Some one below started the elevator downward and then upward. As it went up it thrust the top of the plank violently against the top of the well. This shattered the heavy plank just above his hands with extreme violence and he was thrown into the corner of the car in a heap." ". . . he fell off the back of a load of straw and injured his shoulder." ". . . he again fell downstairs—only a few steps—and again injured his right shoulder." " Slipped and fell, and a box or case fell over on him." ". . . while directing some work where a floor was being replaced and the boards were up, he tripped on a beam and fell on his right side against another beam, probably breaking some ribs." ". . . he received an injury to his left shoulder when trying to move a large rock with a pitchfork. He felt something snap in his shoulder joint and suffered a sharp, severe pain at the same time." "He injured his right shoulder by falling from a truck." ". . . he was pulling some lumber off a truck and when it slid off quicker than he expected he fell backward and injured his left shoulder." ". . . he fell four feet, striking on the pavement, and inj ured his left shoulder." "... he slipped on an oily floor, and hurt his right shoulder and left shin." ". . . he fell from a staging about six feet to the floor below, and injured his right shoulder." ". . . he fell from a ladder and sustained injuries to the left shoulder and ribs." ". . . he was on a roof sawing a plank, and was standing on an extension ladder, which fell with him thirty-one feet to the ground. His right shoulder was injured, and his nose was cut" "Strap from machine fell off wheel and hit patient on right shoulder." ". . . he was working with others on a bridge in Rumford, Maine, helping to receive some cement in a frame from a bucket. In some manner, the bucket swung in the wrong direction and the patient fell from the bridge a distance of fifty feet." ". . . he was lifting a concrete block and felt something give in his left shoulder." ". . . he fell injuring his left shoulder." ". . . he had started to crank a hoisting truck when the starter began to work and the crank flew round and struck him on the right shoulder." "Slipped on ice." "Fell yesterday and sustained a contusion over outer end of right clavicle." ". . . while helping to unload a truck, a derrick knocked down a platform above him, and something, probably a heavy plank, fell on him and others working with him. He was knocked out by the blow, and cannot describe exactly the manner in which the plank struck him, but he knows it injured his shoulder and elbow and there was blood streaming down his arm." "He was pulling hard on a gunny sack, which gave way, and he fell over and thinks he struck his right shoulder." ". . . she tripped and fell on the floor at her work. She dislocated her right shoulder, bruised her knees severely and cut her face." "He was standing on stony ground swinging a sledge hammer, when he had to step back quickly. As he did so, he lost his footing and the sledge hammer, which he was swinging, carried on around his body so that his left shoulder was in an awkward position. He felt something snap in the left shoulder."

One may interpret the mechanism which produces this injury in several ways, but a sudden character is common to all of the accidents, which are generally falls. It is my belief that the rupture usually takes place from sudden elevation of the arm in attempting to regain balance, particularly if the hand is at the same time grasping a heavy object. Under these conditions a tremendous strain must be suddenly thrown on this little tendon as it attempts to quickly overcome the inertia of the arm, and perhaps, in addition, that of some heavy object held in the hand. In my first case, the woman attempted to throw a heavy, wet blanket over a clothes-line. It seems to me that this case, like a "slowed down movie," typifies the kind of strain which occurred in most of the other accidents. I believe that the even more sudden effort to regain balance during a fall caused the damage, probably before the patients struck the ground. For anatomic reasons one cannot, in falling, strike on the supraspinatus, because it is protected by the acromion.
Undoubtedly, however, in some cases, the tendon may have been torn in conjunction with dislocations, because of the leverage of the humerus on the fulcrum of the acromion. This mechanism will be explained in Chapter IX.

(5) A sharp pain in the shoulder at the time of the accident is almost always spoken of, although occasionally complaint of it is not volunteered. Sometimes patients say that they have felt something actually snap and think that they have broken a bone. Sometimes they feel that something has struck them on the shoulder. It has been explained on page 9 in the chapter on anatomy that histories of striking on the head of the humerus are unreliable because the acromion intervenes, and on page 144 that in falling, the arm is usually raised before the top of the shoulder can strike the ground. Consequently it seems to me that these tendons must usually be ruptured by indirect violence or sudden efforts of the muscles to overcome the inertia of the dependent arm, especially if there is a weight as a pick or shovel in the hand at the time, or the hand grasps something to save the man a fall. Often the fall is so sudden and the man so confused that the only thing he can understand is that he has hurt his shoulder and attributes the pain to having hit something as he fell.

(6) So far as I can judge from histories, there is then usually an interim of a few hours after the acute, immediate pain has somewhat subsided before the more severe pain comes on. Often the employee does not even consult a doctor at once, but tries to work the day out, favoring his arm. Perhaps he does not report the accident to his foreman. In the evening the pain becomes worse, and later in the night intolerable. He calls the doctor, or sits up in a chair, or "walks the floor." Next day he is pretty sure to report that he cannot work, but may persuade an accommodating foreman to let him "hang around" for a day or two until he gets better. These patients usually think the injury of no great consequence and expect "to have it wear off." This hopefulness is generally confirmed by the doctor's opinion, who perhaps may never have heard that such lesions occur. This attitude of mind of both patient and doctor is the main cause of delay in diagnosis and appropriate treatment.
It seems to me that the following theory is the probable explanation of the interim between the sharp pain when rupture occurs and the intense pain which appears some hours later. These tendons are not very vascular, and when they tear, there is probably very little bleeding; what there is, would come from the tissue between the bursa and the tendon. The interim spoken of would come during the period it would take this slight hemorrhage to distend the joint and bursa somewhat, i.e., enough to start a tension pain. This would create some spasm, and the tension caused by this would stop the slight bleeding. It would take several nights or perhaps a week for tension and spasm to subside and the hemorrhage to absorb. During this period the acute pain would continue.

(7) Inability to raise the arm is a constant symptom, but one must be on guard not to mistake unwillingness for inability. After almost any shoulder injury there may be pain when attempt is made to raise the arm, owing to the fact that the head of the humerus has to be forced upward to gain its fulcrum on the glenoid. The mere fact that the muscles have to exert tension to do this, causes pain in whatever structure about the shoulder may be injured. Therefore, the examiner must be sure that an honest effort is made to ignore the pain and elevate the humerus. It takes experience to tell whether such an effort is made, and one judges it by the degree of tension palpable in the deltoid. Even in the case of trivial injuries, such as ruptures of a few fibers of the supra- or infraspinatus, the symptom of inability to raise the arm may be pronounced, simply from the fact that the power to exert the appropriate muscles is inhibited by sensitiveness to pain. As explained on page 59, the deltoid needs the assistance of the supraspinatus and of the short rotators to hold the head of the bone on its fulcrum in order to have proper direction for its power; If the supraspinatus is torn, contraction of the deltoid brings the arm upward on the vertical axis of the humerus, and the amount the shoulder is raised will depend on the amount that the scapula, moving via the. sterno-clavicular joint and at the acromio-clavicular joint, can rise and rotate on the chest wall.
Formerly I thought that it was necessary to have this symptom of inability to raise the arm absolutely demonstrable in order to make the diagnosis of rupture of the supraspinatus, but experience has shown that, even when the supraspinatus is torn across its full width, the other short rotators can sometimes hold the head of the humerus on its fulcrum sufficiently to permit the patient to weakly perform elevation. However, as will be explained under No. 10, this elevation is never accomplished with a normal scapulo-humeral rhythm.

(8) A negative X-ray is almost always reported after these in juries. I believe that in the near future we shall be able to make the X-ray of more use in this diagnosis, either by using injections into the joint of non-radiable fluid, or by developing a soft tissue technique which will show the rupture. However, at present, negative X-rays are the rule, for ruptures which do not involve the bony facet of insertion are not shown in the film. A negative X-ray is of some positive importance, however, for it rules out the two conditions which are likely to make confusion in the diagnosis, that is, fracture of the
greater tuberosity and the presence of calcified material in the tendon. In long-standing cases changes in the structure of the trabec-ulae of the tuberosity which may be shown by the X-ray do take place. These are described on page 92.

(9) In the symptom complex of this condition, lack of restriction of motion takes a very important part, and this lack of restriction can be best determined when the patient is stooping from the hips with the knees extended. The patient should stoop (Fig. 47) to the horizontal position, letting the arms hang loosely toward the floor. In this position the deltoid is relaxed and there is no fulcrum needed in order to have the arm passively raised, i.e.-, brought forward into complete elevation (quadruped extension) ; in fact, even if this is not passively done, the patient has to exert but little muscular power
to swing the arm forward into this position. This he is usually able to do without much pain. The examiner may then hold one hand on the scapula and with the other raise the lower end of the humerus, so that he takes the full weight of the arm and permits the patient to stand upright with the arm still in complete elevation. Such a procedure eifectually rules out restriction from adhesions. Even if the supraspinatus is torn, the patient can retain the arm in this up right position. If he stoops again he can lower it without much pain, and then if he rises to the upright position with the arm relaxed,
the humerus will, by gravity alone, come into its normal position at the side of the body.
When I say that lack of restriction is an essential symptom, I must not be taken too literally, for there is often, in fact usually, in these cases, a very little restriction in extreme elevation and in rotation, probably due to the presence of fluid.

(10) Faulty scapulo-humeral rhythm is a sine qua non for this diagnosis. When one sees a patient who in raising the arm lets it ascend to the horizontal while maintaining (quadruped) flexion of the scapulo-humeral joint, and then slowly and painfully (perhaps with a little help) proceeds to complete elevation by motion in the scapulo-humeral joint, and finds that when the patient 'allows the arm to descend, he keeps the scapula and humerus fixed in (quadruped) extension until he reaches the horizontal, and then quickly flexes it, a presumptive diagnosis oi rupture of the supraspinatus
can be made. Ascent in flexion, descent in extension, might be a slogan for students to learn in this connection. To express this lack of scapulo-humeral rhythm in other words, we may say that the normal ratios of the movements of the joints in elevating the arm, explained on page 59, disappear. Instead, in the first part of the movement only the motions of the scapula on the chest wall are concerned; then the relations of the humerus and scapula change, wholly above the horizontal. In the descent of the arm the reverse is the case—no scapulohumeral motion takes place above the horizontal, but all below it. While the symptom is a sine qua non to the diagnosis of complete rupture of the supraspinatus, it is also present in most cases of minor ruptures and in many cases of calcified deposits. It therefore is an indispensable but not a pathognomonic sign.

(11) The tender or sensitive point is not complained of by the patient as a rule, and in fact he is unconscious of its exact location until the examiner finds it, when he usually says: "You have your finger right on it." Without your aid in locating it he will perhaps know that there is a tender point, but locate it deep under the acromion or even in the spasmodic deltoid muscle down near its point of insertion. In fact, the lower portion of the deltoid is usually also tender. Examination of this part of this muscle in all these patients nearly always shows that there is some thickening and sensitiveness, as compared to the normal side. In the old, chronic cases the sensitiveness at the point of rupture may not be very noticeable, and even when the exact point is pressed the patient will hardly admit that it is tender. Presumably in fresh cases it would be especially sensitive.

FIGURE 41. POSITION OF HANDS FOR EXAMINATION OF SHOULDER

The left thumb lies along the depression below the spine of the scapula and the tip of the forefinger is just anterior to the acromion. The other three fingers cross and hold the clavicle. Thus the shoulder girdle is firmly held and any motion of the scapulo-humeral joint is at once detected.

In speaking of the 11th, one is necessarily obliged to consider the remaining symptoms, since the tender point is at the gap between the ends of the torn tendon, and this gap is the reason for the sulcus and eminence, which may be felt just anterior to the edge of the acromion, when the arm is in dorsal flexion. If the examiner remembers his anatomy, the tender point, sulcus and eminence will be found to be at or near the insertion of the tendon of the supraspinatus. It is the passing of this irregular sulcus and eminence under the acromion and acromio-clavicular ligament which causes a jog, a wince, and a soft crepitus, as the sensitive, irregular base of the bursa disappears under the acromion when the arm is brought forward by the examiner. The two figures (41 and 42) present the condition, it seems to me, more vividly than could any description. However, I will give a few brief additional points under each one of the remaining headings.

FIGURE 42. TIP OF FINGER PRESSING ON EMINENCE AND ON SULCUS
The plane of this diagram is halfway between the coronal and sagittal.It is, perhaps, the most important diagram in the book for the reader entirely to understand, for it is the ability to put the finger in this position which enables one to make the clinical diagnosis of rupture of the supraspinatus tendon. The dotted line represents the contour of the bursa. Compare this with Figure 44, which shows the contour of the bursa when filled with the calcified material, and also with Plate II, Fig.3, which shows a large calcified deposit in exactly the situation in which the rupture lies in this diagram. In this one the sulcus is immediately under the tip of the finger and the' eminence just external to it, but in Figure 3 the eminence would be just under the finger. Therefore, as explained on page 148, the tender point in a case of rupture is represented by a depression, but in cases of calcified deposit, by an eminence at the corresponding position.

(12) The sulcus is just about big enough to be filled by the tip of the finger, as indicated in the diagram. It is nearly always found to be larger at operation than one would guess from palpation before incision.

(13) The eminence is an eminence only by contrast with the sulcus. It consists of normal tuberosity with perhaps a remnant of the tendon attached to it. In elderly men without injury to the shoulder one can often feel the tuberosity because the tendon is more or less atrophied, so that at times it is hard to be sure whether the tendon is torn or merely atrophic. However, in most cases of ruptured supraspinatus the eminence is conspicuously large and one is quite sure of its existence. It is well to say here that the eminence which is found in cases of calcified deposit is not on the tuberosity itself, but proximal to the tuberosity in the tendon at just the point where ruptures so often occur. Furthermore, the tenderness is usually greater on the eminence in cases of calcified deposit than it is on the eminence in the cases we are speaking of.

(14) As may be seen under Pathology, the supraspinatus is nearly always torn if any of the other short rotators are, but it is very common to have portions of the adjacent tendons torn, so that the tenderness, eminence and sulcus may be a little internal or external to the mid-point of the insertion of the supraspinatus itself. This latter may be determined pretty accurately by placing the forearm in flexion and drawing a line from the mid-point of the flexure of the elbow to the mid-point of the head of the humerus. The bicipital groove lies about its own width external to this line, and the supraspinatus is on the top of this line and to the outer side of it for about three-quarters of an inch. The insertion of the infraspinatus is just external and also partly in front of that of the supraspinatus, for, as explained in Fig. 6, the two insertions nearly cross each other. The insertion of the teres will be found nearly exactly on the mid-point of the head of the humerus on its outer aspect. Be careful, in determining this, that the forearm is flexed at. the elbow and held straight forward. The insertion of the subscapu-laris can be determined by putting the arm in the anatomic position and placing the examiner's forefinger just external to the tip of the coracoid process, which is always palpable, as shown in Fig. 6.

(15) The jog is noticeable to the patient himself, and sometimes is visible as well as palpable to the examiner.

(16) The patient nearly always winces as the jog occurs, but in long-standing cases he may not do so.

(17) The soft crepitus is not like the crepitus in fractures. It is of a more velvety, gristly character. When one has become familiar with it, it is easily distinguished from the kind of crepitus often found in the shoulders of old working men, which resembles the crepitus one frequently feels over the prepatclla and olecranon bursas and about the other joints.

(18) When the sulcus, eminence and tender point have once passed beneath the acromion as the arm is elevated, there is a sense of relief on the part of the patient which is usually apparent in his countenance. When the arm is almost fully elevated (there is often so much fluid in the joint and bursa that absolutely complete elevation is not attained), the patient is relatively comfortable. His pain will appear again when flexion occurs at the level of the shoulder, after the arm has descended with humerus and scapula locked, to a horizontal position. At this time the jog and crepitus are usually again palpable. As this occurs the patient leans toward the affected side and lowers the whole arm quite suddenly.
These eighteen symptoms must be present soon after the accident, but the difficulty is to estimate the degree of the rupture at this time. Partial ruptures must give much the same symptoms as complete ones at this stage, and the degree of spasm must vary, as well as the courage of the patient as he makes a voluntary effort to raise the arm. Immediate diagnosis cannot be easy at this stage. However, the progress of the case makes the diagnosis easier and easier, although valuable time elapses. If exploration is not done these symptoms remain the same and the following points in the course of the case will tend to confirm the diagnosis.

Character of Pain. Practically every patient whom I have seen has given the history that during the first few nights after the accident the pain was severe or intense. Gradually this severe pain changes to a nagging, annoying one, sufficient to greatly interfere with the night's rest, but bearable without drugs. It is usually located near the deltoid insertion far below the actual lesion. Pain of this character continues week after week and with but little change for many months. It is aggravated by the attempt to work, and the patient's resistance to it is gradually lowered as he becomes more and more worn out by restless, painful nights. I am convinced that this pain is very severe as well as prolonged, for I have heard many strong laboring men state that they have never suffered such pain in their lives. It is more the persistence of it than the pain at any one time which wears them out. They often say: "If I could only get a good night's rest I could work during the day." Practically they find that working during the day gives them bad nights, and therefore nearly all of them, in spite of their courage, give up work after a time. Of the series of a hundred cases, only eighteen stated that they had worked for even a brief period. They say that they may go to sleep for a while, but wake with pain in the shoulder or in the region of the insertion of the deltoid, and that they have great difficulty in getting the arm into a comfortable position again. When they do, they go to sleep only to wake up in a few hours for another change of position. Sometimes they get up and walk about or apply hot water bags or other household remedies. It is very characteristic of these cases to have complaint of pain out of proportion to the physical signs, and therefore they receive little sympathy.

Atrophy of the spinati, as shown by prominence of the spine of the scapula, always occurs after these injuries, but does not appear for about three weeks. After it has once appeared it persists, and is apparent for a long time even in the operated cases.
In very few of the cases that I have seen years after the injury was it absent. The atrophy may be more conspicuous in the infraspinatus, which is the larger muscle. Whether the fact that the infraspinatus is always also atrophied, is due to the crossing of its fibers of insertion with those of the supraspinatus so that they are always also torn to some degree, or is due to the fact that the two muscles are supplied by the same nerve, i.e., the suprascapular, I do not know, but it is a fact that atrophy of both is a constant sign. Of course atrophy of these muscles occurs in any chronic condition of real severity affecting a shoulder joint, so that the presence of atrophy does not necessarily indicate this diagnosis, but its absence would he strong evidence against it. In a few long-standing cases I have seen only a small amount of atrophy. It is usually very pronounced. As a rule the deltoid is not much atrophied and may even be hypertrophied.
The general condition of the patient is a factor in diagnosis, for he gets into a vicious circle. He is out of work so that all the muscles of his body become enfeebled. He often cannot afford good food, and he may, therefore, be ill-nourished. Add to this the constant depletion of his energy from restless, painful nights, and we may readily account for the fact that while previously he was a strong, healthy man, he now appears haggard and unhappy.
The mental condition also is poor, for worry on account of inability to work, and that he may never be able to work again, is enhanced by the fact that the physician he consults is unable to tell him the cause of his trouble, and all attempts to relieve him by ordinary remedies absolutely fail. Seeing these cases months after their accident, I am frequently told, "Nothing they have done has done it any good."
The actual physical deterioration from worry is still further aggravated by the doubt that is thrown on their veracity by the physicians employed by the insurer. Usually by the time they are sent to see me some months later, their attitude of mind is defensive, and they at once begin to express their disgust with being told that they ought to go to work and think less about the pain.
This attitude of mind becomes still worse when they are actually accused of hysteria or malingering. They say they want to work. "Do you think I would lie around like this if I could earn $24.00 a week?" They become embittered at their treatment by society in general in spite of the fact that they may still be receiving their compensation.
At length they may lose their self-respect, and brooding over their hard luck take to drink. My second patient was such a case. He had had a good job which he enjoyed; after his injury became discouraged, and evidently decided to let things go and to use up what money he had saved, in drinking as much as he had a mind to. The person for whom he formerly worked, instead of losing sight of him, looked him up, and, realizing that he must have some real trouble with the shoulder, sent him to a doctor who referred him to me. The result of the repair of his tendon was not only that he was able to work, but that he refrained from drinking and worked for ten or more years for the same people who formerly employed him.
Unfortunately the attitude of the relatives of such an old man with a disabled shoulder is apt to become somewhat like that of the doctors who have been unable to diagnose and relieve him. His own family after a while get to think of him as a burden, and since they can see nothing the matter, such as a limp or a deformity, are inclined also to think that he has "laid down" before his time. In recent years, however, we see more signs of sympathy, for the compensation such patients may receive will perhaps be the chief support of the family.
Undoubtedly many such cases eventually turn up as recipients of charity and eventually die in state institutions. It is not surprising to me that the material reported in this book, which was accumulated by Dr. Akerson at a hospital for the indigent, shows such a high percentage of instances of these lesions.
I would venture to predict that if one should see the patients who are chronic nuisances to industrial insurance boards, and the physicians connected with the administration of compensation for industrial injuries, most of those complaining of shoulder disability would have this particular lesion.

Some patients may continue to work. There are rare individuals who, in spite of the disability, have the courage and otherwise sound health to continue to work in spite of the soreness, awkwardness, loss of power, and painful and restless nights. About one-fifth of my series attempted to work for a time before they gave in and sought compensation. I have no doubt that there are others who have never given in.
This is a lesion which tries a man's character, and, since it usually occurs in later life, is often the cause of permanent incapacity, for even if the use of the arm returns in good measure at the end of a year, the patient's habit of work has been destroyed, his muscles have become soft. If he has the courage to go to work again, he will find it difficult to get a job. Those courageous men who do work in spite of the lesion, become more or less free of serious symptoms in from two to five years. As has been explained under Pathology, compensatory changes take place so that the eminence absorbs, the sulcus partially fills, and an excess of fluid allays friction. After several years even the night discomfort disappears, and weakness in abduction, atrophy of the spinati, friction rubs, the fluid sign and occasional pain in certain positions may be the only aftermaths of the injury.

Hypertrophy of the Deltoid. Perhaps it would be better to make this heading "well-developed deltoid as contrasted to the spinati," for the hypertrophy is not striking except when compared to the condition of the spinati. It is a fact that, in the long-standing cases, the deltoid itself is as well developed, or even more so, than that of the other side. I explain this because it has to do most of the abducting work of the arm unaided by the supraspinatus. It not only misses its help, but acts at a disadvantage as explained in Fig. 3. Hence it retains its development or even hypertrophies. My third case had a deltoid like a ham, but at the end of five years he could only feebly perform abduction and could not raise even a slight weight in that hand above his head. He had refused operation.

The Fluid Sign. Among the auxiliary signs and symptoms I find some help from what I call "the fluid sign." I had studied shoulders for many years before I realized how fluid in the true shoulder joint behaves. When the arm is by the side, the fluid sags in the relaxed axillary portion of the capsule. When the arm is elevated the axillary portion of the capsule is stretched tightly below the rounded head of the bone, and the fluid is driven upward where the capsule is now relaxed. In case there is a rupture of the supra-spinatus tendon, the fluid is forced through the gap and distends the bursa in the subdeltoid portion beneath the upper fibers of the deltoid.
Stand behind one of these patients, who is holding both arms as straight as he can toward the ceiling, and you will see that the contours of the two shoulders are quite different. When there is a considerable amount of synovial secretion, absolute complete elevation of the arm is prevented by the mass of fluid. Another interesting point is that when there is fluid the friction is largely prevented as the arm is elevated. When it subsides pain reappears. This phantom improvement by the formation of fluid is not uncommon.
Patients who continue to work in spite of their pain develop fluid, as do people with various affections of the knee. The fluid continually pumping in and out of the bursa dilates it and a true hydrops may result (p. 478). One finds in long-standing cases that the bursa is very large. (See case Fig. 44.) Some fluid, from a dram to an ounce, is a constant operative finding in these cases. It may not be noticed when the bursa is first opened, but if one elevates the arm and puts the axillary portion of the capsule on the stretch, the thick, straw-colored fluid runs out of the wound. Sometimes there is enough to distend the bursa even in the anatomic position, and when the first incision into the bursa is made, it obscures the field and has to be sponged out.
This behavior of the fluid was forced on my attention when I used to put the arm in abduction after suture. This caused the weeping wounds described on p. 248, and this serious and annoying complication led me to reason out the facts.

INCOMPLETE RUPTURE

Although there is no sharp anatomic distinction between complete and incomplete rupture, there is the practical one that cases of the former will not recover completely unless the tendon is sutured, while cases of the latter may heal in a natural manner. One which is typically complete involves the whole supraspinatus tendon, with perhaps parts of the adj acent tendons. One which is typical of the incomplete form need neither involve the whole width nor run through the whole thickness of the tendon. In its minimum phase it may be only an evulsion of a few fibers from the tuberosity; in its maximum phase it would be a borderline case of complete rupture. In its acute phase it may be definitely due to trauma; in its chronic phase the tendinitis overshadows the traumatic history.
The reader who has the patience to finish this book will inevitably remain confused about the lines of distinction which I have attempted to draw among the six most common clinical entities which affect the shoulder, i.e., complete and incomplete tendon ruptures, rim rents, calcified deposits, tendinitis and arthritis. In fact, I must leave the reader puzzled, for I am still puzzled myself. I can only confront him with the puzzle—show him that there is a puzzle. Personally, I believe that these rim rents and incomplete ruptures are the cause of the great majority of sore shoulders, and yet I believe they usually occur in degenerated tendons. For example, a man might have degenerative changes in both shoulders without symptoms and then, after trauma to one tendon, have severe local symptoms without any signs of trouble in the other shoulder.
One cannot even divide complete and incomplete lesions by the criterion of whether or not there is a direct communication from the bursa to the joint through the rupture, for the size of the opening is important also. Yet splitting hairs on a definition is not worth while. Practically, it is convenient to say that when one opens the roof of the bursa and finds the cartilage of the joint exposed to view through a rent in the floor of the bursa, we are dealing with a complete rupture. If there is no communication at all or only a small hole in the base of the bursa, we would class the case as incomplete. Of course the persistence of a direct communication between the joint and the bursa, even if small, is a most important point, because it alters the mechanics, as indicated on the cover of this book. Yet the size of the hole is also important if it is large enough to permit erosion of the joint cartilage (Plate VII, Fig. 8) by friction on the acromion.
It seems to me highly probable that incomplete rupture is much more common than complete. Since I have only operated upon cases where very pronounced symptoms existed, I have naturally found many more instances of the complete form, but in my observations on the cadaver, or on living cases in the clinic, I have much more often found incomplete lesions. I have not kept a numerical account and therefore cannot give the exact number or even the proportion.
Dr. Akerson's statistics give the best measure we have, but are subject to the criticisms on page 65. Similar observations may be made by any one having access to autopsy material. Moreover, when the economic importance of this lesion is appreciated, and the principles of efficiency become applied to the practice of medicine, such observations must be made.
I am inclined to think the table on page 469 also gives a low proportion of the incomplete ruptures, because so many cases in the other classes probably had this lesion besides the lesion which caused their classification. For instance, rupture of the supraspinatus is a not uncommon complication of dislocation and of circumflex paralysis, and many of the minor unclassified cases may have also been instances of this lesion. On the other hand, I have usually found at operation that the rupture was more extensive than I had previously thought, so that a good proportion of the supposed incomplete type may have been complete.
Referring to the chapter on Pathology, it will be seen that incomplete ruptures of four kinds are described:
(a) A few of the lower fibers on the joint side, together with the synovial reflection, may be torn out; these I call "rim rents."
(b) Some of the central fibers may be parted without tearing either the joint side or the bursal side of the tendon.
(c) The rupture may extend vertically through the whole tendon, making a communication between the joint and the bursa, without involving the whole breadth of the tendon.
(d) The fibers on the bursal side may be eroded without complete communication with the joint.
I believe that type (a) is synonymous with the cases so frequently found at autopsy where the sulcus is bare and eburnated, i.e., the condition I speak of as "rim rents." I think that type (b) may be the precursor of calcified deposits. Types (c) and (d) may be among the cases which give "tendinitis" symptoms out of proportion to the traumatic history.
Since I do not intentionally operate on incomplete ruptures, what I have to say in regard to these minor lesions is more theoretic than what has been stated concerning the complete ruptures.
All four varieties should be distinguished from the complete form by the persistence of considerable power in elevation, because the mechanics of the pull of the supraspinatus are not greatly altered. I have not operated unless there was decided loss of power.
The other cardinal symptoms, jog, crepitus, atrophy, sulcus, eminence and local tenderness, will be present, although any one of them or all of them may be found in less pronounced degree than in the complete cases. Type (c) might be recognizable, as the fluid sign should be present because joint and bursa communicate.
The diagnosis of the incomplete type is therefore made chiefly by the persistence of a considerable amount of power in the elevated or abducted arm and some doubt about the presence of some of the other symptoms and signs. Complete cases are usually so absolutely typical that no doubt remains. Complete cases do not form adhesions, while many incomplete cases do.
If the surgeon is sufficiently informed about the anatomy, pathology and surgery of this particular region, I believe that when in doubt he should explore the bursa through a half-inch incision. If he finds a communication through into the joint, let him close it, but if no opening exists, let him back out, for we do not yet know what to do to these incomplete ruptures.
Before closing this chapter, I may say that I believe these lesions to be the most common form of shoulder injury. My slogan has been that complete rupture of the supraspinatus is the most common cause of prolonged disability from industrial accidents to the shoulder. I feel that I have proved this at least to my own satisfaction. I may now add that the incomplete form accounts for the majority of minor shoulder disabilities. This I have not proved, for I do not operate on these cases, but the frequent presence of broadened sulci found in any .series of autopsies in elderly people is convincing to me. The clinical examination of employees with sore shoulders often shows symptoms suggestive of this lesion. Possibly opaque fluid injected in the joints might confirm the diagnosis. I have not felt justified in doing this, for exploration seems to me quite as free from danger. I certainly should try this experiment on patients now if I had in mind some definite plan for relieving them, if I did find broadened sulci indicative of incomplete ruptures, but I do not yet conceive of a plan by which to promptly cure them.
The appearance that I think opaque fluid in the joint would show in cases of complete rupture is indicated in the cover design.

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FREQUENCY OF COMPLETE RUPTURE OF THE SUPRASPINATUS TENDON

There are certain reasons for believing that this is a far more common lesion than is generally appreciated.
1. The writer's personal experience.
2. The statistics of Dr. Akerson.
3. The lack of attention paid to lesions of the shoulder in general; i.e., of end result studies of large series of shoulder injuries.

1. Personal Experience. The above chart shows that the writer's experience in operating upon these lesions was confined to two periods of about three years each, when attentive study was given to relatively large groups of shoulder cases. In the first period (1911 to 1913 inclusive) an intensive study was made of the shoulder cases at the Massachusetts General Hospital. The author resigned from that hospital in 1914 and was not reappointed until 1929. Other activities and a period in the army during the war intervened, without opportunity to operate on such cases, although I continued to make occasional impartial examinations for the Industrial Accident Board. In 1926, owing to the interest of Dr. Henry C. Marble and Dr. W. A. Bishop, who are directors of Insurance Clinics, I again gave intensive study to a group of shoulder cases, and the chart again ran to a peak. This led to increased interest in other clinics, so that other surgeons (e.g., Dr. Wilson) began doing these operations, which accounts for the decline at the end of my chart, although the rate of frequency, if we included other surgeons' cases, would not show this decline.
In other words, the chart shows that whenever I gave intensive study to a group of shoulder injuries, I was able to diagnose some of these cases and to demonstrate them by operation. My work received little attention after the first period but since the second, largely owing to the changes brought about by the Workmen's Compensation Laws, the importance of the lesion is becoming recognized by industrial surgeons in this state. I do not know just how many cases were seen during these two periods, and therefore cannot give the exact percentage of the cases examined which were instances of this lesion, although the limits may be stated pretty positively. For instance, the first fifteen cases were found among less than 200 patients, and the second fifteen cases were from an uncertain number, but probably less than 100. This means that the frequency of occurrence was about 7%% to 15% of all shoulder lesions that came under my observation.
By referring to my records for the twenty years since I recognized the first case, I find that I have seen in all about one thousand shoulder cases. Of these more than one hundred have been positively diagnosed as instances of complete rupture and many more as incomplete. This would justify an estimate of between 10% and 20%. It would require an amount of labor disproportionate to the present object to go over these records to apportion the exact percentage, since it is sufficiently clear that I have made this diagnosis in not less than 10% and perhaps more than 20% of all shoulder cases. If cases of partial rupture were included the percentage would be at least doubled.
The figures in the annual Reports of the Industrial Accident Board help us only in a negative way, for this diagnosis is not classified. Their tabulations of the durations of disability are not carried over from year to year, so that we cannot obtain a list of the cases in which disability is protracted. This is unfortunate, for this list would probably be largely composed of cases of rupture of the supraspinatus.
The report of the Industrial Accident Board for the year 1928, Table 7, gives the following figures in regard to shoulder injuries. It is supposed to cover every accident occurring in industry in this state.

The last two columns, "Sprains and Strains," and "All Other," are the ones which would probably contain most of these ruptures, although a large number must be included under dislocations and fractures. If we double the figures where both shoulders were injured, the total of the two columns would be 748, five per cent of which would be thirty-seven. During the same period, July 1, 1927, to June 30, 1928, I personally made the diagnosis in seventeen cases which were referred to me by Insurance Clinics or by the Board for "Impartial Examination." Since I probably see but a small fraction of these shoulder injuries of doubtful diagnoses which occur annually in this state, the estimate of thirty-seven is surely a minimum one. The maximum reasonable estimate would double this and also include twenty-five per cent of the 125 dislocations. It seems to me pretty well proved that not less than thirty-seven and very likely more than one hundred injuries of this type occur annually among Massachusetts employees.
At first sight thirty-seven, or even a hundred, neglected shoulder injuries in a state of 4,200,000 inhabitants does not seem a very serious matter, but as each insured case may cost the state $4,000 for compensation (aside from the pain endured and the economic loss of productive effort in labor), the amount of money involved is considerable (37 X $4,000 = $148,000). This fact mates this obscure injury more interesting, and, if we multiply by 100, still more so. My opinion is that the larger figure is a more accurate estimate. If we included partial ruptures which heal after a few months, but which cause a large total of lost time, the annual expense to the state for injuries of this small tendon can be reasonably estimated to be over half a million. Furthermore, there must be many such injuries which are not industrial.
In addition to the above reasons for believing that this lesion is not rare, I may say that in a single set of twenty dissecting room subjects I have always been able to demonstrate one or more instances. When I have been asked to speak to small groups of doctors or students, I have usually been able to find a subject on whom to demonstrate the diagnostic signs of this lesion, by asking at adj acent clinics for cases complaining of inability to raise their arms. I feel quite confident that I can demonstrate (recognized or unrecognized) instances of this lesion by examination of the cases under treatment in the out-patient departments of any large general hospital in any city of the United States, and, in fact, probably in most parts in the world, where there are many persons over forty doing laboring work. This does not necessarily mean that there are large numbers, for each case is apt to be a patient for several years, meanwhile going from one hospital to another in search of relief.
2. Dr. Akerson's statistics, already given on page 67, give us a maximum estimate, because nearly all the observations were made on elderly subjects of the laboring class, in whom a previous injury could only be assumed, for there were no histories negative or positive of accidents. There is a splendid chance for a clinical research at the Long Island Hospital, in future, to correlate autopsy findings with retrospective histories of shoulder injury, taken from patients before death comes. It would be a time-consuming job, but it would help us to decide the important question of whether these lesions can occur without injury, and it might lead to the saving of many thousands of dollars, not only in compensation, cost of medical care and economic loss, but in maintenance of the indigent. Dr. Akerson's work might in this way lead to a saving of more than the cost of his entire department. Similar opportunities exist in like institutions from one end of the country to the other.
3. The Lack of Attention to Shoulder Injuries. There is a voluminous literature on fractures and dislocations (especially on habitual dislocations) of the shoulder, but, with the exception of Dr. Meyer's work (loc. cit.) and an investigation now being undertaken by Dr. Fowler of Evanston, 111., I know of no systematic observations from autopsy findings in this part of the body. Nor are there any serious studies of similar clinical cases. If the End Result system of organization existed in our hospitals and insurance clinics, these cases of prolonged disabilities would be automatically revealed, studied and eventually prevented by early operation.
Thus my confidence that these lesions are common is enhanced because no one has evidence to. contradict me, and a few support me. It is clear that Dr. Meyer finds similar lesions, although he explains them as the results of attrition. Dr. Fowler will, I believe, as he has already told me, confirm some of my findings and give support to those of Dr. Akerson.

ARGUMENT

This book is not written to show that I have had good results in this class of cases. My argument is merely that this lesion exists; is not uncommon; has characteristic symptoms which permit accurate diagnosis; and, since I have been able by suture of the tendons to greatly relieve a few cases, even though the diagnosis was belated, it is highly probable that the prolonged and trying symptoms from which these patients suffer, when not operated upon, might be prevented by early diagnosis and the prompt use of a minor surgical operation, which should not be difficult, if promptly done.
If I can offer reasonable evidence for the clauses italicized, it seems to me that the conclusions in the last clause of the above paragraph would be sustained sufficiently to justify prompt exploratory operation when the symptoms suggest this diagnosis.

POSSIBLE ACCURACY OF DIAGNOSIS

I have already established the existence of this lesion, endeavored to estimate its frequency and have described the characteristic symptoms. Evidence is now offered to sustain the statement that accurate diagnosis is possible. The following extracts, taken verbatim from my pre- and post-operative reports to insurance companies, show that a'positive diagnosis of this lesion may be made. Every case operated upon during the last sixteen years, in which I have demonstrated a complete rupture of the supraspinatus, is given. Even in the cases operated upon prior to 1916, one may find that my definite pre-opera-tive diagnoses in the records of the Massachusetts Hospital are correct, in all but five cases in which the diagnosis was simply " subacromial bursitis." With each of the abstracts given below the case number is stated. The reader will find further information about each of these cases by referring to these numbers in the Table on pages 255 to 260 in Chapter VIII.

CASE No. 57.
Preop. Diag. "The injury which he sustained two years ago, I believe to have been a rupture of the supraspinatus tendon and the upper portion of the capsule of the shoulder joint."
Op. Findings. "As soon as the bursa was opened it was apparent that the entire supraspinatus tendon had been torn away, for the cartilage of the bone showed where the supraspinatus tendon should be. A small stub of the tendon still remained attached to the tuberosity. Further exploration showed not only that the supraspinatus tendon, but the upper portion of the infraspinatus tendon was also torn, but the subscapularis was intact. The long tendon of the biceps could be seen crossing the field just at the edge of the subscapularis. The proximal portion of the supraspinatus had retracted so far into the subacromial space that only a rather unsatisfactory portion of it could be pulled upward and attached to the stub on the tuberosity. It was evident that the atrophy which had taken place in the two years left practically no hope of the restoration of the complete function of the muscle or tendon."

CASE NO. 75.
Preop. Diag. " I have no hesitation in making a diagnosis of rupture of the supraspinatus tendon, nor in advising an operation to suture it and clean off the ragged vegetations at the edges of the old rupture."
Op. Findings. " Showed supraspinatus entirely torn off and retracted far under acromion. Biceps tendon lying at inner edge of rupture."

CASE NO. 88.
Preop. Diag. "I feel that the diagnosis of subacromial bursitis is correct, but that the underlying cause of the bursitis was a ruptured supraspinatus tendon. This has now partially healed—enough to renew the power of abduction but not enough to make the point of rupture smooth. The result is an irregularity on the base of the bursa which in abduction impinges on the acromion and acromio-clavicular ligament."
Op. Findings. "On opening the bursa the ruptured supraspinatus tendon was beautifully demonstrated, the tendon having been torn from the tuberosity, leaving none of the original attachment on the bone. It had retracted about a half inch and the torn end could be seized with a tenaculum."

CASE NO. 88.
Preop. Drag. " He has the following signs indicating that his trouble is a ruptured supraspinatus tendon and his history is typical of this lesion.
"1. There is an acutely tender spot on the greater tuberosity at the normal point of insertion of this tendon.
"2. I can, I believe, feel at this point a sulcus where the tendon is torn.
"3. There is a painful jog in the motion as he raises his arm.
"4. There is velvety crepitus as he does this.
"5. After the arm has been elevated one can easily pull it down, although the deltoid muscle can be felt strongly contracted.
"6. There is a feeling of fullness under the upper part of the deltoid as if there was fluid in the bursa."
Op. Findings. "Free straw-colored fluid. Cartilage of head of humerus and the greatly swollen and injected biceps tendon visible on retracting the margins of wound in deltoid. The tear of the supraspinatus tendon was complete and the tendon of the infraspinatus was also almost completely torn. The proximal ends had retracted so as to be barely reached by Allis forceps to enable passing a suture."

CASE NO. 89.
Preop. Diag. "Patient presents to me typical symptoms of supraspinatus. He can abduct his arm slowly and with a hitch which gives an obvious sudden change in the relative position of the humerus and the scapula. He cannot maintain his arm extended against any considerable pressure."
Op. Findings. "Routine bursal incision disclosed a very extensive tear of the supraspinatus tendon. The biceps tendon had disappeared and could not be located except possibly as a few fibers in the anterior part of the joint."

CASE NO. 96.
Preop. Diag. "Examination shows pretty typical signs of a ruptured supraspinatus tendon, except that the friction rub is masked by the presence of joint fluid in the bursa. The outlines of the bursa are visible through a heavy deltoid as evidence of this fluid. It is well shown when the patient attempts to abduct the arm. The arc of abduction cannot be performed without a typical jog in the motion. The patient himself feels this and complains of pain during it. There is tenderness over the bursa."
Op. Findings. "Routine bursal incision showed a typical rupture of the supraspinatus tendon which did not involve either the subscapularis or the infraspinatus; making a gap pulled away from the tuberosity of about one-half inch width. Through this, on opening the bursa, the cartilage of the head of the humerus was visible. By retracting a little, the biceps tendon could be seen to the inner side, greatly congested."

CASE No. 97.
Preop. Diag. "Diagnosis. Rupture of supraspinatus tendon (left) complete and of severe grade. The same on right but incomplete and partially repaired. Probably rupture of the long heads of both biceps tendons."
Op. Findings. "The supraspinatus tendon was completely ruptured -and the upper portion of the subscapularis also. The biceps tendon had disappeared, evidently having been torn off the glenoid and retracted into its groove."

CASE No. 98.
Preop. Diag. "Examination shows very typical tenderness, crepitus, abduction weakness and the jog in motion typical of a ruptured supraspi-natus tendon in the right shoulder."
Op. Findings. "Routine bursal incision showed the supraspinatus was completely ruptured and also a part of the tendon of the subscapularis over the biceps tendon, and also a portion of the infraspinatus. The joint cartilage was exposed for about a half inch to the outer side of the bicipital groove and there was a tag of tendon still attached to the tuberosity just external to the groove."

CASE No. 102.
Preop. Diag. "Examination shows a decided atrophy of the muscles about the right shoulder, tenderness and irregularity of the tissue over the greater tuberosity, a painful jog in the motion of abduction, free external rotation, persistence of passive and loss of active complete abduction. These signs and the history are characteristic of rupture of the supraspinatus tendon. He also has' a rupture of the long head of the biceps, if one may judge by the contour of the belly of the muscle."
Op. Findings. "Free joint fluid found in bursa, which was large. The supraspinatus tendon was about half torn away from the tuberosity and the torn tendon retracted only about one-half inch, exposing a small extent (about) one-quarter inch of the edge of the joint cartilage. The opening was not large enough to view the tendon of the biceps, so I made an incision about one-half inch long into the bicipital groove and identified the biceps tendon. It was large and normal in appearance, so that it is likely that the apparent atrophy of the outer belly of the muscle in this case was due to simple disuse from reflex pain."

CASE NO. 106.
Preop. Diag. "Examination of the right shoulder shows typical signs of a rupture of the supraspinatus of considerable degree. One can feel the sulcus on the facet of insertion from which the tendon has been evulsed. There is fluid in the bursa."
Op. Findings. "The roof of the bursa was thickened. When incised, free straw-colored fluid escaped, about one dram. The supraspinatus was found torn from its attachment and retracted far under the acromion. About one-half of the insertion had evulsed from the facet. The other half was torn about one-half inch from the facet, leaving a thickened, irregular, whitish mass about the size of a large lima bean attached to the tuberosity."

CASE No. 107. Reported in text.

CASE No. 108.
Preop. Diag. "The diagnosis is fairly certain of a partial rupture of the supraspinatus, and also a rupture of the long head of the biceps."
Op. Findings. "The complete supraspinatus tendon had been torn close to the tuberosity and was retracted about an inch and a half. The infraspinatus and subscapularis were intact, but the biceps tendon had been torn completely off the glenoid and had retracted part way, instead of wholly into the sheath, leaving a frayed end protruding at the edge of the articular surface. In repairing I used this by sewing the supraspinatus to it and the subscapularis, anchoring the biceps tendon in its groove as I did so."

CASE No. 112.
Preop. Diag. "Examination shows the following: A slight atrophy of the intrinsic muscles of the shoulder, a soft crepitus which occurs with a snap just as the tuberosity passes under the acromion in abduction, a tender point on the greater tuberosity at the insertion of the supraspinatus tendon, a tendency of the scapula to follow the motions of the humerus, a flaccid condition of the outer head of the biceps muscle. These signs indicate that he has torn the supraspinatus tendon from its attachment on the tuberosity, and probably has also torn the biceps tendon from its adjustment on the glenoid."
Op. Findings. "This displayed a perfectly typical complete rupture of the supraspinatus tendon without rupture of either the subscapularis or infraspinatus. The biceps tendon was slightly frayed at its inner edge where there were two small papilloma-Iike, whitish excrescences, the size of one-quarter of a pea. The stub of the ruptured tendon was still attached to the tuberosity, but had worn down to a falciform edge; similar falciform edges showed on the lateral aspect of the tear; i.e., the unruptured edges of the subscapularis and infraspinatus. By lifting the edge towards the subscapularis, a pinkish, inflamed biceps tendon was demonstrated. A few fibers of the outer portion of this had been ruptured as spoken of before. There was only a moderate amount of joint fluid seen at any time. The edges of the torn surfaces were refreshed, and the parts sutured in place with three heavy braided silk sutures."

CASE No. 115. See history on page 389

CASE No. 119.
Preop. Diag. "Typical ruptured supraspinatus tendon. Atrophy, crepitus, jog, fluid, loss of power very great. Biceps O. K. Rotation free, tender sulcus."
Op. Findings. " The tendon was much thicker than usual and less retracted, so that the triangular gap was longer transversely than vertically. . . . There was quite a stub on the tuberosity, enough to suture. The biceps tendon was so badly damaged that there were but a few strands of it left and these were adherent to the roof of the joint. Most of the tendon had retracted into the groove and become adherent there. None was left crossing the joint surface and none was seen in the joint, although it might have been imbedded there behind the head."

CASE No. 123.
Preop. Diag. " This patient has the typical symptoms of a rupture of the supraspinatus tendon of considerable extent, but not enough to prevent his having a fair amount of power in abduction—although with pain. He has atrophy of the spinati, scapulo-humeral spasm, a j og in the motion of abduction, the fluid sign with limitation in complete abduction, a tender, palpable defect on the greater tuberosity where the tendon should be attached."
Op. Findings. "An exploratory incision a half inch long was first made and it was at once apparent that the supraspinatus and the infraspinatus tendons were evulsed from their facets, leaving no stubs of tendon. The biceps tendon, which was double at this point, was greatly swollen and inflamed and presented as soon as the roof of the bursa was opened. To its inner side the subscapularis and the inner portion of the tendinous expansion of all the tendons lay intact, and to its outer side was bare joint cartilage and the top and posterior portion of the greater tuberosity from which the tendons had been torn. The facets were smooth and the superficial parts of them had not been carried away by the tendons. The incision was enlarged to an inch and a half and a good view of the field obtained. It was found that the teres minor had also been evulsed. The whole posterior part of the capsule and conjoined tendon of the above muscles was retracted downward and outward. It was impossible to draw this back and to suture it in place."

CASE No. 127.
Preop. Diag. "At my first examination I did not make the diagnosis in this case, although it had been suggested by Dr. Marble, but on my second
examination, seventeen days later, I wrote, 'H--- is better, but I have
changed my opinion about the diagnosis. I am now quite confident that he has a ruptured tendon and should be operated upon. I think Dr. Marble was correct in his original diagnosis.' "
Op. Findings. "A small exploratory incision was first made over the point of tenderness. As soon as the roof of the bursa was incised, an irregular, whitish mass of tendon about as large as a thumb nail popped out of the incision. It proved to be the proximal portion of the torn tendon and was about one-quarter inch thick. It evidently turned on itself as the arm was abducted and caused the catch which the patient himself could accurately localize, There was about a tablespoonful of straw-colored fluid in the bursa. The incision was then enlarged to about two inches and a good view of the lesion obtained. This case differed from others on which I have operated in that the tear did not involve the whole thickness of the tendon, but left a very thin layer toward the joint surface so that there was not a demonstrable communication with the true joint. However, the layer was so thin that the cartilage could be seen through it. The ruptured portion formed a little flap about a square inch in extent, attached only to the proximal end and evulsed on the distal end from the facet of insertion. I have seen similar cases in the cadaver where the distal end had not evulsed. It is a fact that lamination of the tendon is found in many cases, but this is the first one on which I have operated where the laminated portion evulsed without the lower surface also tearing. The free portion seemed rather necrotic but was clearly rather recently ruptured. The torn surface was rather bulbous, as if partially healed. Near the lesion and to its inner side was a streaked, red area which was excessively tender when touched, but the torn end itself had no sensation and was not so made by the novo-caine. It is to be assumed, therefore, that the pain in these cases is not due to the tissue pinched but to the uninjured tissue on the tuberosity which does the pinching."

CASE No. 128.
Preop. Diag. " My opinion is very strong that he has a ruptured supraspinatus, but I am a little uncertain as to whether it is not a renewed injury in an old lesion. X-ray is very strong evidence of this. Clinically, I should not suspect it. In either case I should advise immediate operation as soon as arrangements can be made."
Op. Findings. "On opening the bursa there was found to be evidence of old inflammation in the bursa, as well as recent light adhesions. The supraspinatus was torn away from the tuberosity to the extent of about one-half inch, and little of the bursal floor remained untorn, but there was a gap directly into the joint through which the cartilage could be seen. This gap was about one-quarter of an inch in extent. The tendon had retracted very little and I was able to close it with four silk sutures, two of heavy silk and two of light silk."

CASE No. 129.
Preop. Diag. "Signs of ruptured supraspinatus tendon were present at my previous examination, but they are much more prominent now than they were at that time. He has a very distinct crepitus, sulcus, eminence, scapulo-humeral spasm, tenderness at the border of the tuberosity; localized tenderness, atrophy of the supraspinatus, sign of fluid when both arms are elevated. I agree with Dr. Marble in the diagnosis and would advise operation in this man's case."
Op. Findings. "The bursa was first opened by a half-inch exploratory incision. A small amount of free fluid escaped and it was readily seen that the supraspinatus tendon was ruptured and greatly retracted. . . . The tendon was partly evulsed and partly ruptured at the 'palisade junction.' The complete tendon was involved with possibly some of the infraspinatus. As in another recent case (H--- ) there was still some tissue remaining
on the joint side so that the cartilage was partly covered with a turgid, deep-red, softish tissue containing a few obvious whitish tendinous bands. One of these was especially noteworthy because it was very sensitive, and the patient winced when it was touched. I excised it because it did not seem to be of sufficient strength to make up for its sensitiveness. The biceps tendon lay to the inner side of the rupture buried in inflamed synovial folds, but not injured, unless the strand of tendon above alluded to had been stripped off it. The bulk of the proximal end of the supraspinatus tendon had retracted far under the acromion and could barely be drawn into the field."

CASE NO. 135.
Preop. Diag. " I feel very confident that he has a rupture of the supraspinatus tendon. I am not sure that there was not a previous rupture and that this latter accident merely increased the trouble. However, there is no question in my mind but that his chances will be much better if his bursa is explored and suture is done, if the tendon is ruptured."
Op. Findings. "No blood or fluid on opening bursa. A complete rupture of the supraspinatus, with extension across the bicipital groove, about one-half inch into the subscapularis. Definite indications that the rupture was fairly recent; i.e., very little separation between the distal and proximal portions. Stub of tendon still attached to the tuberosity over most of its extent. No new-formed falciform edge. Biceps tendon flattened and superficially reddened in portions beneath rupture. Parts satisfactorily sutured together with pedicle silk; five stitches. In my opinion, the condition found indicated a recent rupture of a tendon which had already been partially ruptured."

CASE No. 137.
Preop. Diag. "Examination shows that this patient has a symptomless, chronic bursitis, with crepitus in the right shoulder. The left shoulder shows the typical signs and symptoms of a rupture of the supraspinatus tendon. Since he has considerable power in abduction—although the abduction is painful, and accompanied with a jog and crepitus—I am inclined to think that the rupture is not extensive enough to involve the adjoining tendons. Even though this man is sixty-two, and it is four months since the injury, I would advise him to have the tendon sutured to the tuberosity."
Op. Findings. "A one-half inch exploratory incision was made and the bursa opened. Rupture of the supraspinatus throughout its whole extent was disclosed. The rupture extended also, to a slight extent, into the insertion of the infraspinatus. The sulcus and tuberosity were bare, except for a very slight amount of tag of tendon near the edge of the bicipital groove. The incision was enlarged to two and one-half inches to permit suture."

ERRORS IN DIAGNOSIS

But a skeptical reader may now ask for a statement of how many cases I have operated upon under this diagnosis and have failed to find a complete rupture of the tendon. I give below a similar set of verbatim extracts from the records of nine cases during the same sixteen years, the only ones in which I have made a positive diagnosis and have not been confirmed by the operative findings.

CASE No. 76.
Preop. Diag. "I believe this patient has a ruptured supraspinatus tendon, at the point of the insertion of the tendon in the tuberosity. This diagnosis is consistent with the X-ray appearances seen in the films taken by Dr. George. These films show an irregular opacity in the area of the bursa, which may be due to extravasated blood or to crumbs of bone torn off the tuberosity."
Op. Findings. The operative notes in this case have been lost, but I clearly remember that the condition proved to be a case of calcified deposit which had recently ruptured into the bursa, leaving a defect in the tendon very similar to a true rupture, but containing blood and calcified material.

CASE NO. 80.
Preop. Diag. "This is unquestionably a case of ruptured supraspinatus tendon of considerable extent, but the main symptoms are due to a tuft of synovial granulations from the remnant of the supraspinatus tendon still attached to the tuberosity."
Op. Findings. " The walls were much thickened and there were synovial tags in the region, over the tuberosity, showing more or less chronic inflammation. The tender point, which could be felt prior to the operation and was thought to be a tag of tendon remaining on the tuberosity, proved to be a rounded elevation, markedly circumscribed and about one-half inch in diameter, slightly longer in the axial direction than the transverse. This was acutely tender when pressed on. It was incised and found to be the insertion of the tendon of the supraspinatus attached to an osteophyte at the edge of the joint cartilage. There was no direct evidence of a rupture of the supraspinatus tendon. If there had been one, it must have healed. No communication with the joint was demonstrated. The essential pathology was probably the hypertrophic arthritis which was evident in other joints. (Patient's age was 77.)"

CASE NO. 91.
Preop. Diag. "The history and symptoms are typical of a ruptured supraspinatus tendon in the right shoulder, with some adhesions of the bursa, or blocking of the motion by the remains of the torn tendon impinging on the acromion. I think the latter."
Op. Findings. "The base of the bursa was deeply congested and swollen, but there was no demonstrable tear of the tendon of the supraspinatus. There were light adhesions in the bursa which were broken up with the finger. The short rotators and capsule were greatly contracted and were slowly stretched until full external rotation and abduction could be attained, and the wound closed."

CASE No. 105.
Preop. Diag. " I have little doubt that this patient has a rupture of the supraspinatus tendon of considerable extent."
Op. Findings. " Incision through the roof of bursa with the escape of about one dram of clear, straw-colored fluid. Exploration revealed an intensely inflamed zone on the greater tuberosity, approximately the size of a half dollar with red periphery and white center, resembling the condition seen in calcified cases. An inflamed fold moved back and forth over this as the patient's arm was moved. This fold was excised. The point of the knife was used to puncture the tendon in several places in the inflamed area with the purpose of allowing a new blood supply by attaching the scar to the inflamed base. There was no indication that the supraspinatus tendon had been ruptured."

CASE No. 110.
Preop. Diag. "The whole tuberosity is tender and it is hard to find a definite spot from which one can say the tendon has been torn. With the exception of this, his symptoms are fairly characteristic of a ruptured supraspinatus. From the relaxed condition of the biceps muscle and particularly of its outer head, I am inclined to feel that the biceps tendon is torn from its attachment on the glenoid. Indeed this may be the main lesion.
"I should advise inspection of his bursa under local anaesthesia and suture of the tendons if they are found torn. If there is no tear in the base of the bursa, I should advise opening the joint between the supraspinatus and the subscapularis and inspecting the tendon of the biceps.
"Remarks. This case is atypical in the age of the patient (17). Ruptured supraspinatus lesions are usually in elderly men. The character of the accident is unusual; sudden abduction efforts are more common as causes. There has been comparatively little pain, especially in the first week, and usually one has a history of swelling over the bursa in the first few days. Palpation over the tuberosity is a little atypical. For these reasons I cannot be as positive as I sometimes am, but I am sufficiently certain of a rupture to feel that in the boy's place I would want to have an exploration. Little harm would be done if this is negative, which I am confident it will not be."
Op. Findings. "The exploratory instrument was first introduced into the bursa, which was found to be full of adhesions and consisted of a series of pockets of walled synovia. Through the exploratory instrument it could be definitely determined that the bursa had been subacutely inflamed, but that there was no tear in the supraspinatus tendon. There was no fluid in the bursa. As both Dr. Baker and I thought that the biceps tendon was probably torn, the incision was enlarged to about one and a half inches, and the bicipital groove was incised. It did not contain the tendon, which evidently had retracted downward. The arm was put through the accustomed motions of rotation and abduction while a finger was introduced into the bursa to break up all the adhesions existing there. When the adhesions had been broken, which was easily done, the motion of the arm was normal. No steps were taken to repair the biceps tendon."

CASE No. 111.
Preop. Diag. "The shoulder presents typical signs of a ruptured supraspinatus tendon of a considerable degree. He has my fluid sign— characteristic velvety crepitus, a jog in motion, a tender irregularity on the greater tuberosity and weakness in abduction. He is able, however, with a little coaxing, to abduct the arm, but has very irregular action of the humerus on the scapula as he does this. There is still some ecchymosis in the anterior portion of the arm over the bicipital region, as if after the injury blood may have escaped down the tendon sheath; the tendon, however, appears to be intact."
Op. Findings. "Exploration of the bursa showed no fluid. No communication was found between the bursa and the joint. The bursa was adherent over about half the extent of the lower portion. On separating the adhesions it was evident that the supraspinatus had been torn, but had spontaneously healed; the tissues were red and swollen with white patches here and there. I therefore closed the wound in the usual manner without doing anything in the way of an operation."

CASE No. 120.
Preop. Diag. "The left shoulder presents very typical signs of an extensive rupture of the supraspinatus and possibly of the long head of the biceps. There is slight but decided atrophy—consistent with a history of two weeks. There is a very tender point on the tuberosity, scapulo-humeral spasm, a j og in motion and the fluid sign. In the stooping position the patient can abduct and hold the arm abducted as he straightens up."
Op. Findings. "Routine bursal incision. Adhesions prevented easy access, for roof was stuck to base over an area as large as a quarter over the greater tuberosity. These were separated and showed that the tendon of the supraspinatus was bright red, swollen, and covered with tags of vascular adhesions. The line of demarcation of the affected area was very sharp on the outer side, so that the contrast between the yellowish white to the right and the turgid red at the left was very decided. It suggested an infarction. Although there was some free fluid in the bursa there was no communication through the inflamed area to the joint. The supraspinatus tendon, if ruptured at all, must have been torn beneath the base of the bursa without communicating with the bursa. Several small incisions were made with the point of the knife to relieve tension in the tendon. Through one of these a tiny bit of white nondescript tissue protruded. This was saved for pathologic examination j I am pretty sure it was necrotic tendinous substance. The wound was closed as usual without endeavoring to suture the roof of the bursa. The pathology found at this operation may be explained in two ways, or as a combination of both ways. There was certainly an acute bursitis with recent adhesions, but it was impossible for me to say positively that this localized acute inflammation over the site of the supraspinatus tendon was due to a rupture of the tendon beneath the base of the bursa. It might have been due, as suggested by the evidence of osteitis shown in the X-ray, to a chronic necrotic process in the tendon. The extrusion of the bit of necrosed tendon from the incision also supports this. So does the symptomless condition in the well shoulder. It seems to me that if we accept the man's history that the condition of the shoulder was O. K. before he helped lift the case, that the whole picture can be explained by the supposition that there was a necrotic process going on in the tendon which had weakened it so that it partially evulsed without tearing into the bursa. This would explain all which was found at the operation, and my opinion is that this theory truly does account for the facts. I have had several other similar cases and have frequently seen evidence of such lesions in the cadaver."

CASE No. 126.
Preop. Diag. August 12, 1929. "I have little doubt that this patient has a mild rupture of the supraspinatus, but as the power in abduction is good, operation need not be considered. It is probably not an extensive rent. I suspect both from the clinical signs and from the X-ray that he has had an old lesion here for some years. It seems to me that the best plan of treatment would be to let him rest a few weeks and to have him attend your clinic three times a week for massage. If he does not feel able to go to work again in a month, let me see him again." Sept. 22, 1929. "Examination is as on August 19th. My opinion that he has a small rupture of the supraspinatus is somewhat strengthened by the fact that the symptoms have not improved. As he is only forty-two, I am inclined to advise an exploratory incision under novoeaine to confirm the diagnosis and, if necessary, to suture the tendon. The spot at which he complains of tenderness is so localized that it seems likely we shall find some lesion at this region."
Op. Findings. Oct. 23, 1929. "Under local ansesthesia no rupture of the tendon was demonstrated. The walls of the subacromial bursa were thickened and the bursa contained a little fluid. There was nothing found which indicated any recent injury other than the presence of this chronic bursitis. The wound was closed after taking out a small specimen of the synovial lining for pathologic examination." (This showed chronic inflammation.)

CASE NO. 181.
Preop. Diag. "In my opinion, he has a chronic subacromial bursitis in consequence of a rupture of the tendon of the supraspinatus."
Op. Findings. "A half-inch exploratory incision showed that the roof of the bursa was thickened and adherent to the floor beneath. The wound was enlarged to about one and one-half inches and the adhesions freed, partly by cutting and partly by tearing with the finger. Several small bursal sacs had replaced the usual large one. These sacs lay beneath the adhesions which permitted a certain amount of motion. The adhesions were red and inflamed looking. There were one or two small calcified deposits which were wiped out. The periphery of the bursa outward and backward under the acromion was more normal in appearance and not adherent. The total area involved by the adhesions was about the size and shape of a fifty-cent piece over the greater tuberosity and insertion of the supraspinatus tendon. The most acute tenderness was felt at this point, although there was a little sensitiveness over the bicipital groove. Two or three tags of inflamed serosa were removed for examination and a very small bit of tendon at the point where the adhesions centered was clipped out for examination."

In most of these nine cases, although there was not a complete rupture, there was some evidence of partial rupture beneath the base of the bursa. However, I did not confirm this supposition by cutting through the base, for it seemed to me that its tissue formed a bridge over the gap which would assist in healing the tendon. I am inclined now to think that I have been too conservative, for several of these cases had long convalescences, and it might have been wiser to explore beneath the base of the bursa.
At the danger of repetition, I wish to state that I do not intentionally operate, unless I think the ruptures are complete, because I feel confident that where the rupture is complete, healing will not take place unless suture is done. I am not sure enough of what the treatment of partial ruptures should be, to make me urge operation, even if I were sure of the diagnosis. Therefore, the above nine cases may be considered to be errors in diagnosis, although by no means as negative explorations. The difficulty is to tell beforehand whether or not there is actually a complete rupture which needs suture. I think the fact that during a period of sixteen years I made the diagnosis correctly twenty-one times, and incorrectly in only nine cases, shows that the diagnosis is not difficult. When in doubt, such a trivial operation as exploration would be justified, even if the proportion of errors was three to one.
In several of the nine cases it is to be noted that the mistake could have been avoided by more reliance on the fact that if there are decided restricting adhesions the diagnosis is not established. In the first case the X-ray indicated the presence of a calcified deposit and should have warned me not to make the mistake, although I should have operated at any rate. In several of the other cases where a mistake was made, the notes indicate that I was in decided doubt about the diagnosis before the operation, and, therefore, the incision as a matter of fact was "exploratory."

END RESULTS IN OPERATED CASES

We next come to the clause "since I have been able to relieve a few cases even though the diagnosis was belated." By referring to pp. 255-260, the reader may see that, excluding cases where there was a coincident fracture of considerable extent, I have operated on thirty-seven cases. In four of these the tendon was retracted to such a degree that I could not even attempt a suture. I have been unable to trace two patients operated upon about twenty years ago. Deducting these six cases we have thirty-one in which an attempt was made to suture the tendon. The results have been as follows: poor, four; fair, seven; good, twenty. That is, two out of every three operations were successful in that the results enabled the patients to return to work, although in most cases only after the elapse of months.
A very few, but not many, of my results have been perfect in the sense that the arm was just as useful and just as painless as before the injury; but many of them have been good in the sense that the arms have been relatively painless and quite, if not completely, useful. When I have written "good" I mean that the operation was well worth doing. When I have written "fair" it should convey that, in my opinion, there was some improvement from the operation, but that it was hardly worth doing. "Poor" means that the sum total of relief of the suffering of the patient was not sufficient to compensate for the pain and trouble which were incident to the recovery. There have been no bad results in the sense that any joint was made worse by the operation, but in at least two of the "fair" cases (Cases 83 and 112, see p. 175) the patient's point of view would have been that the result was poor, because his symptoms were not improved in spite of his post-operative pain.
There are many factors to account for the lack of perfection in the results, such as the age, the length of time the operation has been delayed, coincident disease, and above all, the desire of the patient to get well. The non-industrial patient is more readily pleased by improvement which lacks perfection than is the employee, who prefers compensation and no work, to double the pay plus work which would undoubtedly cause some pain and discomfort.
This compensation factor always causes some delay in the convalescence. Hard times have the same effect.
However, my argument does not need to show that all results should be perfect. I could give many excuses for the failures, but will be contented to present the following table.

In three of the four poor results, the tear was very extensive and the repair unsatisfactory; three had weeping wounds from excessive fluid drainage without frank sepsis (see p. 248), and all four had secondary operations. The seven cases of fair results were all improved to a considerable extent but have not actually gone to work again permanently.
There was one death which might possibly be attributed to the operation. This patient, Case No. 123, was drowned while in bathing at one of the beaches three weeks after I did an exploratory operation. The operation had shown that the tendons were too badly injured to admit of any attempt at repair. The wound healed by first intention, and as the patient enjoyed going in bathing I permitted him to do so about ten days after the operation. On the twenty-first day he was drowned. He was known to have had a heart lesion. The medical examiner reported "Death by drowning," and did no autopsy. I myself can see no connection between the operation and the drowning, but two doctors offered testimony at the Industrial Accident Board that the patient had had pulmonary embolism from the operative wound. The Board, however, did not accept their testimony, because there was no autopsy or other reason to support their diagnosis.
I feel that the proportion of good results is a sufficient reason for advising this operation, even in late cases. With greater experience and improved technique it is likely that the percentage of good results will be increased, but, as in many other surgical conditions, prompt recognition and treatment will be of greater importance than the difference in surgical skill between experienced and inexperienced operators, provided the pathologic condition is thoroughly understood.

END RESULTS IN UNOPERATED CASES

As most of my cases have been "industrial" the question of compensation becomes an important factor in estimating the period of disability. Cases who have no prospect of compensation will unquestionably go to work sooner; for instance, Case 119, a painter who had his own shop, began doing some work within a month after his operation. On the other hand in some cases, the compensation becomes equivalent to an old age pension. I have spent much time and money in tracing the unoperatcd cases of both partial and complete rupture, and have obtained enough information to venture the estimates on page 124 as to the probable costs of each. My estimate of $300,000.00 for 100 cases of complete rupture is also sustained by figures on ten patients on whom I did operate and therefore established the diagnosis. In five of these (delayed) cases the operation was a practical failure, but the patients were no worse off in consequence, and therefore were in a similar status to those in which no operation was done. In the other five the operation was essentially successful.

(The law limits total compensation to $1,000 so that these figures do not cover the period the patient is still disabled after his compensation ceases. The figures also include all medical and surgical charges.)

Case 96 in the first group had a delayed convalescence but eventually was able to go to work again as a steamfitter. Case 127 in the second group was a similar one. The reader may shift either case to the other group if he is disposed to exaggerate either average figure. Although it would not be fair to use the second group at all in computing the cost of 100 unoperated cases, by using it we may obtain an average minimum figure — $2,143.00. Therefore, the figure for 100 cases must be somewherebetween$200,000.00and$4-00,000.00.
Pain and disability are difficult to estimate in figures; these estimates are presented to impress on the reader that this lesion is important.

REFERENCES

BTTCHOLZ, C. H., Der Abriss der Supraspinatusshue, Arch. f. klin. Chir., Berlin, 1922, cxxi, 255-264.
CODMAN, E. A., Abduction of the Shoulder. An interesting observation in connection with Subacromial Bursitis and Rupture of the Supraspinatus, Boston Med. and Surg. Jour., 1912, clxvi, no. 24, 890-891; Also: Complete Rupture of the Supraspinatus Tendon. Operative Treatment with Report of Two Successful Cases, Boston Med. and Surg. Jour., 1911, clxiv, no. 20, 708-710; On Stiff and Painful Shoulders, As Explained by Subacromial Bursitis and Partial Rupture of the Tendon of the Supraspinatus, Boston Med. and Surg. Jour., 1911, clxv, no. 4, 115-120; The Pathology and Treatment of Lesions in and about the Shoulder Joint. The Industrial Doctor, 1926, iv, No. 8,121-131; Obscure Lesions of the Shoulder; Rupture of the Supraspinatus Tendon, Boston Med. and Surg. Jour., 1927, cxcvi, no. 10, 381-387.
FOWLER, E. B., Rupture of Spinati Tendons and Capsule repaired by new operation, Illinois M. J., 1932, lxi, 332-334.
KITCHEN, A. S., Surgery of the Supraspinatus Muscle, Journ. Michigan M. Soc,
1920, xix, 64-67.
METER, A. W., Absence of the Tendon of the Long Head of the Biceps. Jour. Anat. and Phys., 1913-1914, xlviii; Also: Anatomical Specimens of Unusual Clinical Interest, Am. J. Orthop. Surg., 1915, xiii, 86; Unrecognized Occupational Destruction of the Tendon of the Long Head of the Biceps Brachii, Arch. Surg.,
1921, ii, p. 130; Further Observations Upon Use-Destruction in Joints, Jour. Bone and Joint Surg., 1922, iv, p. 491; Evidences of Attrition in the Human Body, Proc. Am. Assn. Anatomists, Anat. Rec, 1923, xxv, 142; Further Evidences of Attrition in the Human Body, Proc, Am. Assn. Anatomists, Anat. Rec, xxvii, 211, 1924; Further Evidences of Attrition in the Human Body, Am. Jour. Anat., 1924, xxxiv, 241; Spontaneous Dislocation of the Tendon of the Long Head of the Biceps Brachii, Arch, of Surg., 1926, xiii, 109; Spon
taneous Dislocation and Destruction of Tendon of Long Head of Biceps Brachii j Fifty-nine Instances, Arch, of Surg., 1928, xvii, no. 3, 493-506; The Minuter Anatomy of Attrition Lesions, Jour. Bone and Joint Surg., xiii, 841, 1931.
WARNER, F., Injury to Tendons and Joints, Intn. J. Surg., N. Y., 1918, xxxi, 196. WILSON, P. D., Complete Rupture of Supraspinatus Muscle. J. A. M. A., 1931, 483.

So far as I know there is at present no literature on the subject of this chapter which deserves serious study, except that comprised in the above references. I have no doubt that Doctor Meyer and I refer to the same lesions which were studied by Doctor Akerson and can be found by any one who wishes to look for them in similar material. Doctor Meyer's attention has been focused on the long head of the biceps; mine has been focused on the supraspinatus. Probably both of us are in a measure right, and in great measure wrong, but at least we have opened up the field for future students who wish to relieve persons incapacitated by lesions in this region of the body.

NON-OPERATIVE TREATMENT OF RUPTURE OF THE SUPRASPINATUS
TENDON

I think every general surgeon who could see one of the complete cases at operation would agree that no form of physiotherapy could influence beneficially one of these lesions, except in a subjective way. The subjective symptoms might possibly be alleviated to a certain degree by massage or by diathermy, but as a matter of fact, nearly all patients say that these agents are of little help. From the very nature of the lesion, manipulations and forced exercises can do no good and might do some harm. If it is determined that a patient is not to have an operation, there are two rational plans of treatment: (1) Fixation in elevation to relax the tendon, improve the blood supply and approximate the torn ends; (2) Gentle "stooping exercises" to help nature smooth off the irregular surface of the lesion. This is merely an aid to nature's own partially successful method.
Fixation in elevation, to be effective, would necessarily have to be instituted soon after the injury, and would require at least three weeks. It would be useless in old cases, yet even in the old cases one can see, when the bursa is open on the operating table, that there is a tendency toward approximation of the torn ends of the tendon as the arm is abducted. Of course, in these old cases the proximal end is retracted and cicatrized in its retracted position. Even prolonged fixation in such cases could accomplish little except in possibly diminishing the size of the defect. This tendency to approximation observed at operation in old cases, when the arm is abducted, shows that it is probable that if the rupture were small, this treatment, if immediately instituted, would be worth while. If I were the patient, I would prefer incision and suture to this problematical and uncomfortable, even if reasonable, plan.

The "stooping exercise" method is founded on the pathologic findings described in Chapter III. Clearly nature has developed this method of absorption of the tuberosity to restore function after this accident, for as these patients, after a year or two of misery, improve somewhat, it is fairly clear that this method of smoothing off the eminence and sulcus which caused the jog is the best she can do. Nature's plan is the combination of this slow smoothing-off of the tuberosity and meanwhile increasing the supply of fluid, which, as the lower portion of the capsule becomes tense in any action, is forced up to the site of friction.
The idea of the stooping exercises is to begin this process with the weight taken off the arm so that the irregular surface is not forced up under the acromion by muscular tension. If the patient stands and elevates the arm, the very point which is sore becomes the fulcrum on the acromion for the deltoid to exert its power. When the patient stoops with the arm relaxed, the scapula can be abducted on the humerus without the need of the fulcrum either on the glenoid or acromion. Gravity takes the place of the power of the deltoid.
It is clear that until a patient can swing his arms freely in the stooping position without pain, he is not ready to use the arm when standing.
To patients who refuse operation I explain these mechanics and impress on them what I have said in the last paragraph. I also try to teach them to sleep with the arm abducted, with the hand behind the head. Palliatives in the form of drugs or physiotherapy are not often required in these cases. The pain is always bearable, if they do not increase it with work or exercise which make a fulcrum of the sore point. I think I can accomplish more with these patients by explanation of the mechanics of their trouble than I can with any palliative measures. Show a workman the normal function of the joint, the necessity of the supraspinatus to maintain the fulcrum on the glenoid, the tendency, without it, for the fulcrum to ride on the sore spot where it touches the acromion, the changed action of the weight of the arm when stooping or lying with the hand behind the head, and, as a rule, he will get your drift. He knows about levers and weights. When he understands his condition, he will get rid of the fear element and realize that though his arm is impaired, he has not really lost the use of it. He has learned that he has lost the use of certain motions unless he is willing to stand the pain. This education has more therapeutic value than drugs or electrical treatment. Massage, of course, may do good in stimulating the nutrition of the tissues, but it cannot unite the tendon.

It has seemed to me best to present my operations on the shoulder tabulated in this way, rather than to give complete case histories of each patient. Many of the cases have been used in the text to illustrate different points, sometimes only the occupation being used and perhaps in another place the preoperative diagnosis given to compare with the operative findings, etc. Under the comments at the right of this table the page numbers are given when the individual cases are referred to in the text. Should any one desire to do so, he could, by referring to these pages, make up brief individual case histories. As a rule, the cases which have been spoken of in the text are those in which the result was poor or fair. Those which I have considered good, lack detail. On the whole, compared with the results of the cases in the rest of the table, the outcome in the cases of complete rupture has been relatively poor. The reader is urged to bear in mind that in all the cases on which I have operated my attempts were more or less delayed, for only cases 18, 27, 42, 49,106,115,127, 128, 129 and 135 were done within two months of the accident. In cases 49 and 115 suture was impossible, and cases 27 and 42 could not be traced over a period of years, although the immediate results were good. I probably should not have written this book at all had the results all been good, for one of my chief objects is to urge prompt diagnosis and immediate operation.
Some of the cases marked "poor" actually did obtain some improvement. For instance, Case 88 worked over a year after the operation and then had another accident, so that his total compensation was the maximum allowed by law. Case 89 has worked steadily as a watchman after he had made a settlement with the insurer. I feel that I have certainly not exaggerated the benefits of surgery in these delayed cases, for I am sure something was accomplished in all of them, even in cases such as number 115 where no suture was attempted, for at least a definite diagnosis was made, as a basis for a settlement. If, as I hope, eventually the profession comes to realize the importance and frequency of this lesion, and the laboring class becomes educated to take it seriously, exploration through a small incision will be the rule in doubtful cases. When the insurance companies become interested in the problem, I shall be glad to cooperate in making a more extensive survey of the economic side than that which is presented on page 176.

REFERENCE

Wilson and Fowler have modified my operative methods. References to their articles will be found at the end of Chapter V.

OPERATIVE TREATMENT OF RUPTURE OF THE SUPRASPINATUS
TENDON

The best time to operate would be immediately after the injury. When in doubt of the diagnosis, exploratory incision of the bursa should be done. The technique of this incision is the same as that which has just been described for use in cases of calcified deposits. Practically the whole base of the bursa can be inspected through this incision and the exact extent of the rupture determined. The incision is then enlarged inward or outward at either end for a half-inch, depending on the direction of the tear. On account of the herringbone structure of the deltoid it makes little difference whether or not the enlargement of the incision is at an angle with the first one. A good exposure can be obtained with an incision one and one- half to two inches in length. Do not enlarge upward farther than the coraco-acromial ligament.
Assuming that the operation is done soon after the accident, it would seem that no special directions would be needed. The surgeon knowing the normal relations would restore them by appropriate sutures and close the wound in his favorite manner. It seems to me that this immediate operation would be very easy, but I have not been able to operate on one of these cases in an early stage.
In general the operation has two main objects: the repair of the tendon to give power to the arm, and the making of a frictionless lower bursal surface to relieve inflammation and pain. Perhaps the latter is more important, for even a powerful arm, if painful, is not as useful as an arm which is rather weak in the power of abduction but not painful. It is important to keep these two objects in mind, for although in some cases both can be attained, it is sometimes necessary to take a choice between them, because the tissues may be so damaged and retracted that good approximation is impossible. In such a case we may wish to discard all hope of restoring power and devote our whole effort to trying to allay friction. For instance, the tuberosity could be excised wherever it is free from tendinous attachment, and hence is useless. This might diminish the pain by removing the eminence.
One must not feel too discouraged, however, about his repair work, for on several occasions I have opened a bursa a second time and found a smooth base and no visible sign of my suture, which, at the end of my previous operation, had appeared rough and clumsy with the ends of the tendons not even approximated but held "a distance." (See p. 245.) Even in a certain number of the delayed cases which I have operated upon, there has been little difficulty in making a satisfactory suture aiming for both objectives, but in other cases, there was little or no hope of making a smooth, even suture which would leave no rough eminence or sulcus. The latter is particularly likely to be the case where the tendon is evulsed from the tuberosity, leaving no stub to hold the stitches. In a few cases the retraction was so great that no suture could be attempted at all.

Special Points and Special Difficulties

I have found that in the old cases on which I have operated, it is seldom easy, often difficult and sometimes impossible to repair the tendon. It seems best to list the difficulties and then to discuss each.

Position on table
Mobilizing the tendons
The long head of the biceps.
Drilling the tuberosity or removing it.
Suturing the rent.
Formation of a new sulcus.
Frictionless surface
Material of suture.
Shape of needles.
Closure of bursa. Disposal of fluid.
Postoperative treatment.
1. The arrangement of the position of the patient on the table to permit proper mobilization of the arm during the operation, is an important factor in technique. The point of the shouldeT is a difficult region on which to work, for both the surgeon and the assistants. It slinks away and the patient's head and neck seem to wish to take its place. (See Fig. 50.) I should like to stress the importance of so placing a heavy sand bag under the shoulder and another under the corresponding hip that the patient is half turned on his side, while the head, with the face turned away, is at a lower level than the point of the shoulder. The shoulder should be slightly over the edge of the table toward the operator, so that the arm may be allowed to hang down in a position of dorsal flexion when desired. This position throws the distal portion of the supraspinatus tendon forward for the maximum distance from under the acromion.
The operator and assistant stand on the same side of the table, while the anaesthetist and nurse with the instrument table are on the other side. A second assistant is welcome, and often almost necessary, because the first assistant must at times give his entire attention to holding the arm and the nurse may be occupied with retractors. Much of the facility with which the operation is conducted depends on the assistant who holds the arm, for his ability to rotate just at the right time will enable the operator to put his needle at just the right point in the somewhat small field. Since the lips of the incision do not move appreciably, the operative field is really controlled by the assistant as he rotates the humerus, bringing this side of the rent or that into a position which the operator desires.
The maneuver already described, of letting air into the joint and bursa, is often a great help. The position in which to place the sutures is best illustrated by a diagram. (Fig. 52.) While this is the ideal, it is seldom possible to carry it out exactly, for too often the retracted, stiffened tissues cannot be worked into nice apposition.

FIGURE 52. METHODS OF PLACING SUTURES
a illustrates the writer's suggestion that the biceps tendon may be sutured to the supraspinatus in some cases when the former has been already torn from the edge of the glenoid, b, c, and d suggest the method of placing the sutures in the ruptured supraspinatus and in the tuberosity. The ideal is c, for in this case the lines of incision have been carried up on each side of the supraspinatus to mobilize it. d illustrates Dr. Wilson's method of cutting a slot to receive the supraspinatus tendon, e and / offer a suggestion for operation in a case where the short rotators have been entirely evulsed from the head of the humerus. Fascia lata might be passed through a drill hole and through a slot over the tuberosity to form an anchorage for the tendons.

2. Mobilizing the tendons. When one considers that each one of the short rotators is separated from the other by a definite bony partition through most of its extent, and it is only the last three-quarter inch which is welded with the others into the terminal conjoined tendon or cuff (Fig. 10), it would seem easy to isolate any one tendon so that the more or less elastic muscle belly could be stretched enough to bring the tendon down again to the tuberosity and suture it there. However, if you try this on a normal shoulder at autopsy, you will find it is not easy, and when you try it on a ruptured tendon in which operation has been delayed for many months, you will find it impossible.
In the first place, you are cramped for room by the acromion and coraco-acromial ligament so that you cannot see the muscle bellies even in the normal shoulder. In the second place, if you dissect back more than an inch on either the supraspinatus or infraspinatus, you run the risk of wounding the suprascapular nerve, and if you do, you may lose your power in those muscles forever.
In order to get at these tendons more effectively, I used to use the "sabre-cut incision," which gave a perfect exposure and every possible opportunity. (Plate VIII.) Even then the mobilization was only a little more satisfactory, so I have given up this incision. Practice has given me a little more confidence, and I believe now I can do almost as well through the simple routine incision. Dr. William Rogers has suggested removing the deltoid attachment with the periosteum from the acromion and suturing them back at the end of the operation." This seems rational, but I have not tried it and do not know whether one may rely on having the deltoid origin anchor again satisfactorily. I have sometimes thought that a subcutaneous osteotomy of the base of the acromion might mobilize it enough even without division of the coraco-acromial and acromioclavicular ligaments to allow easy access. The trouble with any incision which mobilizes the acromion is the long period which one must wait for union to occur before moving the joint. I am inclined at present to do all the mobilizing I can through the routine incision, and I find that I am constantly improving in my ability to do this.
It is probably best to remove the falciform edge of new tissue and to refresh the edges of the tendon itself. I attribute some of my imperfect results to my failure to do this. One learns by experience to put the suture back of the falciform edge, for the latter has no strength and the stitch at once tears out. One is tempted not to remove the edge because it is obviously difficult to close the rent without using it, and it seems folly not to save all the tissue one can. It might be contended that the falciform edge may have more tendency to unite than the real tendon substance, which has very little blood supply, so that perhaps I may be wrong in recommending the removal of this new tissue with which nature is attempting to repair the damage. The method of closure which seems to me the best is illustrated in Fig. 52.

3. The long head of the biceps. The problems connected with how to deal with the long head of the biceps when it is found exposed, owing to the retraction of the ruptured tendons, are not a few. I can only discuss them and do not pretend to solve them. Although I am not in agreement with some of Meyers' views on the importance of the role of the biceps tendon in shoulder injuries, I feel that his observations ought to be known to every one who operates on these cases. To my mind, the rupture of the supraspinatus is the primary and important lesion which uncovers the biceps tendon, makes it slip a little at the top of the bicipital groove and to tend to be caught between the tuberosity and the acromion. At any rate, one often finds it a conspicuous, pink, inflamed-looking, swollen band lying across the j oint cartilage at the bottom of the rent. ( Plate VIII.) The portions exposed in the rent look inflamed; those covered by the remaining intact part of the capsule are white, glistening and normal. It is pretty obvious that our suture should cover up the biceps tendon without interfering with it otherwise. It usually lies just under the inner edge of the rent, but if any of the subscapularis fibers are involved, it lies entirely exposed. Sometimes it is not found at all, for it has been torn away from its glenoid attachment and has retracted down the bicipital groove. Sometimes it is split in two, longitudinally. Often it is flattened and frayed at the edges. Varying proportions of it may be ruptured. It may be composed of indefinitely separated longitudinal strands, some of which have become welded into the capsule. It may have little, rice-like tags on its edge. However, almost always the parts which do not become exposed in the gap left by the supraspinatus are normal in appearance.
When it has ruptured from the glenoid, it may be held high in the groove by a few remaining bands, and we can capture it and pull it up. What shall we do with it? We might try to suture it back on the glenoid, or rather on the fibrocartilage which surrounds the glenoid. Or we might attach it to the proximal portion of the supraspinatus, or to the capsule, or anchor it in the groove, or excise a part of it and use it to repair the supraspinatus. We might even take a relatively normal biceps tendon, clip its attachment off the glenoid, anchor the tendon in the groove, and then use the redundant portion to fill the gap in the supraspinatus. (Fig. 52a.) This would give the biceps muscle a fixed origin, and we would at the same time obtain a firm attachment for our supraspinatus. We should only have lost whatever function the long head of the biceps has from having its attachment on the glenoid rather than on the humeral head; i.e., the outer head of the biceps would no longer be of use in motions of the humerus on the scapula, but could still apply its power in flexing the forearm on the humerus. What then is this function which we should lose so far as scapulo-humeral motion is concerned?
The function of the biceps muscle is fourfold. First, it is a flexor of the forearm on the humerus. Second, it is one of the flexors (or extensors?) of the whole arm on the scapula; in a sense, therefore, it is a weak abductor or elevator of the arm. Third, the external insertion on the tubercle of the radius enables it to act as a supinator of the radius and hand. Fourth, the long head of the biceps passing through the intertubercular groove helps to retain the head of the bone on the glenoid, and stabilizes the head in the various degrees of rotation, as the arm is elevated. This function is well illustrated by the findings in two of my cases, which at operation showed that except for the subscapularis, the whole of the capsule with the tendons of the supraspinatus, infraspinatus and teres minor had been evulsed, yet the head did not tend to dislocate; apparently it was held in the joint'by the long head of the biceps, and by that only. We lose nothing in the first function, little in the second, none in the third and but a problematic amount in the fourth, by using it in the way suggested in Fig. 52a.
So far as the action of the shoulder joint is concerned, particularly with reference to the functions of flexion of the arm on the scapula and of the forearm on the humerus, the origin of the short head of the biceps from the coracoid process is more important than that of the long head from the edge of the glenoid. The coracoid origin is sufficient to give power in these motions; the long head is chiefly a stabilizer and one of secondary use so far as the application of power is concerned. For instance, in cases in which the long head of the biceps is ruptured and no other lesion has occurred, the function of the shoulder remains almost normal.
The short rotators are sufficient to maintain the fulcrum on the glenoid in most positions of the arm, but where these short rotators are damaged, I am confident that the long head serves a very useful purpose in guiding the head of the humerus and restraining it from forging upward and getting its fulcrum on the acromion. I therefore regard it as important to keep the long head of the biceps intact if possible.
I have notes that in some of my operated cases, the biceps was torn away from its glenoid attachment. In such cases in future I intend to search for the distal end of the tendon and to anchor it with stitches in the bicipital groove, and also to the supraspinatus tendon, thus abandoning any idea of retaining its stabilizing function and being content with retaining its power as a flexor of the forearm. At present I see no good mechanical way of re-attaching it to the glenoid so as to make it function in guiding the head of the humerus as the latter is abducted. One is apt to think of the long head of the biceps moving up and down in the intertubercular groove, but this is not what actually happens. The humerus moves up and down on the tendon; it is not the tendon which moves through the groove. (See Fig. 52.) On the whole, I should say that if the operator finds that the biceps is so damaged that he thinks it will not in future form a smooth cord on which the humerus can ride up and down, he had better use it, as described above, to replace the lost substance in the supraspinatus.

4. What shall we do if we find there is no stub of supraspinatus tendon left on the tuberosity to which we may suture the proximal portion? In long-standing cases we find a tuberosity completely bare of tendinous substance, and perhaps somewhat eroded. Since this tuberosity is useless unless we can suture the tendon to it, it might as well be removed. I have not hitherto excised the tuberosity in cases in which I could not suture, but it might be well to do so. Such an excision would make the surface which must ride under the acromion less apt to cause friction. Nature does exactly this by causing recession of the tuberosity. As a rule I have drilled two holes in the tuberosity with an ordinary shoemaker's awl, and passed a heavy silk suture through these holes and the tendon so as to draw the tendon as nearly as possible to the facet of insertion of the supraspinatus. This can usually be accomplished, but occasionally the supraspinatus is so retracted that I cannot quite draw it down to the bone.
I have on several occasions made a sort of plastic so that I covered the suture with part of the roof of the bursa, believing that the repair of the tendon comes not from the tendon itself, but from the adj acent synovial membrane which is much richer in vascular supply.

5. Another operative problem is how to repair the rent. As explained in the chapter on pathology, these rents are in a general way triangular, with the base on the humerus and the apex retracted, the apex being usually the center of the supraspinatus, and the sides the lateral expansions which are united to the neighboring tendons. The ideal way to close would be to bring the center of the apex to the center of the base, but if the retraction is great and the base is small, the triangle is so prolonged upwards that one is tempted to close the gap from side to side until very near the base, and then to make
the last suture a triangular stitch. This method is easier, but it does not bring back the normal relations. However, it is a feasible method to use where there is much retraction. The exact way in which to put the sutures does not seem important, that is, whether they are mattress sutures or interrupted or continuous.

6. Formation of a new sulcus. If the reader will refer to Chapter IV, and especially to Plate VI, Figs. 3-4, and their legends concerning the remarkably effective method which nature has devised to attach the supraspinatus tendon to its facet, he will feel great doubt as to whether the surgeon will ever be able to imitate it with any degree of success. We need much study and experimental work before we can rely on being able to create a line of living cement such as the "blue line," with its pores for the finger-like processes. At present, from what we know of histology, it seems doubtful
whether in adult life such a method of union of tendon to bone can ever be achieved. However, we know that tendon can form a fairly firm cicatricial attachment to raw bone. What is the best practical way to secure this ?

If it were possible, we should wish to have the new tendon form on the raw surfaces of the sulcus and of the tuberosity down to the actual edge of the joint cartilage. When I drill the tuberosity I try to drill it as far as the cartilage edge, and I usually erode the bone of the sulcus with the point of a knife or curette, so that the tendon will have a little better chance to become attached by granulation. Dr. Philip Wilson has improved on my operation by cutting a slot around the cartilage edge and drilling through the base of the tuberosity. He then passes a slip of fascia lata through the drill holes to be attached above to the supraspinatus. He thus makes a more ideal suture, so that the tendon fills the entire sulcus and thus gains a firm hold on the tuberosity. It remains to be seen whether nature will tolerate such attachments indefinitely.

7. A frictionless surface for the base of the bursa is a most important point. Dr. Wilson's method has this advantage. It would be repetition to discuss this further, but I should like to repeat that even in those cases where the suture at the end of the operation has seemed rough, it may nevertheless be so changed by the healing process that a surface is produced which at a later operation appears smooth and normal.

8. I use silk sutures because I want them to endure long enough for new, strong, scar tissue or tendinous substance to form over them. I use a fairly heavy pedicle silk for the main suture, which passes through the holes in the tuberosity or between the proximal and distal portions of the tendon. I have on four occasions reopened the bursa later to remove these silk stitches because the patient complained of pain. The following are the findings in these four cases:

CASE 18
Mr. R. H. S. Age 60. M. G. H. No. 181765 E. S., Mar. 26, 1912. A typical case of complete rupture of the supraspinatus, one and one-quarter inches wide. Although much retracted, the tendon was caught and sutured in place with three mattress sutures. The functional result was good, but he continued to have more or less pain, apparently from the formation of a considerable amount of dense inflammatory tissue about the site of suture. On Feb. 13,1913, under novocaine, the bursa was again opened and the tendon was found not only completely repaired, but there was a large amount of dense hypertrophic, callous-like tissue about the sutures. This mass impinged on the acromion in abduction; most of it was removed with the scissors and a new opening made through the supraspinatus into the joint, so that some of the synovial fluid could flow into the bursa and lubricate it. The result of this operation has been satisfactory. Twelve years later, on June 9, 1925, he called to see me because of a slight injury to his left shoulder. The right, on which I had operated, had given him no trouble in the intervening years, although he had worked steadily as a coachman.

CASE 29
Mr. M. M. W. Age 39. M. G. H. No. 184216 W. S., Aug. 5, 1912. A clear case of badly ruptured supraspinatus tendon. The tendon was sutured with heavy silk and function was restored. During the following year he had much pain on use of the arm in his work as a laborer. The bursa was again explored and the silk sutures and some of the chronic inflammatory tissues lying about them were removed. I also made a new opening into the true joint to permit the fluid to flow into the bursa. This was followed by improvement but not by complete relief. No late report. Note that entire repair of the rupture had taken place.

CASE 88
Mr. T. M. Age 50+. Operated on at Faulkner Hospital, July 24, 1926, six months after his injury. The supraspinatus, infraspinatus and part of the subscapularis were found to be torn away, exposing the biceps tendon, which was greatly inflamed. There was much fluid in the joint. A very unsatisfactory suture was made, and the tuberosity had to be drilled. The arm was put up in abduction. Mild sepsis occurred and there was much fluid drainage, so that the wound took several weeks to heal. Some of the deep sutures were taken out. In spite of this the result at first was good, and he returned to his work after five months. He worked for a year and three months, although in some pain, and then had another slight injury. On July 2, 1928,1 again explored the bursa and found that most of the sutures had pulled away, leaving the condition practically as bad as at the first operation. This was as bad a result as I have ever had. The patient was for a time benefited, but in the end gained nothing by the operation, for I did not attempt a second suture.

CASE 112
Mr. A. C. Age 62. Operated on at the Trumbull Hospital on June 11, 1928, three months after his injury. A typical complete rupture of the supraspinatus was found and satisfactorily sutured. The immediate result appeared to be good. However, the patient would not go to work again, complained bitterly of pain on use of the arm and became very neurasthenic. On Feb. 7, 1929, I again explored the bursa, thinking that if I took out the deep sutures some of the irritation might be relieved. My notes say:
"I operated on him yesterday under novocaine ansesthesia. Dr. B. E. Wood was present and Dr. Stevenson assisted. Incision was made just inside the old scar and the bursa was opened. It was clearly shown that the former suture had been effective in restoring the insertion of the tendon. Moreover, the floor of the bursa was smooth and shiny, and there did not appear to be any cause for friction over the site of the suture. One heavy silk suture could be seen just below the transparent synovial lining of the base of the bursa; this was easily pulled out, but the other two sutures were buried deeply in the new-formed tendon and were found and removed with difficulty, as I was anxious not to weaken the tendon in so doing. In two of the sutures the knots were apparently untied; in one the knot was still present, but almost untied. At first I thought that the knots of the two untied ones had been left behind, but on reflection I think it is more reasonable to suppose that they had become untied as the tissues increased in amount and grew into the knots, which were cut very short. Yet it is possible that they broke off and remained in, although the total amount of silk in the untied ones appears greater than in the tied one by more than double. At any rate, very little silk could have been left behind.
"I did not feel satisfied that the silk was causing any trouble, for there appeared to be no inflammation about it, and the tender point of which the patient complained was nearly a half-inch away from the sutures, on the edge of the greater tuberosity close to the bicipital groove. That there was some inflammation at this point was made clear by finding a little crumbly, soft, cheesy tissue close to the synovial sheath of the biceps tendon, which in certain positions bulged slightly. The repair of the tendon was weakest at this point, and I fear that my search for the sutures weakened it still more, although not to an extent sufficient to interfere with function, and recompensed by the finding of this suspicious tissue. Two tiny bits of this tissue were saved for pathologic examination. (Plate V, Fig. 5.) The patient still claimed to be unable to work in January, 1931.
Since three out of four cases, which were explored a year or so after the first operation, showed not only firm tendons but hyper-trophied ones, it seems to me that it is proved that suture may be effective. In each case I was surprised to see how well nature had restored the even convexity of the floors of the bursae, which at the completions of the operations had been quite irregular and rough at the suture lines. All four cases, if operated on immediately after their injuries, might have had excellent results; as it was, although two of the four cases had good results, little was gained by the other two patients, unless they may take some satisfaction as demonstrators of the fact that these tendons even when badly broken may be repaired.

9. The shape of the needles is dictated by the shape of the field of operation and by the fact that a tremendous strain is put on them. They must be either fully curved or half curved, not over a half-inch long and with very strong shank and eye. One has to
work between the acromion and the tuberosity, where there is very little room, so that even a curved needle such as is used in ordinary operations is too large to be turned about in this space.

10. Shall we close the roof of the bursa or shall we merely close the muscle, leaving the roof of the bursa free to allow the synovial secretions to seep into the areolar tissue?
As I have previously stated, there is usually in these cases a considerable synovitis with a large amount of fluid. If the bursa is closed tight, this fluid forms under tension and causes pain. Closure also tends to keep blood in the bursa which would otherwise be washed out by the fluid itself. I prefer the idea of leaving the roof of the bursa unsutured to allow this fluid to escape, but I am not prepared to say positively that it is not better to suture the bursa and allow free motion after the operation to pump fluid out between the stitches. The fact is, in cases where there is much fluid (and these cases are usually those that have continued to work in spite of the friction and pain), the fluid seeps into the soft tissues to an extent which causes marked swelling and sometimes induces an edema and suggestion of sepsis. This used to be a frequent complication when I put the arm in elevation, permitting the lower side of the capsule to be held tense and therefore driving the fluid up toward the wound. Now that I treat them without restraint, I do not have this complication

11. The postoperative treatment. I find that my tendency has been, as the years go by, to allow more motion and to allow it sooner. I usually pad the axilla with a small pillow and then let the arm lie on it in a position a little more abducted than that in which the arm rests in a sling, contriving as best I can to keep the hand away from the front of the abdomen, because the tendency of the patient after these operations is to get the arm in a strongly internally rotated position, and therefore the recovery of the power of external rotation is slow. After the first night is over, I remove the dressing and let the patient put the arm in any comfortable position which he can find. Each day I exercise it in a way which is difficult to describe, but which is a matter of personal touch. The general purpose of the exercises is to let the patient bend his body from the hips with the arm relaxed, as described under the stooping exercises (Fig. 47). As in treating fractures near joints, I try to make the patient do as much active and passive motion of the arm as I believe I can without displacing the fragments. It is impossible to lay down more definite directions, but I may say that by the end of the first week I expect the patient to be able to bend his body at the hips to a right angle, and to let both the injured and well arm fall in a relaxed position at right angles to his body. By twisting his body from side to side so as to make one shoulder higher than the other, alternately, he can also move the joint without contracting the shoulder muscles. During the second week he is encouraged to swing the arms a little in both directions in this stooping position. The wound should be soundly and completely healed and the patient discharged from the hospital in from ten days to two weeks. After that he is encouraged to take the stooping exercises.
If the patient is cooperative and understands the mechanics of the operation and can use common sense in taking his exercises, he gets on fairly smoothly, but there is pain of an annoying although not of a serious degree, not only for weeks but for months. I do not think this would be the case where the operation was done immediately after the accident. In convalescence it is a good rule to restrain the patient from exercising his arm in the erect position until he has learned to abduct it freely and strongly in the stooping position. (See Fig. 47.) In long-standing cases the nerves of the region have already become sensitized and are slow in returning to a normal condition. Much of this postoperative soreness in the delayed cases is due to the sensitiveness and synovitis acquired between the date of the injury and that of the operation.

THE SABRE-CUT INCISION

Reprinted from the Bos. Med. & Surg. Jour., Mar. 10, 1927. It does not differ greatly from Kocher's posterior incision, but is more appropriate after a preliminary exploratory cut anterior to the joint.

FIGURE 1

"Sabre-cut" seemed an appropriate name for this incision, for it might well be made by the downward cut of a sabre on top of the shoulder. An incision is made through the acromio-clavicular joint and continued with a saw through the base of the acromion. The anterior point of the incision would be continuous with a previous routine bursal exploratory incision. When the acromion has been sawed through, an epulet of tissue, consisting of the deltoid muscle and the acromion process from which it arises, is formed to be pulled outward and downward. This step is accomplished' with ease, for it is only held by a little areolar tissue and a few fibers of the trapezius attached to the upper margin of the detached portion of the acromion. The upper posterior fibers of the deltoid must be separated a little to gain mobility. In sawing the base of the acromion one must bear in mind the suprascapular nerve which supplies the supra- and infra-spinatus muscles and lies between them, a little below the saw-cut. It is deep enough to be out of the way of the saw but not of gross carelessness.

FIGURE 2

The second diagram shows the structures exposed when this epulet is pulled downward and outward. Even without dissection one can identify the subscapularis, supraspinatus and infraspinatus as they emerge to join together their tendinous expansions beneath the base of the bursa. To one unfamiliar with this dissection the smooth convex surface of this base appears to be the articular surface of the humerus. The subacromial and subcoracoid or coraco-humeral bursse are nicely shown. As explained in previous papers, they are often intercommunicating and are always functionally one bursa although frequently, as in this instance, separated by one of the diaphanous nictitating folds. Notice the separated portion of the acromion and see how easily it will fit back into place.

FIGURE 3

The third diagram is identical with the last except that the supraspinatus and capsule have been cut across into the true joint and the ends of the supraspinatus depicted as retracted. The stub of the tendon is still attached to the tuberosity beneath the base of the bursa, while the muscular belly is retracting into the supraspinatus fossa. The glenoid and the articular surface of the humerus are exposed, with the long head of the biceps arising from the superior edge of the glenoid lying across the cartilaginous surface of the head of the humerus.
This is exactly the condition I have found at operation again and again in the living, except that there is seldom so much of a stub of tendon still attached to the tuberosity. Quite frequently it is entirely evulsed from the latter, requiring drilling of the tuberosity to resuture it. I have always found the base of the bursa to be torn across with the tendon. The point of least resistance appears to be about the subbursal portion of the tendon. In fact the tendon itself is very short, the muscle fibers beginning within a half-inch of the attachment.
In the long-standing cases on which I have operated the biceps tendon is found inflamed, swollen and bright pink in color, forming a striking contrast with the white articular surface of the humerus. Sometimes it is apparently absent entirely, having been evulsed and then retracted downward into its sheath.
To close this incision the parts are sutured back into place in the reverse order of these diagrams. It is probably safer to wire the acromion process, although catgut in the soft parts holds it well. I do not advise attempting to close the bursa even in the exploratory operation; a stitch or two in the muscle holds the edges in sufficient apposition and excess fluid may drain into the areolar tissue.

The pendulum will probably swing in future toward postoperative treatment in abduction and back again to adduction. Dr. Wilson now uses abduction after the sabre-cut incision and complete repair of the insertion into the bone by the use of fascia lata. It is possible that this method has the advantage of creating a larger gap between the head of the humerus and the acromion and the coraco-acromial ligament, because reunion of the mobilized acromion process would take place at a higher level, since it is pressed upward by the abducted humerus.

The Sabre-Cut Incision. Although I have personally given up the sabre-cut incision for cases of rupture of the supraspinatus, it is still used by others, especially by Dr. Wilson. It gives a splendid opportunity to repair the tendon or any other structure in the shoulder joint, but it is really a major operation, while the one I use is a minor one. The main reasons why I seldom use it are three. In the first place, I have learned to work through the routine incision in such a way that I can do the operation without cutting any ligaments or bone. This improvement has come about not only from doing the operation in dorsal flexion, but by using the method of rotating the humerus so that each desired point is placed in the middle of the small incision at the appropriate moment for a stitch. One assistant has to manipulate the arm in unison with the wishes of the surgeon. In the second place, I have found that after division and suture the acromio-clavicular joint may remain somewhat unstable.
A third reason is less technical and more in the domain of human nature. In Industrial Surgery there is not a frank understanding between surgeon and patient as in their ordinary professional relation. The patient is apt to have the element of compensation too strongly in mind, as compared to a cooperative tendency to make the best of the surgeon's attempt to better an injured limb, although both know it may never again be "as good as new." The extent of the sabre-cut incision exaggerates in the patient's mind the degree of the injury and the scar would certainly be impressive to a commission or jury.

Frontispiece

RUPTURE OF THE SUPRASPINATUS TENDON

FRONTISPIECE

THANKS to Dr. F. B. Mallory I was able to obtain the autopsy specimen of a case of a completely ruptured supraspinatus, from which this painting was made by Mr. Aitkin.
The skin and subcutaneous tissues were removed; then the fibers of the deltoid separated and held apart by retractors as in the usual routine incision. The diamond-shaped area between the two retractors is the floor of a rather large bursa. Nearly the whole right half of this floor retains its normal, smooth, whitish appearance, but in the left-hand portion of the base or floor is a roughly triangular area which represents the gap formed by the retracted supraspinatus tendon. At the right of this triangular gap, the long head of the biceps appears just beneath the falciform edge of the portion of the musculo-tendi-nous cuff formed by the subscapularis. In the left angle of the triangular area is seen a falciform edge formed by some of the superficial fibers of the infraspinatus. Just superior to this are a few vertical fibers of the deep posterior part of the supraspinatus which have not been evulsed. This was a. very thin, tenuous bit of tissue. The remaining central portion is roughly divided into three parts. The upper, bluish third is the exposed cartilage of the true joint. On its shiny surface near the very edge of the true joint cartilage, we see the high light of the reflection of the window. The lower third of this central space shows a typical "volcano" on the tip of the tuberosity, such as those depicted in Plate V, Figure 1, and in Figures 36 and 40. Between this "volcano" and the cartilage, and also occupying about one-third of the central area and bounded on the right by the margin of the biceps tendon, and on the left by the film-like, untorn edges of the infraspinatus and supraspinatus, we see a red, granulation-like irregular surface. This is the pathologically changed facet of insertion of the supraspinatus tendon and of a portion of that of the infraspinatus from which the tendons have been torn. Compare Figure 40, which is the Rontgen picture of the same specimen.
It must be understood that this picture represents the result of an injury experienced, in all probability, many years before; the tuberosity is in the recessing stage, and the edges of the torn tendons have become smooth by becoming falciform. The distal stub of the supraspinatus tendon, which was probably present in the first few months after the injury, being functionless, has disappeared. The proximal end of the tendon has retracted upward and could only be demonstrated if the newly formed falciform edge of the whole rent were removed. Even in this old case it could be isolated, pulled down and attached to the tuberosity, although with difficulty. One can readily imagine the pain which this patient endured during the first few years after his injury from the mere mechanical irritation from the tuberosity striking on the edge of the acromion during efforts at elevation of the arm, although nature has gradually nearly smoothed off the former prominent tuberosity, and, by partial healing of the edges of the torn structures, has made a new base of approximately spherical surface to pass under the acromion. The writer's operative efforts have mostly been concerned with relieving the results of such conditions. When the general practitioner has learned to recognize the symptoms of these lesions within a few days of their occurrence, suture of such torn tendons will be easily and successfully accomplished.

==References==
<references />

File:Clavicular reconstruction utilizing iliac crest autograft.mov

2023-02-17T06:42:43Z

Alexandre.laedermann:

Clavicular reconstruction utilizing iliac crest autograft

File:Pseudarthrose clavicule.mov

2023-02-17T06:41:51Z

Alexandre.laedermann:

Clavicular reconstruction utilizing iliac crest autograft

Shoulder:Pathologies of the Clavicle

2023-02-17T06:36:46Z

Alexandre.laedermann: /* Clavicular nonunion */

==Clavicular fracture==

==Clavicular nonunion==

===Cure clavicular nonunion===

Shoulder:Pathologies of the Clavicle

2023-02-17T06:36:14Z

Alexandre.laedermann: Created page with "==Clavicular fracture== ==Claviculkar nonunion== ===Cure clavicular nonunion==="

==Clavicular fracture==

==Claviculkar nonunion==

===Cure clavicular nonunion===

Shoulder:Rotator Cuff Pathology/Rotator Cuff Tendinopathy

2022-07-12T09:46:43Z

Alexandre.laedermann:

=What would Codman have thought about this?=

The pathology of the subacromial bursa and...

CHAPTER III
THE PATHOLOGY OF THE SUBACROMIAL BURSA AND OF THE SUPRASPINATUS TENDON

I do not propose to review in detail the pathology of such general conditions as tuberculosis and syphilis, which, of course, may occur in this region, but merely to attempt to describe such pathologic changes as I have myself seen at operation in about two hundred explorations of the bursa on living patients. I have kept no record of the number of times I have studied the bursa in the cadaver, but I am sure I have opened over five hundred subacromial bursae, perhaps a thousand. It is significant that most of the pathological changes which I have noted had not been previously described, at least, so far as this particular bursa is concerned; and, per contra, the conventional pathologic conditions, such as suppurative inflammation, "rheumatic changes," syphilis, tuberculosis, new growths, etc., have seldom been observed by me. In the shoulder these lesions are relatively rare. On the other hand, lesions peculiar to this region are so often present that I have observed some of them in probably one-third of all the bursae I have examined in the dead, and, of course, in nearly all of the living cases. Fortunately, within the last few years, I have had the privilege of studying a much more systematic series of observations made by Dr. I. B. Akerson of the pathologic staff of the Harvard Medical School and pathologist to the Long Island Hospital of the Institutions Department of the City of Boston. We have published together in the Annals of Surgery for January, 1931, an article on "The Pathology Associated with Rupture of the Supraspinatus Tendon." The following quotation is from this paper:
"The present study has been made from autopsy material obtained at a large municipal hospital for chronic conditions. The patients sent to this hospital are people who are aged and down-and-out, and owing to the chronic character of their diseases, cannot be cared for at the other Boston hospitals. Dr. Akerson has made a study from one hundred specimens taken from fifty-two consecutive autopsies, and the percentage of cases showing evidence that the supraspinatus tendon had been ruptured at some time during the lives of these patients is high—39%. It may, therefore, be taken as a maximum, and it may be expected that pathologists performing routine autopsies in general hospitals for acute diseases, where the ages average considerably younger, will find a decidedly smaller percentage. We have made no attempt to correlate the past histories of these patients as to trauma or occupation with the autopsy findings. It would have been hardly possible under the circumstances.
"As a routine method of examination of these cases, we recommend the pathologist to employ the form of incision which we use in operations on the living. A cut is made on the anterior aspect of the shoulder joint from the acromio-clavicular articulation downward for about two inches. The fibers of the deltoid are separated and retracted and the roof of the bursa is incised between two pairs of forceps as one opens the peritoneum. When the lips of the wound are retracted, the surface of the floor of the bursa can be made to pass in review by rotating the humerus. The base of the normal bursa is smooth and spherical and almost as colorless as the cartilaginous surface of the head of the bone, though it lacks the bluish luster of cartilage. Most rents in the tendons of the short rotators usually appear in this base as communications directly into the joint and are readily visible. Occasionally the tendon is ruptured beneath the base of the bursa, which is left intact. In the ordinary autopsy it would take but a few minutes' extra time to examine both bursa. If lesions are found, the head of the bone with the insertions of the short rotators can be removed and studied. This was the method used by Dr. Akerson and his findings are good evidence that some sort of pathological process has been at work in the subacromial bursae of these patients during their lifetime. One must understand that these findings are those accumulated by each individual subject in many years. They are end-results, not acute lesions."
Dr. Akerson has continued his observations and at the present date (January, 1933) has recorded his findings on 200 shoulder joints in 102 subjects. I am greatly indebted to him for the opportunity of studying this material and the many microscopic sections he has made from it.

It seems best to list under five headings the pathologic conditions which may be found at autopsy or at operations on the living:
Changes occurring: (A) In the bursa itself; (B) In the musculotendinous cuff itself; (C) In the tuberosities; (D) Within the joint; (E) When the musculo-tendinous cuff has been ruptured so that a free communication has been established between the joint and the subacromial bursa.

*In four of these cases the tendon was not found (i.e., had retracted).

A. CHANGES WITHIN BURSA

Normally the incised roof of the bursa is as thin or thinner than the peritoneum,- but when acute or chronic inflammation is present it may be as thick as blotting paper. It is apt to be especially firm in old, chronic cases of complete rupture of the cuff, when fluid is present. Normally it is transparent and film-like. In acute cases it may be opaque and reddish in color. In chronic cases it is whitish and firm.

(1) The roof of the bursa seldom shows any pathology, but in cases of long-standing bursitis from complete rupture of the supra-spinatus, one frequently sees by X-ray, or one can palpate from within the bursa, hypertrophic changes at the acromial edge. Such changes may also be found in muscular laborers without symptoms.
(2) Calcified material in the bursa. Calcified deposits do not form in the bursa, but in the tendons. They may remain in the tendon substance for years, but the usual sequence of events is that they gradually work through to, or enlarge enough to reach, the base of the bursa, where they produce a mound-like swelling resembling a little boil, with a white center and a turgid zone about it. Up to this time there may have been no symptoms or very slight ones. Then some slight accident or unusual effort or even some customary action, as in turning over in bed, causes tension in the tendon resulting in rupture of a few superficial fibers, so that the little crater discharges into the bursa, where the calcified particles at once become diffused and may be readily delineated by the X-ray. An acute bursitis is produced; fluid is secreted with which the calcified particles mingle; fibrin appears and the specks of calcium become entangled in it. I have several times operated at this stage within a few days of the perforation and removed from the bursa a delicate film of fibrin shaped like a watch glass. Grossly the film is whitish in color and the microscope shows calcified particles scattered throughout its substance like stars in the sky.

FIGURE 34. PEFORATION INTO BURSA
Diagrammatic illustration of a calcified deposit bursting into the subacromial bursa. This should be compared with Fig. 4 in Plate II, which was taken from the case alluded to below.

Soon after the material is thus forced into the bursa and becomes enmeshed in fibrin, the particles are rapidly eliminated, probably by the prompt action of leucocytes. This is not the case while they still remain in the tendon. When the operation on these cases was within a few days of the perforation, I have been able to readily remove the film of fibrin almost intact, but in one case, on the sixth day after perforation, I found the film so firmly adherent that no attempt was made to remove it, because I should have had to use a curette and feared that I might destroy the membrane and get obstinate adhesions in its place. Through the kindness of Dr. H. F. R. Watts, who followed the patient with weekly X-ray pictures, I found that absorption of all the calcified material took place within three weeks of the perforation. The patient was then free from symptoms. I was encouraged in making this decision in this case by the fact that I had previously had a number of cases in which rapid disappearance of the particles had taken place without any operation. I now feel that perforation is nature's method of getting rid of this condition and that the average case, where perforation into the bursa has occurred, if left entirely to nature without any treatment, would follow this course. I think this fact accounts for the encouraging results sometimes obtained by all sorts of treatment, whether diathermy, foreign proteids, alpine lamp or surgery. This favorable course is not always the outcome, however. The inflammatory reaction may be too intense, and adhesions and consequent "frozen shoulder" result. It may be months before the adhesions loosen and full motion returns. Sometimes the whole deposit is not discharged into the bursa and the residue may give trouble later.
Under this heading we have discussed only the bursitis caused by the perforation of the calcareous material into the bursa. The study of the deposits themselves will be taken up again under Section B.
(3) Defects in the base of the bursa. These defects are nearly always at the same critical point, almost in the center of the base, where the red zones, calcified deposits and "straps" occur. The description of these defects properly belongs under the next division of our subject, for they consist of lesions of the tendon itself, whether partial or complete. Should the reader undertake to verify my statements by observing the conditions found by incising the bursa in a series of autopsies, he will be surprised at first by the variety of appearances which tears in the tendons may cause. After he has seen the inside of fifty or a hundred bursae, the secondary appearances due to the synovitis set up by the lesion will cease to distract him and his surprise will then consist in seeing how much alike the fundamental lesions are.
In other words, the superficial appearances of these defects vary with the extent of the rupture, the amount of joint cartilage exposed through the rent, the position of the lesions, the proliferation of the adjacent membrane, the extent of exposure of the biceps tendon, the degree of involvement of the adjacent tendons, the duration since the accident, the extent of formation of a falciform edge, the amount of recession or hypertrophy of the tuberosity, etc. Yet after sufficient experience, rupture of the tendon of the supraspinatus will be seen to be the basis of almost all the lesions. His chief doubt will be as to whether degeneration of the tendon always precedes rupture, although he will be convinced that rupture has certainly occurred whether the tendon was previously sound or senile in texture.
(4) Synovial villi. These are the most common evidence of pathology one encounters in the bursa itself. It is difficult to say that a given degree of roughening of the serosa is abnormal. Is callus on the palm pathologic? It may be that in the same way some
of these villi represent overuse rather than inflammation. On opening the bursa one sees strands of filmy tissue crossing the space after the air has been let in. Sometimes instead of being attached at their ends to both floor and ceiling, one end will be free so that the capillary villous will drift about in the bursa. In such cases the whole floor of the bursa is apt to be velvety with lesser villi and thickened nictitating folds. The center of this process is usually over the attachment of the supraspinatus to the tuberosity. In fact, this point seems to be the locus minoris resistentia of this bursa. We seldom find lesions of any kind in which this point is not involved. It seems to be the place where there is the most mechanical stress. It is here that the supraspinatus is at the greatest disadvantage in overcoming inertia in starting the upward motion of the arm. The
sudden contraction of the deltoid may jam this point on the acromion or coraco-acromial ligament if the supraspinatus is not on the qui vive. Here also would come the greatest friction in occupations requiring repeated elevation of the arm. At any rate, lesions of the bursa as a rule are found on the base at this point. I have recorded
none on the roof except a general synovial thickening.
There is a vast difference in the appearance of these synovial villi in life and after death. In life they are often pink or red, but in the cadaver they are limp and colorless and do not readily attract notice. In my opinion their presence is evidence that there has been inflammation and adhesion of the bursal surfaces, followed by resolution of most of the adhesions. They are probably homologues of pleural bands and are remnants of organized exudate. They are very frequently found and are to be expected in the bursas of the type of human being usually found in the dissecting room.
(5) Bands. In a few cases at operation I have found thick, cord-like bands of fibrous consistency similar to the bands one frequently finds in the olecranon or prepatellar bursa. One very typical case was in a man who had for years climbed electric light
poles, usually carrying heavy weights as he did so. A very painful, chronic bursitis with loud friction sounds developed. Excision of the bands restored normal use of the arm. Such cord-like bands are relatively uncommon in this bursa although frequently found in the prepatellar bursa. They must not be confused with the film-like synovial villi spoken of above, nor with the " straps " alluded to under No. 9.
(6) The normal nictitating folds formed by double layers of the movable periphery and described in Chapter I, page 27, may become inflamed and swollen. I have occasionally seen them bright red, resembling inflamed conjunctiva. They are sometimes the sole cause of a mild, chronic, non-adherent bursitis, giving intermittent, elusive symptoms such as twinges in certain motions.
(7) Adhesions. As stated previously, I have come to believe that the bursa, like the peritoneum, possesses the function of rapidly forming protective adhesions to confine inflammation, and also the ability to absorb them and thus restore, in whole or in part, the mobility of the adjacent tissues. For instance, the diaphanous folds which often partially separate the subacromial and subcoracoid portions of the bursa may, when inflammation arises in one portion, wall off the affected part after the manner of water-tight bulkheads in a modern steamer. It is not uncommon to find blotches of calcareous deposit, which have escaped into the bursa, thus localized.
In my experience adhesions never occur in the strictly subacromial portion of the bursa, and are most common in the subdeltoid portion and in the fold partially separating this from the subcoracoid portion. They are seldom very dense in any situation. They are always absorbed or rendered pliable in time by nature's own processes. Frozen shoulders from this cause invariably recover. I have probably relieved the minds of more patients by this assurance than by my best operative efforts on their bodies.
(8) A slight amount of fluid in the bursa may occur in any acute or chronic bursitis, but if on opening the bursa and abducting the arm, a large amount, i.e., several drams spurt out, one may be quite confident that the supraspinatus is ruptured and that there is a free communication between joint and bursa. As in other joints where there is synovitis, we may assume that nature supplies this fluid to reduce friction.
(9) Straps. These are damaged tendon fibers. One sees just over the supraspinatus insertion a circular area about an inch in diameter, which seems to be worn as if from friction. It is ragged and frayed. On close inspection there is a thin strap of fibers running in the same direction as the supraspinatus fibers and really composed of tendon tissue. The strap is perhaps a half inch square, attached above and below to the supraspinatus and lying on it or in it, but separated from it by a space. It is usually separable into a half dozen parallel strands. It can be lifted up except where it is attached at its two ends and perhaps by filmy material on its sides. It is very thin but quite firm. I have not been able to make out positively whether these lesions are caused by friction and consequent inflammation, or are remnants of the effect of the discharge of a calcified deposit in years gone by, or are the results of partial ruptures. If you abduct the arm this little strap will buckle up off the tendon on the top of the greater tuberosity like an inch worm. Section of such a case showed that the deeper parts of the tendon were a series of such "straps" on a smaller scale. The tendon seemed to be split in layers.
Dr. Akerson is studying a series of normal supraspinatus tendons at different ages and has kindly allowed me to have some of his sections. At all ages there appears to be a tendency for the tendon fibers to lie in loosely attached planes or laminations parallel to the joint surface as in Fig. 9. In the pathologic tendon these rifts or separations become complete and "straps" are formed. One receives the impression that normally these bands of tendon may each in turn take the maximum strain as the arm is elevated. Also that any one of them singly may tear or evulse from the denser portion of the attachment.
(10) A deep red, more or less circular zone of turgid membrane lying on the base of the bursa in the region of the supraspinatus facet is a not uncommon finding in the class of cases described on page 216 as tendinitis. Often this zone has a whitish central area which corresponds to the portion of the tendon just proximal to its insertion. The calcified deposits are usually surrounded by similar red, circular zones. Those referred to under this heading differ, because no white deposit is obtained when the whitish area is incised with the point of a knife, nor does any show in the X-ray. In one such case after puncture with the knife a few little rice-like grains of material popped out through the opening. Under the microscope the rice bodies appeared to be bits of necrotic tendon. In another case a little fluid came out under tension. In several other cases I have excised bits of tendon and found invariably the peculiar degenerated condition illustrated in Plate VI.
It will be more appropriate to consider the cause of this condition in the tendon under heading B. The point which I wish to make under this heading is that the red, circular zones are visible from the bursa in both these cases and in the calcareous cases. The deep red, circular zone seen on the base of the bursa is due to congestion of the subsynovial vessels. It is very superficial and does not extend into the tendon, which itself is very anasmic. In fact, the gross appearance of the whitish center in both cases suggests there has been an infarction. The reader should refer in this connection to page 232.

B. CHANGES OCCURRING IN THE MUSCULO-TENDINOUS CUFF ITSELF

(1) Degeneration in the collagen of the tendinous fibers is so common that it is difficult to find in elderly subjects an example of normal tendinous substance. Even in the case which I have used as an illustration of the normal insertion of the supraspinatus (Fig. 9), a few of the fibers showed early changes. Fig. 5, in Plate VI, is taken from this case. It shows small areas of collagen which take a deep red stain with hematoxylin and eosin, and at first sight resemble muscle fibers.
In practically all the bits of tissue which I have taken from the tendons at operation or from the specimens Dr. Akerson has examined, these same changes are found in some degree, whether the specimens came from tissue adjacent to calcareous bodies, partial or complete ruptures, or from the non-calcareous cases which I am disposed to call "tendinitis."
Little pathologic work has been done on lesions of tendons in any part of the body, so there is not much in the literature to help us to interpret our findings. Indeed, there is little to say beyond the fact that hyaline degeneration occurs and is not accompanied by invasion of lymphocytes or leucocytes, or other usual inflammatorysigns. The degenerated areas vary greatly in their staining reactions, which may be as blue as cartilage or as red as muscle with hematoxylin and eosin.
I am convinced that some of the central fibers of a tendon may tear without those which are superficial to it on the bursal side, or beneath it on the joint side, being ruptured. In one case in the living, I opened up a little cavity in the tendon which contained fragments of degenerated or necrosed fibers. There was no apparent opening from the cavity which contained these little bodies, either toward the joint side or the bursal side. They were not calcified. It seems to me highly probable that the calcareous deposits represent nature's failure to heal such internal lesions in the tendon. However, one might take the opposite view that central degeneration first took place; then fragmentation of the degenerated areas; still later calcification of the fragments; finally, discharge into the bursa and, soon after, absorption as described on page 69.
We must at present confess that we do not know what the first step in the retrograde process is. It may be traumatic infarction, or perhaps due to a general toxic condition.
It stands to reason that there must be a stage in the course of the calcified lesions just prior to the time when X-ray evidence can be obtained, when necrotic tendon fibers would be found without any calcium in them. Perhaps some day we shall be able to diagnose such cases, and by simply puncturing the tendon remove the tension and obtain prompt relief. This is certainly possible now as soon as the calcium is dense enough to show in the X-ray. In such cases the little cavity contains only a milk-white fluid.
(2) Calcified deposits. These peculiar and interesting areas are probably the next most common lesions to villi, although in the dissecting room, partial ruptures of the supraspinatus will be found much more often. This is because the deposits are temporary and undergo natural absorption, leaving no evidence behind, unless perhaps defects in the tendons. Many partial and all complete ruptures, on the other hand, leave a permanent defect. In living patients the deposits are probably more common or at least more often diagnosed, because, when pronounced, they show in the X-ray. I am convinced, however, that many are small and escape notice, for I have seen some in very clear films which are not larger than a pin-head and others which cast but a faint shadow, easily missed if they had overlapped the contour of a bone. Many escape notice entirely and perhaps never give symptoms. Some are microscopic. (Plate VI.)

PLATE II. CALCIFIED DEPOSITS

Figure 1. The deposit appears to be double. The larger mass lies in the supra-spinatus tendon, while the smaller mass is in the portion of the infraspinatus tendon which lies, in part, anterior to it. (See Chapter I, Fig. 6.) The long diameter of the latter is probably perpendicular to the plane of the plate. The motions of this arm were free, and without symptoms, although the patient had acute symptoms in the other shoulder, shown in Fig. 2.
Figure 2. The shadow of the deposit consists of a diffuse portion and a small dense portion. The diffuse portion was due to calcined material in the supraspinatus tendon, which had not yet perforated into the bursa, although it was on the point of doing so at the time of operation. It had infiltrated the substance of the tendon and muscle far beneath the acromion. In both shoulders the shadow of the deposit corresponds very well with the normal position of the tendon. The dense portion was probably in the infraspinatus.
Figure 3. Shows a large, dense deposit in a patient with subacute symptoms, who still possessed a normal extent of motion in his shoulder joint, although he had acute pain during elevation when the mass impinged between the tuberosities and the acromion process. The calcified material had not yet escaped into the bursa, although the X-ray shows outlying specks of calcium in the superficial parts of the tendon. As is the case in most instances, the deposit was made up of small, dense masses. The tuberosity shows characteristic atrophy in the trabeculae. At operation in both this case and in that shown in Fig. 2, the floor of the bursa showed a red zone with a white center. Contrast these three figures with Figures 4 and 5, which show the bursa distended with the material.
Figure 4. Should be compared with Fig. 34, for it shows a similar outline of the extruded particles. In some cases, e.g., Fig. 44, the lower portion of the bursa appears to be bilocular, the particles having accumulated by gravity in the fluid at the bottom of these pockets. One should understand that in these figures we detect merely the outline of the bursa, as if in section, but that in reality the bursa lies also in the antero-posterior plane and forms a concavo-convex cap over the tuberosities.
Figure 5. As in the last case, one may be sure that the deposit has burst into the bursa if the bulk of the material shows external to the tuberosity in the unro-tated antero-posterior view.
Figure 6. Illustrates a case alluded to in the text (p. 78) in which a second operation was done. There is a remnant of the deposit still left in the infraspinatus after the first operation, which was on the supraspinatus, but the long, oval deposit is in the subscapularis and was removed at the second operation. Compare this figure with another case where the deposit was in the subscapularis and is shown in the outline drawing, Fig. 43.

The deposits do not arise in the bursa itself, but in the tendons beneath it. Most instances occur in the supraspinatus tendon close to its insertion, but a considerable number are found in the tendon of the subscapularis and in the tendons of the infraspinatus and of the teres minor. I formerly did not identify them in these tendons. As will be seen later, one does not see these tendons in operating, and at first I contented myself with removing the deposit and making no particular effort to determine its exact situation. It took me some years to realize how easy it is to determine the situations of the tendons when operating by placing the arm in exactly the mid-position between external and internal rotation and palpating the bicipital groove. Since, after the bursa is opened, one usually has no difficulty in locating the deposit by the circle of blood-red congestion about its whitish or yellow center, it has seemed superfluous to ascertain which tendon contained it. I later learned that there might be two or more deposits each in a different tendon. In one patient failure to remove both at the first operation resulted in a second attack of acute symptoms and a second operation. On page 230 the importance of accurate X-ray localization is emphasized.
The size of the deposit varies greatly, ranging from that of a pinhead to a shadow, two or three inches long, of the supraspinatus tendon and muscle as in Plate II. Such large shadows are very rare, and the deposit is seldom bigger than a lima bean. The consistency varies also and may be that of a milk-white fluid or of a hard, yellowish crystalline substance. Usually it closely resembles in color and consistency ordinary zinc ointment. Sometimes it is cheesy and yellowish, like the contents of a wen. In acute cases- it is not difficult to remove, but in some chronic cases of long standing it is very gritty and seems incorporated in the fibers of the tendon so that one cannot curette it all out without removing much semi-normal tendon with it. One sees whitish, stringy fibers in the little pit from which it is being removed. Sometimes it shells out very easily with a definite contour. In my own operations I have avoided removing any tendon, preferring to leave some of the deposit in the fibers, than to excise tendon which might return to normal and become of use in future function. Brickner has removed enough for sections, and Moschcowitz has studied them. Harbin has not hesitated to remove some tendon and reports good results in spite of this. On a few occasions I have found the deposit surrounded by a small amount of granulation-like tissue, largely composed of foreign-body giant cells, but in these eases the deposit had probably perforated into the bursa.
Several times I have had careful chemical analyses made.
Dr. James L. Stoddard made for me an analysis of the material from one of these cases.
"The following report on the bursal deposit shows it to be a mixture of calcium phosphate, calcium oxalate, and organic matter, mostly fibrin.
Gross: A pasty, white mass, in part blood tinged, springy and a little elastic on stretching, moist, with an extremely fine, even texture, and with no evident structural elements which hinder division at any point.
Microscopic: Small ovoid colorless bodies, varying enormously in size. Some are at the limit of vision with an oil immersion lens, and show marked Brownian motion; all gradations exist up to bodies several times the diameter of a red cell. They are all the same in qualitative appearance. They are slightly refractive, less so than fat, have usually a somewhat irregular oval shape, but the edge is always smooth and even. Nothing but the bodies is visible in the specimen.
Chemical—Qualitative: No color with Sudan 3; hence not fat.
Insoluble in acetic acid, alcohol or ether.
Soluble for the most part in fairly strong HC1.
On heating to yellow heat, chars, smokes, and burns briefly with a yellow flame, and gives a burnt feather odor. Leaves a gray ash.
Ash dissolves easily in weak acetic acid with evolution of C02, showing original substance to have contained oxalate.
Gives no murexide test for uric acid. No test for cholesterol (Lieberman-Burchard test).
Solution in strong KOH acidified with acetic acid gives off slight trace of H2S, detected on lead acetate paper. This is probably due to presence of fibrin, which also explains the consistency of the deposit.
Solution of ash gives heavy phosphate test with ammonium molybdate.
Chemical—Quantitative: A small sample of the deposit was ashed, weighed (weight 86 mg.), dissolved in HC1, filtered from char, ammonium oxalate added, the solution neutralized, and the precipitate analyzed quantitatively for calcium as in the blood calcium method (Clark's modification of the Kramer-Tisdall method).
The filtrate was made acid with acetic acid, and a calcium acetate solution added to precipitate the excess oxalate which would interfere with the phosphate determination. The filtrate from this precipitation was analyzed for phosphate by the blood phosphate method (Brigg's modification of the Bell-Doisy method).
"Result: Calculated back to Ca3(P04)2 and Ca204, H20 gives respectively: calcium phosphate 55.8%, and calcium oxalate 44.2% of the inorganic matter of the dried, unashed specimen. The amount of organic matter was not determined. Of the ash there was 14% not to be accounted for by figuring all the phosphate as calcium phosphate, and the remaining calcium as carbonate. Part or all of this 14% was due to char, and part may have been due to other inorganic matter (perhaps some magnesium salts, etc.). (The ashing was done at the lowest possible heat, but of course some of the calcium carbonate may have decomposed into oxide, which would raise a little the undetermined fraction.) One of the most interesting features is the peculiar microscopic appearance of the specimen, with this non-crystalline precipitate of fairly definite shape."
Maxwell Harbin (Arch, of Surg., Vol. 18, No. 4, P. 1491, Apr., 1929) reports a case which from the X-ray film is very clearly a case of perforation of one of these deposits into the bursa. He made a rather extensive excision and gives the following report of the chemical analysis of the specimen, together with a low power photomicrograph.
"The bursa, as well as the necrosed tendon (Fig. 8), was excised. It is of interest to note the considerable variety of earthy substances which exist in the necrosed tendon. Inorganic phosphates were present to a considerable degree. Calcium was easily discernible with a trace of calcium, iron, carbonates and chlorides. The specimen was composed of tough, white fibrous substance covered in certain areas by a cream-colored cheesy substance. A few grit-like particles were found in the cheesy material. Some hardened blood was present. Analysis of tissue removed from the supraspinatus tendon showed the following:

"The white fibrous substance was apparently dense fibrous connective tissue. The yellow cheesy substance was composed of fat, protein and a fair amount of calcium phosphate." Comment by E. A. C.: Confessedly Dr. Harbin had excised some tendon and fat, and the analysis was not made from the pure deposit as in my case.
One of my assistants, Dr. T. W. Stevenson, made the following observations:

Study of a Calcareous Deposit

A little of the material was suspended in normal saline and observed under the microscope. Many small bodies of variable size, mostly round or oval in shape, were seen. The smallest were the size of bacteria or smaller and the larger ones were about the size of white blood cells. Scattered over the slide were many large, round or oval bodies 10-15 times the size of a white cell. They presented a peculiar appearance in that they were concentrically striated. The appearance resembled that of the gall stones pictured in MacCallum's Pathology. The center of these bodies is slightly clearer than the periphery. This central nucleus (?) resembles a white cell and is about that size. The concentric rings are very distinct, but two or three in each body are more pronounced than the others.
When a little of the material was suspended in concentrated sodium hydroxide solution, the bodies were turned slightly more yellowish. The striations were more marked. No dissolution or other change occurred up to one hour.
Concentrated nitric acid caused no change.
Glacial acetic acid caused no change.
Thin smears were made and fixed by heat. They were stained and the following results noted:
Gram's Stain: No organisms were seen. The calcareous bodies decolorized and were stained an even red with no striations visible.
Methylene blue stained the bodies an even blue and concealed the striations.
Ziehl-Neilson stain showed no acid fast organisms or bodies.

Stern of Cleveland has reported that these deposits are modified fat, but I can find no evidence to support his contentions.
Dr. Robert Chambers was kind enough to investigate some of the small bodies for me with his dissecting microscope. He found, when he attempted to pull them apart, that they were quite elastic and sprang back to their original shape.

I have repeatedly made microscopic examinations of fresh specimens of the material removed and they always consist chiefly of the little, round and ovoid bodies above described. I have never succeeded in dissolving them in ether. Their real character remains a mystery to me, but I am satisfied they are not fat.
Moschcowitz in 1915 said: "The calcification is present either in the form of discrete, sharply circumscribed, sand-like masses, embedded as it were in a cavity within the tendon; or as diffuse, finely granular masses, shading imperceptibly into the surrounding tissue structure; or as finely granular amorphous material, lying within the tendon or the granulation tissue." Concerning another case he said: "In no specimen was the slightest tissue reaction noted, in the form of round cell infiltration, granulation tissue or the formation of new blood vessels."
It seems to me that the latter statement is more characteristic of the early uninflamed stages in the tendon when the trouble is forming and the bursa is not yet involved. The first description is that of a more acute case when the deposit has caused a reaction in the base of the bursa. It seems to me probable that new blood vessels, etc., proceed into the tendon from the synovia. In such cases, unless the bursa is involved, it is striking that blood vessels, lymphocytes and the usual microscopic phenomena of inflammation are lacking, and yet there is clear evidence of degenerative change. I hazard the suggestion that it may be found that tendon repair differs from the repair of other tissues in this respect; i.e., that necrosis must first proceed to a point where it involves an adjacent vascular tissue before vascularization will take place.
Moschcowitz did not definitely state his opinion on the question of precedence of lesion or trauma, for he was evidently influenced by Brickner's belief that this calcification process was a prompt reaction to a trauma. My own belief is that the deposit has probably been present long before the trauma with which it is associated by the patient.
Moschcowitz continues: "The necrotic tissue can have only two sources: (1) Degeneration of the blood and serum consequent upon the primary trauma. (2) The breaking down by coagulation necrosis of the tendinous structures." He excludes the first because there is no blood pigment; the tissue is too homogeneous and plastic in appearance; the line of continuity of the necrosed portions with the solid portions is a gradual one. He also states that it used to be generally accepted that calcification never occurs in any but dead or inert tissue, but that in consequence of recent experiments, which he quotes, it seems that calcification may be a matter of only a few days in areas rendered anaemic by tying arteries. Yet he says it does not follow experimental suture of tendons.
It seems to me that we are indebted to Moschcowitz for the best statement of the pathologic findings, but that he has been too strongly influenced by Brickner's clinical belief that in these cases calcification is an immediate result of trauma. He also quotes me as believing this, but I do not recall that I ever did believe it, and I certainly did not state this in my writings. I did believe, and do still, that some slight injury, long before, may have pulled the fibers apart and started the process. Since tendons contain few blood vessels, evidence of hemorrhage is not required to support the likelihood of this theory.
There are two other interesting points in Moschcowitz' paper. One is that he was unable to find in the literature of pathology that any effort had been made to study the minute pathology of these lesions. He was only able to find Wright's report (on one of my cases, and which I had quoted) and another by Wrede, which was inconclusive. The second is that he prophesies that since in other tissues where one finds calcification one eventually finds some ossification, we should presently find ossification in an instance of this lesion. I have not yet been able to find such an instance proved microscopically. One must not be deceived by bits of the tuberosity in a retracted supraspinatus tendon.
Similar formations are sometimes found in other tendons, as in the quadriceps and the gluteus medius, and I know of one case in the flexor carpi ulnaris. Dr. .J. H. Wright told me that a similar pathologic process was found in the heart valves.
The question of whether infection has anything to do with the condition has ceased to interest me, as I have always closed the wounds and have never seen even mild sepsis develop. Many times I took cultures which were always negative. Nor have I been able to definitely associate the condition with distant foci as evidence of toxaemia. Of course, many patients have bad teeth, but in no instance has there seemed to be any association, for as soon as the deposits are removed the patients promptly recover, whether the teeth have been extracted or not. In one instance extraction of a tooth was at once followed by acute symptoms in the shoulder, which soon subsided and disappeared altogether. However, I strongly recommend every patient with bad teeth to have them attended to, although I do not consider the causative connection scientifically established.
There is no constitutional condition which I have associated with the lesions, for they occur in the lean or the fat, in the active or sedentary. My chief reason for believing that they are primarily due to trauma or overuse is that their pathology may best be accounted for on this hypothesis. Furthermore, I do associate them to some extent with occupation, for they occur in people who habitually use their arms in semi-abduction, as stenographers, accountants, machine operators and surgeons. I think that automobile driving may have a tendency to encourage this formation. In fact, any occupation or avocation which requires undue use of the abducted or elevated arm.
(3) Defects due to ruptured supraspinous tendons. In spite of my known interest in the subject and the goodwill of many friends in active surgical practice, I have never seen, either on the operating or autopsy table, a fresh rupture of the supraspinatus tendon. It merely happens that no one recognizes these cases in time. I have seldom operated within three weeks after the injury, although I strongly believe in immediate operation. The earliest case was three days after the injury, and in this case, unfortunately, there had also been a prior one. Decided changes occur in the first few weeks, so that one finds the ends of the torn surfaces covered with fresh tissue which disguises the exact anatomic relations of the parts. However, experience in operating at varying intervals after the trauma, combined with dissections on the cadaver, has given me a fair idea of the method of healing which nature attempts. We must examine again the normal anatomy.
The continuity of the semi-circular conjoined insertion of the four muscles (see p. 17) is interrupted by the groove for the biceps tendon which separates the two tuberosities and theoretically the insertions of the subscapularis and supraspinatus. The facets of insertion of these two muscles are widely separated in anatomic diagrams, but as a matter of fact, their common expansion bridges the groove and makes them continuous, although thin just over the groove. Ruptures almost always involve this portion over the groove and it is very often the internal limit of the rupture, which as a rule extends from this point outward, involving the portions of the cuff made up of the supraspinatus and part of the infraspinatus expansions. Occasionally the tear crosses the bicipital groove and involves the subscapularis portion of the conjoined tendon. In at least one dissecting room specimen the tear extended inward from the groove and involved the subscapularis portion alone.
When one opens the bursa in these cases the biceps tendon may or may not be exposed, according to whether or not the tear extends across above the bicipital groove. It is usually to be found just under the edge of the inner side of the rent. If it is exposed it is seen as a bright pink band crossing the bluish surface of the shining articular cartilage. It is not only pink and inflamed looking, but may be twice its natural size. One finds that below and above the point where the biceps tendon is exposed by the retraction of the ruptured supra-spinatus, it is still of normal size and white and shiny. When not exposed, but lying just under the edge of the portion not ruptured, it is not abnormal looking. Frequently it cannot be found, for it has been torn off its attachment on the glenoid and has been pulled by its own muscle belly down into the bicipital groove. The proximal end sometimes sticks in the upper portion of the groove, and at other times retracts way down it and curls up in a coil just above the muscle belly. Occasionally it is found to be much frayed, which probably indicates repeated jamming between the head of the humerus and the acromion. Sometimes the frayed edges are adherent in the groove, and have little rice-like bodies attached to them.
From what I have said about the cuff of conjoined tendon in which the tendons of each muscle and the capsule are welded intimately, and since ruptures always occur in this portion, it will be more readily understood that when I speak of any one tendon as rupturing I mean the portion of the cuff represented by that tendon. Since the gap of the rupture is held on each of its edges by the conjoined tendon, the retraction of the muscle makes the rent triangular. The interweaving expansions of the tendon on each side still hold it to a certain extent, and the pull of the muscle is distributed on the conjoined tendon on each side as if it had a Y attachment. The middle of the inverted Y retracts farthest and the sides slope toward the base on the tuberosity. The shape of the whole rent is therefore roughly an equilateral triangle, with its base on the tuberosity and its apex disappearing under the acromion. The width of the tear is the width of the base; restoration would be made if the apex were sutured to the middle of the base. The base itself is inflexible, being either the bony seat on the tuberosity from which the tendon was evulsed or an inelastic stub of tendon still attached to the tuberosity. The size of this triangular rent varies from a half inch to an inch and a half base. Sometimes only a few fibers are torn, and at other times most of the conjoined tendon. In one case I found that the whole cuff with all the tendons had been evulsed, and that the head of the humerus was free under the deltoid. (See case report on pp. 389, 390, 391.)
A skin wound of triangular shape healing by second intention, i.e., granulation and epithelialization from the edges, becomes rounded before it heals; so do these triangular defects in the supra-spinatus, so far as the edge of the rent is concerned. They differ from the skin defect because there is no bottom or bed of granulations, so must heal entirely from the periphery, and complete closure of the hole is therefore unlikely. In the skin ulcer this peripheral healing is epithelial and spreads over the surface of the granulations on the base as ice, beginning at the edges, skims over a pond. In the tendon defect the peripheral tissue is fibroblastic not epithelial, and fibroblastic reconstruction is dependent on a new formation of blood vessels instead of mere multiplication of cells to skim over another tissue which will feed them. Now it happens that tendon is a tissue in which there are exceedingly few blood vessels to form the basis of new granulations, so that the conditions for healing are still more unfavorable. I have already stated that it is my own belief that tendon repair does not usually take place from within, but from the synovial or areolar tissues adjacent to it. It is likely, therefore, that the synovial covering acts in these cases something like epithelium to cover the edges, and also as an agent to expedite the new supply of blood vessels. At any rate, I have had the opportunity to see on the operating table the appearance of these rents at various stages from a few days to two years after the accident. Even three weeks after the rupture, the triangular appearance is sometimes a little rounded by bridging of the corners and extension from the sides of an almost transparent new tissue, presenting a falciform edge toward the center. In later cases this edge is harder and more extensive, but always presents the falciform margin, which lies on the cartilaginous joint surface in the manner of the semilunar cartilages of the knee joint—clearly to avoid friction.
Obviously, as this circle gets smaller, either by the contraction of the tissue of which it is composed (cf. contraction of surface scars), or by more tissue forming toward the center, the smaller and more circular the defect becomes, until possibly the hole between the bursa and the joint might be entirely closed. Assuming that there is still a stub of tendon attached to the tuberosity, it seems possible that healing in this manner would eventually occur in young, well-vitalized tissues, but in the aged, with barely vitalized tendons, little change would tike place after the first few weeks. This supposition is strengthened by reference to the age table, which shows that I have never operated on a young man and demonstrated a rupture of the tendon.
In those cases in which the tendon is actually evulsed from the facet, a complete circle with a falciform edge is not formed as healing progresses, for the bone forms a defect in the circle. The base of the former triangle is the bone of the tuberosity. It may be bare and as a rule has no granulations; sometimes there is a little velvety tissue on it. On microscopic section of the bare facet, one finds a little skim of fibrous tissue over the spongiosa, and that is all. As a rule there is a little plaque of dense bone beneath this, and at the periphery of the defect some raised "productive" bone. These bony changes are shown in the X-ray. Healing in these cases would appear to be at still more of a disadvantage than when a stub of tendon is left on the tuberosity. It is not unusual to find both, some stub and some bony defect. From the operator's point of view a stub of tendon is a great advantage, for where evulsion has occurred he must drill the tuberosity in order to suture the tendon. A knowledge that a falciform edge is present is also important for the operator, for in most cases he must remove it and pare down to the real tendon tissue before he sutures. The new tissue in this falciform edge is seldom strong enough to hold a suture, and would be in the way of the sound tissue. (Fig. 12.)
Referring to Fig. 6 will help the reader to understand the points at which rupture or evulsion is likely to take place. The figure shows that the insertion of the tendon into the bone is very superficial, and the shell of the surface of the bone is very thin. Under high magnification very many minute prolongations of the tendon are inserted into this thin shell of bone. (The structure suggests to my mind a room full of people hanging to the ceiling by having all their fingers deeply thrust into the plaster as into finger holes in a bowling ball.) As a practical matter this network of attachment to the tuberosity does hold against excessive pull except in elderly people when the attachment is pulled out. In most of the cases I have seen at operation it was apparently evulsed at the line of junction, but soon after the injury a stub of tendon would probably have been found. Such stubs probably slowly disappear.
Referring again to Fig. 9, it will be seen that stress on the supra-spinatus tendon in the direction of its normal pull may result in four different forms of break in continuity:
a. The tuberosity, facet and all may be pulled away. This may occur without making a communication between the base of the bursa and the joint. Since the fixed portion of the base of the bursa is on both tuberosity and tendon, it is likely that the whole bursa follows the displaced tuberosity, and the bony gap is filled in by callus from the peripheral torn periosteum. (See p. 317.) I am quite sure that this is the rule, although my opinion is formed on that very untrustworthy guide, "clinical experience." Cases of fracture of the tuberosity get well much more promptly and with less pain than do ruptures of the tendon, and differ in their minor symptoms from the latter. Moreover, in the two cases cited I have opened the bursa and felt beneath its unruptured base the fragment of tuberosity. In most fracture cases the bursa is not involved because it is higher than the usual line of fracture. (See p. 273.) It seems to me probable that in all cases where the tuberosity is involved, whether it is broken off alone or with several fragments, that the line of cleavage in the bone is just external to the firmly attached base of the bursa, which in fact strengthens the bone locally like a patch. In other words, I think that if one opened the bursa by my routine incision in a series of fresh cases of fracture of the tuberosity, he would not find the bursa full of blood and communicating directly with the two raw fractured surfaces and thus into the joint. Sometimes this would be true when the fragment as shown by the X-ray is drawn inward as far as in Fig. 35, but not in the usual case as in Plate IX.

FIGURE 35. RETRACTED FACET AND DROPPING SHOULDER I have found this Rontgenogram, unlabeled among my papers, so that I cannot give, as I usually have in my other illustrations, a statement that the condition was proved by operation. However, the picture is so characteristic of a retracted supraspinatus facet that I do not hesitate to use it. Such a condition is far more serious than most of the major fractures (Fig. 59). Even without knowing the history in such a case I should be confident in saying, from the X-ray alone, that the patient has a post-dislocation condition, where there is "dropping shoulder" due to deltoid paralysis and where the supraspinatus facet of insertion lias been pulled by the muscle beneath the acromion. It also shows some bone formation from shreds of periosteum retracted to a lesser degree by the adjacent tendons. As in cases 71 and 115, the dislocation has probably not been really reduced. These appearances indicate operation.

b. Evulsion may occur at the point of insertion and the superficial part of the facet be carried inward by the retracted tendon. Since this little shell of bone would show very faintly in the X-ray, and also since it would have been absorbed in the long-standing cases which form the bulk of my experience, I cannot speak very positively about it. In a few cases I have seen remnants of it attached to the retracted end of the tendon, and I have often noted its absence on the tuberosity. In some cases it seems that the minute, finger-like processes are evulsed from the bone without taking the bone with them. Occasionally part of the tendon is evulsed, leaving bare bone, while the remaining portion leaves a small stub on the tuberosity.
c. True rupture of the tendon leaving a stub on the tuberosity usually occurs at the narrowest place shown in Fig. 6, leaving the broad, semi-cartilaginous fibro-cartilage still attached to the bone as' a stub. This amount is barely sufficient to permit a good hold with a stitch. I have occasionally seen a larger stub, perhaps three-quarters of an inch in length. In these few cases this larger stub was very vascular and of deep purplish red color like a cock's comb. On one occasion such a stub popped out of the wound as soon as the roof of the bursa was incised. The vascularity of such a stub sug
gests that there must be a considerable blood supply in the bony facet. The desiccated bone shows many vascular channels in the sulcus, and near the upper end of the bicipital groove. Both those cases in which there is evulsion and those in which a stub is left necessarily have a direct communication established between the joint and the bursa. In cases where bursa and joint communicate there is always more or less straw-colored fluid in the joint which washes back and forth into the bursa, rising in the bursa when an effort is made to raise the arm, and falling back into the joint as the arm is relaxed and lowered. This process dilates the bursa and in extreme cases leads to hygroma of the shoulder, as described on p. 478.
d. A fourth condition of great clinical importance consists of those cases in which a portion of the tendon is torn to a degree insufficient to tear the base of the bursa itself, so that a film of tissue is left between the joint and the bursa. I allude to these cases as "partial" ruptures or "rim rents." Repair takes place to a certain degree from the thickening of the film of bursal base. I have found few such cases in the living, probably because they do not cause a degree of disability to make me advise operation, but I have frequently seen this condition at autopsy. If one removes the head of the humerus with the short rotators attached and examines the sulcus which surrounds the articular edge, one finds the attachment of the supraspinatus extremely thin, so that when held up to a bright light the attachment is found to be Y-shaped and the central portion between the limbs of the Y is diaphanous. The sulcus at this point is correspondingly broad instead of being a cleft, as it is in the normal joint (Fig. 10). It appears that the portion of the tendon on the joint side, together with its joint synovial lining, has pulled off, leaving the bone bare.
I believe this fourth division accounts for many of the industrial shoulder injuries which recover after a few weeks or months, and which I have in the past classified as relatively trivial cases of traumatic subacromial bursitis (see Plates III and IV, pp. 101 and 102).
It seems legitimate to assume that in such injuries as almost or quite cause a dislocation of the shoulder, the synovial reflexion and the portion of the tendon on which it is reflected, might be torn away from the articular edge, leaving the bone trabecule bare at this point. There would be slight bleeding, which might gradually fill the joint and distend it. This hemorrhage would in turn be replaced by an excess of synovial effusion, which might be kept up by the individual continuing to use the arm. Motion might prevent the formation of fibrin to act as a basis for new granulations and fibrosis in the bed of bone. Even if pain were sufficient to start scapulohumeral spasm, the effusion might hold the parts apart and prevent proper healing. If the patient were old, and the tissues already weak, healing would be even more unlikely. At any rate, it is very common to find at autopsy that the sulcus is bare.

FIGURE 86. VOLCANOES AND CAVERNS
Deeper section through the same tuberosity as that shown in Plate V, Figure 1. The ends of the canals of invasion of vascular tissue appear as caverns. As these caverns and volcanoes are frequently found in X-ray films in cases of tendinitis, as well as in cases primarily due to rupture of the tendons, intensive study should be given to them.

C. CHANGES IN THE GREATER TUBEROSITY

(1) Excrescences. Pathologic changes in the tuberosity may readily be detected by the X-ray. In many cases of old, complete ruptures of the supraspinatus and in some cases of partial rupture, the relative thickness of the tendon and of the tuberosity is changed, so that there is a notch in the base of the bursa. Thus the tuberosity forms a distinct eminence and may cause a jog and friction as it passes upward under the acromion. The result is a stimulation of the bone cells in the tuberosity and irregular excrescences form at the region where undue friction occurs. This new formed bone is very spongy and probably later atrophies, because in the very old cases one finds that complete recession of the whole tuberosity has taken place. Atrophy of the tendon without actual rupture might cause enough irregularity in the base of the bursa to begin a little irritation. A vicious circle of atrophy of tendon, inflammation of tuberosity, osteitis, excrescences, greater jog and greater friction, greater atrophy, etc., might be established. At the same time hypertrophic changes on the acromial edge are stimulated.
(2) Caverns. Very frequently where this superficial osteitis occurs on the tuberosity, there is also absorption of the bone beneath its surface. This absorption of the bone results in the formation of little caverns which contain vascular tissue. I am inclined to think that they represent the early stages of what I call recession.
(3) Eburnation. By eburnation I mean an increased deposit of lime salts which result in the hardening of a definite area of the bone. Such areas of eburnation are frequently found at the insertions of these tendons in working men. In the X-ray a heavy plaque of bone is shown where the tendon is inserted in the sulcus. In some cases where the fibers of insertion have been damaged, there appears to be an increase of this bony deposit, so that when this is found in a case of suspected rupture, it is a confirmatory sign. It is not, however, of much importance practically. In my opinion, this appearance is evidence of the existence of low-grade, chronic inflammation, and I think that it is possible that the increase of this bony substance may interfere with the nutrition of the finger-like processes which hold the tendon in the bone at this point and tend to weaken the hold which these processes have there.
(4) Bursal osteitis. Osteitis caused by this irritation on the tuberosity may sometimes involve the outer side of the tuberosity as well as its tip. The base of the bursa may be the seat of chronic inflammation, so that irregularities will be shown by X-ray on the appropriate portion of the tuberosity, external and below the insertion of the tendon, on the outer aspect of the bone.
(5) Recession. I have referred above to the atrophic changes which take place in the sulcus and tuberosity long after ruptures of these tendons have occurred. It is highly probable that most ruptures occur at the line of junction of the tendon tissue with the palisade-like fibrocartilage adjacent to the bone shown in Fig. 9. When I have operated within a few weeks after the accident, this stub of tendon was usually present. In the very late cases, however, the tuberosity has usually been found to be quite bare, and not only bare, but atrophic. Instead of showing a normal sulcus and tuberosity, these structures are more or less leveled off, or, as I prefer to say, there has been a gradual recession of the tuberosity after the stub of tendon has worn away or been absorbed. The sulcus and tuberosity were no longer of use, but were actually an impediment to elevation of the arm. Without the pull of the tendon to fulfill its normal functional demand, the tuberosity had gradually disappeared. In the very old cases, such as many of those Dr. Akerson found at autops}', or the case mentioned on page 108, the recession of the tuberosity was so marked that one could hardly tell, by superficial examination, where the old cartilaginous edge ended, or where the area normally occupied by the sulcus and tuberosity had been. This region now wa.s smooth, covered with a thin fibrous layer, and continued the rounded contour of the articular head. This recession of the tuberosity may be detected also by the X-ray. Note the dotted line in Diagram C and also Plate IV.
(6) Trabecular atrophy. In all long-standing lesions of the bursa, whether or not they are due to rupture of the tendons, the X-ray shows that the trabeculae beneath the base of the bursa are more or less atrophied. This produces a dark area in the X-ray film which corresponds with the portion of the tuberosity on which the base of the bursa rests. In the normal bone the trabeculae are, to be sure, less dense in this region than in other parts, but where the atrophy is pathologic, the outline of this more translucent area is indefinite and not as plainly marked as in the healthy bone. I presume that the trabecular are absorbed because there is chronic congestion of the small vessels of the marrow spaces in the region. This kind of atrophy is sometimes very marked in acute cases of bursitis due to calcified deposits. In such cases it slowly disappears after the lesions have healed.

D. CHANGES WITHIN THE JOINT ITSELF

(1) The common lesions of the long tendon of the biceps have been alluded to on p. 85.
(2) Rupture on the joint side of the tendons (rim rents). We have already considered under B, lesions of the tendons at this point, but since they do occur here, they necessarily involve the joint. Normally the true joint cartilage forms a very sharp angle with the insertions of the tendons, as shown in Fig. 10. Fig. 9 shows some of the fibers beginning to tear at this synovial reflection. Diagram D shows an extensive tear so that the rent-has come through to the most superfici fibers of the tendon. The reader should visualize this vertical section so as to understand that the rent also extends along the curve of the edge of the joint cartilage to a considerable extent, leaving the sulcus bare, perhaps for an inch or more. This condition I like to call a "rim rent," and I am confident that these rim rents account for the great majority of sore shoulders. It is my unproved opinion that many of these lesions never heal, although the symptoms caused by them usually disappear after a few months. Otherwise, how could we account for their frequent presence at autopsy?
(3) Eburnation of the sulcus has already been spoken of under the last heading, but it is unavoidably listed here again because it lies at the periphery of the joint.
(4) Raised articular edge. Not infrequently we find in elderly subjects, a very slight, rounded, corona-like elevation of the edge of bone under the articular cartilage. It is difficult to say whether it is really pathologic in character. It might be regarded as evidence of a chronic arthritis. However, it is frequently present as shown by X-ray, in joints of which the patient makes no complaint. So far I have been unable to attribute any clinical significance to it.
(5) Adhesions of the extensions of the joint. The reader will recall the so-called bursal extensions of the joint which lie beneath the infraspinatus and subscapularis. It is highly probable that the margins of these, especially the margins of the one beneath the subscapularis, may be stretched or torn so that habitual dislocation may readily occur. On the other hand, adhesions between their surfaces would necessarily limit the motions of the joint. I mention these extensions because some future investigator may be able to make some observations of clinical importance concerning them, but my personal experience with them is nil, for I have not even studied the question systematically on the cadaver. Albert (1893) mentions a case of tumor in the axilla caused by distention of the subscapularis bursa, but I have never observed such a case.
(6) Fluid in the shoulder joint is considered on page 115. The chief point which I wish to make in regard to it at present is, that in elevation of the arm the lower portion of the capsule is stretched tight and fluid is forced upward into the rim rents or, if there is a communication through the whole tendon, into the bursa itself. Theoretically, if there is fluid in the joint and the tendon is not ruptured, elevation of the arm should also tend to dilate the bursae beneath the subscapularis and infraspinatus.

E. WHEN THE MUSCULO-TENDINOUS CUFF HAS BEEN RUPTURED
So THAT A FREE COMMUNICATION HAS BEEN ESTABLISHED
BETWEEN THE JOINT AND THE SUBACROMIAL BURSA

The considerations under this heading are merely presented as a review of the others, with the particular idea of accentuating what I believe is nature's method of compensating for these lesions, i.e., dilatation of the bursa by joint fluid, gradual absorption of the tuberosity and atrophy of the stub of tendon in order to form a new, smooth surface.
(1) Indicates the fibro-synovial edge which is formed very soon after the injury and which must be pared away before the tendon is sutured.
(2) Erosion of articular cartilage. It is obvious from what has been said that after rupture of the musculo-tendinous cuff, more or less articular cartilage will be exposed on the base of the bursa, and that the cartilage at this point would be subject to contact with the acromion when the arm is elevated. In old cases at operation or in specimens of extensive tears found at autopsy, one frequently sees a superficial erosion of the joint cartilage with clearly marked outlines separating it from the undamaged surface. These areas of erosion are consistently limited by the size of the rent. Perhaps it is better to say that these areas of erosion are always somewhat larger than the rent, because in different degrees of rotation of the humerus different parts of the articular surface can be exposed through the same rent to pressure on the acromion as the arm is elevated. In practically all the cases where an extensive rupture exists, there is some osteitis on the edge of the acromion, which would increase the wear and tear made by the articular surface touching the acromion through the gap. This erosion of the joint surface is always superficial. It is possible that in some cases the process is reversed. It may be that the rough acromial edges wear through the tendon.
(3) Is the stub of tendon which remains on the tuberosity for some weeks or months after the injury, but since it is functionless, eventually disappears.
(4) Represents the dotted line which limits the recession of the tuberosity.
(5) Is the fluid in the dependent axillary portion of the capsule.

In the above description of the pathologic changes which I have observed in this region, I have endeavored to confine my remarks to the essential features which I am sure that any one who is earnestly studying these joints will be able to verify. Such a student may also find many other atypical little irregularities in the tissues close to the lesion in the tendon, which I have not thought it worth while to describe. However, when one has examined a considerable number of joints, these changes will seem relatively unimportant and entirely secondary to the lesions described above. One must not allow one's self to be deceived by these secondary changes, although sometimes the congested, inflamed synovial folds are the most striking lesions visible.
Before closing this chapter it is well to add a word about the question previously brought up as to whether some form of necrosis in the tendons themselves, such as age induces in the walls of arteries, is largely responsible for the various lesions or at least for their failure to repair. The facts that most of my cases are aged, many are bilateral, and that I have observed no cases in young people are strongly suggestive of this idea. Moreover, the traumatic cases as well as the calcified cases show a similar degeneration of the tendons under the microscope, although many of the latter are in somewhat younger people.
It seems possible that these lesions may occur merely from gradual deterioration of the musculo-tendinous cuff. The frequency with which they are found at autopsy would suggest this, as well as the reasons spoken of in the last paragraph. When a tendon has disintegrated to a great degree of weakness, even a slight effort might break away the rest of it. However, this is not usually the case, for all but two of my operated cases of complete rupture of the supraspinatus gave a very clear history of serious trauma. Dr. Wilson's cases also had histories of trauma, with one exception. The findings at operation in the three exceptions were similar to those in definitely traumatic cases. Moreover, the results obtained by operation were excellent; in fact, both my cases were demonstrated at a medical meeting as perfect results. How can we account for this combination of a non-traumatic history with typical operative findings and excellent results? If the lesions were caused by a progressive disease we should not expect good results.
It happens that in both of my cases I strongly suspect that the injury had occurred when the patients were drunk. Since I believe that the usual cause of this injury is a sudden attempt at elevation of the arm to maintain balance during a fall, I think it is quite likely that such an injury may occur to a reeling drunkard. Therefore, I feel that before we say that these lesions are ever non-traumatic, careful inquiry should be made into the possible chance that the injury occurred while the patient was intoxicated. The early symptoms are not necessarily very marked, and would readily be masked in a case of a steady drinker.
Goldthwait has suggested that faulty posture underlies the weakness of the tendons. I am convinced that overuse of the arms in abduction without giving the tendons time to let their circulation do its duty, because they are perpetually stretched, has much to do with these lesions. I have no doubt that trauma may rupture a healthy tendon, but I think rupture from trauma occurs in the great maj ority of cases in aged tendons made weak by overuse, age, or toxic conditions. Dr. Akerson suggests that long-continued disuse might weaken aged tendons to such an extent that they would break under very slight strains and perhaps without much pain.
Whether or not injury precedes or follows degeneration in the tendons, it is a fact that complete rupture of the supraspinatus tendon may be diagnosed and even in late cases may sometimes be successfully repaired by surgery.

PATHOLOGIC HISTOLOGY

In studying the lesions that have been discussed, we should first have some idea of the normal microscopic landmarks which may become altered by injury or disease. The diagram (Fig. 37) should be compared with Fig. 9 in Chapter I, which shows an enlargement of the normal insertion of the supraspinatus tendon in the region where pathologic changes usually take place.

FIGURE 37. DIAGRAM OF MICROSCOPIC REGIONAL LANDMARKS
The relative sizes of the structures and cells have been altered in order to simplify the figure, which should be compared with a photograph of an actual section of this region (Fig. 9).

1. "The Critical Portion" of the tendon is the half inch proximal to the palisades. It is in this region that calcified deposits gather and where complete rupture frequently occurs, although partial ruptures usually begin at the edge of the cartilage. As has been said, even under the microscope one cannot distinguish, in this part of the tendon, between joint membrane, capsule, tendon substance, and bursal floor, because they are here welded into one single structure. Nor is there a clear line of demarcation on the proximal side of the short tendon, where the muscle begins.
2. "The Torpedo Cells" are so called from their shape. They are probably merely modified cartilage cells which lie in the palisades with their long axes parallel to the columns. They closely resemble the cells of the adjoining articular cartilage, but their intercellular substance is more fibrous. They seem to function in making the columns, or palisades, and also in forming the blue line.
3. "The Palisades," i.e., the portion of the tendon inserted in the tuberosity, is thus named because of its columnar fibers. In cases of complete rupture of the tendon, the stub, which often remains on the tuberosity, represents this structure. It is fibro-cartilaginous in consistency and contains many "torpedo cells."
4. "The Blue Line." With the hematoxylin and eosin stain there is always, in adults, a blue line (of course, really a surface) where the palisades are inserted into the bone. The blue line is not present in infancy and even in a specimen from a girl of eighteen (Plate VI), it is not well developed; i.e., the cells stain blue, but there is little deposit outside the cells as compared to the amount of blue non-cellular material one finds in older patients. The blue line is very close to the surface of the bone, but appears to be fenestrated for the insertion of the tendon.
5. "The Armor of the Sulcus" is the superficial layer of bone on the facets which we find in the dried specimen, and is really the cortical bone beneath the blue line. Like the trabecule it takes a pink stain. The armor in a normal tuberosity should be almost smooth on its surface; i.e., in section it should give a definite regular outline. It is a surprisingly thin layer considering the stress it must bear; beneath it are marrow spaces and cancellated bone.
6. "The Synovial Reflection" is the angle between the edge of the articular cartilage and the palisades. It is described on pages 15-16, Chapter I, and is illustrated in Figs. 9 and 10. In dissecting room subjects this angle is seldom normal; there is almost always evidence of rupture of some of the columnar fibers of the palisades, as in Fig. 9.
7. "The Finger-like Processes" pass through the blue line, and form a singularly strong attachment to the bone beneath. These processes usually contain cells similar to the torpedo cells but apparently charged with calcium, for when close to the bone they take a deep blue stain.
8. "The Articular Cartilage" definitely begins at the very edge of the sulcus where the tendon is inserted. There is a sharp line between it and the "palisades"; i.e., the synovial reflection.
9. "The Cancellated Bone," or Spongiosa, forms the bulk of the head of the humerus. The spaces usually contain fat and scattered marrow cells, and are not normally very vascular. Both the blue line and the armor are continuous with similar but less pronounced structures, beneath the articular cartilage, where there are no finger-like processes and where there appears to be a cleft between the blue line and the bone under the cartilage.

PLATES III AND IV

The cuts in Plates III and IV are made from direct photographs of some of Dr. Akerson's slides of old lesions found at autopsy. Those on the left are enlarged two diameters, and those on the right about four diameters in each case.

PLATE III

Figure 1 shows a beginning tear of the fibers at the synovial reflection, a little more extensive in degree than that shown in Fig. 9 in Chapter I.
Figure 2 shows a still more extensive rupture of the deep fibers, i.e., a. " rim rent." More than half of the tendon has been torn away, leaving portions of the columnar fibers (palisades) still attached to the tuberosity. The little hook which is in the center of the small circle is all that remains of the former synovial reflection. One small cavern is present in the tuberosity, which also shows evidence of slight excrescences.
Figure 3. A section from the same specimen as that shown in Plate V, Fig. 6, but taken near the edge of the gap, so that there is continuity of some of the superficial portion of the tendon with the external part of the palisades. It would be hard to explain this section or No. 4 by erosion from contact with the acromion process.
Figure 4. Another section from the same specimen which shows a partial rupture in the central portion of the tendon, and yet the fibers are continuous with the palisades, superficial to, and also beneath, the torn fibers. Most specimens show, when sectioned, this same irregularity in the extent of rupture in the different layers of the tendons. Compare the frontispiece, and imagine the degree of tearing in each layer which would be shown by a section at the left of the rupture.

PLATE IV

Figure 1. A very old complete rupture in which recession has taken place; no evidence of either sulcus or tuberosity left; the whole surface of the tuberosity has become rounded off to avoid friction. It is not enough to say by friction. The process of recession is a response to friction rather than a result of it. The fibrous layer which occupies the place of the tendon is not true tendon substance, but a portion of the roof of the bursa, the entire fioor of which has disappeared.
Figure 2. A recessed tuberosity where no sign of sulcus or eminence remains. In the falciform edge of the torn tendon is a small oval speck of bone which formerly was the facet of insertion of the tendon. This is pretty definitely proven, not only by the gross appearance of the specimen, but by the fact that under high magnification one can still see evidence of the blue line on the periphery of the fragment. In this way nature manages to reduce friction even where a fragment of tuberosity is evulsed.
Figure 3. Section through an excrescence which has deformed the armor and the blue line in this region; yet under high power there are none of the usual evidences of inflammation, such as lymphocytes or increased fibrosis of the marrow spaces. The synovial reflection is relatively normal and so are the palisades, internal and external to the excrescence.
Figure 4. A rim rent where all the tendon is torn away from the sulcus except the superficial portion which extends into the periosteum. Partial recession has occurred. Some of the columnar fibers are still present in the deformed sulcus.

PLATE V. DRAWINGS OF COMMON PATHOLOGIC FINDINGS
Figure 1. Section of the greater tuberosity in an old case of rupture of the supraspinatus. It shows the presence of "caverns" containing vascular tissue. The section is taken through an excrescence or "volcano." A section of the same specimen taken in a more transverse plane shows the caverns as rounded, cystlike spaces.
Figure 2. High power picture of the lower end of one of these caverns, indicating the vascularity of the tissue within.
Figures 3, 4 and 5. Illustrations of a few of the varied appearances presented by villi found in chronic inflammation of the bursa. Fig. 8 shows fibrous, vascular and fatty changes, and Fig. 4 shows richly cellular areas. The section, Fig. 5, showing infiltration with polynuclears was taken from the case reported on page 247. There was no gross evidence of suppuration in this wound, but old silk stitches were causing irritation of the tissues.
Figure 6. Section through an old rupture of the supraspinatus tendon. The tuberosity is in process of recession and has become atrophied except for an excrescence at the outer margin. The blue line has almost disappeared. The armor is lacking because for years there has been no functional stimulus. Eventually such a tuberosity would become almost completely rounded off.

PLATE VI. HISTOLOGY OF TENDINOUS INSERTIONS

PLATE VI

1. Section .through the attachment of the supraspinatus tendon of an infant. The center of ossification of the articular head is present, but those for the tuberosities have not yet appeared. The tendon takes a bright pink stain, while the cartilage, which is to form both the articular surface and the tuberosity, is purple.
2. Higher magnification of the "synovial reflection" in the same specimen. It shows the line which separates the tendon from the cartilage which is later to form the tuberosity. The coloration of the intercellular substance (i.e., the acidity or alkalinity of the tissue), rather than the morphology of the cells, is the distinguishing feature. Sections of this region from children up to at least the age of twelve show no very definite blue line of demarcation between these two structures, but in sections from a girl of eighteen (Fig. 3) there is the suggestion that the blue line is in process of formation. It therefore probably begins to form somewhere between twelve and eighteen.
3. Section through the cortical (armor) bone of the tuberosities in a girl of eighteen. In this section the blue material appears to be chiefly in and about the cells (bone corpuscles?) in the armor. It suggests that these cells are instrumental in causing the blue deposit. They appear to leave it behind as a kind of shellac for the finished adult surface of the armor of the tuberosity. Whether they die when they have finished this work or whether they leave the deposit behind and proceed upward to become fibrocartilage "torpedo cells" is a matter for histologic research. The present theory is that they do not proceed up into the tendon. In this young girl, the bone below the blue line is rich in cells, but in adult life (Fig. 4) there are relatively few living torpedo cells in the armor. Dr. Wolbach tells me that the formation >of this blue line resembles to some extent histologically the formation of enamel in a tooth.
4. This section shows what is usually found in an adult specimen. The blue line appears to be entirely extracellular and the fibrocartilage cells, which I have called "torpedo cells," in the palisades are very conspicuous. There often occur little masses of purple, crystalline collections, as indicated in this picture, just above the blue line. They are sometimes found even further up in the palisades. Their appearance suggests that they may be somewhat abnormal deposits, due to the failure of the cells to leave their blue staining material in the region of the surface of the bone. It is possible that a knowledge of their formation would throw light on the formation of the peculiar calcified deposits which occur in the tendon at a higher level. In both Figures 3 and 4, notice the finger-like processes which pass down (or it may be pass up?) through foramina in the blue line. Evulsion of these fibers may occur or a portion of the blue line may be retracted with the tendon.
5. A section taken from the supposedly normal adult tendon shown in Figure 9. On study with high power it shows deeply staining areas in the tendon substance which give evidence of abnormality of the collagen. It also shows abnormal changes in the torpedo cells.
6. Early changes in the character of the collagen of the fibrocartilage which composes the palisades. When the collagen is in this condition, the degenerative portions may be indicated by either a bluish or a pinkish stain with H and E.

We may now briefly take up the changes which are often found in these structures.
1. The critical portion of the tendon may show many shades of stain according to the degree of necrosis. It may contain large calcified areas or minute specks or merely necrosed fibers without any deposit. It may show rupture of all the fibers or of only those of the central or peripheral parts.
2. The torpedo cells undergo very interesting alterations. They may become calcified or enlarged into peculiar giant cells, or they may fade.
3. The palisades often show irregular staining qualities indicating necrotic changes; broken fibers, rice bodies, etc.
4. The blue line is a curious structure which is present at most points in the body where cartilage or tendon is attached to bone. It may become irregular on its surface or embossed by the formation of bony excrescences beneath it. It may be torn out in patches by the tendons.
5. The armor may become greatly thickened (eburnated) in laboring men from excessive use of the tendon. It may also become thickened from chronic inflammation in the tendon. Where the blue line is destroyed, the armor is thin; e.g., after recession of the tuberosity it is usually quite thin, and the blue line has disappeared.
6. The synovial reflection is almost always changed to some degree as rim rents form. In most elderly patients we find at the angle of reflection that the columns of the palisades are more or less torn.
7. The finger-like processes may also show evidences of necrotic changes if staining reactions may be considered evidence. I strongly suspect that increase of the calcium deposits in the blue line may choke off these fibers so that the tendons may be more easily pulled out.
8. The articular cartilage may show thinning and superficial loss of substance but usually appears unchanged even to the very edge.
9. Vascular caverns may be formed in the spongiosa near the facets.
There are many other interesting and suggestive points about the pathologic histology of these lesions, but the above-mentioned changes may be readily confirmed by any one who has access to autopsy material. This is an uncultivated pathologic field except for Dr. Aker-son's work. Correct interpretation of the common findings is greatly needed so that our clinical results may be improved. To my mind one of the most promising leads for the pathologist is that concerned with the extreme sensitiveness which the tendons show to hematoxylin and eosin stains. Sometimes the necrotic portions are pink or red, and sometimes blue or purple. Notice the staining of the section from the infant's humerus. Why should the contrast be so pronounced? In the adult why is the bone red and the blue line blue? What phases of necrosis attract the blue or the red stain? Could these tissues be acidified by either local or general use of drugs? Could the pathologic process in tendinitis be checked by increasing or diminishing the acidity of the blood or in any way by altering its constituents ?

REFERENCES

CODMAN-, E. A., AND AKERSOH, I. B., The Pathology Associated with Rupture of the Supraspinatus Tendon, Annals of Surgery, Phila., 1931.
GHUBER, W., Hygrom der Bursa mucosa subacromialis, Oesterr. Z. f. prakt. Heilk., Wien, 1869, xv, 819; Also: Ein Hygroma retroglenoidale scapula?, Arch. f. path. Anat., etc., Berlin, 1875, lxv, 288-241.
MOSCHCOWITZ, E., Histopathology of calcification of the spinatus tendons, as associated with subacromial bursitis, Proc. N. Y. Path. Soc, 1915, n.s., xv, 1-7; Also: Am. J. M. Sc, Phila., 1915, cl, 115-126.
SCHWABZ, E., Untersuchungen tiber die Entstehung der Zotten und Reiskorper in Hygromen sowie die sogenannte "fibrinoide Entartung" des Bindegewebes der Schleimbeutelwand, Dtsch. Z. f. Chir., 1931, ccxxxv, 1-3; Also: Dtsch. Z. f. Chir., 1982, ccxxxv, 140-163. (Contains some excellent photomicrographs of the so-called rice-bodies which are often found in bursa? and which are demonstrated again and again in Dr. Akerson's collection; references are given to most of the important articles on the pathology of bursa; in general, but there is no mention of the subacromial bursa.)
STIEDA, A., Zur Pathologie der Schultergelenkschleimbeutel, Arch. f. Klin. Chir., Berlin, 1908, lxxxv, 910; Also with BERGEMANN, Ueber die mit Kalkablagerung einhergehende Entziindung der Schulterschleimbeutel, MUnchen med. Wchn-schr., 1908, lv, 2699-2702.
Brief references to the pathology of this region are also made in some of the papers listed at the end of Chapter VI.

Calcified deposits in the supraspinatus tendon

CHAPTER VI

As far as I know, the first patient to be operated upon for this -condition was Miss McM., age 24, Massachusetts General Hospital, No. 127430, June, 1902. I assisted Dr. F. B. Harrington to incise and drain what we took to be an abscess of the subacromial bursa. A culture of staphylococcus aureus was obtained, but the wound showed no sign of infection and promptly healed. I believe now that the culture was contaminated, for I have never been able to obtain a culture from one of these cases since. On reading the record now the description seems impossibly stupid, for in spite of the fact that I was even then interested in the anatomy of the bursa, and also had been an enthusiastic pioneer in using the X-ray for six years, I did not put two and two together and realize that the condition was what we now call a "calcified deposit." It was not until May 17, 1905, when Dr. C. F. Painter asked me to see with him another doctor who was in such acute pain that he begged to be operated upon, that we suddenly understood almost as much as we know now about the condition. Yet I think that even then we were the first surgeons to realize what these cases were and how easy it was to relieve them.
I mention these experiences to illustrate how blind the human mind may be to facts which are perfectly obvious, and when such facts are clearly demonstrated how difficult it is to diffuse them so that they may be generally applied. Rontgen's discovery had for several years made the lesson we learned from this case plain for any surgeon to read, yet no one had seen it in just the right light. Those who happened to know about the anatomy of the bursa may not have happened to be able to read the X-ray, or to have had an appropriate patient, who, like our friend Dr. D., urged us to "try anyway." We tried and relieved him at once, yet today right in this city there are probably patients with the same condition being treated week after week as "neuritis." Dr. Painter and I have both written about our experience; other surgeons have confirmed what we say; we have continued to get excellent results from this operation; yet twenty-seven years have elapsed and some cases are still treated without even the diagnosis being made or the X-ray even used. Dr. Painter has reported this case in his original article, March 21, 1907; I also reported it in my paper published June 9, 1908, as follows:

"The patient, Dr. D , is a man of 37 years of age, of heavy (200 pounds) physique and plethoric constitution. His previous history is unimportant, except that ten years ago after playing baseball all one summer he used to have a great deal of pain and soreness in his right shoulder joint. Since that time he has had at intervals a great deal of pain and tenderness in the joint. The pain bothered him particularly at night and was at times severe enough to prevent his sleeping well. He stated that until within a few days he had been able to move his arm without any trouble in all directions; for instance, behind his neck, behind his back, and over his head, without especial pain. There have been times, however, when it was difficult for him to raise the hand over his head, but when it was once put in this position it was comfortable for a time. He used to occasionally put it in this position at night; after lying with the hand behind his head for some time, he would then put it down by his side again. In doing this there was always pain during the motion. He recalls at times having his wife wake him just as he was going to sleep with his hand behind his head and tell him to put it down by his side, so that he would not go to sleep in that position and find it stiff on waking. External and internal rotation of the arm could be gone through without giving any trouble whatever.
Eight days ago while in New York he suddenly noticed that the point of his shoulder was tender and painful and that the motions were much restricted. He could with difficulty get into his clothes, but could not reach his hip pocket as he had been accustomed to. During these days the soreness had persisted and there had been great pain, sufficient to prevent sleep at night and to require large doses of morphine; the only comfortable position was sitting with the elbow supported. The pain was so great as to make him desire immediate operation.
Examination showed that the external and internal rotation of the humerus on its long axis is restricted about one-half the normal arc. Abduction or elevation of the arm is impossible on account of the pain caused in the neighborhood of the greater tuberosity. Attempts at passive elevation of the arm showed that the scapula moves in conjunction with the humerus.
An X-ray from the posterior view shows a pyramidal shadow in the region of the subacromial bursa just above the greater tuberosity and external to the tip of the acromion, the base of the mass being downward and about an inch in length. Between the base and the greater tuberosity is a translucent band about a quarter of an inch wide, occupying the position normally occupied by the tendon of the supraspinatus. The mass is apparently in such a position that the tuberosity could not ride under the acromion without compressing it.
Operation, by Dr. C. F. Painter, May 17, 1905.
Under the impression that the mass shown in the X-ray was caused by a calcification either of the bursa or its base, a vertical incision of about two inches in length was made through the skin and between the fibers of the deltoid on the point of the shoulder over the greater tuberosity. When the fascia beneath the deltoid was reached a small opening was made in the subdeltoid bursa, and this was enlarged with scissors to an extent great enough to admit the forefinger. The aspect of the bursa was not abnormal inside except for some firm adhesions anteriorly which made it difficult to separate the plane of the bursa from the neighborhood of the bicipital groove and the anterior part of the greater tuberosity. With the finger in the opening, it was found that during the rotation of the humerus, a mass corresponding to the shadow seen in the X-ray could be felt to pass beneath the finger. This mass evidently lay at the base of the bursa on the top of the greater tuberosity. An incision was made into it permitting the escape of about half a drachm of sebaceous material resembling the contents of a dermoid cyst. The cavity, which resembled a wen or dermoid, was thoroughly curetted and the walls excised. The base of it was evidently the tuberosity and tendon of the supraspinatus; the roof was the base of the bursa. When the sac had been entirely removed, it was found that the motion of the joint under ether was perfectly normal, rotation and abduction being easily performed. The incision in the bursa was not closed and the skin was drawn together with silkworm gut and the arm put in the ordinary sling position.
Remarks :
The point of particular interest in this case is the persistence of the function of rotation in spite of the limitation by abduction. It is obvious that the position of the cyst allowed rotation with comparative freedom, but that attempts at abduction would crowd the cyst between the greater tuberosity and the acromion process and caused pain and spasmodic rigidity of the joint. The acuteness of the symptoms within the last eight days is explained by an inflammatory condition in the cyst. The previous attacks were probably due also to the same cause. That this inflammation did not involve the bursa to any great extent is shown by the persistence of rotation. Since the bursa was not inflamed it would be readily seen that the symptoms which the patient complained of in regard to going to sleep with the arm behind his head can be explained, for the cyst having once got under the acromion was relieved of pressure. In other words, it was only when the cyst was inflamed by over exercise that its presence was noticeable, unless elevation of the arm crowded it between the acromion and the tuberosity.
The relief obtained by this operation was immediate and permanent.
It will be seen by comparing these notes with the description of the operation by Dr. Painter that the calcareous deposit seemed to me to lie not in the bursa, but beneath its base, and in or adjacent to the tendon of the supraspinatus."

It was difficult to find a heading for this chapter, and the one chosen is not satisfactory. An explanation of why it is not satisfactory may help the reader to understand the subject the caption is supposed to define. "Calcified subdeltoid bursitis" is a term in common use for the same condition, but this could not be accepted as a title for three reasons. First, the calcified deposits are rarely in the bursa, but lie beneath its base in the substance of the tendon of the supraspinatus or in one of the tendons of the other short rotators. To be sure, occasionally after inflammation has occurred the softened tissue containing a deposit bursts (See Plate II, Fig. 4) and the calcified particles are diffused throughout the bursa, the outlines of which may then be delineated by the X-ray. Fig. 44 shows an instance of this, but Figs. 45 and 46 are instances of the usual condition where the deposit is in its place of origin in the substance of the tendon, entirely beneath the base of the bursa. Therefore, "calcified subdeltoid bursitis" is a misnomer. It is also a wrong term because, as is explained on page 18, subacromial is a better term than subdeltoid. A third reason is the use of the word bursitis, as the noun which "calcified" is used to qualify. The bursitis is secondary to the pathologic process in the tendon. One may find no inflammation of the bursa and yet a large deposit beneath it may be demonstrated by the X-ray. It is only when the deposit is large enough, or the inflammation about it is great enough, to cause interference with the function of the bursa, that the symptoms of "bursitis" appear.
Our chosen title is also unsatisfactory because the offending deposit may not be in the supraspinatus tendon but in one of the other tendons underlying the base of the bursa, for instance, in that of the subscapularis. The infraspinatus and teres minor tendons may occasionally be involved. (See Figs. 45 and 46.) Sometimes two, three or even four tendons in the same patient are the seats of deposits. It seems to me highly probable that in most cases which show the deposit in one tendon there may be also a "tendinitis," or at any rate a degenerative change in the other tendons, which is not accompanied by much calcification, and therefore is not demonstrated by the X-ray. Furthermore, I am confident that I have seen instances in which the same tendinitis has produced bursitis by involving the base of the bursa before any calcification dense enough to be demonstrated has taken place. We might change the title to "Calcified and Uncalcified Changes in the Tendons of the Supra-spinatus, of the Subscapularis, of the Infraspinatus and of the Teres Minor; the Secondary Changes they may cause in the Subacromial Bursa overlying them, in some cases producing the Clinical Condition known as 'Subdeltoid Bursitis,' which should be called 'Subacromial Bursitis.'"
Even this extensive heading can be criticized, because there are still many cases never diagnosed as bursitis, but which pass as "neuritis." I might head the chapter "The Usual Cause of Neuritis in the Arm and Shoulder."
In 1908 I wrote as follows regarding subacromial bursitis: "The cases which are to be discussed in this paper are by far the most common lesions of the shoulder joint. It is the writer's experience that more patients seek hospital treatment for lesions involving the subacromial bursa than for all other lesions of the shoulder joint, including tuberculosis and fractures, added together." "Not only is this true, but it is also true that more cases of subacromial bursitis seek hospital treatment than all the cases of the supposedly more common forms of bursitis such as 'miner's elbow,' 'housemaid's knee,' and 'weaver's bottom.' In those clinics in which these statements are apparently not true it will be found that these cases are passing unrecognized under the diagnoses of brachial neuritis, periarthritis, muscular rheumatism, circumflex paralysis, contusion of the shoulder, fibrous ankylosis, gout, rheumatism and other vague terms."
These convictions have gained strength with the years, although I now wish that I had expressed them in better English. It may be almost taken for granted that cases diagnosed as neuritis, rheumatism, and arthritis of the shoulder, are really instances of subacromial bursitis; those with a distinct traumatic history being usually cases of bursitis due to rupture of the supraspinatus, and those of spontaneous origin being instances of the process I have tried to define above. Perhaps this seems a sweeping statement to the many physicians who still believe there is such a thing as brachial neuritis in otherwise healthy people; yet the statements are made in all sincerity by one who has studied the shoulder intensively for twenty-five years.

FIGURE 48. VARIED VIEWS OF A CALCIFIED DEPOSIT IN SUBSCAPULARIS

Tracings from three different films of a case in which a calcified deposit had formed in the subscapularis and had caused acute bursal symptoms. The deposit lying in the substance of the subscapularis tendon of course did not move about in relation to the lesser tuberosity; the apparent change of position is entirely due to changes in the relation of the bones in consequence of rotation of the humerus. The first film was taken in the anatomic position, and the deposit is overshadowed not only by the contours of the humerus but by the acromion. The second film was taken in internal rotation and the deposit appears to have moved over to the top of the glenoid. The third figure shows the deposit when the arm is akimbo; i.e., partly abducted and internally rotated. The deposit appears to have traveled to the lower edge of the glenoid.
This patient was operated upon by the writer, and the deposit removed. The incision was the same as in cases in which the deposit is in the supraspinatus; the affected area was just as readily brought under the incision by external rotation of the arm.
Deposits in the subscapularis are more frequently horizontal in their long axes than when they are in the other tendons. Compare Plate VI, Fig. 6. Sometimes they are not horizontal as in another case shown in d and e.

In order to make the condition plain the shadow of the deposit has been slightly intensified in these cuts. In the anatomic position (d) the deposit shows as a small speck internal to the bicipital groove, which in most antero-posterior X-rays can be located by the dense line of the outer edge of the lesser tuberosity. This line is an important landmark in X-ray interpretation, for by its position one may determine to a certain extent the degree of rotation of the humerus, and therefore make a reasonable guess at which facet shows on the contour of the greater tuberosity. Figure e is taken with the humerus held nearly horizontally and rotated inwardly as far as possible; i.e., the arm is in a high akimbo position. The deposit now shows in profile on the lower margin of the head of the humerus. Compare this plate with Figure 26, which shows an arm in the hammock position, in which the profile of the lesser tuberosity appears superior to the head of the bone.

The relation of trauma to the calcified cases is not yet clear. Since I first studied the subject I have always felt that it was highly probable that an acute or chronic injury to the tendon must occur long before the deposit appears. The pathologic histology of the lesion itself might be accounted for by faulty repair of an injury in tissue which has little vascularity and would be slow to restore itself. This was J. H. Wright's view from some tissue which I gave him. On the other hand, the fortuitous finding of the specimen shown in Plate VI, Fig. 5, indicates that the first change may be degeneration in the interstitial part of the tendon. Moschcowitz feels that the primary process is a tendinitis. Meyer, investigating from anatomic material, feels that both the biceps tendon and that of the supraspinatus may be attenuated from friction in overuse. I take issue with Meyer on the ground that I believe that destruction by friction per se does not occur in living tissue directly. Friction would first produce inflammation with resulting attenuation and atrophy of the part. I would expect in such tissue, if the local area became sufficiently poor in synovial lubrication, that congestion, tenderness and protective reflex spasm of the adjoining muscles would occur long before friction per se could do any damage. Whether the attrition be directly from friction or indirectly from atrophy following inflammation due to friction, the fact is that we rarely find ruptures of the supraspinatus in any but the aged laboring classes. The calcified cases on the contrary occur in young or middle-aged people, and moreover, they are usually not in people who do heavy laboring work, but in the more highly educated classes who do sedentary work, using the arms in a slightly abducted position for hours (See p. 135, Chap. V).
Since the calcified cases are, as a rule, in the middle-aged, and the rupture cases in persons at least elderly, some relation may exist. Perhaps aged cases in which rupture occurs had the tendinitis and calcified deposits in their earlier years, and thus had their tendons weakened and made prone to rupture. Or perhaps in youth strains which would rupture the tendons in older people result in merely the rupture of a few fibers. The capacity for repair is then great and restoration results. The same force in middle life might cause a slightly greater damage with hemorrhage into the tendon followed by faulty repair and calcification. Still later in life the same force might tear the aged tendon hopelessly. A partial parallel to this hypothesis is found at the knee, where the same kind of force in early youth avulses the tibial tubercle; in middle life the patella is the weakest point and gives way transversely, but in the aged the quadriceps extensor tendon yields in many cases. In other words, the relative tensile strength of the tissues has changed with age.
Although it is the rule that cases of calcified deposits recover with no known sequelae, I am more and more inclined to think that they must result in some atrophy of the tendon, whether they are absorbed naturally or are removed. I cannot believe that complete and sound repair takes place. This belief arises chiefly from a study of the microscopic changes which consist largely of a necrosis of the fibers. I incline to the belief that these same tendons may be prone to rupture in later years.
The Workman's Compensation laws (through the pertinent questions they put into the mouths of the members of Accident Boards and of Insurance lawyers) are sharpening the wits of modern Industrial surgeons in many ways and are having their effect on shoulder surgery also. As these little calcified deposits now cause loss to the insurance companies, they are assuming more importance than when they only bothered the individual patient. We are confronted with cases in which a slight trauma is alleged to have occurred and in which, after a lapse of a few days or weeks, disability has appeared and the X-ray shows the shadow of a deposit. Did the lesion precede the trauma? If so, did the accident aggravate the symptoms enough to make the difference between inability and ability to work? May the occupation which called for unusual or repeated use of the affected tendon have caused the lesion prior to the alleged accident? Since in cases not associated with accident at all the symptoms frequently come on suddenly, might not the association with a trivial accident be merely fortuitous?
The answers to these questions can be founded on so little in the way of statistics or demonstrable facts that they come into the realm of expert testimony and are matters of opinion only. I will try to set down my own opinions and what few reasons I have to support them.

Precedence of trauma or lesion (i.e., of a single definite trauma). Since in a general way we know that the process of calcification of dead or injured tissue requires a considerable time, it is pretty clear that the lapse of only a few days after the trauma before the X-ray was taken would indicate that the lesion had existed prior to the trauma. The same would probably be true a week or two after the trauma, but there would be increasing doubt as the interval progressed from weeks into months. I incline in general to think that the lesion precedes the trauma even when the X-ray is taken months later because (1) I have seen no instances where an early X-ray showed no deposit and yet a later film demonstrated one. (2) Because I have seen many cases where the X-ray did show a deposit soon after the trauma. In other words, in my experience the calcification usually preceded the trauma and I have never been able to satisfy myself in any case that it followed the accident.
It not infrequently happens that the X-ray will show a quiescent deposit without any symptoms in the supposedly well shoulder, as well as in the traumatized one. In fact, bilateral deposits are so common as to make us doubt whether acute trauma is ever a cause. They suggest that the primary cause is a general one. For instance, a systemic one; an attitudinal one; a congenital morphologic one. Yet in persons who use to excess both arms in their daily work, a chronic traumatic cause might be postulated even in bilateral cases.

Aggravation by trauma. Any one who has seen the bursa opened at operation and beheld the angry, red tumefaction with its white or yellow summit would agree that a blow on the inflamed area or even a sudden excess of tension on the tendon might aggravate the condition. One can readily see that the softened area might burst and spread its contents into the bursa under such circumstances. And it is clear that a trauma need not be very severe to do this. Yet to have the deposit burst into the bursa is in my opinion nature's way of curing it (Fig. 34). The acute symptoms are often soon followed by complete and permanent relief!

Excessive use as a cause. I am inclined to believe that this is the most common contributory cause if not the primary one. There are many instances besides "writer's cramp" and "housemaid's knee" to support the statement that in our division of labor the abuse or overuse of particular organs or tissues results in pathologic changes. Millions of years of heredity have not prepared the modern stenographer or machine operator to keep their supraspinatus tendons stretched and under tension, on the qui vive hour after hour, day after day. While only a few individuals in these employments have a severe tendinitis or bursitis, I believe that could we see the supraspinatus tendons from a series of stenographers who have worked steadily five years or more, some pathologic change would be found in them. Miners do not all have "miner's elbow," but I venture to say that all those who habitually work on their elbows would show hypertrophic and degenerative changes in their olecranon bursas. It is therefore my opinion that when disability arises from these calcified deposits in industry, the presumption should be that they are "Industrial," unless it can be shown that the occupation is not of a nature to demand overuse in this region of the body, or that the patient at home pursues an avocation which causes such abuse. Nevertheless it would require many months or years of such abuse to produce a typical "calcified deposit," for the minute pathology of these lesions is of a chronic type, although the inflammation about them may be very acute.

Coincidence of onset with trauma. It is certainly true that many cases have a sudden onset of acute symptoms with no history of trauma. It is easy to suspect in any given case that trauma was only an afterthought to get compensation. I have suspected this was so in some cases, but in others there was a clear history of accident, leaving little room for doubt that the accident precipitated the symptoms. It seems to me that no rule can yet be formulated and each case must be decided on its own merits; the more vague the story, the less likelihood that the course of the trouble was influenced by the trauma. The character of the occupation, the condition of the other shoulder, the duration of the kind of work, and other circumstances should be taken into account. At present my tendency is to consider such cases as instances of coincidence, even when the symptoms followed soon after the accident and the X-ray was taken weeks later. It is so easy to hit any sore spot in the body and to attribute the soreness to the blow which drew attention to it! Add to this the incentive to obtain compensation and the psychologic fact that it is human nature to influence one's self into any belief in which one's fancied interest lies. Nevertheless I would not deny that a single trauma (if well proved and of sufficient force) could be the direct cause of the onset of disabling symptoms. Furthermore, in doubtful cases it is only just to remember that it is likely that the occupation itself may have been the underlying factor.

Symptoms. Symptoms may be absent entirely and yet the X-ray may show a large deposit. This fact is particularly striking in the bilateral cases, for one side may be symptomless and the other the cause of agony. Radiologists not infrequently find these symptomless deposits accidentally. Yet these facts do not prove that the disease may run its entire course without symptoms. On the contrary, since we often see a large deposit in a case which has had symptoms for only a day or two, it is clear that a symptomless case may at any time present symptoms. Therefore, we doubt whether any case ever runs its whole course without symptoms. Most of the bilateral cases I have seen had one symptomless shoulder at first, but perhaps a year or two later had typical symptoms come on in the other. I have yet to see a case in which a good-sized deposit disappeared without ever causing pain or restriction. Beyond question the X-ray demonstrates that spontaneous absorption takes place in most cases, although some such instances may be errors of X-ray interpretation. Some certainly discharge into the bursa and are absorbed from there. Whether there are actually cases which never give symptoms and run their whole course without complications, I do not know. Many never give severe symptoms.
Most cases run a subacute course, a few are exceedingly acute, and a few are truly chronic. An attempt to classify cases strictly in this way results in confusion, for we find many cases which are borderline and others which in their course pass through all three stages.
The usual history is not of acute pain at the beginning. The first symptom noticed is a slight, painful "hitch" during certain movements of the arm, such as in raising one's arm to put on a coat or in placing an object on a shelf. Sometimes reaching across a table for some object, as a pen or a salt cellar, causes this feeling. Women complain that they cannot do their hair. Little attention is paid to this until it becomes associated with every such motion. The slight pain becomes expected and eventually dreaded before such motions are performed, so that the patient corkscrews his arm in a peculiar way to avoid the "hitch." Instinctively he learns to rotate outwardly as he abducts and thus avoids pinching the inflamed point under the coraco-acromial ligament as the arm is raised. Presently the sensitiveness reaches such a point that involuntary scapulo-humeral spasm is produced, and the normal, smooth division of motion between the movement of the scapula on the chest wall and the elevation of the humerus on the scapula is destroyed.

Loss of Scapulo-humeral Rhythm.
Normally when one raises the arm to a position pointing straight toward the ceiling, much of the motion is performed by rotation and elevation of the scapula on the chest wall, while the remainder is performed by the true joint. (See Fig. 25.) The two motions go on pari passu, so that as one watches from behind it is impossible to say that either motion proceeds faster than the other. In nearly all affections of the joint or bursa, this even distribution of motion is destroyed, because the sensitive point, unwilling to move, sends its reflex telegram to the short rotators to lock the joint in a fixed position and to hold it there by spastic tension. This phenomenon is one of the most important for the student of shoulder conditions to learn, and its behavior in these cases of calcified deposit is very characteristic. At first it is not complete, the spasm being semi-voluntary in the sense that the individual can control the inhibition of it to a certain extent. For instance, in mild cases the spasm holds the joint fixed as the arm makes its upward journey for about ninety degrees. Then the individual semi-consciously relaxes it and the joint surfaces themselves carry out the remaining ninety degrees to complete elevation. When the sensitiveness is still greater, even a strong effort of will cannot relax the spasm and the arm only ascends so far as it can through the scapular motion—almost straight out from the shoulder laterally. Later the spasm holds continuously night and day until firm adhesions form, producing a fibrous ankylosis which effectually splints the inflamed parts until they heal. When healing has taken place the adhesions gradually stretch and motion of the joint slowly returns. The course of this whole process in the most severe case is about two years. The fixation is never permanent. The great majority of cases do not have this severe course. Probably none would unless delayed by injudicious treatment.

The cardinal symptoms of the whole picture are pain, spasm, limitation and atrophy. These four symptoms may make a variety of complexes according to their relative severity. In one case pain may be the predominant one; in another, spasm; in a third, adhesion. I have seen cases which ran an almost painless course as if the spasm was started at once without the sensation of pain being experienced. The painful stage when the spasm is intermittent or semi-voluntary was absent; spasm from the early days was complete and adhesions took place before pain was felt in any considerable amount. The ankylosis stage persisted for months, the patient's chief complaint being from the limitation of movement. Some cases have relatively little spasm, no adhesions and constant pain. As a rule the amount of pain is inverse to the amount of restriction. The physician may relieve the pain by fixation of the arm and allow the adhesions to occur at once, but as I shall show later this is bad practice, unless the patient is one who can afford to avoid using the arm for many months. In most cases the "hitch" stage persists for many weeks with gradually increasing pain until past the stage of semi-voluntary spasm when restriction dominates the picture.

Pseudo-neuritis. If there has been a long, painful stage all the adjoining nerves become sensitized and the phenomena we call "neuritis " supervene even when fixation has occurred. The pain or hyperesthesia, originally mainly felt in the circumflex distribution about the shoulder and near the insertion of the deltoid halfway down the arm, becomes more diffused. It shoots up into the neck, on to the back of the shoulder blade and down the distribution of the radial nerve to the thumb and forefinger. Even the ulnar and median nerves may become sensitized, the hand and fingers swell and the skin over them becomes glossy. The picture is that of "brachial neuritis," but removal of the calcified deposits relieves it!
When the patient has hugged this painful, tender, useless arm to his side for weeks it presents a most unnatural, misshapen appearance. The back of the hand and upper flexor region of the forearm are swollen, while the anterior portion of the wrist is not. The fingers are partially flexed and cannot be extended even passively. Meantime the sleepless nights, incessant pain, and the dread of incapacity and uselessness have had their dismal effect on the patient, who may reach a very pitiable condition. Drugs have only too often added to the unhappiness of the individual—the family has a querulous invalid to care for.
Fortunately this picture is not the usual one nor is it frequent at present in this community, for nowadays the X-ray is sought for most joint conditions and locates the deposit; the condition is treated more hopefully and intelligently than when the diagnosis of "neuritis" was more common. Mild cases are far more frequently seen today.
Pain at night and inability to get into a comfortable position is the most uniform and constant complaint in all stages of this disease whether in acute or chronic form. Even the adherent cases cannot sleep for long on the affected side. The average patient tells you that he could put up with the pain in the day if he could only get a good night's sleep. In the early stages before there is much spasm, relief may be obtained by sleeping with the hand behind the head. In this position the tender point lies beneath the acromion, where it has plenty of room and where the supraspinatus tendon is relaxed. It is probably the most favorable position for the blood supply to repair damages. Women seem to assume this position more readily than do men. If a patient told me that she had pain in doing her hair and could not get her arm comfortable at night without putting her hand behind her head, I should be pretty certain that she had a calcified deposit in her shoulder. If she added that there was pain in the lower fibers of the deltoid near its insertion in the humerus, I should feel still more certain. If I found a raised, tender point about the size of the tip of the finger on the greater tuberosity which moved as the humerus was rotated, I should consider the clinical diagnosis established, although subject to confirmation by the X-ray.
The location of pain in the region of the lower fibers of the deltoid six inches or so below the real lesion, is a curious but very constant phenomenon in these cases, in all stages of their course. The complaint of pain in this region is almost diagnostic without other symptoms. I am uncertain whether it is to be explained as reflex pain or as directly due to spasm of the lower deltoid fibers. If one compares the two arms by taking the lower parts of the deltoids between fingers and thumbs of both hands simultaneously, one finds a distinct thickening, and there is often tenderness, too, on the affected side, such as would be produced by a tonic spasm of the fibers. The pain located here may be subordinated in the acute cases to the local pain in the bursa. One can in acute cases mark out the exact limits of the inflamed bursa by carefully pressing with a pencil tip and obtaining the patient's cooperation in locating the line of transition to acute tenderness. This is a very definite line and it may sometimes be vaguely seen when the bursa is distended with fluid and fibrin. Even when the bursa is the maximum tender point, the lower deltoid region may be the seat of maximum pain. There may be no local tenderness over the bursa and yet much pain and some tenderness in the lower deltoid.

Acute cases are characterized not only by the above-mentioned, distinct, local tenderness, but by excessive spasm and pain on the slightest motion of the joint. An acute attack may at any time appear in the course of a subacute or chronic case, but the most severe attacks usually appear without warning or known cause, though sometimes following a slight trauma. They represent the onset of bursitis from extension of the inflammation about the deposit in the tendon beneath the bursa. The symptoms are those of an acute bursitis and are homologous with similar acute inflammations in other serous cavities, i.e., congestion, friction, pain, protective spasm, fibrinous exudate, adhesion, cicatrization, partial absorption. The acute stage is therefore brief, lasting a week or two. It is during this period when the bursa is full of fibrin that it may be outlined as described above. The patient may wake at night with agonizing pain in the shoulder and be unable to move the shoulder joint more than a few degrees. Tenderness over the bursa is exquisite. Spasm has fixed the joint rigidly so that the arm is held in the sling position and the patient cannot be persuaded to move it in the least. One can take the patient lightly by the thumb and he will follow submissively where he is led, his whole body on the alert to avoid using the joint in the slightest degree. He cannot by any possibility sleep on the affected side and usually tells you that since the pain began he has "walked the floor" or had to sit up in a chair. For several nights no ordinary remedies give relief and considerable doses of morphine may be required. Exploration of the bursa at this stage usually shows that it contains fluid and fibrinous exudate overlying the boillike elevation on its base with its crimson, turgid periphery and whitish center. Until one has seen this appearance it is hard to realize how much these patients suffer. It is in such cases that the relief by operation is particularly striking, but they often get well promptly without operation or any treatment at all.

FIGURE 44a. BURSA DISTENDED BY FLUID CONTAINING CALCIFIED PARTICLES (Natural size) Case 141

FIGUBE 44b. A DISTENDED BUBSA IS CONCAVO-CONVEX (Size reduced one-half)

a. Shows the greatest distention of the bursa which I have ever seen from this cause. The film was taken by Dr. A. W. George, who referred the patient to me. I have, however, seen many bursse as much distended as this, in cases of rupture of the supraspi-natus, where the constant influx of fluid from the joint during efforts at abduction has dilated the bursa. Notice the gravitation of most of the calcified material to the bottom of the sac, which is bilocular, and yet enough particles have clung to the lining to cause its outline to show in the film. Case 141.
b. Schematic drawing to show that a distended bursa is a concavo-convex cap beneath the deltoid and placed in an antero-lateral position over the insertions of the short rotators.

Such acute symptoms subside in one to two weeks, some cases being followed by adhesions of the bursal surfaces which last many months. More often, especially if the physician has not tried to help, the patient by binding up the arm, the spasm subsides, the soreness disappears, normal motion returns, the "hitch" reappears and the condition is the same or better than before the attack. There are various stages between these two extremes; in some cases the attack seems to clear up the whole trouble, but often more or less spasm and restriction remain for months. I am quite positive that in the cases which clear up, the soft material has perforated into the bursa and been absorbed there. In those cases which have been through an acute attack and on which I have operated long after, I have found the deposit drier and firmer and more crystalline in composition and more intimately combined with the fibers of the tendon than those operated on in the acute stage. The deposit is likely to be firmer in chronic cases which have never had an acute attack. Apparently in acute attacks invasion of leucocytes about the deposit produces a sterile pus which mixes with the finely divided calcareous matter and softens it to the consistency of cream or butter. This creates tension in the substance of the tendon and tends to make the softened matter point into the base of the bursa. For some unknown reason perforation does not occur into the joint. It is the inflammation of the synovial base of the bursa which produces the symptoms so suddenly and starts the sequence of friction, pain, spasm, exudate, etc. At operation one usually finds the softened material under tension, so that when the white or yellow head of the boil-like center is nicked with the knife the material is squeezed out, as if it had been pent up. The operation gives relief to the tension and is effective in the same manner as in opening a boil. It is an interesting fact that under local anaesthesia the patient may express relief as soon as the tension is lessened. It seems that in these acute cases there are two kinds of pain, a deep, severe ache due to tension in the tendon, and the friction pain of the inflamed bursa.
I hesitate to describe a chronic form of this condition, since I have seldom known of an instance of more than three years' duration. Nor do I know how long symptomless deposits may exist. What I mean when I speak of a chronic case is one which lasts many months without going through an acute or adherent or neuritic stage. A case in which throughout its course the symptoms are confined to the painful "hitch," pain in the lower deltoid and a distinct rotating sensitive point, I should call chronic. In such cases the amount of the deposit as shown in the X-ray is usually small, perhaps minute, or even not demonstrable. Probably many such patients never consult a doctor. I see them more often among my friends who tell me casually about their symptoms, having heard that I am "interested in shoulders." Patients who consult me and have X-ray proof of the diagnosis and are told that the deposits are no harm in themselves, and that no operation is necessary unless the pain is severe, seldom come back to report when they are well. So that I can only give my impression that mild chronic cases do exist and that their duration, like the subacute ones, is seldom more than three years. As this was being written a patient on whom I had operated for a severe acute attack in his right shoulder, nearly eleven years ago, called to see me about his left shoulder. The right had remained well. Reference to my old notes showed that X-rays had revealed a deposit in his left shoulder at that time. He had been conscious that the left shoulder was not well, but it gave him no real bother until about six weeks ago, when mild symptoms began. They are still mild and he is taking diathermy. X-rays show that there is no deposit at present and there is a slight roughening of the tuberosity at the facet of the supraspinatus tendon, but there is no such roughening on the right side, which was operated upon. Evidently in this case the left ran a truly chronic course without complications. This one case, so far as it goes, indicates that the ultimate damage to the tendon may be greater if the deposit is not removed.

Atrophy of the spinati is found in all cases which have had severe symptoms for more than a few weeks. I have observed it in acute cases as soon as three weeks after the onset, and it doubtless may occur even earlier than this. Looking at the patient from behind one sees the spine of the scapula on the affected side more distinctly. In adherent cases this appearance is very pronounced and the shrinkage of the muscles may be so great that complete paralysis is suggested. I am inclined to think that in the worst cases the muscular bellies are in a condition resembling that of the muscles of the forearm in Volkmann's paralysis, which in fact is an ischaemia. However, they regenerate better under appropriate treatment. In such cases I am satisfied that rough manipulation under ether may rupture the muscles themselves rather than the adhesions in the bursa and joint. Atrophy of the deltoid is also usual; I have known of cases being mistaken for circumflex paralysis. The biceps also is as a rule more or less weak, and in long-standing cases all the rest of the muscles of the arm show the result of lack of use. The teres group is usually found in spasm and it is difficult to tell the amount of atrophy, for they are contracted in contrast to the spinati which atrophy in a stretched position. When one stands back of the patient and with forefingers in the axillae and thumbs behind the posterior axillary folds, and one palpates the muscles near the border of the scapula, one finds that those of the affected side are thicker and firmer than those of the normal side. Nevertheless, there may be atrophy of these muscles. The fact is that the spastic teres muscles are shortened by adduction of the arm and thus appear thick on palpation. Yet they may be shrunken as a whole although short and thick from constant spasm. These spastic muscles are always somewhat tender. This thickening and local tenderness of the teres group should not mislead us, for the cause of their sensitiveness and spasm is. not local in these muscles.
In examining for shoulder lesions of any sort it is important to note the condition of the spinati. Atrophy of these muscles is an accompaniment of all lesions of the shoulder joint of a serious inflammatory nature. I do not find it in cases of malingering and of hysteria. Furthermore, its degree is a fair gauge of the gravity of the lesion, and also serves to gauge the prognosis.
It may be seen from what I have said about the symptoms caused by calcified deposits in the tendons, that a strict division of cases into acute, subacute and chronic cannot be made. I cannot take my own series and pile them in three groups of records after this manner. Neither can I separate them into adherent and non-adherent cases satisfactorily". Restriction of motion may be slight or complete and of all degrees between. Yet these divisions are all clinically useful, though ill-defined, and mean something, at least for a time, in individual cases. A corollary can be drawn from this that prognosis is uncertain. One cannot tell in a given case exactly what its course is to be. This makes advice as to treatment and comparison of results very difficult.

Restriction of motion is usually in one or both of two different arcs of motion, i.e., in external rotation and in elevation. When elevation is restricted and external rotation is free, one should suspect at once a condition in which the inflammation about the calcified deposit is great enough to make a mound in the base of the bursa, but has not yet created irritation of the synovial lining of the bursa. Rotation is painless because the inflamed, raised spot can rotate under the deltoid without striking any hard or any firm tissue. On the contrary, when abduction or elevation is performed, the inflamed mound is pinched between the tuberosity and the acromion or coraco-acromial ligament. The pain thus caused instantaneously produces scapulo-humeral spasm and the upward movement is restricted. Let this patient stoop over as far as possible with his shoulder muscles relaxed and the arm abducts on the body by gravity. The tender point rides easily under the acromion in this position because the supraspinatus is not acting to produce tension about the deposit, nor is the deltoid pulling the humerus vertically upward against the acromion. If the patient then fixes his shoulder voluntarily, he can stand upright with the arm elevated.
Such cases as I have just described can usually be separated from malingerers, because one can always find the rotating tender point where the deposit is, for it is easily felt as it passes beneath the deltoid fibers. Furthermore, having made the patient stand with the elevated arm, he will be seen to have a "hitch" or a period of scapulo-humeral spasm as he lowers it from the vertical position, and the tender point in its downward journey again passes the narrows under the acromion. This sign is also a sine qua non of complete rupture of the supraspinatus, but in the latter no calcified deposit is shown by the X-ray.
A symptom which is occasionally seen in these cases is what I call the "down-it-will-go" symptom. It is rather infrequently complained of, but often acknowledged if asked for. Patients with complete rupture also show it. A patient will say that the arm is paralyzed or that he is afraid it is going to be paralyzed. He reaches for some small object or is carrying one, and "down-it-will-go." It seems to be an involuntary sudden relaxation of the grasp. It frightens the patient, although it is usually spoken of diffidently or with an apologetic laugh. It is irregular in its occurrence. I cannot explain it, but my theory is that it is a phenomenon associated with position sense. I have already stated that in some cases spasm starts without pain. In a case of circumflex paralysis which I observed, and on which I operated under local anaesthesia to see whether the supraspinatus was torn, I found that the interior of the bursa and the joint were completely insensitive although the skin sensation was present. In a doctor on whom I was operating under local anaesthesia for a calcified deposit I could at will start spasm without pain by touching the base of the bursa. These observations indicate that the bursa and joint are supplied by nerves which do not transmit ordinary tactile pain but serve to excite the scapulo-humeral reflex. It may be that this "down-it-will-go" symptom is something caused by this set of nerves, when, in reaching for the object, the sensitive point comes against the acromion. Without consciousness the grasp relaxes in order to get rid of the weight which, by leverage, increases the pressure on the tender point. In this connection we also have the phenomenon that the pain in these cases is as a rule attributed to a point near the lower insertion of the deltoid.

FIGURE 45. CALCIFIED DEPOSIT IN THE TERES MINOR
In interpreting X-rays of calcined deposits one must be sure of the position in which the film is taken in order to say positively that the calcified material has escaped from a tendon into the bursa. This is particularly true in cases where the deposit is in the teres minor, as in this picture. The insertion of the teres is very low and if, as in this case, the view is taken with the head of the bone in inward rotation, the deposit appears to lie in the bursa, when in reality it is still confined within the tendon substance

FIGURE 46. CALCIFIED DEPOSIT IN THE INFRASPINATUS
Figure 46 was taken with the plate on top of the shoulder and the rays nearly parallel with the long axis of the humerus, in order to bring out the bicipital groove. The prominent deposit in this case was in the infraspinatus, as is shown by the fact that it is about one-half inch exterior to the bicipital groove. There is also some deposit in the supraspinatus which shows poorly in this picture, for it is overshadowed by the tuberosity.

There should be some differences between the symptoms of cases of deposit in the subscapularis and in the supraspinatus. The location of the tender point, whether inside or outside of the bicipital groove as shown by the maximum spot of tenderness, is my usual way of differentiating. Careful study of the X-ray is confirmatory. Whether the symptoms themselves differ I am not sure. One would think that external rotation would be limited in subscapularis cases, but I have not found this true enough to rely on. A recent quite acute case had no such limitation. Another case of bilateral subscapularis deposit which occurred in my own household had symptoms quite like those in a supraspinatus case except in the location of the tender spot. My series of cases is not large enough to make comparison, but the point is important because it helps in performing the operation.
The X-ray should confirm a diagnosis of calcified deposit, but one should be very exacting in demanding excellent technique and films made from several angles before making a negative diagnosis when the clinical picture is typical. This is particularly important in ruling out a deposit in the subscapularis tendon. A recent instance was only positively diagnosed by a fourth film which showed the deposit in profile. The deposit was large, but in the first three positions the shadow overlaid the bone in such a manner as to elude experienced eyes, although after the fourth film it could be identified in each picture. A very slight rotation of the humerus may throw the shadow over the bony outline, especially if, as often happens, there is only a mere fleck of calcareous material. Even a large recent deposit of little density is easily overlooked. The Rontgenologist must learn to take pains to get each facet of insertion in profile.
Even before calcareous material is demonstrated by the X-ray, the diagnosis on clinical signs alone may be made with a considerable degree of certainty.

Treatment.

Since the prognosis of these cases is always eventually a good one, and since in any given case the probable course cannot be foretold with certainty, no treatment of a dangerous nature can be considered. Even a risk of any permanent minor damage would be unwise. All cases, whether treated or not, in which I have known the late result, have recovered without permanent complications of any kind. Recovery is only a question of time. The object of treatment is purely one of the relief of symptoms. Any one who wishes may endure the whole course of the trouble without other treatment than palliative remedies such as occasional doses of aspirin or the application of an ice bag or a hot water bottle. Many acute cases following perforation recover in a few weeks. Some persons prefer to endure daily pain month after month rather than to submit to a minor operation or go to the trouble and expense of prolonged treatment by physiotherapy. My personal opinion is that surgical removal of the deposit is practically free from danger, sure to relieve the severe symptoms at once, and, in fact, that it generally will relieve all really troublesome symptoms within a few weeks. It is not a painful operation; it can be done with local anaesthesia; it requires only a few days of hospitalization, and there is very little postoperative pain as a rule. It seems to me that the patients whom I have followed through an acute attack suffer more in forty-eight hours than does a patient who has been operated upon in his whole convalescence. I have performed the operation on a number of doctors, who have previously had acute attacks, and they have been of the same opinion. Furthermore I have seen, in subacute and chronic cases, the constant neuritic type of pain with consequent loss of sleep, reduce patients to a very serious physical condition, the relief of which would justify a much more dangerous operation. It therefore seems to me that it is better to have the deposit, if large, removed as a routine, than to run the risk of either an acute attack or of severe chronic pain. It is quite reasonable for a patient to say, "But I may never have any severe pain, and then the operation will have been unnecessary." This is quite true and the answer is that there is little objection to waiting until the actual pain makes the prospect of operation more welcome. It would be hard to say for another individual how much annoyance and loss of sleep is equivalent to the operative pain and discomfort. Certainly pain sufficient to prevent work is enough to demand an operation of the trivial character of this one. Statistics as yet cannot show in a given case what the chances are that serious pain will ensue.
I think it is fair to say that the severe pain is relieved at once by the operation and that the patient may expect the return of full use of his shoulder in from three to six weeks, although he may feel twinges of pain in extreme positions of the arm for several months.
In general my attitude is: "If I had your trouble I would prefer operation as the best way to avoid pain and disability. You will get well anyway, but your total pain and discomfort is pretty sure to be worse and likely to be much worse, if you are not operated upon. I advise you, but I do not urge you, to have this deposit removed. There is no danger of your having a crippled arm or any permanent trouble, whether treated or untreated."
Many patients, on receiving this advice and reassurance that they will not lose the use of their arm, prefer to endure the pain, annoyance and discomfort. Others ask what other treatment there is apart from surgery. The answer is that aspirin and similar drugs will help them bear the pain, particularly at night. Morphine will relieve the pain, but its use for more than a few nights is of real danger, for the pain may last many months and a pitiable habit result. No drugs are known which will cause absorption of the deposit when taken internally. Since the deposit is deep in the tissues and covered by skin, fat, fascia, muscles and blood vessels, in which the blood is circulating, no local applications as ointments, linaments, iodine, etc., can reach the lesion and do good. The most that can be expected would be slight, temporary relief from counter irritation, such as is gained by hot or cold applications. Massage and manipulation and active or passive exercises might be harmful unless most judiciously performed. After the acute symptoms are gone these agents may be helpful in restoring motion if it has become restricted. Very acute cases are apt to be very brief cases, and their spontaneous recovery may be coincident with surgical or other therapy.
I know of no form of electrical treatment which might be expected to remove the lesion except diathermy. It is rational to hope that the use of this form of physiotherapy might help nature to absorb the deposit and resolve the exudate about it. It is held that diathermy heats living tissues through and through, and the effect of this heat on such deposits has been claimed to cause absorption. Since these deposits are naturally absorbed in varying periods, it is difficult to be sure that their disappearance under treatment by diathermy is not a coincidence. No attempt so far as I know has been made to check up a series of cases so treated with an untreated series. The same criticism applies to the results of surgical removal, but we know then, that the deposits, and symptoms as well, are removed. In some cases I have operated after the patient had been treated with a course of diathermy, and yet found a large deposit. In others so treated the X-ray has continued to show the deposit for some months after the symptoms were relieved. However, it makes little difference whether or not the deposit is removed, if the pain disappears. I have known of a few cases in which this has happened after a few weeks or months of treatment by diathermy. They were relatively mild cases. In others I have operated when diathermy failed to remove either deposit or pain. Furthermore, after perforation in the bursa has occurred the deposit absorbs spontaneously within a few weeks. Yet if a patient wishes some treatment other than operative, I advise diathermy. I do not use it in my own work for two reasons. First, being inexperienced with its use, I should fear the danger of burning the patient more than I would the danger of surgery. Second, I know that operation permanently cures; I have some faith that diathermy will assist the natural process of repair.
Dr. E. B. Mumford of Indianapolis, who is a prominent orthopedic surgeon, believes that diathermy is the treatment of choice (Jour. A. M. A., Vol. 97, No. 10, 1931, pp. 690-694). He gives details of his technique. "All of our cases became well by this conservative form of treatment and in all cases with a deposit shadow, the deposit either entirely disappeared or became much smaller in size and less dense in the X-ray. In none was surgery necessary. The average number of treatments was twenty-one, given daily for the first two weeks and then twice a week. Relief from pain was obtained in from three to ten days. The end result was complete restoration of function without pain. Ten cases have been checked at the end of one or more years and no recurrence noted."
I am far from denying that diathermy is effective. It is too bad that comparative tests of different forms of treatment cannot be made. One thing is greatly in favor of diathermy, and that is that it is necessary for a surgeon to know the anatomy and pathology of this particular region if he is to obtain uniformly excellent results by operating.
There is one form of treatment not uncommonly given, which I believe is to be heartily condemned, i.e., fixation by strapping or bandage. In my opinion many of these cases are made worse by this treatment, which encourages adhesion of the roof of the bursa to the inflamed tendon. All the periarticular structures become fixed, the muscles atrophy and become ischemic and contracted. Many months may pass before the joint moves again, although ultimately it always does become mobile. The neuritic symptoms are particularly troublesome in such cases, although sometimes the ankylosis is entirely painless and the patients are only inconvenienced by the restriction. Spontaneous scapulo-humeral spasm is a sufficient guard for the inflamed joint and we should neither add to it with straps and bandages nor fight it with forced motions. Active "swinging exercises," with the patient in a stooping position, should be used in most cases. When the patient stoops the strain is taken off the supraspinatus and it is far easier to move the joint. I regard it as very unwise, until the convalescence is well advanced, to allow the patient to exercise the arm in a standing position because this forces the supraspinatus to cooperate with the deltoid in supporting the weight of the arm. The pain caused by this at once starts scapulohumeral spasm and the joint ceases to move. It is better to let the patient stoop with the arm hanging relaxed. If the patient straightens up again as soon as spasm begins, he will in fact adduct the arm. In other words, when one stoops with the arm relaxed one abducts (elevates) the arm on the body; when one straightens up with the arm relaxed, one brings the arm into the anatomic position.

FIGURE 47. STOOPING EXERCISES

The principle of the stooping exercises is that they permit the patient to abduct the arm by gravity and therefore no fulcrum is needed. If a patient elevates the arm in the standing position, the humerus obviously must obtain a fulcrum on either the glenoid or on the acromion or on both, while in the stooping position no fulcrum is necessary. In the standing position the little supraspinatus must pull the tuberosity firmly to keep the latter from touching the acromion. In the stooping posture it may remain relaxed.
Since the sore point in most lame shoulders is on the tuberosity at just the region where it tends to obtain a fulcrum on the acromion, it is highly important that the patient with a damaged supraspinatus should not delay his recovery by frequently raising his arms. The exquisite tenderness which arises in these cases is nature's defensive effort to warn the patient not to use the arm in this way.
When the patient with the sore shoulder is in the stooping posture he can much more readily brush his hair, button the back of his collar or perform any other motions. He can, for instance, learn to put on his shirt and coat over the lame arm when stooping, and then after he has risen to the erect position put on the other sleeve.
When in the stooping position, either lateral or antero-posterior motions can be done with a pendulum-like movement without great muscular effort. In this position the humerus not only tends to avoid a fulcrum, but actually the weight of the arm helps to stretch the contracted tissue of the joint.

The principle of "stooping exercises" is useful in many ways. Gentle exercises of this kind prevent adhesions following the acute or subacute attack. Vigorous exercises loosen up adhesions already formed. Gentle postoperative exercises hasten convalescence; too vigorous ones start scapulo-humeral spasm and delay recovery. It is unwise to give passive exercise or permit active exercise which causes even moderate pain. Yet to fix the arm in bandages to relieve pain is also unwise. When one has seen the inside of these inflamed bursas one can readily understand the danger of either fixation or over exercise. Gentle motion, unhampered by bandages or spastic muscles, is indicated to prevent adhesions. The patient should be allowed to change the position of the arm as freely as he cares to. He should be instructed to keep it in external rotation as much as possible, because an arm held in the sling position is in internal rotation, and if it adheres in this position, it requires a long time to gain normal external rotation. We should avoid scapulo-humeral spasm not only because it promotes adhesions, but because much of the actual pain due to the spasm pressing the inflamed parts together. Spastic muscles are not only painful but tender.
In two early cases with very small deposits and mild symptoms I have tried the experiment of keeping the patient in bed with the arm abducted, in the way in which I treat cases in the non-calcified type. (See p. 218.) This treatment seemed desirable for several reasons. It is the natural position assumed by many patients to obtain ease; i.e., they sleep with the hand behind the head. In this position the supraspinatus is relaxed and its tendon is not stretched; this would permit an active blood supply to promote repair. This position would bring the inflamed portion of the tendon wholly under the acromion, where it could not adhere readily, and if it did adhere would tend to loosen from mere gravity. Both cases were soon relieved.
Another form of treatment remains to be mentioned—aspiration as suggested by Flint. After Flint's publication I tried this once with some success. I am satisfied that in this case I actually punctured the deposit and allowed it to leak into the bursa and thus relieved the pain. This was not exactly Flint's plan, but may also have been his achievement in his cases. I have opened so many bursas without finding much fluid that I doubt the wisdom of trying this procedure. Like most needling in other tissues, it seems to me to carry all of the disadvantages of an exploratory incision and some serious ones of its own. It would be rational to thrust a large aspirating needle into the deposit under guidance of the fluoroscope, but I would prefer to be operated upon were I the patient.
As in the case of many other ailments which affect the human body, there is great variation in the degree and duration of the pain it produces. Even very acute cases may recover completely in a few weeks with the simplest palliative treatment. Therefore any form of therapy is deceptive in its results. I have often had a patient postpone accepting my advice for operation and seen recovery promptly ensue! No surgeon should feel as did Jack Horner and say, "What a big boy am I!" after removing one of these deposits. These rapid cures occasionally occur after any of the other forms of therapy, for nature does the work in spite of what we do at the same time. Yet at the present date, I can unhesitatingly say that unless there is some good reason to the contrary I should advise operation in all painful cases, and in all cases where the deposit is as large as a lima bean, even if there is no pain. I sincerely believe that operation is a far less serious matter than fixation, and no more dangerous than diathermy or intravenous therapy.

END RESULTS IN CASES OP CALCIFIED DEPOSITS

The following study is based on an analysis of twenty-nine replies to a questionnaire recently sent to patients on whom I had operated for this condition long enough ago to indicate whether there have been any unpleasant after effects, due to the operation, recurrence of the lesion or other complications. The period elapsed since the operation was ten to twenty-four years in nine cases, five to ten years in eight cases, and one to five years in eleven cases. All these patients stated that they had had no further trouble of any kind with the shoulder which had been operated upon, but ten had had similar trouble of minor degree in the other shoulder. In most of these cases there had been evidence of deposits in the other shoulder at the time of operation.
These data confirm my impression that when these patients have been operated upon their symptoms do not return in the same shoulder. Furthermore I have not known of any late complication which followed about forty other similar operations on patients who did not reply to this particular inquiry.
Two patients whose deposits were in the subscapularis, will be given separate consideration later, and are not included in the following resume of the replies to the questionnaire. As in the case of most questionnaires, some of the answers were not satisfactory. For the sake of brevity, doubtful replies to individual questions will be omitted without making such notes as "answer equivocal," or "not stated." Consequently in the following analyses the sum of numbers in each statement will not always be twenty-nine.
Antecedent Trauma. Twelve stated that the attack followed a definite injury; thirteen stated that there had been no injury; three were uncertain. These figures are also in accord with my whole experience, which is that the injuries are usually trivial, and often uncertain. In compensation cases one is tempted to think that the history of injury may be purely an afterthought, although about half the cases may be said to give a definite enough history of trauma to account for rupture into the bursa. For instance, the twelve injuries were:

No. 79, business man, "Throwing baseball"; No. 81, iron worker, " Pulling on heavy bar"; No. 103, osteopath, "Fall"; No. 105, no occupation, "A bad fall down stone steps, and a sudden wrench later on"; No. 113, physician, "Fell on elbow with arm held rigidly against chest"; No. 121, surgeon, "Fall on stairs with violent swing of arms in attempt to preserve balance unsuccessfully"; No. 122, housework, "Wrenched shoulder in effort to avoid fall on staircase"; No. 138, osteopath, "Fall" ; No. 140, business man, "Fall from a horse"; No. 142, a business man, "In making motion of throwing spear felt a severe pain and was unable to raise the arm."; No. 143, waitress, "Raising tray."

The duration of symptoms prior to operation varied from a few days to ten years in one case. One man even stated twenty years, but the continuity was somewhat doubtful. There were eleven cases who stated that symptoms had existed from six months to five years, and two from one to six months. Ten were acute, that is, there had been no pain until within two weeks.

Relief of Pain. In acute cases pain was at once relieved by the operation and in chronic cases there was very little pain after the first few days. Eight patients reported no pain or actual relief from pain immediately after the operation. In other words, a really acute case is so much relieved by the incision that he may ignore the postoperative pain, but a chronic case, who has had no previous acute pain, is more aware of any later discomfort from the wound itself. Only seven mentioned pain after the first day and only one after the fourth day.
The subacute, annoying symptoms in convalescence varied from one to four weeks in most cases, but one case complained of some pain for seven weeks.

Use of Arm. Most patients began to use their arms within a few days and used them with more and more freedom from day to day. As a rule it took from one to three months before perfectly free use returned. By the end of three months all but two patients had ceased to be even annoyed by the shoulder. The symptoms of these two cleared up within seven months. One of these was an iron worker who continued to have pain on using a sledge hammer when he returned to work fourteen weeks after the operation.

Return to Work. In most cases the patients returned to work or to their regular avocations after a month or less, only three cases requiring more time, the longest being the above-mentioned iron worker. (An industrial case.)

Hospital Days. The time spent in bed averaged three and a half days. None were absolutely confined to bed. The time in the hospital averaged five and a half days; three patients remained only three hours; six remained ten days for convenience, not from necessity. All wounds united by first intention.

From the point of view of the operator, who does not endure the pain, the results of this study may be summarized as follows: In acute cases the severe pain is relieved at once by the operation, and even in chronic cases the postoperative pain lasts only a few days. Within a few weeks the patient is about his usual pursuits, although he still has transient pain in extreme motions and cannot lie comfortably on the operated side. Then follows a period of a few months during which certain motions may cause annoying, sharp, brief twinges, and at night the arm may still cause a minor amount of discomfort. These symptoms become less obvious, and presently days together pass without a thought of the shoulder. This period is indefinite, but is to be measured in months, not in years.
In order to get the patients' points of view I included in the questionnaire a request for a statement on their general impression about the efficacy of the operation. The following answers were given:

Case No. 51, a physician, "Operation entirely relieved my acute pain which had been present for several weeks. The other shoulder has been involved since, and has cleared up with no treatment. It was never as acute as the operated one"; Case No. 55, a physician, "... as I suffered so intensely for so many months and was entirely relieved within a few days after the operation. If you remember my operation was performed under local anaesthesia. My recovery was a very quick one and as nearly as I can remember I was able to do my regular work in a very short time. In April (2 and a half mos.) I was playing golf with no discomfort whatsoever"; Case No. 56 (from patient's physician), "I feel quite sure he thought it a success. Patient died of angina" (9 yrs. after op.) ; No. 62, "To me the desirability of the operation is unquestioned, in competent hands, however. The pain is so wearing and causes such nerve irritability that the sooner it is over the better. I consider my operation a great success, and would advise any one to put up with the temporary inconvenience"; No. 63, "Grand in every way"; No. 65, "Am pleased to say that I have no pain whatsoever and have perfect use of my arm; in fact, I have had since about two weeks after the operation"; No. 66, "I have never been quite able to make up my mind as to the efficacy of the operation. On the one hand I have had no discomfort in that shoulder; on the other hand, the ease with which I am able to control any kick up in the other shoulder by avoiding gouty foods and drinks leads me to believe that it might have been possible to cure it without an operation"; No. 68 (See Plate II, Fig. 8), "Extremely successful, has never bothered me since"; No. 72, a surgeon, "I obtained immediate relief at the time of operation and aside from some soreness of the wound, I was perfectly well, and as I remember it, I was operating within six or seven days of operation, the exact date I do not remember"; No. 73, "85-90% improvement" (This patient, a physician, had had symptoms for ten years) ; No. 79, "100% successful"; No. 81, "To secure any lasting benefit, I think that an operation is the only thing"; No. 85, "Similar to the removal of an aching tooth, pain all gone, only the soreness which would follow any deep gash in the body, would say no operation could be more efficacious"; No. 93, "Excellent"; No. 103, a physician, "Decided success"; No. 105, "Unqualified approval. The X-ray showed a quiescent bursa in the other shoulder. I have been a bit careful and when there has been the least twinge, have rested it. But even that has only happened three or four times in these years "; No. 113, a physician, "Absolutely perfect. The relief from pain and the conviction that there will be no recurrence are beyond price. Personally, I believe that any other procedure is a waste of time"; No. 114, "A wonderful operation. I walked home from the hospital three hours afterwards, and never had any pain or discomfort at any time except for a month when trying to use arm too strenuously. I recommend it heartily "; No. 121, a surgeon, " I was strong for it! At the end of one week I deliberately broke up adhesions by playing golf. After this the soreness subsided rapidly. The right shoulder bothered three months ago, no known trauma. Symptoms have now all subsided"; No. 122, "My impression is that the operation was very successful, and at times when my other shoulder troubles me I often wish I had both shoulders operated on"; No. 133, "Excellent results. I do not recall that I had any pain following my operation, with the exception of the few days I was in the hospital, and this was more from the soreness of the incision rather than actual pain from the shoulder. It was quite some time before I had the absolute free use of my arm, but I should say this was due to my lack of exercising it. However, it is absolutely perfect and I have used it a great deal"; No. 134, "I consider the operation entirely successful"; No. 140 (See Plate II, Figs. 1 and 2), "No question but that the operation, immediately, and apparently permanently, removes the trouble"; No. 141 (See Fig. 44), "Operation afforded me a very welcome relief after about four weeks of almost steady pain, and, although even now I do not put any more strain on my shoulder than I can help, it feels as strong as it ever did. I would not hesitate to undergo a like operation again to relieve like pain"; No. 142, "The result was most satisfactory. On only three or four occasions have I realized I had a shoulder and then only a slight soreness for a day or two after having used it perhaps a little too strenuously"; No. 143, "Good."

I am quite certain that most of my other patients to whom this questionnaire was not sent, or who did not reply to it, had as favorable results, because I have heard from most of them occasionally for many years after my operations. Details of some of these cases may be found in the Table on pp. 255-260.
I also have notes on about an equal number of cases who were not operated upon, usually because I thought the symptoms too trivial, but in some cases, because the patient refused operative treatment after having my assurance that in time they would recover at any rate. In most of these cases, especially in those in whom perforation had already occurred, the results have been as good as in those operated upon, although it seemed to me the patients suffered more. Many have recovered as promptly under some form of palliative treatment, as if I had operated upon them, but a few have had prolonged convalescences and suffered a great deal. My brother, a business man, had acute attacks in both shoulders for several months each, at different times. He would not sacrifice the time to be operated upon, but obtained some relief from diathermy. On the whole it seemed to me he suffered more than any case has suffered after the operation, but he did not lose a day. This was a subacute case with no restriction. As a rule I have operated on only the worst cases. In fact, I seldom advise operation unless the pain is severe. The unoperated series is, therefore, in the main composed of much milder cases, for those with severe pain welcomed operation.
For the sake of my argument that operation is wise in those cases where the pain is hard to bear, it is not necessary to attempt to contrast the periods of disability in an unoperated series with those that were operated upon, because the operated series shows many cases where the symptoms prior to the operation had existed much longer than they persisted in any case after it.
It does not seem to me worth while at the present time to go into this question in greater detail, because it is evident to me from a study of the unoperated cases that these patients eventually recover under any form of treatment which is not actually detrimental. The question is wholly one of relief of symptoms, not of the removal of a condition which is in itself dangerous or likely to lead to permanent disability. Although I am inclined to think that those cases which are not operated upon may ultimately have weaker tendons than those in whom the deposit is removed, I have no statistical proof of this, nor have I ever known of complete rupture of the supraspinatus occurring as an aftermath of this lesion. My reason for thinking that the tendons are weakened is more on account of the frequency of finding, at autopsy, defects which might be accounted for on this hypothesis.

Deposits in the Subscapularis. It may be that deposits in the subscapulars are less responsive to surgery than when they occur in the other tendons. I have had experience with only two cases, but they were both instructive to me, for I criticize myself for being content with removing one large deposit and making no effort to be sure there was no deposit in the other tendons.

Case No. 84. This was an acute case of two weeks' duration in a single woman of 46. I operated February 2nd, 1926, and removed a deposit from the supraspinatus. The result was satisfactory. However, about two years later, very acute symptoms returned in the same shoulder. This time the X-ray clearly showed a large deposit in the subscapulars and the remains of a smaller one in the supraspinatus. (Plate II, Fig. 6.) I operated again and removed the subscapularis deposit. The immediate result was as good as before, but the convalescence was more protracted in the subacute stage. She was an accountant and used the typewriter a good deal. She states that she went back to work two weeks after the first operation and four weeks after the second one, but her reply indicates some residual trouble: "Always occasional twinges since. Always 'cranky' as to normal use—have to turn certain way to put arm over and upward."

I am inclined to think that I might have saved this patient the second operation by a more careful X-ray study at the time of the first operation, for evidence of the other deposit may have been present at that time.

Case No. 117. A maiden lady of 64, who had a large calcified deposit in the subscapularis. (See Fig. 43.) She had had subacute symptoms for four weeks before the operation. According to her reply she had a longer and more stormy convalescence than any of my other cases have had; i.e., the acute pain after the operation lasted six days; the subacute pain three and a half months, and the occasional twinges ten months. It was a year before she forgot about the arm entirely. There have been no after effects.

This patient did not answer the question about the general impression of the efficacy of the operation, but it is clear that she suffered somewhat more after the operation than she did before it. She was operated upon in another city, and I did not have direct care of her convalescence, as I have in almost all the other cases. I was, however, in telephone communication with her doctor, and saw her from time to time during the year following. There seemed to be no very distinct reason why she should have had a longer convalescence than the other cases, but there were several possible reasons, which it seems worth while to discuss because they may have some future importance. In the first place, the deposit was in the subscapularis, a rather unusual situation. The operation was not difficult, because outward rotation of the arm easily brought the deposit under the wound which was made in the usual situation in the deltoid. I did not, in her case, incise any of the other tendons, and there may have been a tendinitis in those tendons which was the cause of the delay. Also, she did have some haematoma in the wound, which might have accounted for the postoperative pain being longer than usual. It is my usual custom to lightly bandage the arm to the side for the first night, and next morning to remove the bandage and allow the patient to place the arm in any position he chooses. There was some delay in removing the bandage in this case, I am told, because the patient seemed to have so much pain. It is possible, also, that the patient was one who, in her anxiety to be conscientious in her statements, has given an impression in the answer that her pain was greater than it was.

As these two cases were the only unsatisfactory ones I have had, and as they were the only ones in which there were large deposits in the subscapularis, it would be logical to attribute the slow convalescences to the location of the deposit. Two cases do not give much opportunity for logic when complicated by the factors of the personalities of doctors and patients. It may be that I could have saved both patients a considerable amount of pain by more thoroughness, and it may be that the two ladies were not of a satisfactory type for surgery, and would have been better satisfied with diathermy. At any rate, they represent my two worst results from operations for calcified deposits. In spite of the somewhat stormy convalescences I believe both patients were saved much suffering, for they seemed to me to be cases of severe type. The operation is a trivial one from a surgical standpoint, but to some people an operation is an operation, and those who would be inclined to take a surgical experience too seriously may well be treated with palliative measures.

BIBLIOGRAPHY FOR CHAPTER VI

ALLEN, A. R., Penn. M. J., 1911, xiv, 843; Therap. Gaz., 1911, 3, s., xxvii, 546. BAER, W. S., Johns Hopkins Hosp. Bull., 1907, xviii, 282-284. BERGEMANN and STIEDA, A., MUnchen med. Woch., 1908, lv, 2699-2702. BERRY, J. McW., Am. J. Orthop. Surg., 1916, xiv, 476-483. BETAGH, G-, Policlin., Roma, 1904, xi, sez, chir., 1930. BLANCHARD, W., J. Orthop. Surg., 1920, ii, 466. BOCK-OVEN, S., U. S. Vet. Bur. M. Bull., 1930, vi, 549-550. - BOU PUJOL, A., Arch, de ginecop., Barcelona, 1909, xxii, 99-104. BRENCKMANN, E., and NADAUD, P., Arch, d'elec. med., 1932, xl, 27-29. BRICKNER, W. M., Intern, clin., 1911, 1929; Am. J. Surg., 1912, xxvi, 196-204; Med. Rec, 1915, lxxxvii, 121 and 498; Am. J. M. Sc, 1916, cxlix, 351-864; Interstate M. J., 1915, xxii, 331-343; J. A. M. A., 1916, lxvi, 912; Am. Atlas Stereoroentgenol., 1916, i, 34-36; Am. J. Surg., 1916, xxx, 108-110; Am. J. Orthop. Surg., 1916, xiv, 231; J. A. M. A., 1917, lxix, 1237-1248; Midland M. J., 1918, xvii, 33-37. BROWN, A. J., Surg. Gyn. and Obs., 1919, xxix, 381-386. BUCHOLZ, C. H., J. A. M. A., 1917, lxix, 968; book, Lea and Febiger, 1917, Arch. f. klin. Chir., Berlin, 1922, cxxi, 255-264. BUCKLEY, C. W., Pract., 1914, xcii, 777-787; Proc. Roy. Soc. Med., London, 1913-14, vii, 59-70. BUTLER, P. F., and ELWARD, J. F., Am. J. Roent., 1925, xiii, 536-541. CALATUYAD, C, and ESTOPINA, L., Rev. espanol, de electrol y radiol. med., Valencia, 1912, i, 325-383. CAMPBELL, W. F., Med. Times, 1916, xliv, 244. CARNETT, J. B., and CASE, E. A., S. Clin. N. Am., 1929, ix, 1107-1126. CARNETT, J. B., S. Gyn. and Obs., 1925, 404-121; S. Clin. N. Am., 1930, x, 1309-1817; Radiology, 1931, xvii, SOS-SIS. CODMAN, E. A., Boston Med. and Surg. Jour., cl, 14, 371-374, 1904; Boston Med. and Surg. Jour., cliv, 22, 613-620, 1906; Records of the Massachusetts Medical Society, June 9, 1908; Boston Med. and Surg. Jour., Oct. 22, 29; Nov. 6, 12, 19, 26; Dec. 8, 1908. COLE, W. H., Surg. Clin. N. Am., 1923, iii, 1361-1363. COLLEY, F., Dtsch. Z. f. Chir., 1899, liii, 563-574. COMBEAU, Gaz. d. hdp., Paris, 1868, xli, 207. CONLOMB, Rev. d'orth., Paris, 1922, 3, s., ix, 251-253. COOPER-MAN, M. B., N. Y. State J. M., 1926, xxvi, 807-814. COUES, W. P., Boston M. and S. J., 1921, clxxxiv, 176-179. CUMSTON, C. G., Ann. Surg., 1913, lvii, 143. DAWBARN, R. H. M., Boston M. and S. J., 1906, cliv, 691. DAY, H. F., Boston M. and S. J., 1918, clxxviii, 389-392. DEERING, G. E., Phys. Therap., 1930, xlviii, 362-366; Am. J. Electrotherap. and Radiol., 1917, xxxv, 170-176. DESPLATS, H., J. d. sc. med. de Little, 1891, i, 265-271; Bull. off. Soc. franc, d'electro-ther., Paris, 1904, xi, 289-301; Ann. d'electrobiol., Paris, 1904, vii, 674-685. DIALTI, G., Cesalpino, Arezzo, 1908, iv, 169-176. DICKSON, J. A., S. Clin. N. Am., 1924, iv, 1053-1063. DOLLINGER, G., Orvosi hetil., 1932, lxxvi, 27-29; Zentrbl. f. Chir., 1982, lix, 579-583. DONLEY, J. E., Boston M. and S. J., 1911, clxv, 273. DOUGLAS, J., Ann. Surg., 1917, lxvi, 230. DUNLOP, J., Am. J. Orth. Surg., 1916, xiv, 102. DUPLAY, Rev. part. d. trav. de med., Paris, 1896, liii, 226; Semaine med., Paris, 1896, xvi, 193-194; Med. Week, Paris, 1896, iv, 258; Med. Press & Circ, London, 1900, n.s., lxix, 571-573. ECCLES, McA., West London Med. J., London, 1920, xxv, 87. ELMSLIE, R. C, Br. J. of Surg., 1932, xx, 78, 190-196. ELY, L. W., Am. J. Orth. Surg., 1914-15, xii, 447-450. ERB, K. H., and FRIEDRISZIK, W., Dtsch. med. Woch., 1982, lviii, 1004-1005. FALTA, Wien, med. Woch., 1920, lxx, 1414-1416. FIELDS, S. O., N. Y. M. J., 1915, ci, 163. FISHER, C. F., West Virginia M. J., 1927, xxiii, 250-252. FLINT, J. M., J. A. M. A., 1913, lx, 1224. FORT, F. T., Kentucky M. J., 1911, ix, 897-899; Railway Surg. J., 1912-13, xix, 8-14. FOWLER, E. B., Illinois M. J., 1932, lxi, 332-334. FRAUENTHAL, H. W., Internat. Clin., 1918, 28 s., iv, 60. FREUND, L., Wien klin. Woch., 1917, xxx,
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Almost all of the above articles are brief reports of the first few cases of calcified deposit which were observed in each locality, and give illustrations of the X-ray findings. In my opinion the articles by Brickner, Carnett, Harbin and Stieda are the most instructive. The article by Kiister in 1902 did not mention calcified deposits, but I am quite sure that the cases which he observed were such cases. His excellent and brief article was, so far as I know, the first rational description of subacromial bursitis. It was called to my attention some years after I had written my first paper, but was in fact written before mine.
Duplay's first article appeared in the Archives General de Medecin, Nov., 1872, but it apparently was not at first appreciated. Another paper in 1896 received more notice and literal translations were at once printed in two English Journals (see ref. above). Most European authors credit to him the introduction of the term "Periarthritis of the Shoulder" (periarthrite scapulo-humerale, periarthritis humero-scapularis). The chief advances in our knowledge of the subject since Duplay's contribution have been due to the use of the X-ray (discovered in Dec, 1895), so that we have been able to study separately the cases in which there is a calcified deposit or in which a fracture of the tuberosity had taken place. Except for that of Dickson and Crosby, quoted on page 224,1 have found no important study of the type of cases to be considered in the next chapter in which little if any calcification is found.
The articles by Baer and Painter both appeared in 1907 and I think were the first articles in this country to recommend surgical removal of the deposits. Bergemann and Stieda recommended surgery in Germany in 1908. Most of the articles advise some form of physiotherapy. It has seemed unnecessary to me to print the titles of all these papers on account of the large amount of space that this would require. Doubtless most of these authors would today be able to give as detailed a study as I have given in this chapter, but many of the articles show a lack of knowledge of minor points which have probably become plain to most of them during the intervening years. For instance, none of the articles seem to give proper consideration to the fact that nature's method of cure is by evacuation of the calcified material into the bursa. Many of the authors seem to think that the origin of the particles is in the bursa, and hence use the term "calcified bursitis." A good many attribute the onset of the trouble to recent trauma.
Most striking is the length of the bibliography of this chapter as compared to that of the last one on complete rupture of the supra-spinatus, which, to my mind, is so much more important and disabling a lesion than that caused by calcified deposits. The reader should refer to the comparison of costs on the scheme on page 124. Even the brief bibliography that I have given at the end of that chapter is partly composed of articles which really do not refer to the subject, and are only related to it. In fact, my papers and that of Wilson are really the only ones devoted to the subject. It seems to me most important for the profession to learn to differentiate between these two common causes of shoulder disability. As a matter of fact it is essential on the patient's account that rupture of the supraspinatus tendon should be recognized and operated upon promptly, whereas, the treatment of calcified deposits is a matter of choice, although my personal opinion is in favor of prompt surgical removal of the deposit. There is so little difference between the results of surgery and the results of any form of palliative treatment that I do not feel in these cases, as I do in those of ruptured supraspinatus, that their treatment is essentially surgical.

My own articles have been extensively quoted (often incorrectly) in American and English literature. This has been one reason why I have taken so much pains in this chapter to enter into the minor details of this comparatively insignificant lesion, cases of which recover in due time by nature's own methods. This chapter may also be of some importance because I am able to report the results of many cases which were operated on a long time ago. However, I feel that in some of these patients, whether or not operated upon, the tendons have probably been weakened through destruction of the tendon fibers so that had they been subjected to unusual trauma they might have ruptured more easily than normal ones. As stated in the chapter on Pathology, there is some doubt as to whether the defects so frequently found by Dr. Akerson may not have been sometimes due to destruction of the tendon by these calcified deposits years before autopsy. In the cases which I have reported as operated on for complete rupture, there was no doubt in my mind from the pathology found that the lesion was purely traumatic, although I could not, of course, determine whether there may not have been a weakened tendon before the actual rupture. In no case did I get a definite history of a calcified deposit in years previous to the rupture. Autopsy specimens from cases known to have had these calcified deposits in earlier years, and in whom there had been no operation or history of later trouble, might clear up this point.

THE TECHNIQUE OF THE OPERATION FOR REMOVAL OF CALCIFIED DEPOSITS

In most cases this operation can be done through an incision about one-half inch in length, but it will be perhaps safer for both patient and surgeon if an incision an inch and one-half is made to allow ample room to identify the anatomic landmarks. I will assume that the incision is of this size, although I have developed a technique of doing it through an incision just large enough to admit a nasal speculum with recurved tips. The only objects of this modification are to have less scar and less chance of intrabursal adhesions and perhaps less postoperative pain. Since even with the larger wound, i.e., one inch and one-half, opening the bursa as widely as possible, the scar is small and postoperative pain slight, and adhesions more of theoretic than practical importance, one should not hesitate at any time to enlarge a half-inch wound.

FIGURE 49
On the left is a figure showing the size of the open exploratory incision, which is also sufficiently large for the removal of most calcined deposits. The figure on the right shows the size to which it is necessary to enlarge the incision in order to suture a rupture of the supraspinatus by the author's method. Both figures depict a normal bursa with the edges of the roof caught with sutures and held apart to show the smooth, white, convex base which covers the tuberosity and insertions of the tendons. In the lower portion of both figures a nictitating fold is represented. By rotation of the humerus, the whole base of the bursa may be inspected through the small left-hand incision. Lesions are seldom found at any other situation than on that part of this base which is just above the greater tuberosity. The writer believes that the little exploratory incision is almost harmless, provided the surgeon understands what he is looking for and does not attempt to explore further if the pathology is not at once evident when the bursa is opened.

Anaesthesia.
I prefer to do this operation under local anaesthesia in suitable cases, because it is easier for the patient. However, it is easier for the surgeon to have the patient under general anaesthesia, because local anaesthesia does not relax the spasm, and renders it necessary to be more accurate in cutting down directly on the lesion. Even if no spasm is present before making the incision, it may be started up by touching the inflamed region with a retractor or other instrument. In a recent case the reflex spasm could be produced at will by touching the surface near the lesion, yet the touch of the instrument caused no sensation of pain. The patient was an intelligent doctor, and could describe his sensations accurately. When the retractors were out of the wound he could rotate the arm, but when they were in the wound he found himself unable to overcome the spasm by force of will, although he felt no pain except when I endeavored to force the rotation.
Although the operation can be done under such circumstances, it is unsatisfactory. I have found it so difficult to anaesthetize the base of the bursa where the deposit is, that now I do not attempt to do so. The tendon near its insertion is so dense that it is difficult to inject the novocaine, and this is as painful as incising the tendon; possibly more so.
Local anaesthesia does not permit a thorough exploration of the bursa, but when one is familiar with the local anatomy one does not need to see the whole bursa. When the patient is under ether, by a certain maneuver the arm can be pulled downward and forward, and the surgeon's forefinger introduced between the tuberosities and the acromion. When air once gets into this opening the atmospheric pressure is overcome, and the subacromial space remains open, permitting inspection and palpation of the whole bursa. This maneuver is more especially useful in cases of rupture of the tendon. In this case the joint is not held together either by atmospheric pressure or by the tension of muscles. Manipulation of this type is not necessary, and cannot, of course, often be done under local anaesthesia, but probably might be done under regional anaesthesia. I regard the latter as too serious a procedure, and would prefer a general anaesthetic.
From the patient's point of view, in spite of these drawbacks I favor a local anaesthetic, provided the surgeon knows where the deposit is, and can go directly to it through a small incision. It is then a trivial operation. But if the deposit cannot be accurately localized, and the anatomy is not clear in the surgeon's mind, general anaesthesia would be preferable in order to allow for some unnecessary manipulation and rough handling. I have operated on many doctors, and had a chance to hear their commendations or objections. I am told that the actual curetting of the lesion is painful, but not more than can be readily borne. The incision of the skin and muscle, and of the bursal roof, is not felt at all.
Some patients are obviously poor subjects for local, and others for general anaesthesia. Surgical judgment on general principles is needed. I should advise any surgeon to do his first few cases under ether, for in spite of all the directions I can give, the anatomy is difficult to describe, and one is easily confused unless very familiar with it. The facts that the structures to the right or left of this small wound are reversed in relation to the surgeon's position as to whether he stands on the acromial or axillary side of the wound, and are also reversed in right and left shoulders, add to the puzzle.

FIGURE 50. OPERATIVE POSITION
This is an important figure. The writer did not realize the advantage of placing the patient in this position, until he had done many of these operations, which had been attempted with the patient either in recumbency or in a sitting posture, strapped in a chair. The latter was a very satisfactory position after the strapping had been adjusted if the assistants could be trained to work in this unusual attitude. However, the cases were too infrequent for any routine to be established. Until one operates on these cases one does not realize how elusive is the shoulder on the operating table, and, since the field is entirely controlled by the position of the humerus in relation to the scapula, how any minute change in the position of either the arm or of the body is at once transmitted to the tiny wound. Gradually I worked out this position, and find that it gives the best possible exposure, and enables one, if the assistant is attentive, to perform a very satisfactory suture through the very small incision.

Preparation.
The patient is placed on his back on the table, and small sand bags or folded sheets are put under the shoulder blade and corresponding hip. This slightly raises the shoulder. It is well to draw the patient as close to the edge of the table as may be, so that when desired the elbow can be pushed backwards below the plane of the table—a maneuver which may be needed to expose the upper part of the bursa. The patient's face should be turned toward the opposite shoulder, and the anaesthetist and patient's head protected with a "goiter apron" tied around the patient's neck.
I always arrange a sterile dressing over the hand and forearm, so that during the operation the arm may be manipulated by the operator or assistants. A convenient way is to sterilize the shoulder and arm to below the elbow, and then to draw a sterile pillow slip over the hand, forearm and elbow, and attach it with sterile bandages as high on the upper arm as desired. The arm may then be drawn through the hole in a laparotomy sheet, and moved about at any stage of the operation.

Position of Incision.
In deciding on the point at which to incise, one must Temember that the skin incision will remain stationary, and that by rotation of the humerus the point at which the calcified deposit lies may be brought beneath the incision. The deltoid muscle, which forms the bulk of the tissue which must be cut through, also remains nearly completely fixed. It moves a negligible amount when the humerus is rotated. One must remember also that the sides of the subdeltoid portion of the bursa move considerably in rotation of the humerus. For instance, having incised the skin and muscle, it is possible to continue the incision in such a manner that it would be entirely outside of the bursa; i.e., it might not penetrate the bursa at all when the arm is in extreme internal rotation, but if the cut were made with the arm in external rotation, the bursa would be opened. To make the operation easy, one would desire to have the skin incision as nearly opposite the calcified deposit in the base of the bursa as possible. I have found that the incision best on the average is directly anterior to the head of the humerus, with its upper end near the acromio-clavicular joint, and its lower end at about the level of the top of the bicipital groove. In thin subjects one can feel the bicipital groove through the deltoid, and it is always well to do this if possible, because the acutely tender point will lie external or internal to the groove, according to whether the deposit is in the supraspinatus or subscapularis. The expansions of these two tendons bridge the bicipital groove, but their real attachments are to the greater and lesser tuberosities on each side of the groove. I have sometimes seen the deposit apparently over the groove, but it had probably extended from the tendon on one side or the other.
If one cannot feel the groove before making the incision, one can always determine its position by palpation in the wound after the deltoid has been incised. It is well to do this in every case, for often the exact location of the deposit can be made previously by X-ray, and one can readily locate the subscapularis and supraspinatus if the groove is determined. Sometimes the floor of the bursa does not show sufficient indication of the deposit to guide the surgeon. In such a case the tip of either tuberosity may be readily determined with the point of the knife, and the tendon incised just above it. When a little of the white deposit appears, the incision can be enlarged in the line of the fibers of the supraspinatus or subscapularis, as the case may be.
In order to determine the position of the bicipital groove, one may take it as a good rule that when the elbow is flexed at a right angle, and the posterior part of the elbow put down on the table at the side of the patient so that the axis of the forearm stands directly vertical to the table, the bicipital groove will be at the most anterior portion of the prominence caused by the head of the humerus. From this point, rotation of the forearm either way brings the tendons into view according to the obvious anatomical arrangement. (Pigs. 6 and 51.)

Incising the Deltoid Muscle.
Separating the fibers of the deltoid muscle is a little more difficult than parting those of the rectus in abdominal incisions, owing to the fact that the fibers of the deltoid are more or less "herringbone" in arrangement. The incision seems to close right up on withdrawal of the knife, so that it is difficult to find the line again. I therefore usually put another instrument, as the point of a hemostat, in along the knife before withdrawing it, so that with my knife in my right hand and the hemostat in my left, I push the fibers apart as the assistant places two aneurism needles as retractors to take the places of my two instruments. These hold the line of incision, and the fibers of the deltoid are cut upward and downward to equal the length of the skin incision. Small, broader retractors are then introduced, exposing the upper surface of the roof of the bursa.

If the above has been understood, it will be seen that the skin incision and the deltoid incision are simple and standard. If correctly placed they would lie over the very top of the bicipital groove in the above-mentioned position, with the forearm vertical to the table. It is by no means necessary to hold the arm in this position while the skin and muscle are incised, but when the bursa is to be opened, the arm should be held in this position, the assistant being ready to rotate it one way or the other as the surgeon desires. Make sure that this point is understood.

This figure should be studied with the last one, although for convenience the patient is here represented as standing up while the operator looks downward from above, and the assistant, holding the elbow at the side, rotates the forearm and consequently the humerus beneath the wound. The figures below represent the incision and its relation to the bicipital groove as the humerus is rotated. The Incision remains stationary while the facets of insertion pass beneath the incision. A thorough understanding of these two diagrams is most important.

Incising the Bursa.
The incision in the deltoid having been made, and the fibers retracted, it is well for the assistant to rotate the arm, and in most cases the roof of the bursa is so transparent that the base beneath it can be seen to move as the arm is rotated. In cases in which the bursal wall is thickened from old inflammation, one cannot see through it, but one can palpate the tuberosities moving beneath it. Since it is important not to allow any blood to enter the bursa, small sponges should be ready.
It is well to tie up vessels before making the incision into the bursa, for if blood fills it, it is harder to determine the appearance of the base. At this stage the roof of the bursa is picked up with two pairs of forceps, as is customary when incising the peritoneum. A cut is made between the two forceps, and the air rushes into the bursa, so that the incision can then be enlarged upward and downward as desired. A normal bursa has a white, shiny floor, but a circular zone of deep red injected tissue is usually the guide to the area where a deposit lies. This deep red tissue, resembling that of a bloodshot eye, surrounds a white or pale area about one-half the size of a ten cent piece. Sometimes this area is obviously under tension and mounded up like a boil. At other times when the inflammation is less, the affected area is not raised, and there is only a barely perceptible whitening where the calcium deposit shows through the synovial floor of the bursa. Before incising this area it is well to look the rest of the bursa over, to make sure that there are no other lesions. The X-ray will probably have already determined whether there is more than one deposit, but even if the X-ray does not show more than one deposit, there may be a second one, so that in case of doubt, I believe it is better to prick any suspected area with the point of a knife. I have done this many times, and have seen no variation which could be attributed to this practice in the convalescence of these patients. Sometimes such exploratory punctures of the tendons have fortunately led to the finding of a second deposit, for the patient may suffer an attack of inflammation about one deposit, and then later have another attack due to inflammation about another deposit. While immediate attention to the inflamed deposit is the most important thing, it is desirable when possible to remove or free any other deposit. I recall few cases of deposits which were not surrounded by red zones.
Experience has shown that we rarely find any lesion of the bursa except at the points close to the attachments of the tendons, and these points may all be inspected by simply rotating the arm through its full arc while the wound is held open. It is a little harder to see the extreme edges upward and downward, but practically the whole bursa may be inspected by merely rotating the arm. Pushing the elbow backward (dorsal flexion) tends to demonstrate the upper edge, and pushing it forward reveals the lower limits of the bursa. I have never recognized any lesion of the roof of the bursa. Lesions at the attachment of the supraspinatus are the most common, those at the attachment of the infraspinatus next, and those of the attachment of the subscapularis perhaps a little less common. This relative frequency also holds good in regard to traumatic rupture of these tendons. One must remember that the three tendons are closely incorporated at their attachments, and that these attachments to some extent overlap.

Removing the Deposit.
To return to the operative technique—we may assume that we have reached the point of incising a calcified deposit which we have found in the supraspinatus tendon. According to the stage of the pathologic process, whether acute or chronic, the calcified mass will be softer or harder; in the earlier stages it is little more than a milky fluid; in the older stages it is hard and gritty, coherent and sometimes encapsulated. In most cases it is of the consistency of ointment; often it resembles the contents of a wen. On incision this material usually escapes as if under tension. Sometimes this is very striking. A little nick is made, and there emerges a ribbon of whitish material just as one sees when a tube of zinc oxide ointment is squeezed. Sometimes, however, there is not much tension, particularly in the old cases, and the particles of calcareous matter seem to be incorporated in the substance of the tendon so that they cannot be curetted out without removing shreds of tendon with them. Occasionally the material occupies a well-formed pocket, and one gets the impression that it is wholly removed with the curette. I have oftentimes been content with merely incising one of these pockets, making no effort to curette out all of the material. The symptoms have disappeared quite as satisfactorily as in cases where a thorough curetting was done. Some surgeons, notably Brickner and Harbin, have stated that they excised all the calcified material. I am sure that if they do this, they will remove a considerable amount of tendinous substance which will be replaced with very little scar tissue, so that the tendon will be much weaker. I have sometimes thought that possibly cases of rupture of the supraspinatus tendon from trauma may be particularly common in cases which have had previous attacks of this so-called calcified bursitis, which has weakened the tendon. At any rate, I feel that it is well to do as little damage to the tendons as possible. Attempts to "excise the bursa" are absurd and indicate an entire lack of knowledge of the local anatomy, physiology and pathology.

Closing Incision.
Having removed with the curette the major portion of the deposit, I wipe the cavity out, but do not attempt to sew up the incision in the tendon or in the bursa. Most other writers have recommended that the roof of the bursa be sutured. I have rarely done this, believing that it is better to allow the fluid formed by the synovial secretion of the bursal walls to seep into the areolar tissue. This would naturally wash out any particles of calcium and blood which remained in the bursa. If the bursa is closed these particles might cause adhesions, and perpetuate inflammation. Then, too, in a few cases in which I have closed the bursa, I think there has been more postoperative pain, due to distention of the bursa with blood and serum. I have not found that the adhesions due to the incision healing down to the tuberosity cause any permanent restriction of motion. It appears that the bursa itself reforms as a rule, perhaps not as a simple space, but as several small spaces.
I close the muscle with a few loose catgut stitches, because I have found that unless I do so the wound eventually heals with a depression between the fibers of the deltoid. Therefore, it is better to see that the deltoid muscle returns to its normal contour. Perhaps it is better to close the roof of the bursa, but it would need a considerable number of cases to prove it, for my experience is sufficient to show that it is certainly not necessary. It may add some slight shred of advantage, but I think not. The skin is closed as in any other surgical wound.

Postoperative Treatment.
After the operation I treat the patient just as I would a normal person who had a similar wound caused by an accident. The arm is carried in a sling most of the time for a few days. In about a week or ten days the patient can use the arm in a gingerly way, and can manage to dress himself, and use a knife and fork. Discarding the sling, I then encourage "swinging exercises" in a stooping position. When these become free the "standing exercises" are prescribed. In from three to six weeks the patient should be well, except for occasional twinges of pain and soreness and slight restriction in extreme degrees of motion. These twinges of pain are not severe or incapacitating, and I suppose are due to the irregular contours of the bursal surfaces after the incision. They slowly disappear. My tendency is to allow any free use which does not cause pain.

Finer Points and Occasional Obstacles in the Operation.
In ladies it is well to have the patient try on a low-neclced dress, and to make the incision at a point where the scar will be concealed by the shoulder strap. Since rotation of the humerus covers a considerable arc, the site of the skin incision can be varied a good deal. I have tried a horizontal incision once, but the scar seemed to have a tendency to stretch more than does a vertical one.
I want to repeat that it is important to tie all bleeding vessels before opening the bursa. The blood supply of the skin on the point of the shoulder is very active, and this is increased in cases of longstanding inflammation. Many small vessels sometimes have to be clamped to obtain a dry field. At the extreme upper angle of the wound there is one which is especially annoying, for it retracts into the muscle and readily drips into the open bursa, obscuring the field. As the wound is deep and small, even a little blood causes delay.
Incising the bursa itself may prove confusing, especially where there are adhesions. Normally the roof of the bursa is even thinner and more delicate than the normal peritoneum, but where there has been inflammation in the bursa, it may be as thick as blotting paper, and quite opaque, so that it is hard to see the floor rotate beneath it as the arm is moved. In such cases one usually finds straw-colored fluid in the bursa. In some cases where the deposit has broken through into the bursa, flecks of deposit in sheets of fibrin or milky fluid will be found in the bursa. Such cases would probably get well without operating.
It is not easy to open the bursa in some cases or even to know when your knife has passed through it into the areolar tissue in the nictitating folds. In case confusion arises, keep the arm in the position advised with the forearm vertical to the table, and cut down on the outer lip of the bicipital groove at its upper extremity. Do not cut directly on the bicipital groove, for you might unnecessarily open the sac about the tendon, if the bursal surfaces were adherent. This would probably do no harm, for in the cases of exploration for a ruptured biceps tendon I do not hesitate to do this and have had no unpleasant results. However, it does not help to locate the bursa, so it is best to recognize the groove by palpation before incising.
Adhesions of the surfaces of the bursa may make it difficult to open. In two cases I have opened directly into the space containing the deposit, passing through the two adherent surfaces of the bursa without separating them. Such an experience might give the impression that the deposit was in the bursa. In my experience adhesions are not the rule. They vary, when present, from recent film-like strands hardly more solid than fibrin to dense scar tissue which effectually prevents rotation. As a rule, one readily opens into a good, large bursa, and the white or yellowish deposit surrounded by the turgid, red zone is as conspicuous as it well can be. The confusion comes in long-standing cases when the acute inflammation has subsided, and is replaced by firm, relatively bloodless adhesions about a very small deposit.
It is quite possible that in cases where the deposit is in the subscapulars, a quicker and smoother convalescence might be obtained by pushing the bursa up from below, or from the inner side, and removing the deposit from beneath it without opening the bursa at all. This would leave a smooth bursa, and avoid the twinges of pain which the roughened surfaces produce if the bursa has been opened. I have done this in one case. However, it is surer and safer in most cases to incise directly into the bursa, and be guided by the red zone.
Remember that when the incision is once made, only gentle retraction is necessary. Rotation of the humerus, by using the forearm flexed at a right angle, should take the place of retraction of the lips of the wound. It would be unfair to a patient to attempt to open his bursa unless the meaning of the above sentence was clearly understood. (Fig. 516.)
I have operated on a few cases after the calcified material has perforated into the bursa, but I think now that these operations were probably unnecessary. So many similar cases have promptly got well without any treatment, that I suspect that although my operated cases also promptly got well, the operations had little to do with the recovery. In opening the bursa in these cases a few days after the perforation, I have found a film of whitish fibrin between the two bursal surfaces. Under the microscope little particles of calcium were found thickly scattered through the fibrin, accounting for its whitish look. Recently I have seen two such cases demonstrated by X-ray, on which I did not operate, and the symptoms cleared up as promptly as if I had removed the fibrin.
It seems to me that the time when operation is most indicated is when the deposit has begun to cause subacute symptoms and has not yet perforated. It is in such cases that the mound on the base of the bursa is found, and from which the white material exudes as soon as it is punctured.
I am inclined to think that spontaneous perforation will by nature relieve the symptoms in a few weeks, although it brings on the acute symptoms during the first few days. Operation, diathermy, puncture, injection of proteids, violet light or other treatment may easily get the credit for the good result. It seems a pity that comparative series of such cases treated by different methods cannot be arranged and controlled by a series of untreated cases. It is at least a comfort to know that all the cases under any treatment get well. The object of treatment is only to find the easiest, quickest, and most comfortable way.
My feeling at present is that when the X-ray shows that the deposit has become diffused in the bursa it is unnecessary to operate, unless the quantity is great, as in Fig. 44. One can tell that it has become diffused if the film shows that the deposit lies outside of the tuberosity and, vice versa, if it lies within the contour of one of the tendons it cannot be in the bursa. (See Plate II.)
Sometimes after perforation a portion of the deposit remains in the pocket in the tendon, and this gives a "shirt-stud" shadow in the X-ray.
Be on your guard in interpreting the shadow cast by the bursa with a film of fibrin in it containing the diffused particles. Remember that the bursa is a very thin concavo-convex space, and therefore the mass of material in a lateral view seems greater than it really is. (See Fig. 45.)

Shoulder:Glenohumeral Instability/Posterior Instability

2022-04-14T16:08:03Z

Alexandre.laedermann: /* B2: Structural dynamic posterior instability */

==Bullet Points==

*Posterior shoulder instability is not as rare as previously thought.
*Diagnosing posterior instability may be difficult because patients often report vague symptoms not linked to a clear history of traumatic shoulder dislocation.
*This condition is consequently often misdiagnosed or patients experience a delay in diagnosis.
*It that encompasses different acute and chronic pathologies involving the labrum, the cartilage, the capsule, bony lesions.
*A tear between the posterior labrum and the glenoid cartilage without complete detachment of the labrum is described as a Kim lesion. It is postulated that this lesion is due to posterior force acting on the posterior-inferior glenohumeral ligament as it attaches to the posterior labrum.
*Numerous classifications exist, none having unanimity.
*Risk factors for recurrent instability are: (1) age below 40 at time of first instability; (2) dislocation during a seizure; (3) a large reverse Malgaigne (Hill-Sachs) lesion; (4) glenoid retroversion, and (5) a high and horizontally oriented acromion in the sagittal plan.
*Hyperlaxity is multidirectional but instability is almost exclusively unidirectional.
*Physical examination comprises the articular range of motion, the rotator cuff, and jerk, Kim and O’Brien tests.
*Three views plain radiographs, including true anteroposterior of the glenohumeral joint, scapular Y (scapular lateral), and Bernageau views are the mainstay of imaging in the setting of shoulder instability.
*An internally rotated humeral head gives a rounded appearance on anteroposterior view, which is called the lightbulb sign.
*In case of a suspicion about posterior dislocation of the shoulder, additional imaging including, depending of the type of instability, magnetic resonance arthrography (MRA) or computed tomography (CT) is required.
*Acute or recurrent posterior dislocations can be treated conservatively, by soft tissue or bony procedures.
*Surgical options include anatomic reconstruction as well as non-anatomic procedures such as subscapularis tendon transfer, allo-/autograft reconstruction, derotation osteotomy or shoulder arthroplasty.
*Treatment of locked dislocation depends on the extent of the articular defect size of the humeral head, duration of the dislocation and patient-specific conditions such as age and activity levels.

==Key words==
Posterior shoulder stabilization; Functional instability; Soft tissue injuries; Locked dislocation; Subluxation; Epidemiology; Labrum; ABC classification; Treatment options; Arthroscopy; McLaughlin procedure; Bone block; Clinical outcomes; Complications.

==History==
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==Anecdote==
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==Epidemiology and Mechanism==
Posterior dislocation of the shoulder accounts for around 20% of all shoulder dislocations, which is much higher than the 4-5% prevalence previously mentioned in the literature.<ref>Song DJ, Cook JB, Krul KP, Bottoni CR, Rowles DJ, Shaha SH, Tokish JM. High frequency of posterior and combined shoulder instability in young active patients. J Shoulder Elbow Surg. 2015;24:186-90. </ref> A reason for this large discrepancy is the challenge of clinical diagnosis, since symptoms are often subtle and patients often lack the typical feeling of posterior apprehension in provocative arm positions.

==Anatomy, Pathoanatomy==
==Soft Tissue Lesion==
===Labral lesion===
Four different types of labral insertion have been described by Nourissat et al.<ref>Nourissat G, Radier C, Aim F, Lacoste S. Arthroscopic classification of posterior labrum glenoid insertion. Orthop Traumatol Surg Res. 2014;100:167-70.</ref> Type 1, 60% of the cases, correspond to a posterior labrum totally inserted in the glenoid, with direct contact with the cartilage, totally flush. In type 2 (20% of the cases), insertion of the superior segment is medialized. Type 3, 15% of the cases, represents an associated medialization of the superior and medial segment of the posterior labrum. Type 4 is a medialized insertion of the all-posterior labrum.

Consequently, a subchondral cleft (labrum and capsule attached but no tear) may be a normal finding.<ref>Campbell SE, Dewitt RM, Cameron KL, Thompson AK, Owens BD. Posterior chondrolabral cleft: clinical significance and associations with shoulder instability. HSS J. 2014;10:208-212.</ref> Surgeons should be aware that while anterior capsule anatomy is quite variable, the posterior capsular insertion tends to be more homogenous in appearance among patients (Figure).

[[File:Abnormal insertion of the capsule.jpg|thumb|A) Normal insertion of the posterior capsule. B) Posterior disinsertion of the capsule.|alt=|center]]

 

===Reverse humeral avulsion of the glenohumeral ligaments (rHAGL)===
[[File:Reverse humeral avulsion of the glenohumeral ligaments (rHAGL).jpg|thumb|alt=|Posterior arthroscopic view of a left shoulder. Observe the humeral avulsion of the capsule.|center]]

===Kim lesion===
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==Bony lesion==
[[File:Bony lesion.png|thumb|Reverse bony Bankart|alt=|center]]

[[File:Humeral head fracture.png|thumb|Humeral head fracture|alt=|center]]

===Reverse Malgaigne (Hill-Sachs)===
This is usually present in patients with chronic locked posterior dislocations or in cases with significant traumatic history (e.g. seizure disorder, electrical injury). Patients with positional posterior instability with ligamentous laxity usually do not present with significant reverse Malgaigne (Hill-Sachs) lesions but may occur occasionally.

==Associated lesions==
Associated intra-articular pathology such as superior labrum anterior posterior (SLAP) lesion, rotator cuff lesions or a paralabral cyst should be also assessed (Figure). Unlike spinoglenoid cysts, posterior or posterior-inferior labral cysts rarely results in impingement of the suprascapular nerve and suprascapular neuropathy.

[[File:Image7-29.jpg|thumb|A) 3D maximum intensity projection reconstruction showing a remarkably voluminous cyst dissecting 9 cm from the glenoidal labrum through the long head of the triceps muscle. B) The patient complains from a lump in his axillary fold.]]

=Definitions=
Dislocation is defined by a complete displacement of the humeral head from its articulation with the glenoid, whereas subluxation represents an incomplete or partial dislocation of the joint. Laxity is a physiologic and an asymptomatic finding, that corresponds to translation of the humeral head in any direction to the glenoid. Hyperlaxity is constitutional, multidirectional, bilateral and also asymptomatic. Hyperlaxity of the shoulder is probably best defined as external rotation elbow at the side equal or greater than 85 degrees (Figure).<ref>Walch G, Agostini JY, Levigne C, Nove-Josserand L. [Recurrent anterior and multidirectional instability of the shoulder]. Rev Chir Orthop Reparatrice Appar Mot 1995;81:682-90.</ref>

[[File:Hyperlaxity of the shoulder.jpg|thumb|Hyperlaxity of the shoulder is defined as external rotation elbow at the side equal or greater than 85 degrees.]]

This finding is most of the time non-pathological (except in soft tissue pathologies like Ehler-Danlos syndrome), is a risk factor for instability but does not by itself demand treatment.<ref>Nourissat G, Vigan M, Hamonet C, Doursounian L, Deranlot J. Diagnosis of Ehlers-Danlos syndrome after a first shoulder dislocation. J Shoulder Elbow Surg 2018;27:65-9.</ref> Hyperlaxity is multidirectional but instability is almost exclusively unidirectional (Figure). From an etiological point of view, the posterior dislocation is typically differentiated into acute traumatic dislocation that becomes locked after 6 weeks if neglected, and recurrent instability.

[[File:Anterior and Posterior Instability.jpg|thumb|center|Observe the anterior and posterior humeral bone loss in case of anteroinferior and posterior instability. Such case is exceptional.]]

=Classification of Posterior Shoulder Instability=

Posterior instability includes a wide spectrum of pathological conditions, which are sometimes difficult to classify homogeneously.

Classifications of posterior instability have been confusing and most attempt of classification failed. The ABC classification has the merit to be correlated to the presence or not of lesion(s), indication for surgery and results.<ref name=":0">Moroder P, Scheibel M. ABC classification of posterior shoulder instability. Obere Extrem 2017;12:66-74</ref>

Table 1: The ABC classification of posterior shoulder instability

{| class="wikitable"
|-
!Header text!!A First time!!B Dynamic!!C Static
|-
|Type 1||Subluxation||Functional||Constitutional
|-
|Type 2||Dislocation||Structural||Acquire
|}

==Group A==
Group A includes all patients with an acute first-time posterior instability event that can either have occurred in terms of a subluxation without engagement of the humeral head with the posterior glenoid rim (A1) or in terms of a dislocation with temporary or persisting engagement (A2). Distinction of this group and the two subtypes is possible by a combination of taking the patient’s history and imaging studies, both applicable even in the acute and painful setting.

===A1: Acute posterior subluxation===

[[File:Instabilité postérieure.png|thumb|center|First-time posterior subluxation (A1). Magnetic resonance image of a young male patient who sustained an acute posterior shoulder subluxation with small reverse Hill–Sachs lesion and minor posterior capsulolabral damage during sports participation without major trauma]]

===A2===

[[File:Post dislocation.png|thumb|Axial A) and saggital B-C) views of a reduced acute posterior glenohumeral dislocation. A) Observe the posterior labral lesion and the reverse Malgaigne (Hill-Sachs) lesion. B and C demonstrate important post-traumatic muscular edema of the posterior rotator cuff.]]

==Group B==
Group B includes all patients with recurrent dynamic posterior instability events that occur during motion either in form of a functional instability (B1) or a structural instability (B2).

===B1: Functional dynamic posterior instability===
In many cases, the instability is voluntary but positional that is, the patient’s shoulder is dislocated/subluxed in the position of forward flexion, pronation, and internal rotation but relocates with the arm brought into abduction and extension. A voluntary dislocation is associated to a normal laxity or hyperlaxity. In voluntary dislocation, an aberrant muscle activation pattern is observed, the patient is able to demonstrate the phenomena and to repeat it with (Video), often, an amused mimic. There is no imaging finding.

[[File:Media3-54.mov|thumb|center|Voluntary dislocation]]

===B2: Structural dynamic posterior instability===
The B2 includes unstable painful shoulder, involuntary and reproducible dislocators.

====Unstable Painful Shoulder====
This condition (micro-instability) is characterized by pain that appears without trauma, without macro-instability (subluxation or dislocation) in a patient that usually does not suffer from hyperlaxity.<ref>Boileau P, Zumstein M, Balg F, Penington S, Bicknell RT. The unstable painful shoulder (UPS) as a cause of pain from unrecognized anteroinferior instability in the young athlete. J Shoulder Elbow Surg 2011;20:98-106</ref><ref>Patte D, Bernageau J, Rodineau J, Gardes JC. [Unstable painful shoulders (author's transl)]. Rev Chir Orthop Reparatrice Appar Mot 1980;66:157-65</ref>

Diagnosis is difficult and should not be confused with posterior static subluxation (B0 glenoid according to Walch)<ref name=":1">Domos P, Checchia CS, Walch G. Walch B0 glenoid: pre-osteoarthritic posterior subluxation of the humeral head. J Shoulder Elbow Surg 2018;27:181-8</ref> that belong to the type C2. Images are often relevant with 52% of reverse Bankart, glenoid or humeral cartilage lesions (28% and 8%, respectively) reported (Video).

[[File:Media11-94.mov|thumb|Posterior labral lesion in a patient suffering from unstable painful shoulder]]

====Involontary====
This type of instability is associated with a clear first traumatic episode. The patient is able to reproduce the painful subluxation/dislocation if not locked. A radiological substrate is found.

====Reproducible====
Reproducible (B2) are voluntary dislocators (B1) that become involuntary after decompensation by a trauma or after losing control of stability. If asked, the patient can reproduce the movement even if the excessive glenohumeral translation leads to symptoms which are sudden, painful and disagreeable (Video). A radiological substrate can be found.

[[File:Reproducible.mov|thumb|Reproducible dislocators. The patient reproduce the movement even if the excessive glenohumeral translation leads to symptoms which are sudden, painful and disagreeable. ]]

==Group C==
===C1: Constitutional static posterior instability===
Glenoid dysplasia is an idiopathic and congenital glenoid retroversion of dysplastic origin. In these conditions the humeral head remain posteriorly subluxated (Walch C glenoid). The retroversion is above 25 degrees, the subluxation above 80%. The posterior rim appears rounded (lazy J). There is moreover a deficient glenoid neck, a hypoplasia of the posteroinferior glenoid, minimal osteophytes, and a preserved joint space in comparison to osteoarthritis.

[[File:C glenoid.jpg|thumb|Figure 9. Axial computed tomography of a right dysplasia shoulder ]]

===C2: Acquired static posterior instability===
This group includes static posterior subluxation, locked dislocation, sequelae of brachial plexus birth palsy,…

====Static Posterior Subluxation====
The finding of static posterior subluxation of the humeral head before the development of posterior bone erosion of the glenoid in young men with radiographic findings of primary osteoarthritis has been described as arthrogenic (pre-osteoarthritic) posterior subluxation of the humeral head,<ref>Walch G, Ascani C, Boulahia A, Nove-Josserand L, Edwards TB. Static posterior subluxation of the humeral head: an unrecognized entity responsible for glenohumeral osteoarthritis in the young adult. J Shoulder Elbow Surg 2002;11:309-14</ref> or Walch B0 glenoid.<ref name=":1" /> This condition could be initially dynamic, eventually evolving into a static condition and may lead to posterior erosion of the glenoid, taking place once there is asymmetrically increased posterior glenohumeral contact forces and possibly associated with increased glenoid retroversion (Figure 9).

[[File:B0.jpg|thumb|Anteroposterior, Neer and axial view of a right shoulder with static posterior subluxation (B0 glenoid)]]

====Locked Dislocation====

[[File:Locked dislocation.png|thumb|Locked dislocation of a left shoulder. Observe the important reverse Malgaigne (Hill-Sachs) lesion.]]

====Sequelae of brachial plexus birth palsy====
Obstetric brachial plexus palsy (OBPP) frequently leads to secondary glenohumeral dysplasia (Video).

[[File:OBPP.mov|thumb|Acquired glenoid dysplasia secondary to obstetric brachial plexus palsy]]

=Etiology=
Injuries typically occur:

*As a consequence of a contact sport or motor vehicle accident. Patients will classically sustain a posteriorly directed force when participating in activities that place their extremity in the at-risk position of anterior forward flexion, adduction, and internal rotation (football players and weightlifters performing bench press or pushups). Interestingly, contact with anterior trauma to an abducted and externally rotated shoulder might also be responsible for posterior dislocations.<ref>Robinson CM, Seah M, Akhtar MA. The epidemiology, risk of recurrence, and functional outcome after an acute traumatic posterior dislocation of the shoulder. J Bone Joint Surg [Am] 2011;93(17):1605–1613</ref>
*After a violent fall.
*After seizures, electric shocks or alcohol intoxication because of uncoordinated muscle contraction (the internal rotator muscles of the shoulder contract with greater force than the external rotators, which causes the humeral head to move superiorly and posteriorly). Anterior dislocation is, however, more frequent in case of seizure.

=Risk Factors=
Risk factors for recurrent instability are:

*Age below 40 at time of first instability. Age is considered an important factor for possible associated lesions. Often, younger patients do not have associated lesions (i.e. rotator cuff), unlike older patients, and consequently, the treatment algorithm for these patients is different. Furthermore, a locked dislocation in an older patient may have different surgical solutions.
*Dislocation during a seizure or electric shock.
*A large reverse Malgaigne (Hill-Sachs) lesion.
*Glenoid retroversion. Please also refer to “Anatomy, Pathoanatomy” section.
*A high and horizontally oriented acromion in the sagittal plan.<ref>Meyer DC, Ernstbrunner L, Boyce G, Imam MA, El Nashar R, Gerber C. Posterior Acromial Morphology Is Significantly Associated with Posterior Shoulder Instability. J Bone Joint Surg Am 2019;101:1253-60</ref> Please also refer to “Anatomy, Pathoanatomy” section.

=Evaluation=
==History==
A thorough history taking is imperative for making an accurate diagnosis of posterior shoulder instability. A detailed description of the offending activity, the position of the arm, and how force was applied may lead the clinician to an accurate diagnosis (please also refer to Etiology section).

In acute or subacute situations, patients report pain with active motion and particularly limited external rotation of the arm. It may mimic a frozen shoulder on examination, especially in cases with an unreduced dislocation.

In recurrent situations, symptoms that are commonly reported are muscle weakness and fatigue, pain, or mechanical symptoms such as clicking or popping. Symptoms intensify with the arm in 90 degrees of forward flexion, adduction, and internal rotation. Rarely do patients report clear sensations of instability or posterior shoulder pain associated with the feeling of a dead arm.

==Clinical Examination==
A detailed physical examination of the shoulder will assist the clinician in accurate diagnosis of posterior instability.

===Inspection===
Examination should begin with inspection, looking for any asymmetry or atrophy of the musculature. Scapular winging also needs to be assessed while the patient is performing active range of motion as it is a sign of posterior dislocation (Video 5).

[[File:Media1-48.mov|thumb|Video 5. Posterior instability leading to winging scapula]]

===Palpation===
Cooper first reported the signs of posterior shoulder dislocation as the appearance of posterior fullness on the affected side.<ref>Cooper A. On the dislocations of the os humeri upon the dorsum scapulae, and upon fractures near the shoulder joint. Guys Hosp Rep 1839;4:265–84</ref>

===Range of Motion===
Shoulder passive and active range of motion should be assessed and compared with the contralateral shoulder. A loss of external rotation must be excluded.

===Specific Tests===
====Jerk test====
The jerk test (posterior stress test) has been considered to be highly sensitive for posterior instability. This test is performed by stabilizing the scapula with one hand, while the other hand holds the elbow with the arm in 90 degrees of abduction and internal rotation (Figure 12). A firm axial compression force is applied on the glenohumeral joint. The arm is horizontally adducted while maintaining the firm axial load. This will cause a posterior translation of the humeral head and as the arm is brought into extension a painful clunk may be appreciated as the humerus reduces and is indicative of a posterior labral tear.

[[File:Jerk.jpg|thumb|Figure 12. Jerk test]]

====SLAP Lesion Test====
=====Kim test=====
A further test for posterior instability is the so-called Kim test, which is a modification of the jerk test.<ref>Kim SH, Ha KL, Yoo JC, Noh KC. Kim’s lesion: an incomplete and concealed avulsion of the posteroinferior labrum in posterior or multidirectional posteroinferior instability of the shoulder. Arthroscopy. 2004;20:712–720</ref>

The patient is supine with the arm abducted at 120 degrees. The examiner takes the patient's wrist with one hand and the elbow flexed at 90 degrees in the other. The shoulder is brought into external rotation. The patient is then asked to flex his elbow against resistance (Figure 13). A positive examination is represented by either pain, a clunk, or a click and indicates either the presence of a superior labral tear from anterior to posterior (SLAP) lesion or a posterior instability.

[[File:Image28-small-72.png|thumb|right|Figure 13. Kim test. The patient is supine, arm abducted at 120 degrees. The examiner takes the patient's wrist with one hand and elbow, flexed at 90 degrees, with the other, and the shoulder externally rotated. The patient is then asked to flex his elbow against resistance.]]

The test is performed with the patient in a sitting position and their arm in 90 degrees of abduction. The examiner holds the elbow and lateral aspect of the proximal arm and applies a strong axial load in line with the scapula. While maintaining the axial load, the arm of the patient is elevated 45 degrees diagonally upward and a posterior force is applied to the proximal arm. The test is positive if the patient complains of pain during this maneuver.

The jerk and the Kim tests are important and help deciding between nonoperative and operative treatment. The combination of a painful jerk and Kim tests has been shown to be 97% sensitive for the detection of a posteroinferior labral lesion.<ref>Kim SH, Park JS, Jeong WK, Shin SK. The Kim test: a novel test for posteroinferior labral lesion of the shoulder—a comparison to the jerk test. Am J Sports Med. 2005;33:1188-1192.</ref> Patients with a painful jerk or Kim test have approximately 85% chance of not improving with rehabilitation and arthroscopic treatment with capsuloplasty is recommended.

=====Active Compression Test (better known as O’Brien’s test)=====
It is an active elevation against resistance, with the patient standing, shoulder flexed at 90 degrees and adducted at 15 degrees, elbow extended (Figure 14). The test is considered positive if there is pain in pronation but not in supination. This is the most sensitive (47% to 78%), but the least specific (11% to 73%) test. When testing negative, a superior labral tear from anterior to posterior (SLAP) lesion is very unlikely.

[[File:1562635352717-lg.jpg|center|thumb|600x600px|Figure 14. Active elevation against resistance test, with the patient standing, shoulder flexed at 90 degrees and 15 degrees adduction, elbow extended. The test is considered positive if there is pain in pronation but no pain in supination.]]

=Scores=
==Beighton score==
Assessment of generalized ligamentous laxity should be performed as this can predispose patients to instability events. The Beighton score is used to assess generalized ligamentous laxity, which has been shown to correlate with shoulder instability.<ref>Cameron KL, Duffey ML, DeBerardino TM, Stoneman PD, Jones CJ, Owens BD. Association of generalized joint hypermobility with a history of glenohumeral joint instability. J Athl Train. 2010;45:253-258</ref> The 5 included criteria are: (1) hyperextension of the elbow beyond 10 degrees; (2) hyperextension of the knees beyond 10 degrees; (3) forward flexion of the trunk, with knees straight, so that palms rest easily on the floor; (4) passive dorsiflexion of the little finger beyond 90 degrees; and (5) passive apposition of the thumbs to the flexor aspects of the forearm. This system is based on a 9-point scale and a higher score (>4) indicates general hyperlaxity (although an external rotation elbow at the side equal or greater than 85 degrees indicates shoulder hyperlaxity (Video 6)).

[[File:ER hyperlaxity.mov|thumb|Video 6. An external rotation elbow at the side equal or greater than 85 degrees indicates shoulder hyperlaxity.]]

=Imaging=
The diagnosis of this injury is often missed at initial examination, despite highly suggestive injury circumstances, notable clinical signs and radiographic evidence.<ref name=":2">Hawkins RJ, Neer CS, II, Pianta RM, Mendoza FX. Locked posterior dislocation of the shoulder. J Bone Joint Surg [Am] 1987;69-A:9–18.</ref>

==Plain Radiographs==
The views that should be included in the workup are a true anteroposterior view (grashey view), internal and external rotation view, a scapular Y view, and a Bernageau view. Posterior dislocation is missed initially on posteroanterior radiographs in 50% of cases, as the humeral head appears to be almost normally aligned with the glenoid.

===Anteroposterior view===
====Acute====
On anteroposterior view, an overlap of the head in relationship to the glenoid can be observed (trough line sign, loss of the normal half-moon overlap sign, Figure 15). Moreover, an internally rotated humeral head gives a rounded appearance, which is called the lightbulb sign. Furthermore, the rim sign is defined as the space between the anterior glenoid rim and the humeral head being > 6 mm indicating a widened glenohumeral space (Figure 16).<ref>Cicak N. Posterior dislocation of the shoulder. J Bone Joint Surg [Br] 2004;86-B(3):324–332</ref>

[[File:Image4-16.png|thumb|Figure 15. Posterior glenohumeral dislocation on an anteroposterior view. Note the loss of the normal half-moon overlap sign.]]

[[File:Image23-small-58.png|thumb|Figure 16. Anteroposterior view that demonstrate lightbulb and rim signs.]]

====Chronic/recurrent/congenital/acquired cases====

[[File:AP dysplasie.png|thumb|Figure 17. AP view of a right dysplasic shoulder. Note the medicalization of the humeral head medial to the base of the coracoid process.]]

===Scapular Y View (Neer)===
The scapular Y view can demonstrate a posterior translation of the humeral head (Figure 18).

[[File:Image24-59.png|thumb|Figure 18. Scapular Y View of a Posteriorly Dislocated Left Shoulder.]]

===Axillary view===
====Acute====
As a Bernageau view is difficult to obtain in acute cases because of severe pain, Velpeau axillary views is an alternative (Figure 19).<ref>Bloom MH, Obata WG. Diagnosis of posterior dislocation of the shoulder with use of Velpeau axillary and angle-up roentgenographic views. J Bone Joint Surg Am. 1967 Jul;49(5):943-9</ref>

[[File:Image26-63.jpg|thumb|Figure 19. Plain radiograph demonstrating a posterior glenohumeral dislocation.]]

====Recurrent/Congenital/Acquired====
Bernageau view is the best to demonstrate posterior glenoid rim deficiency posterior subluxation and associated bone loss.

[[File:Rounded glenoid deficiency.png|thumb|Figure 20. Rounded glenoid deficiency (“lazy J” form)]]

[[File:Image30-small-85.png|thumb|Figure 21. Triangular bony deficiency (“delta” form)]]

==Magnetic Resonance Arthrogram (MRA)==
Contrast enhancement during magnetic resonance arthrogram (MRA) is of great value and will increase the sensitivity of magnetic resonance imaging (MRI) in identifying a soft tissue injury (cartilage, rotator cuff, labral tears (Figure), a patulous capsule (Figure), reverse humeral avulsion of the glenohumeral ligaments (rHAGL, Figure), associated findings such as paralabral cysts) (Figure).

[[File:Image26-small-78.png|thumb|Figure 22. Axial view T2 MRA that show a patulous capsule.]]

[[File:Image12-32.jpg|thumb|Figure 23. Reverse humeral avulsion of the glenohumeral ligaments (rHAGL)]]

[[File:Différentes lésion labrales post.jpg|thumb|Figure 24. From left to right, different types of posterior lesions: Kim POLPSA, GLAD, Bennet and rHAGL Lesions]]

[[File:Posterior cyst.mov|thumb|center|Video 7. Magnetic resonance imaging demonstrating a paralabral cyst related to a posterior labral lesion.]]

==Computed Tomography (CT) Scan==
Computed tomography (CT) scans also help the physicians to analyze the bony morphology of the shoulder joint. Before operative management, it is effectively imperative to assess for abnormalities in glenoid version (mean, 4.9 degrees in normal shoulders)<ref>Weishaupt D, Zanetti M, Nyffeler RW, Gerber C, Hodler J. Posterior glenoid rim deficiency in recurrent (atraumatic) posterior shoulder instability. Skeletal radiology 2000;29:204-10</ref> according to the Friedman technique,<ref>Friedman RJ. The use of computerized tomography in the measurement of glenoid version. J Bone Joint Surg Am 1992</ref> posterior glenoid rim fractures or bone loss, and reverse Malgaigne (Hill-Sachs) lesions. These factors help determining the treatment strategies.

=Treatment=
==Clinical Practice Guideline==
The goal of this section is to provide clinicians with recommendations based on the best available evidence; to inform clinicians of when there is no evidence; and finally, to help clinicians deliver the best health care possible.

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==Conservative (Non Operative) Treatment==
===Acute===
As an initial treatment, for all acute posterior dislocations, acute reduction and immobilization should be attempted. Most acute dislocations have a chance to reduce with closed manipulation. The reduction maneuvers must be done gently and carefully. In order to reduce the humeral head into the glenoid fossa, forward pressure on the humeral head must be applied with the arm in the flexed, adducted and internally rotated position. After reduction, an immobilization is required during 6 to 8 weeks in neutral or 20 degrees of external rotation, depending on the stability.

===Recurrent===
Patients with A1-C1 type of instability tend to have a more favorable result with conservative measures.<ref>Clavert P, Furioli E, Andieu K, Sirveaux F, Hardy MB, Nourissat G, Bouju Y, Garret J, Godenèche A, Mansatet P. Clinical outcomes of posterior bone block procedures for posterior shoulder instability: Multicenter retrospective study of 66 cases. Orthop Traumatol Surg Res 2017;103:S193-S7.</ref><ref name=":0" /><ref>Aydin N, Enes Kayaalp M, Asansu M, Karaismailoglu B. Treatment options for locked posterior shoulder dislocations and clinical outcomes. EFORT Open Rev. 2019;4:194-200.</ref> Voluntary posterior dislocators should not be operated on. Management begins with activity modification to prevent further injury, medications as needed and physiotherapy.

===Physiotherapy===
Physical therapy is focused on strengthening of the subscapularis that will maintain the humeral head anteriorly, posterior deltoid, and the periscapular stabilizers through resisted external rotation exercises.<ref name=":3">McIntyre K, Bèlanger A, Dhir J, Somerville L, Watson L, Willis M, Sadi J. Evidence-based conservative rehabilitation for posterior glenohumeral instability: a systematic review. Phys Ther Sport. 2016;22:94–100.</ref> The aim is to improve the neuromuscular control of the shoulder joint and to regain dynamic muscular stability.

Isokinetic muscle performance testing can assess muscle strength and neuromuscular control ability using time to peak torque and acceleration time in patients with traumatic shoulder instability. The injured shoulder usually shows delayed neuromuscular control in rotations. This information helps clinicians and therapists to implement exercises that aim to restore neuromuscular control in patients' rehabilitation.<ref>Lee JH, Park JS, Hwang HJ, Jeong WK. Time to peak torque and acceleration time are altered in male patients following traumatic shoulder instability. J Shoulder Elbow Surg. 2018 Aug;27(8):1505-1511</ref><ref>Jan J, Benkalfate T, Rochcongar P. The impact of recurrent dislocation on shoulder rotator muscle balance (a prospective study of 102 male patients). Ann Phys Rehabil Med. 2012 Sep;55(6):404-14</ref>

===Electrostimulation===
Functional shoulder instability is caused by underactivity of rotator cuff and periscapular muscles, which leads to subluxation or dislocation during shoulder movement. The goal is thus to stimulate underactive muscles in patients with functional instability during shoulder movement in order to re-establish glenohumeral stability and to decrease pain. This can be performed by different modalities such as transcutaneous electrical nerve stimulation (TENS), Berlin shoulder pacemaker,...<ref>Moroder P, Minkus M, Böhm E, Danzinger V, Gerhardt C, Scheibel M. Use of shoulder pacemaker for treatment of functional shoulder instability: Proof of concept. Obere Extrem. 2017;12:103-108.</ref><ref>Hawk C, Minkalis AL, Khorsan R, Daniels CJ, Homack D, Gliedt JA, Hartman JA, Bhalerao S. Systematic Review of Nondrug, Nonsurgical Treatment of Shoulder Conditions. J Manipulative Physiol Ther. 2017;40:293-319.</ref>

===Shoulder Brace===
Shoulder braces or posture correctors and supports that can center the arm in the socket through improved proprioception and reafferentation. Depending of their design, they can provide secure stability during movement. This type of support could help athletes to return to sport.

==Surgical (Operative) Treatment==

===Acute dislocation===
====Open reduction and surgical stabilization====
Open reduction is indicated in dislocations in which closed reduction cannot or should not be achieved. Several conditions are contraindications (i.e. if fracture dislocation). Reverse Malgaigne (Hill-Sachs) lesions > 25% of the humeral head articular surface in size are often unstable after closed reduction and they also require surgical intervention. Open reduction and surgical stabilization are indicated in such cases with defects 25% to 45% of the humeral head articular surface.

The deltopectoral approach is used to reconstruct the humeral head bony defect by the transfer of the subscapularis tendon with transosseous sutures described by McLaughlin<ref>McLaughlin HL. Posterior dislocation of the shoulder (follow-up note). J Bone Joint Surg [Am]1962;44-A:1477</ref> or by suture anchors described by Spencer and Brems.<ref name=":4">Spencer EE, Jr, Brems JJ. A simple technique for management of locked posterior shoulder dislocations: report of two cases. J Shoulder Elbow Surg 2005;14:650–652.</ref> The posterior subdeltoid approach can also be used and this approach lets the surgeon to fill the defect with autograft and perform a Bankart type capsulorrhaphy.<ref>Dubousset J. Posterior dislocations of the shoulder. Rev Chir Orthop Reparatrice Appar Mot 1967;53:65–85.</ref> If the injury is < 3 weeks old, disimpaction and bone grafting of the defect can be performed. For any glenoid bone loss, an iliac crest bone graft can be used as a block and both approaches can be preferred.<ref>Augereau B, Leyder P, Apoil A. Treatment of inveterate posterior shoulder dislocation by the double approach and retroglenoid bone support. Rev Chir Orthop Reparatrice Appar Mot 1983;69(Suppl. 2):89–90</ref>

[[File:1562915201982-lg.jpg|center|thumb|700x700px|Figure 25. Coronal (A) and axial (B) CT sections of a left-side type IV cephalotubercular fracture. In this situation, the head should not be reduced via the deltopectoral approach, but simply make a small posterior approach through which a tamp is passed (green arrow) which will push the head backwards (C). Anteroposterior and Lamy lateral postoperative radiographs (D and E, respectively).]]

====Arthroscopic reduction and surgical stabilization====

'''''Arthroscopic treatment of a humeral head fracture.'''''
[[File:1562909631408-lg.jpg|center|thumb|660x660px|Figure 26. A) Anteroposterior radiograph and B) CT scan of the left shoulder, revealing a humeral head fracture. Six months after arthroscopic reduction without fixation, the Lamy frontal and lateral radiographs confirm a perfect reduction. The rotator cuff and tuberosities are intact, so secondary displacements are limited. Reproduce from <ref>Godeneche A, Freychet B, Gunst S, Daggett M, Viste A, Walch G. Arthroscopic Reduction of Acute Traumatic Posterior Glenohumeral Dislocation and Anatomic Neck Fracture Without Internal Fixation: 2-Year Follow-up. Orthop J Sports Med. 2017;5(12):2325967117745486</ref>, with permission.]]

===Chronic Instability===
Patients who have undergone at least 6 months of conservative treatment and still experience symptoms are candidates for surgical management.<ref>Gartsman GM, Roddey TS, Hammerman SM. Arthroscopic treatment of bidirectional glenohumeral instability: two- to five-year follow-up. J Shoulder Elbow Surg. 2001;10(1):28–36</ref> Surgical treatment can be considered for the patient with a symptomatic posterior labral tear, unilateral posterior instability with a patulous or incompetent posterior capsule, or in select multidirectional instability patients with predominantly posterior symptoms. Nevertheless, if conservative measures fail then operative management should be considered in those with identifiable pathology. Surgery is required in cases of persistent shoulder pain in chronic instability, in patients with a locked neglected chronic dislocation, or in patients with associated lesions developing a dysfunctional shoulder. There are 2 broad categories of surgical management that focus on either the soft tissue or bony anatomy.

====Soft tissue procedure====
=====Labral Repair and Capsular Shift=====
In patients with purely soft tissue injuries and no associated bone loss or fracture, then posterior capsulorraphy (i.e., capsular shift) and labral repair are the treatments of choice. The use of arthroscopy in these cases has greatly surpassed that of open procedures primarily due to the less-invasive nature of the procedure, improved shoulder mechanics postoperatively, decreased scarring, and the ability to address concomitant lesions including posterior humeral avulsions of the glenohumeral ligament. It may reveal subtle lesions such a small crack or fissuring within the posterior labrum (hidden lesion or “Kim lesion”) (Video).

[[File:Media15-194.mp4|thumb|Video 8. Diagnostic arthroscopy]]

An arthroscopic labral repair is most commonly performed using suture anchor fixation. This often requires the use of 3 to 4 portals to allow for proper anchor positioning and shuttling of sutures. The standard posterior, anterior, and anterosuperior portals are initially created for visualization. In patients in whom the position of the posterior portal is not optimal for working and for achieving angle for glenoid rim access, a 7 o’clock portal or posteroinferior portal is placed under spinal needle localization. This portal has been found to be a safe distance from the axillary and suprascapular nerves. Once all portals have been created the labrum can be prepared through both the posterior and anterior portals. The posterior labrum is then mobilized off the glenoid neck using an elevator or arthroscopic scissor. It should be completely elevated from the glenoid to allow for superior translocation and preparation of the glenoid neck. The rim and neck of the glenoid are debrided with a shaver or a rasp. Repair of the labrum should begin at the most inferior extent of the tear. The anchor is placed slightly superior to allow for a superior shift of the tissue. Anchors should be spaced 3–5 mm apart to avoid fragmentation of the posterior glenoid bone. In patients with a patulous capsule an arthroscopic capsular shift may be performed in conjunction with a labral repair and consists of tightening any redundant posterior capsular tissue. Usually approximately 1 cm of capsule is plicated to the labrum. The exact amount of capsular plication must be individualized to the patients symptoms and over laxity as seen arthroscopically. This should begin at the 6 o’clock position and work in the direction of the 12 o’clock position (Figure).

[[File:Media18-208.mov|thumb|Video 9. Final repair. The posterior labrum and posterior capsule are repaired to the glenoid rim.]]

In some cases, the labrum may be intact and the pathology may be related only to a capsular detensioning. In these cases, the capsular tissue may be lightly abraded with a rasp or with a shaver and capsular retensioning is carried out using the labrum like an anchor. Frequently, a combined labral repair and capsular shift are performed simultaneously and fixated with a suture anchor. In patients with chondral damage leaving exposed glenoid bone, the anchors may be placed slightly further onto the glenoid face to advance the labrum over the chondral defect providing a soft tissue inter-position while repairing the labrum.

=====Rotator Interval Closure=====
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====Treatment of Anterior Humeral Head Defects====
=====Reverse Malgaigne (Hill–Sachs) Rempissage=====

In some cases of posterior instability, a large reverse Malgaigne (Hill-Sachs) lesion may be encountered. If involving more than 20% of the articular surface, a reverse Malgaigne (Hill-Sachs) remplissage may be considered to enhance stability of the joint. The rotator interval is resected to improve visualization of the anterior aspect of the subscapularis tendon (Video 10). The bone bed is therefore prepared as performed during subscapularis tendon repair (Video 11). Anchor(s) is(are) inserted, the sutures are passed through the subscapularis tendon and tied to fill the bone defect (Video 12).

[[File:Media19-213.mov|thumb|Video 10. Once the reverse Hill-Sachs lesion is identified and is determined to be significant, the rotator interval is resected to improve visualization of the anterior aspect of the subscapularis tendon. In these patients, resection of the rotator interval is reasonable since multi-directional laxity is rarely present and/or symptomatic. Courtesy of Stéphane Audebert]]

[[File:Media20-216.mov|thumb|Video 11. The bone bed is prepared as performed during subscapularis tendon repair. Although, in this scenario, the upper border of the subscapularis tendon commonly obstructs direct access. Commonly internal rotation will improve access particularly to the inferior part of the reverse Hill-Sachs lesion. Courtesy of Stéphane Audebert]]

[[File:Media21-221.mov|thumb|Video 12. Anchors are inserted percutaneously through the subscapularis tendon or the rotator interval in the inferior and superior aspects of the reverse Malgaigne (Hill-Sachs) lesion. The sutures are passed through the subscapularis and tight. The procedure is performed for the other suture pairs. Courtesy of Stéphane Audebert]]

=====McLaughlin Procedure (Open Transfer of the Subscapularis Tendon)=====

One of the earliest described techniques involves transferring the tenotomized subscapularis tendon to the humeral defect (from 25% to 45% of the humeral head articular surface) and is known as the McLaughlin procedure.<ref>McLaughlin HL. Locked posterior subluxation of the shoulder: diagnosis and treatment. Surg Clin North Am 1963;43:1621–1622</ref> Hawkins et al reported that if the period of delay is > 6 months, the articular cartilage of humeral head gets non-viable; therefore, the McLaughlin procedure should not be preferred.<ref name=":2" /><ref name=":5">Delcogliano A, Caporaso A, Chiossi S, Menghi A, Cillo M, Delcogliano M. Surgical management of chronic, unreduced posterior dislocation of the shoulder. Knee Surg Sports Traumatol Arthrosc 2005;13:151–155.</ref>

=====Arthroscopic McLaughlin Procedure=====

Godenech et al. and Lavender et al. reported an arthroscopic technique suturing the distal part of the subscapularis tendon into the defect.<ref>Lavender CD, Hanzlik SR, Pearson SE, Caldwell PE. Arthroscopic reverse remplissage for posterior instability. Arthrosc Tech. 2016;1:e43–e47</ref><ref>Besnard M, Audebert S, Godenèche A. Arthroscopic McLaughlin Procedure for Treatment of Posterior Instability of the Shoulder With an Engaging Reverse Hill-Sachs Lesion. Arthrosc Tech. 2019;8:1491-4.</ref>

=====Osteotomy of the Lesser Tuberosity With the Attached Subscapularis (Hughes and Neer method)=====

Several authors modified McLaughlin’s method and described osteotomizing the lesser tuberosity with the attached subscapularis tendon and fixing it to the defective area.<ref name=":5" /><ref name=":4" /> The modified McLaughlin method provides additional bony support for the defective area and is preferred for patients when the injury is older than three weeks.<ref name=":6">Castagna A, Delle Rose G, Borroni M, Markopoulos N, Conti M, Maradei L, Garofalo R. Modified MacLaughlin procedure in the treatment of neglected posterior dislocation of the shoulder. Chir Organi Mov 2009;93:1–5.</ref> Depending on the importance of the bone loss, simultaneous iliac crest autograft, dry morselized allograft, fresh-frozen femoral head bone allograft can be perform.<ref>Khira YM, Salama AM. Treatment of locked posterior shoulder dislocation with bone defect. Orthopedics 2017;40:501–5.</ref><ref name=":7">Kokkalis ZT, Mavrogenis AF, Ballas EG, Papanastasiou J, Papagelopoulos PJ. Modified McLaughlin technique for neglected locked posterior dislocation of the shoulder. Orthopedics 2013;36:912–6.</ref>

The surgery is performed in a beach chair position. The deltopectoral approach is used. First, the biceps tendon is identified as a landmark for the bicipital groove. The lower edge of the subscapularis tendon is detected in order to mark lesser tuberosity. Osteotomy of the lesser tuberosity is performed from lateral to medial, starting from the bicipital groove to the defect of the humeral head.<ref name=":6" /> The lesser tuberosity with the attached subscapularis tendon is elevated in order to demonstrate the head and the glenoid. Reduction is performed and when achieved, the lesser tuberosity with the attached subscapularis tendon is fixed into the humeral head defect using ether screws, anchors or sutures.<ref>Shams A, El-Sayed M, Gamal O, ElSawy M, Azzam W. Modified technique for reconstructing reverse Hill-Sachs lesion in locked chronic posterior shoulder dislocation. Eur J Orthop Surg Traumatol 2016;26:843–9.</ref><ref name=":7" /> Reported results are usually excellent.<ref>Banerjee M, Balke M, Bouillon B, Wafaisade A, Helm P, Akoto R, Shafizadeh S. Excellent results of lesser tuberosity transfer in acute locked posterior shoulder dislocation. Knee Surg Sports Traumatol Arthrosc 2013;21:2884–8.</ref><ref name=":7" />

====Humeral Reconstruction with Autograft or Allograft====
Bone grafting is an unavoidable procedure in insufficient bone reserve to reconstruct the anatomical sphericity and preserve the stability of the reconstructed humeral head after locked posterior shoulder dislocations. Allo- and autografting are both described in the literature. Some authors advocated the use of allografts in obtaining the anatomical sphericity of humeral head rather than preferring non-anatomical techniques by using osteochondral allografts from fresh-frozen femoral heads. Especially in the case of larger defects of up to 50% and young patients with viable humeral bone reserve, fixation of the allografts in defective areas with partially threaded cancellous screws yielded excellent results.<ref name=":8">Diklic ID, Ganic ZD, Blagojevic ZD, Nho SJ, Romeo AA. Treatment of locked chronic posterior dislocation of the shoulder by reconstruction of the defect in the humeral head with an allograft. J Bone Joint Surg [Br] 2010;92:71–6.</ref><ref>Gerber C, Lambert SM. Allograft reconstruction of segmental defects of the humeral head for the treatment of chronic locked posterior dislocation of the shoulder. J Bone Joint Surg [Am] 1996;78:376–382.</ref> In case of bilateral posterior humeral head dislocations, harvesting osteochondral autograft from the side that will undergo hemiarthroplasty and using this graft on the contralateral side is also described in the literature by several authors.<ref>Ivkovic A, Boric I, Cicak N. One-stage operation for locked bilateral posterior dislocation of the shoulder. J Bone Joint Surg [Br] 2007;89-B:825–8.</ref><ref>Torrens C, Santana F, Melendo E, Marlet V, Caceres E. Osteochondral autograft and hemiarthroplasty for bilateral locked posterior dislocation of the shoulder. Am J Orthop (Belle Mead NJ) 2012;41:362–4.</ref> Allo- and autograft reconstructions have a good long-term follow-up.<ref>Gerber C, Catanzaro S, Jundt-Ecker M, Farshad M. Long-term outcome of segmental reconstruction of the humeral head for the treatment of locked posterior dislocation of the shoulder. J Shoulder Elbow Surg 2014;23:1682–1690.</ref><ref>Martinez AA, Navarro E, Iglesias D, Domingo J, Calvo A, Carbonel I. Long-term follow-up of allograft reconstruction of segmental defects of the humeral head associated with posterior dislocation of the shoulder. Injury 2013;44:488–491.</ref>

[[File:Reverse Malgaigne Reconstruction with allograft .mp4|thumb|Video 13. Humeral Reconstruction with allograft ]]

====Posterior Bone Block====
Patients with glenoid dysplasia (retroversion >15 degrees) as well as patients with posterior glenoid defects are at increased risk for failure with soft tissue procedures due to altered underlying bony support. Numerous techniques have been reported to reconstruct the posterior glenoid, including iliac crest bone block (Figure), distal tibial allograft, glenoid allograft, pedunculated acromial graft, and distal clavicular autograft.<ref name=":9">Barbier O, Ollat D, Marchaland JP, Versier G. Iliac bone-block autograft for posterior shoulder instability. Orthop Traumatol Surg Res. 2009;95:100-107</ref><ref>Gupta AK, Chalmers PN, Klosterman E, Harris JD, Provencher MT, Romeo AA. Arthroscopic distal tibial allograft augmentation for posterior shoulder instability with glenoid bone loss. Arthrosc Tech. 2013;2:e405-e411</ref><ref>Petrera M, Veillette CJ, Taylor DW, Park SS, Theodoropoulos JS. Use of fresh osteochondral glenoid allograft to treat posteroinferior bone loss in chronic posterior shoulder instability. Am J Orthop (Belle Mead NJ). 2013;42:78-82</ref><ref name=":10">Schwartz DG, Goebel S, Piper K, Kordasiewicz B, Boyle S, Lafosse L. Arthroscopic posterior bone block augmentation in posterior shoulder instability. J Shoulder Elbow Surg. 2013;22:1092-1101</ref><ref>Sirveaux F, Leroux J, Roche O, Gosselin O, De Gasperi M, Molé D. Surgical treatment of posterior instability of the shoulder joint using an iliac bone block or an acromial pediculated bone block: outcome in eighteen patients [in French]. Rev Chir Orthop Reparatrice Appar Mot. 2004;90:411-419</ref><ref>Struck M, Wellmann M, Becher C, Pastor MF, Smith T. Results of an open posterior bone block procedure for recurrent posterior shoulder instability after a short- and long-time follow-up. Knee Surg Sports Traumatol Arthrosc. 2016;24:618-624</ref>

=====Bone Block through Posterior Approach (Open or Arthroscopy)=====
The standard open technique using iliac crest bone graft has been first described by Hindenach.<ref>Hindenach JC. Recurrent posterior dislocation of the shoulder. J Bone Joint Surg Am 1947;29:582-6.</ref> While promising clinical results have been reported, the procedure is technically demanding, with complication rates up to 36%, including residual instability, osteolysis of the graft, persistant pain and development of osteoarthritis.<ref name=":12">Arciero RA, Mazzocca AD. Posterior Acromial Bone Block Augmentation for the Treatment of Posterior Glenoid Bone Loss Associated With Recurrent Posterior Shoulder Instability. Techniques in Shoulder & Elbow Surgery 2006;7:210-7</ref><ref name=":9" /><ref>Essadki B, Dumontier C, Sautet A, Apoil A. [Posterior shoulder instability in athletes: surgical treatment with iliac bone block. Apropos of 6 case reports]. Rev Chir Orthop Reparatrice Appar Mot 2000;86:765-72</ref><ref>Gosens T, van Biezen FC, Verhaar JA. The bone block procedure in recurrent posterior shoulder instability. Acta Orthop Belg 2001;67:116-20</ref><ref name=":11">Kouvalchouk JF, Coudert X, Watin Augouard L, Da Silva Rosa R, Paszkowski A. [Treatment of posterior instability of the shoulder joint using an acromial stop with a pediculated deltoid flap]. Rev Chir Orthop Reparatrice Appar Mot 1993;79:661-665</ref><ref>Levigne C, Garret Jr, Walch G. Posterior Bone Block for Posterior Instability. Techniques in Shoulder & Elbow Surgery 2005;6:26-35</ref><ref>Meuffels DE, Schuit H, van Biezen FC, Reijman M, Verhaar JA. The posterior bone block procedure in posterior shoulder instability: a long-term follow-up study. J Bone Joint Surg Br. 2010;92:651-655</ref><ref name=":10" /><ref>Servien E, Walch G, Cortes ZE, Edwards TB, O'Connor DP. Posterior bone block procedure for posterior shoulder instability. Knee Surg Sports Traumatol Arthrosc 2007;15:1130-1136</ref> Careful attention must be paid to the positioning of the bone block posteriorly. A biomechanical study showed that a posterior bone block may overconstrain the posterior shoulder and not adequately address inferior instability compared to arthroscopic repair techniques.<ref> Wellmann M, Bobrowitsch E, Khan N, Patzer T, Windhagen H, Petersen W, Bohnsack M. Biomechanical effectiveness of an arthroscopic posterior Bankart repair versus an open bone block procedure for posterior shoulder instability. Am J Sports Med. 2011;39:796-803.</ref>

The posterior bone block procedure can be performed via the same approach or arthroscopically and is accomplished by fixating bone graft to the posterior glenoid rim to recreate the normal contour of the glenoid surface (Video 14). Osseous procedures have fallen out of favor as first line treatment options and are typically reserved for those who fail a soft tissue procedure or have significant bone loss or deficiency.

[[File:Open Posterior Bone Block.mp4|thumb|Video 14. Open Posterior Bone Block]]

=====Arthroscopic Posterior Bone Block through Rotator Interval Approach=====
Following induction of anesthesia the patient is placed in the lateral decubitus position with a warming blanket applied. An iliac crest bone autograft is harvested prior to arthroscopy. A bicortical 25 mm long, 15 mm large and 10 mm thick bone graft is obtained from the ipsilateral iliac crest. Alternatively, the use of acromial spine autograft has been described.<ref name=":12" /><ref name=":11" /> The side without cortex is the one which will be secured against the glenoid. Two 3.2 mm holes are drilled through the graft (Video). The size of the graft is 25 mm long, 15 mm large and about 10 mm thick. Three sutures are placed, one in each hole, and a third passing through both holes to the posterior side of the graft. One suture is placed in each hole of the graft and are tied so that there are sutures at the leading and trailing ends of the graft. These sutures will be used to shuttle the graft into the glenohumeral joint. Additionally, a third suture is passed through the two holes and exits the posterior aspect of the graft. This suture is helpful in maintaining orientation of the graft during shuttline. Attention is turned to the arthroscopic procedure. The arm is placed in balanced suspension with 20° to 30° of abduction and 20° of forward flexion. Standard three portal access to the glenohumeral joint is established including posterior, anterior, and anterosuperolateral portals. A 7 mm cannula is placed into the latter portal. A standard diagnostic arthroscopy using a 30° arthroscope is performed and the glenohumeral joint is then viewed through the anterosuperolateral portal. Quadrant landmarks of the glenoid at 3, 6, 9 and 12 o’clock are marked with an electrocautery, which is important to help correctly place the bone graft later in the procedure. The anterior - posterior glenoid width measured as the anterior - to - posterior distance between 7:30 and 4:30 on the glenoid face is determined with a calibrated probe. Viewing from a posterior portal, a shaver or electrocautery introduced from the anterosuperolateral portal are used to create a window in rotator interval to allow passage of the bone graft.<ref>Lo IK, Burkhart SS. Arthroscopic coracoplasty through the rotator interval. Arthroscopy 2003;19:667-671</ref> Care is taken to preserve the medial sling of the biceps during this step. The arthroscope is returned to the anterosuperolateral portal for visualization of the posterior capsulolabral structures. The posteroinferior labrum is resected off the posterior glenoid neck from 6 to 10 o’clock for a right shoulder using a motorized shaver in the posterior soft point portal. After resecting the posterior inferior labrum, the posterior glenoid is prepared to be flat. The space between the posterior labrum and the posterior glenoid margin is enlarged to receive the bone graft. Traction maneuvers with the shaver lift the fibers of the infraspinatus obliquely away from the glenoid allowing excellent visualization of the posteroinferior glenoid. Occasionally, a 70° arthroscope is necessary to adequately visualize this area. The capsule is released from the glenoid until the infraspinatus fibers can be seen and so that the open space between the glenoid and the capsule is sufficient to allow the introduction of a 10 mm thick bone graft. The posterior glenoid neck is decorticated with a shaver or burr to create a flat surface suitable to graft incorporation. Particular attention is paid during this procedure to prevent suprascapular nerve injury by avoiding working greater than 14 mm medial to the glenoid.<ref>Bigliani LU, Dalsey RM, McCann PD, April EW. An anatomical study of the suprascapular nerve. Arthroscopy. 1990;6(4):301-5</ref> The knowledge of the precise length of the burr can help the surgeon to avoid technical errors. A spinal needle is inserted at 7 o’clock to determine the proper angle of approach for a posterolateral working portal. The skin incision for the anterior portal is enlarged to accommodate passage the bone graft. Via the anterior portal, the graft is passed through the rotator interval in an anterior to posterior direction. This is achieved by means of utilizing the previous sutures in a shuttling technique (Movie). The leading suture of the graft is delivered into the glenohumeral joint through the anterior portal and retrieved out the posterior portal. Pulling this suture shuttles the graft into the joint. Additionally, a Kocher clamp is used to grasp the graft and assist in delivering the graft. Once the graft lies inside of the joint, alternating tension on the three sutures orients the graft. Graspers can also be used to manipulate the graft into the interval between the posteroinferior glenoid and the capsule. The graft is placed at the posteroinferior aspect of the glenoid (between 6 and 9 o’clock for a right shoulder and between 3 and 6 o’clock for a left shoulder), the cancellous side facing the posterior glenoid. This “free hand” step is the most challenging part of the procedure. In our experience when the graft is introduced in the fossa between the glenoid and the capsule, it become sufficiently stable which the need to hold it in place. Once the bone graft lies flush to the glenoid or slightly overhanging out the glenoid, a spinal needle is used to obtain an angle of approach directly perpendicular to the prepared holes and parallel to the glenoid surface. One or two small punctures are usually necessary to address both tunnels. Then a small 4.5 mm cannula is used to place two 1.2 mm K-wires, one in each hole, and a 3.2 mm cannulated drill is used to overdrill the K-wires through the graft and glenoid. Before removing the drill, particular care is paid to maintaining the K-wires in place. The posterior to anterior K-wires be bicortical but care must be taken to avoid excessive penetration which could injury the anterior neurovascular structures or lung.<ref>Slattery SC, Jobe CM, Watkins B. Posterior to anterior transglenoid pins: anatomy at risk. Arthroscopy. 1998 Apr;14(3):285-8</ref> The length of the screws is determined adding the thickness of the graft and the diameter of the glenoid. Two 4.5 mm cannulated screws are then passed over the K-wires with enough compression to secure the graft (Movie). Once the graft is appropriately placed with strong fixation, both K-wires are removed. If the bone graft is prominent, a burr is used to create a smooth congruent arch with the glenoid. Two to three double-loaded anchors are then inserted through the posterior portal along the posterior glenoid rim starting from inferior to superior. The sutures are passed antegrade or retrograde through the capsule without major capsular shift or plication as the bone graft mainly achieves the stability. This procedure closes the capsule to the native glenoid and thus renders the bone block extracapsular (Movie). This step is necessary to protect the humeral articular cartilage from a direct contact with the bone graft. After portal closure, a sterile bulky dressing is applied and postoperative radiographs are obtained. This technique provides excellent visualization of the glenohumeral joint and is accomplished with less damage to the rotator cuff and posterior deltoid compared to traditional open approaches. The results are generally good.<ref>Barth J, Grosclaude S, Lädermann A, Denard PJ, Graveleau N, Walch G. Arthroscopic Posterior Bone Graft for Posterior Instability: The Transrotator Interval Sparing Cuff Technique. Techniques in Shoulder & Elbow Surgery 2011;12(3):67-71</ref>

[[File:Arthroscopic Posterior Bone Block.mp4|thumb|Video 15. Arthroscopic Posterior Bone Block Through Rotator Interval]]

====Glenoid (Scott) osteotomy====
In rare circumstances, patients with increased glenoid retroversion may require correction with a posterior glenoid osteotomy. Scott osteotomy (posterior opening wedge osteotomy) is typically considered in patients with more than 25 degrees of retroversion.<ref>Scott DJJ: Treatment of recurrent posterior dislocations of the shoulder by glenoplasty. Report of three cases. J Bone Joint Surg Am. 1967;49:471-6.</ref> This is typically considered only in revision settings.<ref>Wirth MA, Seltzer DG, Rockwood CA., Jr. Recurrent posterior glenohumeral dislocation associated with increased retroversion of the glenoid. A case report. Clin Orthop Relat Res. 1994;(308):98-101</ref> Graichen et al.<ref name=":13">Graichen H, Koydl P, Zichner L. Effectiveness of glenoid osteotomy in atraumatic posterior instability of the shoulder associated with excessive retroversion and flatness of the glenoid. Int Orthop. 1999;23:95-99.</ref> reported good or excellent results in 81% of 32 patients undergoing posterior glenoid osteotomy, with the best results in patients with atraumatic instability. However, 25% of patients developed postoperative osteoarthritis, highlighting that this procedure should be only considered in select circumstances.<ref name=":13" /><ref>Lacheta L, Singh TSP, Hovsepian JM, Braun S, Imhoff AB, Pogorzelski J. Posterior open wedge glenoid osteotomy provides reliable results in young patients with increased glenoid retroversion and posterior shoulder instability. Knee Surg Sports Traumatol Arthrosc. 2019;27:299-304.</ref>

A posterior opening wedge osteotomy is performed through a posterior approach with the incision typically located in the posterior axillary fold. An osteotomy is completed at the posteromedial neck of the glenoid leaving the anterior cortex intact for stability. A wedge of bone graft (either autograft or allograft) in then inserted to provide the predetermined amount of correction. The graft is then secured with either screws or plate and screws. Press fit grafting techniques have also been described.

[[File:Image48-113.jpg|thumb|Figure 27. Scott Osteotomy]]

[[File:Image49-115.jpg|thumb|Figure 28. Postoperative X-ray of a Glenoid Osteotomy According to Scott]]

===Locked Dislocations, Static Posterior Dislocation or Glenoid Dysplasia===
Locked dislocation may require open treatment via subscapularis transfer or tenodesis, humeral head allograft reconstruction, or shoulder arthroplasty in severe cases.<ref name=":8" /><ref>Finkelstein JA, Waddell JP, O’Driscoll SW, Vincent G. Acute posterior fracture dislocations of the shoulder treated with the Neer modification of the McLaughlin procedure. J Orthop Trauma. 1995;9:190-193</ref><ref>Wooten C, Klika B, Schleck CD, Harmsen WS, Sperling JW, Cofield RH. Anatomic shoulder arthroplasty as treatment for locked posterior dislocation of the shoulder. J Bone Joint Surg Am. 2014;96:e19</ref><ref>Schliemann B, Muder D, Gessmann J, Schildhauer TA, Seybold D. Locked posterior shoulder dislocation: treatment options and clinical outcomes. Arch Orthop Trauma Surg 2011;131(8):1127–1134</ref>

Figure: mettre reverse AWA

===Derotational Osteotomy===
Derotational osteotomy of the humerus has been suggested as a procedure for younger patients with significant humeral head depression. The necessary criteria are a healthy articular cartilage, a humeral head defect involving < 40% of the articular surface, and a patient who is able to participate in an active rehabilitation programme.<ref>Keppler P, Holz U, Thielemann FW, Meinig R. Locked posterior dislocation of the shoulder: treatment using rotational osteotomy of the humerus. J Orthop Trauma 1994;8:286–292.</ref><ref name=":14">Ziran B, Nourbakhsh A. Proximal humerus derotational osteotomy for internal rotation instability after locked posterior shoulder dislocation: early experience in four patients. Patient Saf Surg 2015;9:15</ref> This technique is a viable option for younger age groups since it can facilitate rehabilitation by providing immediate stability.<ref name=":14" />

[[File:Image50-117.jpg|thumb|Figure 29. Derotational Osteotomy]]

===Shoulder Arthroplasty===

Arthroplasty is a viable option in patients with a large humeral head defect and less bone reserve after locked posterior dislocation of the shoulder. If the defect is larger than 45% to 50% of the articular surface and if the glenoid cavity is intact in a chronic dislocation aged > 6 months, hemiarthroplasty is recommended.<ref>Page AE, Meinhard BP, Schulz E, Toledano B. Bilateral posterior fracture-dislocation of the shoulders: management by bilateral shoulder hemiarthroplasties. J Orthop Trauma 1995;9(6):526–529</ref><ref>Hawkins RJ. Unrecognised dislocations of the shoulder. Inst Course Lect 1985;34:258–263</ref> When concomitant glenoid damage or significant glenoid arthritis is present, total shoulder arthroplasty should be preferred.<ref>Checchia SL, Santos PD, Miyazaki AN. Surgical treatment of acute and chronic posterior fracture-dislocation of the shoulder. J Shoulder Elbow Surg 1998;7(1):53–65</ref><ref>Pritchett JW, Clark JM. Prosthetic replacement for chronic unreduced dislocations of the shoulder. Clin Orthop Relat Res 1987;(216):89–93</ref> Reverse shoulder arthroplasty compared to anatomic has the advantage to solve the problem of instability at the same time.

[[File:Glenoid dysplasie AWA.mp4|thumb|Video 16. Reverse shoulder arthroplasty for glenoid dysplasia]]

===Arthrodesis===
Rare case of glenoid dysplasia can beneficiate from glenohumeral arthrodesis. Please refer to [[Arthrodesis|Glenohumeral Arthritis/ Arthrodesis section]].

=Postoperative Rehabilitation=
Postoperatively patients are placed into a neutral rotation splint, position that decreases stress on the posterior capsule (Figure 30). Immobilization is carried out for 6 to 8 weeks after surgery. Passive range of motion and active assist range of motion can then begin under the supervision of a physical therapist. Physiotherapy is focused on strengthening of the subscapularis that will maintain the humeral head anteriorly, posterior deltoid, and the periscapular stabilizers through resisted external rotation exercises.<ref name=":3" /> The aim is to improve the neuromuscular control of the shoulder joint and to regain dynamic muscular stability. Strengthening typically begins during the third postoperative month. Return to sports should be decided on a case-by-case basis but usually return is restricted until 6 months out from surgery.

[[File:Image51-119.jpg|thumb|Figure 30. Post-traumatic or postoperative immobilization into a neutral rotation splint.]]

=Complications=
Complications are specific to patient subsets and the technique of stabilization used. Chronic shoulder pain, allograft collapse, avascular necrosis, non-union, stiffness, omarthrosis and recurrent instability can be seen.<ref>Sperling JW, Pring M, Antuna SA, Cofield RH. Shoulder arthroplasty for locked posterior dislocation of the shoulder. J Shoulder Elbow Surg 2004;13(5):522–527</ref><ref name=":6" /> Patients with recalcitrant epileptic seizures are more prone to redislocation.

==References==
{{Reflist}}
<references />

Shoulder:Glenohumeral Instability/Posterior Instability

2022-04-14T14:55:21Z

Alexandre.laedermann: /* B2: Structural dynamic posterior instability */

==Bullet Points==

*Posterior shoulder instability is not as rare as previously thought.
*Diagnosing posterior instability may be difficult because patients often report vague symptoms not linked to a clear history of traumatic shoulder dislocation.
*This condition is consequently often misdiagnosed or patients experience a delay in diagnosis.
*It that encompasses different acute and chronic pathologies involving the labrum, the cartilage, the capsule, bony lesions.
*A tear between the posterior labrum and the glenoid cartilage without complete detachment of the labrum is described as a Kim lesion. It is postulated that this lesion is due to posterior force acting on the posterior-inferior glenohumeral ligament as it attaches to the posterior labrum.
*Numerous classifications exist, none having unanimity.
*Risk factors for recurrent instability are: (1) age below 40 at time of first instability; (2) dislocation during a seizure; (3) a large reverse Malgaigne (Hill-Sachs) lesion; (4) glenoid retroversion, and (5) a high and horizontally oriented acromion in the sagittal plan.
*Hyperlaxity is multidirectional but instability is almost exclusively unidirectional.
*Physical examination comprises the articular range of motion, the rotator cuff, and jerk, Kim and O’Brien tests.
*Three views plain radiographs, including true anteroposterior of the glenohumeral joint, scapular Y (scapular lateral), and Bernageau views are the mainstay of imaging in the setting of shoulder instability.
*An internally rotated humeral head gives a rounded appearance on anteroposterior view, which is called the lightbulb sign.
*In case of a suspicion about posterior dislocation of the shoulder, additional imaging including, depending of the type of instability, magnetic resonance arthrography (MRA) or computed tomography (CT) is required.
*Acute or recurrent posterior dislocations can be treated conservatively, by soft tissue or bony procedures.
*Surgical options include anatomic reconstruction as well as non-anatomic procedures such as subscapularis tendon transfer, allo-/autograft reconstruction, derotation osteotomy or shoulder arthroplasty.
*Treatment of locked dislocation depends on the extent of the articular defect size of the humeral head, duration of the dislocation and patient-specific conditions such as age and activity levels.

==Key words==
Posterior shoulder stabilization; Functional instability; Soft tissue injuries; Locked dislocation; Subluxation; Epidemiology; Labrum; ABC classification; Treatment options; Arthroscopy; McLaughlin procedure; Bone block; Clinical outcomes; Complications.

==History==
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==Anecdote==
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==Epidemiology and Mechanism==
Posterior dislocation of the shoulder accounts for around 20% of all shoulder dislocations, which is much higher than the 4-5% prevalence previously mentioned in the literature.<ref>Song DJ, Cook JB, Krul KP, Bottoni CR, Rowles DJ, Shaha SH, Tokish JM. High frequency of posterior and combined shoulder instability in young active patients. J Shoulder Elbow Surg. 2015;24:186-90. </ref> A reason for this large discrepancy is the challenge of clinical diagnosis, since symptoms are often subtle and patients often lack the typical feeling of posterior apprehension in provocative arm positions.

==Anatomy, Pathoanatomy==
==Soft Tissue Lesion==
===Labral lesion===
Four different types of labral insertion have been described by Nourissat et al.<ref>Nourissat G, Radier C, Aim F, Lacoste S. Arthroscopic classification of posterior labrum glenoid insertion. Orthop Traumatol Surg Res. 2014;100:167-70.</ref> Type 1, 60% of the cases, correspond to a posterior labrum totally inserted in the glenoid, with direct contact with the cartilage, totally flush. In type 2 (20% of the cases), insertion of the superior segment is medialized. Type 3, 15% of the cases, represents an associated medialization of the superior and medial segment of the posterior labrum. Type 4 is a medialized insertion of the all-posterior labrum.

Consequently, a subchondral cleft (labrum and capsule attached but no tear) may be a normal finding.<ref>Campbell SE, Dewitt RM, Cameron KL, Thompson AK, Owens BD. Posterior chondrolabral cleft: clinical significance and associations with shoulder instability. HSS J. 2014;10:208-212.</ref> Surgeons should be aware that while anterior capsule anatomy is quite variable, the posterior capsular insertion tends to be more homogenous in appearance among patients (Figure).

[[File:Abnormal insertion of the capsule.jpg|thumb|A) Normal insertion of the posterior capsule. B) Posterior disinsertion of the capsule.|alt=|center]]

 

===Reverse humeral avulsion of the glenohumeral ligaments (rHAGL)===
[[File:Reverse humeral avulsion of the glenohumeral ligaments (rHAGL).jpg|thumb|alt=|Posterior arthroscopic view of a left shoulder. Observe the humeral avulsion of the capsule.|center]]

===Kim lesion===
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==Bony lesion==
[[File:Bony lesion.png|thumb|Reverse bony Bankart|alt=|center]]

[[File:Humeral head fracture.png|thumb|Humeral head fracture|alt=|center]]

===Reverse Malgaigne (Hill-Sachs)===
This is usually present in patients with chronic locked posterior dislocations or in cases with significant traumatic history (e.g. seizure disorder, electrical injury). Patients with positional posterior instability with ligamentous laxity usually do not present with significant reverse Malgaigne (Hill-Sachs) lesions but may occur occasionally.

==Associated lesions==
Associated intra-articular pathology such as superior labrum anterior posterior (SLAP) lesion, rotator cuff lesions or a paralabral cyst should be also assessed (Figure). Unlike spinoglenoid cysts, posterior or posterior-inferior labral cysts rarely results in impingement of the suprascapular nerve and suprascapular neuropathy.

[[File:Image7-29.jpg|thumb|A) 3D maximum intensity projection reconstruction showing a remarkably voluminous cyst dissecting 9 cm from the glenoidal labrum through the long head of the triceps muscle. B) The patient complains from a lump in his axillary fold.]]

=Definitions=
Dislocation is defined by a complete displacement of the humeral head from its articulation with the glenoid, whereas subluxation represents an incomplete or partial dislocation of the joint. Laxity is a physiologic and an asymptomatic finding, that corresponds to translation of the humeral head in any direction to the glenoid. Hyperlaxity is constitutional, multidirectional, bilateral and also asymptomatic. Hyperlaxity of the shoulder is probably best defined as external rotation elbow at the side equal or greater than 85 degrees (Figure).<ref>Walch G, Agostini JY, Levigne C, Nove-Josserand L. [Recurrent anterior and multidirectional instability of the shoulder]. Rev Chir Orthop Reparatrice Appar Mot 1995;81:682-90.</ref>

[[File:Hyperlaxity of the shoulder.jpg|thumb|Hyperlaxity of the shoulder is defined as external rotation elbow at the side equal or greater than 85 degrees.]]

This finding is most of the time non-pathological (except in soft tissue pathologies like Ehler-Danlos syndrome), is a risk factor for instability but does not by itself demand treatment.<ref>Nourissat G, Vigan M, Hamonet C, Doursounian L, Deranlot J. Diagnosis of Ehlers-Danlos syndrome after a first shoulder dislocation. J Shoulder Elbow Surg 2018;27:65-9.</ref> Hyperlaxity is multidirectional but instability is almost exclusively unidirectional (Figure). From an etiological point of view, the posterior dislocation is typically differentiated into acute traumatic dislocation that becomes locked after 6 weeks if neglected, and recurrent instability.

[[File:Anterior and Posterior Instability.jpg|thumb|center|Observe the anterior and posterior humeral bone loss in case of anteroinferior and posterior instability. Such case is exceptional.]]

=Classification of Posterior Shoulder Instability=

Posterior instability includes a wide spectrum of pathological conditions, which are sometimes difficult to classify homogeneously.

Classifications of posterior instability have been confusing and most attempt of classification failed. The ABC classification has the merit to be correlated to the presence or not of lesion(s), indication for surgery and results.<ref name=":0">Moroder P, Scheibel M. ABC classification of posterior shoulder instability. Obere Extrem 2017;12:66-74</ref>

Table 1: The ABC classification of posterior shoulder instability

{| class="wikitable"
|-
!Header text!!A First time!!B Dynamic!!C Static
|-
|Type 1||Subluxation||Functional||Constitutional
|-
|Type 2||Dislocation||Structural||Acquire
|}

==Group A==
Group A includes all patients with an acute first-time posterior instability event that can either have occurred in terms of a subluxation without engagement of the humeral head with the posterior glenoid rim (A1) or in terms of a dislocation with temporary or persisting engagement (A2). Distinction of this group and the two subtypes is possible by a combination of taking the patient’s history and imaging studies, both applicable even in the acute and painful setting.

===A1: Acute posterior subluxation===

[[File:Instabilité postérieure.png|thumb|center|First-time posterior subluxation (A1). Magnetic resonance image of a young male patient who sustained an acute posterior shoulder subluxation with small reverse Hill–Sachs lesion and minor posterior capsulolabral damage during sports participation without major trauma]]

===A2===

[[File:Post dislocation.png|thumb|Axial A) and saggital B-C) views of a reduced acute posterior glenohumeral dislocation. A) Observe the posterior labral lesion and the reverse Malgaigne (Hill-Sachs) lesion. B and C demonstrate important post-traumatic muscular edema of the posterior rotator cuff.]]

==Group B==
Group B includes all patients with recurrent dynamic posterior instability events that occur during motion either in form of a functional instability (B1) or a structural instability (B2).

===B1: Functional dynamic posterior instability===
In many cases, the instability is voluntary but positional that is, the patient’s shoulder is dislocated/subluxed in the position of forward flexion, pronation, and internal rotation but relocates with the arm brought into abduction and extension. A voluntary dislocation is associated to a normal laxity or hyperlaxity. In voluntary dislocation, an aberrant muscle activation pattern is observed, the patient is able to demonstrate the phenomena and to repeat it with (Video), often, an amused mimic. There is no imaging finding.

[[File:Media3-54.mov|thumb|center|Voluntary dislocation]]

===B2: Structural dynamic posterior instability===
The B2 includes involuntary and reproducible dislocators.

====Unstable Painful Shoulder====
This condition (micro-instability) is characterized by pain that appears without trauma, without macro-instability (subluxation or dislocation) in a patient that usually does not suffer from hyperlaxity.<ref>Boileau P, Zumstein M, Balg F, Penington S, Bicknell RT. The unstable painful shoulder (UPS) as a cause of pain from unrecognized anteroinferior instability in the young athlete. J Shoulder Elbow Surg 2011;20:98-106</ref><ref>Patte D, Bernageau J, Rodineau J, Gardes JC. [Unstable painful shoulders (author's transl)]. Rev Chir Orthop Reparatrice Appar Mot 1980;66:157-65</ref>

Diagnosis is difficult and should not be confused with posterior static subluxation (B0 glenoid according to Walch)<ref name=":1">Domos P, Checchia CS, Walch G. Walch B0 glenoid: pre-osteoarthritic posterior subluxation of the humeral head. J Shoulder Elbow Surg 2018;27:181-8</ref> that belong to the type C2. Images are often relevant with 52% of reverse Bankart, glenoid or humeral cartilage lesions (28% and 8%, respectively) reported (Video).

[[File:Media11-94.mov|thumb|Posterior labral lesion in a patient suffering from unstable painful shoulder]]

====Involontary====
This type of instability is associated with a clear first traumatic episode. The patient is able to reproduce the painful subluxation/dislocation if not locked. A radiological substrate is found.

====Reproducible====
Reproducible (B2) are voluntary dislocators (B1) that become involuntary after decompensation by a trauma or after losing control of stability. If asked, the patient can reproduce the movement even if the excessive glenohumeral translation leads to symptoms which are sudden, painful and disagreeable (Video). A radiological substrate can be found.

[[File:Reproducible.mov|thumb|Reproducible dislocators. The patient reproduce the movement even if the excessive glenohumeral translation leads to symptoms which are sudden, painful and disagreeable. ]]

==Group C==
===C1: Constitutional static posterior instability===
Glenoid dysplasia is an idiopathic and congenital glenoid retroversion of dysplastic origin. In these conditions the humeral head remain posteriorly subluxated (Walch C glenoid). The retroversion is above 25 degrees, the subluxation above 80%. The posterior rim appears rounded (lazy J). There is moreover a deficient glenoid neck, a hypoplasia of the posteroinferior glenoid, minimal osteophytes, and a preserved joint space in comparison to osteoarthritis.

[[File:C glenoid.jpg|thumb|Figure 9. Axial computed tomography of a right dysplasia shoulder ]]

===C2: Acquired static posterior instability===
This group includes static posterior subluxation, locked dislocation, sequelae of brachial plexus birth palsy,…

====Static Posterior Subluxation====
The finding of static posterior subluxation of the humeral head before the development of posterior bone erosion of the glenoid in young men with radiographic findings of primary osteoarthritis has been described as arthrogenic (pre-osteoarthritic) posterior subluxation of the humeral head,<ref>Walch G, Ascani C, Boulahia A, Nove-Josserand L, Edwards TB. Static posterior subluxation of the humeral head: an unrecognized entity responsible for glenohumeral osteoarthritis in the young adult. J Shoulder Elbow Surg 2002;11:309-14</ref> or Walch B0 glenoid.<ref name=":1" /> This condition could be initially dynamic, eventually evolving into a static condition and may lead to posterior erosion of the glenoid, taking place once there is asymmetrically increased posterior glenohumeral contact forces and possibly associated with increased glenoid retroversion (Figure 9).

[[File:B0.jpg|thumb|Anteroposterior, Neer and axial view of a right shoulder with static posterior subluxation (B0 glenoid)]]

====Locked Dislocation====

[[File:Locked dislocation.png|thumb|Locked dislocation of a left shoulder. Observe the important reverse Malgaigne (Hill-Sachs) lesion.]]

====Sequelae of brachial plexus birth palsy====
Obstetric brachial plexus palsy (OBPP) frequently leads to secondary glenohumeral dysplasia (Video).

[[File:OBPP.mov|thumb|Acquired glenoid dysplasia secondary to obstetric brachial plexus palsy]]

=Etiology=
Injuries typically occur:

*As a consequence of a contact sport or motor vehicle accident. Patients will classically sustain a posteriorly directed force when participating in activities that place their extremity in the at-risk position of anterior forward flexion, adduction, and internal rotation (football players and weightlifters performing bench press or pushups). Interestingly, contact with anterior trauma to an abducted and externally rotated shoulder might also be responsible for posterior dislocations.<ref>Robinson CM, Seah M, Akhtar MA. The epidemiology, risk of recurrence, and functional outcome after an acute traumatic posterior dislocation of the shoulder. J Bone Joint Surg [Am] 2011;93(17):1605–1613</ref>
*After a violent fall.
*After seizures, electric shocks or alcohol intoxication because of uncoordinated muscle contraction (the internal rotator muscles of the shoulder contract with greater force than the external rotators, which causes the humeral head to move superiorly and posteriorly). Anterior dislocation is, however, more frequent in case of seizure.

=Risk Factors=
Risk factors for recurrent instability are:

*Age below 40 at time of first instability. Age is considered an important factor for possible associated lesions. Often, younger patients do not have associated lesions (i.e. rotator cuff), unlike older patients, and consequently, the treatment algorithm for these patients is different. Furthermore, a locked dislocation in an older patient may have different surgical solutions.
*Dislocation during a seizure or electric shock.
*A large reverse Malgaigne (Hill-Sachs) lesion.
*Glenoid retroversion. Please also refer to “Anatomy, Pathoanatomy” section.
*A high and horizontally oriented acromion in the sagittal plan.<ref>Meyer DC, Ernstbrunner L, Boyce G, Imam MA, El Nashar R, Gerber C. Posterior Acromial Morphology Is Significantly Associated with Posterior Shoulder Instability. J Bone Joint Surg Am 2019;101:1253-60</ref> Please also refer to “Anatomy, Pathoanatomy” section.

=Evaluation=
==History==
A thorough history taking is imperative for making an accurate diagnosis of posterior shoulder instability. A detailed description of the offending activity, the position of the arm, and how force was applied may lead the clinician to an accurate diagnosis (please also refer to Etiology section).

In acute or subacute situations, patients report pain with active motion and particularly limited external rotation of the arm. It may mimic a frozen shoulder on examination, especially in cases with an unreduced dislocation.

In recurrent situations, symptoms that are commonly reported are muscle weakness and fatigue, pain, or mechanical symptoms such as clicking or popping. Symptoms intensify with the arm in 90 degrees of forward flexion, adduction, and internal rotation. Rarely do patients report clear sensations of instability or posterior shoulder pain associated with the feeling of a dead arm.

==Clinical Examination==
A detailed physical examination of the shoulder will assist the clinician in accurate diagnosis of posterior instability.

===Inspection===
Examination should begin with inspection, looking for any asymmetry or atrophy of the musculature. Scapular winging also needs to be assessed while the patient is performing active range of motion as it is a sign of posterior dislocation (Video 5).

[[File:Media1-48.mov|thumb|Video 5. Posterior instability leading to winging scapula]]

===Palpation===
Cooper first reported the signs of posterior shoulder dislocation as the appearance of posterior fullness on the affected side.<ref>Cooper A. On the dislocations of the os humeri upon the dorsum scapulae, and upon fractures near the shoulder joint. Guys Hosp Rep 1839;4:265–84</ref>

===Range of Motion===
Shoulder passive and active range of motion should be assessed and compared with the contralateral shoulder. A loss of external rotation must be excluded.

===Specific Tests===
====Jerk test====
The jerk test (posterior stress test) has been considered to be highly sensitive for posterior instability. This test is performed by stabilizing the scapula with one hand, while the other hand holds the elbow with the arm in 90 degrees of abduction and internal rotation (Figure 12). A firm axial compression force is applied on the glenohumeral joint. The arm is horizontally adducted while maintaining the firm axial load. This will cause a posterior translation of the humeral head and as the arm is brought into extension a painful clunk may be appreciated as the humerus reduces and is indicative of a posterior labral tear.

[[File:Jerk.jpg|thumb|Figure 12. Jerk test]]

====SLAP Lesion Test====
=====Kim test=====
A further test for posterior instability is the so-called Kim test, which is a modification of the jerk test.<ref>Kim SH, Ha KL, Yoo JC, Noh KC. Kim’s lesion: an incomplete and concealed avulsion of the posteroinferior labrum in posterior or multidirectional posteroinferior instability of the shoulder. Arthroscopy. 2004;20:712–720</ref>

The patient is supine with the arm abducted at 120 degrees. The examiner takes the patient's wrist with one hand and the elbow flexed at 90 degrees in the other. The shoulder is brought into external rotation. The patient is then asked to flex his elbow against resistance (Figure 13). A positive examination is represented by either pain, a clunk, or a click and indicates either the presence of a superior labral tear from anterior to posterior (SLAP) lesion or a posterior instability.

[[File:Image28-small-72.png|thumb|right|Figure 13. Kim test. The patient is supine, arm abducted at 120 degrees. The examiner takes the patient's wrist with one hand and elbow, flexed at 90 degrees, with the other, and the shoulder externally rotated. The patient is then asked to flex his elbow against resistance.]]

The test is performed with the patient in a sitting position and their arm in 90 degrees of abduction. The examiner holds the elbow and lateral aspect of the proximal arm and applies a strong axial load in line with the scapula. While maintaining the axial load, the arm of the patient is elevated 45 degrees diagonally upward and a posterior force is applied to the proximal arm. The test is positive if the patient complains of pain during this maneuver.

The jerk and the Kim tests are important and help deciding between nonoperative and operative treatment. The combination of a painful jerk and Kim tests has been shown to be 97% sensitive for the detection of a posteroinferior labral lesion.<ref>Kim SH, Park JS, Jeong WK, Shin SK. The Kim test: a novel test for posteroinferior labral lesion of the shoulder—a comparison to the jerk test. Am J Sports Med. 2005;33:1188-1192.</ref> Patients with a painful jerk or Kim test have approximately 85% chance of not improving with rehabilitation and arthroscopic treatment with capsuloplasty is recommended.

=====Active Compression Test (better known as O’Brien’s test)=====
It is an active elevation against resistance, with the patient standing, shoulder flexed at 90 degrees and adducted at 15 degrees, elbow extended (Figure 14). The test is considered positive if there is pain in pronation but not in supination. This is the most sensitive (47% to 78%), but the least specific (11% to 73%) test. When testing negative, a superior labral tear from anterior to posterior (SLAP) lesion is very unlikely.

[[File:1562635352717-lg.jpg|center|thumb|600x600px|Figure 14. Active elevation against resistance test, with the patient standing, shoulder flexed at 90 degrees and 15 degrees adduction, elbow extended. The test is considered positive if there is pain in pronation but no pain in supination.]]

=Scores=
==Beighton score==
Assessment of generalized ligamentous laxity should be performed as this can predispose patients to instability events. The Beighton score is used to assess generalized ligamentous laxity, which has been shown to correlate with shoulder instability.<ref>Cameron KL, Duffey ML, DeBerardino TM, Stoneman PD, Jones CJ, Owens BD. Association of generalized joint hypermobility with a history of glenohumeral joint instability. J Athl Train. 2010;45:253-258</ref> The 5 included criteria are: (1) hyperextension of the elbow beyond 10 degrees; (2) hyperextension of the knees beyond 10 degrees; (3) forward flexion of the trunk, with knees straight, so that palms rest easily on the floor; (4) passive dorsiflexion of the little finger beyond 90 degrees; and (5) passive apposition of the thumbs to the flexor aspects of the forearm. This system is based on a 9-point scale and a higher score (>4) indicates general hyperlaxity (although an external rotation elbow at the side equal or greater than 85 degrees indicates shoulder hyperlaxity (Video 6)).

[[File:ER hyperlaxity.mov|thumb|Video 6. An external rotation elbow at the side equal or greater than 85 degrees indicates shoulder hyperlaxity.]]

=Imaging=
The diagnosis of this injury is often missed at initial examination, despite highly suggestive injury circumstances, notable clinical signs and radiographic evidence.<ref name=":2">Hawkins RJ, Neer CS, II, Pianta RM, Mendoza FX. Locked posterior dislocation of the shoulder. J Bone Joint Surg [Am] 1987;69-A:9–18.</ref>

==Plain Radiographs==
The views that should be included in the workup are a true anteroposterior view (grashey view), internal and external rotation view, a scapular Y view, and a Bernageau view. Posterior dislocation is missed initially on posteroanterior radiographs in 50% of cases, as the humeral head appears to be almost normally aligned with the glenoid.

===Anteroposterior view===
====Acute====
On anteroposterior view, an overlap of the head in relationship to the glenoid can be observed (trough line sign, loss of the normal half-moon overlap sign, Figure 15). Moreover, an internally rotated humeral head gives a rounded appearance, which is called the lightbulb sign. Furthermore, the rim sign is defined as the space between the anterior glenoid rim and the humeral head being > 6 mm indicating a widened glenohumeral space (Figure 16).<ref>Cicak N. Posterior dislocation of the shoulder. J Bone Joint Surg [Br] 2004;86-B(3):324–332</ref>

[[File:Image4-16.png|thumb|Figure 15. Posterior glenohumeral dislocation on an anteroposterior view. Note the loss of the normal half-moon overlap sign.]]

[[File:Image23-small-58.png|thumb|Figure 16. Anteroposterior view that demonstrate lightbulb and rim signs.]]

====Chronic/recurrent/congenital/acquired cases====

[[File:AP dysplasie.png|thumb|Figure 17. AP view of a right dysplasic shoulder. Note the medicalization of the humeral head medial to the base of the coracoid process.]]

===Scapular Y View (Neer)===
The scapular Y view can demonstrate a posterior translation of the humeral head (Figure 18).

[[File:Image24-59.png|thumb|Figure 18. Scapular Y View of a Posteriorly Dislocated Left Shoulder.]]

===Axillary view===
====Acute====
As a Bernageau view is difficult to obtain in acute cases because of severe pain, Velpeau axillary views is an alternative (Figure 19).<ref>Bloom MH, Obata WG. Diagnosis of posterior dislocation of the shoulder with use of Velpeau axillary and angle-up roentgenographic views. J Bone Joint Surg Am. 1967 Jul;49(5):943-9</ref>

[[File:Image26-63.jpg|thumb|Figure 19. Plain radiograph demonstrating a posterior glenohumeral dislocation.]]

====Recurrent/Congenital/Acquired====
Bernageau view is the best to demonstrate posterior glenoid rim deficiency posterior subluxation and associated bone loss.

[[File:Rounded glenoid deficiency.png|thumb|Figure 20. Rounded glenoid deficiency (“lazy J” form)]]

[[File:Image30-small-85.png|thumb|Figure 21. Triangular bony deficiency (“delta” form)]]

==Magnetic Resonance Arthrogram (MRA)==
Contrast enhancement during magnetic resonance arthrogram (MRA) is of great value and will increase the sensitivity of magnetic resonance imaging (MRI) in identifying a soft tissue injury (cartilage, rotator cuff, labral tears (Figure), a patulous capsule (Figure), reverse humeral avulsion of the glenohumeral ligaments (rHAGL, Figure), associated findings such as paralabral cysts) (Figure).

[[File:Image26-small-78.png|thumb|Figure 22. Axial view T2 MRA that show a patulous capsule.]]

[[File:Image12-32.jpg|thumb|Figure 23. Reverse humeral avulsion of the glenohumeral ligaments (rHAGL)]]

[[File:Différentes lésion labrales post.jpg|thumb|Figure 24. From left to right, different types of posterior lesions: Kim POLPSA, GLAD, Bennet and rHAGL Lesions]]

[[File:Posterior cyst.mov|thumb|center|Video 7. Magnetic resonance imaging demonstrating a paralabral cyst related to a posterior labral lesion.]]

==Computed Tomography (CT) Scan==
Computed tomography (CT) scans also help the physicians to analyze the bony morphology of the shoulder joint. Before operative management, it is effectively imperative to assess for abnormalities in glenoid version (mean, 4.9 degrees in normal shoulders)<ref>Weishaupt D, Zanetti M, Nyffeler RW, Gerber C, Hodler J. Posterior glenoid rim deficiency in recurrent (atraumatic) posterior shoulder instability. Skeletal radiology 2000;29:204-10</ref> according to the Friedman technique,<ref>Friedman RJ. The use of computerized tomography in the measurement of glenoid version. J Bone Joint Surg Am 1992</ref> posterior glenoid rim fractures or bone loss, and reverse Malgaigne (Hill-Sachs) lesions. These factors help determining the treatment strategies.

=Treatment=
==Clinical Practice Guideline==
The goal of this section is to provide clinicians with recommendations based on the best available evidence; to inform clinicians of when there is no evidence; and finally, to help clinicians deliver the best health care possible.

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==Conservative (Non Operative) Treatment==
===Acute===
As an initial treatment, for all acute posterior dislocations, acute reduction and immobilization should be attempted. Most acute dislocations have a chance to reduce with closed manipulation. The reduction maneuvers must be done gently and carefully. In order to reduce the humeral head into the glenoid fossa, forward pressure on the humeral head must be applied with the arm in the flexed, adducted and internally rotated position. After reduction, an immobilization is required during 6 to 8 weeks in neutral or 20 degrees of external rotation, depending on the stability.

===Recurrent===
Patients with A1-C1 type of instability tend to have a more favorable result with conservative measures.<ref>Clavert P, Furioli E, Andieu K, Sirveaux F, Hardy MB, Nourissat G, Bouju Y, Garret J, Godenèche A, Mansatet P. Clinical outcomes of posterior bone block procedures for posterior shoulder instability: Multicenter retrospective study of 66 cases. Orthop Traumatol Surg Res 2017;103:S193-S7.</ref><ref name=":0" /><ref>Aydin N, Enes Kayaalp M, Asansu M, Karaismailoglu B. Treatment options for locked posterior shoulder dislocations and clinical outcomes. EFORT Open Rev. 2019;4:194-200.</ref> Voluntary posterior dislocators should not be operated on. Management begins with activity modification to prevent further injury, medications as needed and physiotherapy.

===Physiotherapy===
Physical therapy is focused on strengthening of the subscapularis that will maintain the humeral head anteriorly, posterior deltoid, and the periscapular stabilizers through resisted external rotation exercises.<ref name=":3">McIntyre K, Bèlanger A, Dhir J, Somerville L, Watson L, Willis M, Sadi J. Evidence-based conservative rehabilitation for posterior glenohumeral instability: a systematic review. Phys Ther Sport. 2016;22:94–100.</ref> The aim is to improve the neuromuscular control of the shoulder joint and to regain dynamic muscular stability.

Isokinetic muscle performance testing can assess muscle strength and neuromuscular control ability using time to peak torque and acceleration time in patients with traumatic shoulder instability. The injured shoulder usually shows delayed neuromuscular control in rotations. This information helps clinicians and therapists to implement exercises that aim to restore neuromuscular control in patients' rehabilitation.<ref>Lee JH, Park JS, Hwang HJ, Jeong WK. Time to peak torque and acceleration time are altered in male patients following traumatic shoulder instability. J Shoulder Elbow Surg. 2018 Aug;27(8):1505-1511</ref><ref>Jan J, Benkalfate T, Rochcongar P. The impact of recurrent dislocation on shoulder rotator muscle balance (a prospective study of 102 male patients). Ann Phys Rehabil Med. 2012 Sep;55(6):404-14</ref>

===Electrostimulation===
Functional shoulder instability is caused by underactivity of rotator cuff and periscapular muscles, which leads to subluxation or dislocation during shoulder movement. The goal is thus to stimulate underactive muscles in patients with functional instability during shoulder movement in order to re-establish glenohumeral stability and to decrease pain. This can be performed by different modalities such as transcutaneous electrical nerve stimulation (TENS), Berlin shoulder pacemaker,...<ref>Moroder P, Minkus M, Böhm E, Danzinger V, Gerhardt C, Scheibel M. Use of shoulder pacemaker for treatment of functional shoulder instability: Proof of concept. Obere Extrem. 2017;12:103-108.</ref><ref>Hawk C, Minkalis AL, Khorsan R, Daniels CJ, Homack D, Gliedt JA, Hartman JA, Bhalerao S. Systematic Review of Nondrug, Nonsurgical Treatment of Shoulder Conditions. J Manipulative Physiol Ther. 2017;40:293-319.</ref>

===Shoulder Brace===
Shoulder braces or posture correctors and supports that can center the arm in the socket through improved proprioception and reafferentation. Depending of their design, they can provide secure stability during movement. This type of support could help athletes to return to sport.

==Surgical (Operative) Treatment==

===Acute dislocation===
====Open reduction and surgical stabilization====
Open reduction is indicated in dislocations in which closed reduction cannot or should not be achieved. Several conditions are contraindications (i.e. if fracture dislocation). Reverse Malgaigne (Hill-Sachs) lesions > 25% of the humeral head articular surface in size are often unstable after closed reduction and they also require surgical intervention. Open reduction and surgical stabilization are indicated in such cases with defects 25% to 45% of the humeral head articular surface.

The deltopectoral approach is used to reconstruct the humeral head bony defect by the transfer of the subscapularis tendon with transosseous sutures described by McLaughlin<ref>McLaughlin HL. Posterior dislocation of the shoulder (follow-up note). J Bone Joint Surg [Am]1962;44-A:1477</ref> or by suture anchors described by Spencer and Brems.<ref name=":4">Spencer EE, Jr, Brems JJ. A simple technique for management of locked posterior shoulder dislocations: report of two cases. J Shoulder Elbow Surg 2005;14:650–652.</ref> The posterior subdeltoid approach can also be used and this approach lets the surgeon to fill the defect with autograft and perform a Bankart type capsulorrhaphy.<ref>Dubousset J. Posterior dislocations of the shoulder. Rev Chir Orthop Reparatrice Appar Mot 1967;53:65–85.</ref> If the injury is < 3 weeks old, disimpaction and bone grafting of the defect can be performed. For any glenoid bone loss, an iliac crest bone graft can be used as a block and both approaches can be preferred.<ref>Augereau B, Leyder P, Apoil A. Treatment of inveterate posterior shoulder dislocation by the double approach and retroglenoid bone support. Rev Chir Orthop Reparatrice Appar Mot 1983;69(Suppl. 2):89–90</ref>

[[File:1562915201982-lg.jpg|center|thumb|700x700px|Figure 25. Coronal (A) and axial (B) CT sections of a left-side type IV cephalotubercular fracture. In this situation, the head should not be reduced via the deltopectoral approach, but simply make a small posterior approach through which a tamp is passed (green arrow) which will push the head backwards (C). Anteroposterior and Lamy lateral postoperative radiographs (D and E, respectively).]]

====Arthroscopic reduction and surgical stabilization====

'''''Arthroscopic treatment of a humeral head fracture.'''''
[[File:1562909631408-lg.jpg|center|thumb|660x660px|Figure 26. A) Anteroposterior radiograph and B) CT scan of the left shoulder, revealing a humeral head fracture. Six months after arthroscopic reduction without fixation, the Lamy frontal and lateral radiographs confirm a perfect reduction. The rotator cuff and tuberosities are intact, so secondary displacements are limited. Reproduce from <ref>Godeneche A, Freychet B, Gunst S, Daggett M, Viste A, Walch G. Arthroscopic Reduction of Acute Traumatic Posterior Glenohumeral Dislocation and Anatomic Neck Fracture Without Internal Fixation: 2-Year Follow-up. Orthop J Sports Med. 2017;5(12):2325967117745486</ref>, with permission.]]

===Chronic Instability===
Patients who have undergone at least 6 months of conservative treatment and still experience symptoms are candidates for surgical management.<ref>Gartsman GM, Roddey TS, Hammerman SM. Arthroscopic treatment of bidirectional glenohumeral instability: two- to five-year follow-up. J Shoulder Elbow Surg. 2001;10(1):28–36</ref> Surgical treatment can be considered for the patient with a symptomatic posterior labral tear, unilateral posterior instability with a patulous or incompetent posterior capsule, or in select multidirectional instability patients with predominantly posterior symptoms. Nevertheless, if conservative measures fail then operative management should be considered in those with identifiable pathology. Surgery is required in cases of persistent shoulder pain in chronic instability, in patients with a locked neglected chronic dislocation, or in patients with associated lesions developing a dysfunctional shoulder. There are 2 broad categories of surgical management that focus on either the soft tissue or bony anatomy.

====Soft tissue procedure====
=====Labral Repair and Capsular Shift=====
In patients with purely soft tissue injuries and no associated bone loss or fracture, then posterior capsulorraphy (i.e., capsular shift) and labral repair are the treatments of choice. The use of arthroscopy in these cases has greatly surpassed that of open procedures primarily due to the less-invasive nature of the procedure, improved shoulder mechanics postoperatively, decreased scarring, and the ability to address concomitant lesions including posterior humeral avulsions of the glenohumeral ligament. It may reveal subtle lesions such a small crack or fissuring within the posterior labrum (hidden lesion or “Kim lesion”) (Video).

[[File:Media15-194.mp4|thumb|Video 8. Diagnostic arthroscopy]]

An arthroscopic labral repair is most commonly performed using suture anchor fixation. This often requires the use of 3 to 4 portals to allow for proper anchor positioning and shuttling of sutures. The standard posterior, anterior, and anterosuperior portals are initially created for visualization. In patients in whom the position of the posterior portal is not optimal for working and for achieving angle for glenoid rim access, a 7 o’clock portal or posteroinferior portal is placed under spinal needle localization. This portal has been found to be a safe distance from the axillary and suprascapular nerves. Once all portals have been created the labrum can be prepared through both the posterior and anterior portals. The posterior labrum is then mobilized off the glenoid neck using an elevator or arthroscopic scissor. It should be completely elevated from the glenoid to allow for superior translocation and preparation of the glenoid neck. The rim and neck of the glenoid are debrided with a shaver or a rasp. Repair of the labrum should begin at the most inferior extent of the tear. The anchor is placed slightly superior to allow for a superior shift of the tissue. Anchors should be spaced 3–5 mm apart to avoid fragmentation of the posterior glenoid bone. In patients with a patulous capsule an arthroscopic capsular shift may be performed in conjunction with a labral repair and consists of tightening any redundant posterior capsular tissue. Usually approximately 1 cm of capsule is plicated to the labrum. The exact amount of capsular plication must be individualized to the patients symptoms and over laxity as seen arthroscopically. This should begin at the 6 o’clock position and work in the direction of the 12 o’clock position (Figure).

[[File:Media18-208.mov|thumb|Video 9. Final repair. The posterior labrum and posterior capsule are repaired to the glenoid rim.]]

In some cases, the labrum may be intact and the pathology may be related only to a capsular detensioning. In these cases, the capsular tissue may be lightly abraded with a rasp or with a shaver and capsular retensioning is carried out using the labrum like an anchor. Frequently, a combined labral repair and capsular shift are performed simultaneously and fixated with a suture anchor. In patients with chondral damage leaving exposed glenoid bone, the anchors may be placed slightly further onto the glenoid face to advance the labrum over the chondral defect providing a soft tissue inter-position while repairing the labrum.

=====Rotator Interval Closure=====
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====Treatment of Anterior Humeral Head Defects====
=====Reverse Malgaigne (Hill–Sachs) Rempissage=====

In some cases of posterior instability, a large reverse Malgaigne (Hill-Sachs) lesion may be encountered. If involving more than 20% of the articular surface, a reverse Malgaigne (Hill-Sachs) remplissage may be considered to enhance stability of the joint. The rotator interval is resected to improve visualization of the anterior aspect of the subscapularis tendon (Video 10). The bone bed is therefore prepared as performed during subscapularis tendon repair (Video 11). Anchor(s) is(are) inserted, the sutures are passed through the subscapularis tendon and tied to fill the bone defect (Video 12).

[[File:Media19-213.mov|thumb|Video 10. Once the reverse Hill-Sachs lesion is identified and is determined to be significant, the rotator interval is resected to improve visualization of the anterior aspect of the subscapularis tendon. In these patients, resection of the rotator interval is reasonable since multi-directional laxity is rarely present and/or symptomatic. Courtesy of Stéphane Audebert]]

[[File:Media20-216.mov|thumb|Video 11. The bone bed is prepared as performed during subscapularis tendon repair. Although, in this scenario, the upper border of the subscapularis tendon commonly obstructs direct access. Commonly internal rotation will improve access particularly to the inferior part of the reverse Hill-Sachs lesion. Courtesy of Stéphane Audebert]]

[[File:Media21-221.mov|thumb|Video 12. Anchors are inserted percutaneously through the subscapularis tendon or the rotator interval in the inferior and superior aspects of the reverse Malgaigne (Hill-Sachs) lesion. The sutures are passed through the subscapularis and tight. The procedure is performed for the other suture pairs. Courtesy of Stéphane Audebert]]

=====McLaughlin Procedure (Open Transfer of the Subscapularis Tendon)=====

One of the earliest described techniques involves transferring the tenotomized subscapularis tendon to the humeral defect (from 25% to 45% of the humeral head articular surface) and is known as the McLaughlin procedure.<ref>McLaughlin HL. Locked posterior subluxation of the shoulder: diagnosis and treatment. Surg Clin North Am 1963;43:1621–1622</ref> Hawkins et al reported that if the period of delay is > 6 months, the articular cartilage of humeral head gets non-viable; therefore, the McLaughlin procedure should not be preferred.<ref name=":2" /><ref name=":5">Delcogliano A, Caporaso A, Chiossi S, Menghi A, Cillo M, Delcogliano M. Surgical management of chronic, unreduced posterior dislocation of the shoulder. Knee Surg Sports Traumatol Arthrosc 2005;13:151–155.</ref>

=====Arthroscopic McLaughlin Procedure=====

Godenech et al. and Lavender et al. reported an arthroscopic technique suturing the distal part of the subscapularis tendon into the defect.<ref>Lavender CD, Hanzlik SR, Pearson SE, Caldwell PE. Arthroscopic reverse remplissage for posterior instability. Arthrosc Tech. 2016;1:e43–e47</ref><ref>Besnard M, Audebert S, Godenèche A. Arthroscopic McLaughlin Procedure for Treatment of Posterior Instability of the Shoulder With an Engaging Reverse Hill-Sachs Lesion. Arthrosc Tech. 2019;8:1491-4.</ref>

=====Osteotomy of the Lesser Tuberosity With the Attached Subscapularis (Hughes and Neer method)=====

Several authors modified McLaughlin’s method and described osteotomizing the lesser tuberosity with the attached subscapularis tendon and fixing it to the defective area.<ref name=":5" /><ref name=":4" /> The modified McLaughlin method provides additional bony support for the defective area and is preferred for patients when the injury is older than three weeks.<ref name=":6">Castagna A, Delle Rose G, Borroni M, Markopoulos N, Conti M, Maradei L, Garofalo R. Modified MacLaughlin procedure in the treatment of neglected posterior dislocation of the shoulder. Chir Organi Mov 2009;93:1–5.</ref> Depending on the importance of the bone loss, simultaneous iliac crest autograft, dry morselized allograft, fresh-frozen femoral head bone allograft can be perform.<ref>Khira YM, Salama AM. Treatment of locked posterior shoulder dislocation with bone defect. Orthopedics 2017;40:501–5.</ref><ref name=":7">Kokkalis ZT, Mavrogenis AF, Ballas EG, Papanastasiou J, Papagelopoulos PJ. Modified McLaughlin technique for neglected locked posterior dislocation of the shoulder. Orthopedics 2013;36:912–6.</ref>

The surgery is performed in a beach chair position. The deltopectoral approach is used. First, the biceps tendon is identified as a landmark for the bicipital groove. The lower edge of the subscapularis tendon is detected in order to mark lesser tuberosity. Osteotomy of the lesser tuberosity is performed from lateral to medial, starting from the bicipital groove to the defect of the humeral head.<ref name=":6" /> The lesser tuberosity with the attached subscapularis tendon is elevated in order to demonstrate the head and the glenoid. Reduction is performed and when achieved, the lesser tuberosity with the attached subscapularis tendon is fixed into the humeral head defect using ether screws, anchors or sutures.<ref>Shams A, El-Sayed M, Gamal O, ElSawy M, Azzam W. Modified technique for reconstructing reverse Hill-Sachs lesion in locked chronic posterior shoulder dislocation. Eur J Orthop Surg Traumatol 2016;26:843–9.</ref><ref name=":7" /> Reported results are usually excellent.<ref>Banerjee M, Balke M, Bouillon B, Wafaisade A, Helm P, Akoto R, Shafizadeh S. Excellent results of lesser tuberosity transfer in acute locked posterior shoulder dislocation. Knee Surg Sports Traumatol Arthrosc 2013;21:2884–8.</ref><ref name=":7" />

====Humeral Reconstruction with Autograft or Allograft====
Bone grafting is an unavoidable procedure in insufficient bone reserve to reconstruct the anatomical sphericity and preserve the stability of the reconstructed humeral head after locked posterior shoulder dislocations. Allo- and autografting are both described in the literature. Some authors advocated the use of allografts in obtaining the anatomical sphericity of humeral head rather than preferring non-anatomical techniques by using osteochondral allografts from fresh-frozen femoral heads. Especially in the case of larger defects of up to 50% and young patients with viable humeral bone reserve, fixation of the allografts in defective areas with partially threaded cancellous screws yielded excellent results.<ref name=":8">Diklic ID, Ganic ZD, Blagojevic ZD, Nho SJ, Romeo AA. Treatment of locked chronic posterior dislocation of the shoulder by reconstruction of the defect in the humeral head with an allograft. J Bone Joint Surg [Br] 2010;92:71–6.</ref><ref>Gerber C, Lambert SM. Allograft reconstruction of segmental defects of the humeral head for the treatment of chronic locked posterior dislocation of the shoulder. J Bone Joint Surg [Am] 1996;78:376–382.</ref> In case of bilateral posterior humeral head dislocations, harvesting osteochondral autograft from the side that will undergo hemiarthroplasty and using this graft on the contralateral side is also described in the literature by several authors.<ref>Ivkovic A, Boric I, Cicak N. One-stage operation for locked bilateral posterior dislocation of the shoulder. J Bone Joint Surg [Br] 2007;89-B:825–8.</ref><ref>Torrens C, Santana F, Melendo E, Marlet V, Caceres E. Osteochondral autograft and hemiarthroplasty for bilateral locked posterior dislocation of the shoulder. Am J Orthop (Belle Mead NJ) 2012;41:362–4.</ref> Allo- and autograft reconstructions have a good long-term follow-up.<ref>Gerber C, Catanzaro S, Jundt-Ecker M, Farshad M. Long-term outcome of segmental reconstruction of the humeral head for the treatment of locked posterior dislocation of the shoulder. J Shoulder Elbow Surg 2014;23:1682–1690.</ref><ref>Martinez AA, Navarro E, Iglesias D, Domingo J, Calvo A, Carbonel I. Long-term follow-up of allograft reconstruction of segmental defects of the humeral head associated with posterior dislocation of the shoulder. Injury 2013;44:488–491.</ref>

[[File:Reverse Malgaigne Reconstruction with allograft .mp4|thumb|Video 13. Humeral Reconstruction with allograft ]]

====Posterior Bone Block====
Patients with glenoid dysplasia (retroversion >15 degrees) as well as patients with posterior glenoid defects are at increased risk for failure with soft tissue procedures due to altered underlying bony support. Numerous techniques have been reported to reconstruct the posterior glenoid, including iliac crest bone block (Figure), distal tibial allograft, glenoid allograft, pedunculated acromial graft, and distal clavicular autograft.<ref name=":9">Barbier O, Ollat D, Marchaland JP, Versier G. Iliac bone-block autograft for posterior shoulder instability. Orthop Traumatol Surg Res. 2009;95:100-107</ref><ref>Gupta AK, Chalmers PN, Klosterman E, Harris JD, Provencher MT, Romeo AA. Arthroscopic distal tibial allograft augmentation for posterior shoulder instability with glenoid bone loss. Arthrosc Tech. 2013;2:e405-e411</ref><ref>Petrera M, Veillette CJ, Taylor DW, Park SS, Theodoropoulos JS. Use of fresh osteochondral glenoid allograft to treat posteroinferior bone loss in chronic posterior shoulder instability. Am J Orthop (Belle Mead NJ). 2013;42:78-82</ref><ref name=":10">Schwartz DG, Goebel S, Piper K, Kordasiewicz B, Boyle S, Lafosse L. Arthroscopic posterior bone block augmentation in posterior shoulder instability. J Shoulder Elbow Surg. 2013;22:1092-1101</ref><ref>Sirveaux F, Leroux J, Roche O, Gosselin O, De Gasperi M, Molé D. Surgical treatment of posterior instability of the shoulder joint using an iliac bone block or an acromial pediculated bone block: outcome in eighteen patients [in French]. Rev Chir Orthop Reparatrice Appar Mot. 2004;90:411-419</ref><ref>Struck M, Wellmann M, Becher C, Pastor MF, Smith T. Results of an open posterior bone block procedure for recurrent posterior shoulder instability after a short- and long-time follow-up. Knee Surg Sports Traumatol Arthrosc. 2016;24:618-624</ref>

=====Bone Block through Posterior Approach (Open or Arthroscopy)=====
The standard open technique using iliac crest bone graft has been first described by Hindenach.<ref>Hindenach JC. Recurrent posterior dislocation of the shoulder. J Bone Joint Surg Am 1947;29:582-6.</ref> While promising clinical results have been reported, the procedure is technically demanding, with complication rates up to 36%, including residual instability, osteolysis of the graft, persistant pain and development of osteoarthritis.<ref name=":12">Arciero RA, Mazzocca AD. Posterior Acromial Bone Block Augmentation for the Treatment of Posterior Glenoid Bone Loss Associated With Recurrent Posterior Shoulder Instability. Techniques in Shoulder & Elbow Surgery 2006;7:210-7</ref><ref name=":9" /><ref>Essadki B, Dumontier C, Sautet A, Apoil A. [Posterior shoulder instability in athletes: surgical treatment with iliac bone block. Apropos of 6 case reports]. Rev Chir Orthop Reparatrice Appar Mot 2000;86:765-72</ref><ref>Gosens T, van Biezen FC, Verhaar JA. The bone block procedure in recurrent posterior shoulder instability. Acta Orthop Belg 2001;67:116-20</ref><ref name=":11">Kouvalchouk JF, Coudert X, Watin Augouard L, Da Silva Rosa R, Paszkowski A. [Treatment of posterior instability of the shoulder joint using an acromial stop with a pediculated deltoid flap]. Rev Chir Orthop Reparatrice Appar Mot 1993;79:661-665</ref><ref>Levigne C, Garret Jr, Walch G. Posterior Bone Block for Posterior Instability. Techniques in Shoulder & Elbow Surgery 2005;6:26-35</ref><ref>Meuffels DE, Schuit H, van Biezen FC, Reijman M, Verhaar JA. The posterior bone block procedure in posterior shoulder instability: a long-term follow-up study. J Bone Joint Surg Br. 2010;92:651-655</ref><ref name=":10" /><ref>Servien E, Walch G, Cortes ZE, Edwards TB, O'Connor DP. Posterior bone block procedure for posterior shoulder instability. Knee Surg Sports Traumatol Arthrosc 2007;15:1130-1136</ref> Careful attention must be paid to the positioning of the bone block posteriorly. A biomechanical study showed that a posterior bone block may overconstrain the posterior shoulder and not adequately address inferior instability compared to arthroscopic repair techniques.<ref> Wellmann M, Bobrowitsch E, Khan N, Patzer T, Windhagen H, Petersen W, Bohnsack M. Biomechanical effectiveness of an arthroscopic posterior Bankart repair versus an open bone block procedure for posterior shoulder instability. Am J Sports Med. 2011;39:796-803.</ref>

The posterior bone block procedure can be performed via the same approach or arthroscopically and is accomplished by fixating bone graft to the posterior glenoid rim to recreate the normal contour of the glenoid surface (Video 14). Osseous procedures have fallen out of favor as first line treatment options and are typically reserved for those who fail a soft tissue procedure or have significant bone loss or deficiency.

[[File:Open Posterior Bone Block.mp4|thumb|Video 14. Open Posterior Bone Block]]

=====Arthroscopic Posterior Bone Block through Rotator Interval Approach=====
Following induction of anesthesia the patient is placed in the lateral decubitus position with a warming blanket applied. An iliac crest bone autograft is harvested prior to arthroscopy. A bicortical 25 mm long, 15 mm large and 10 mm thick bone graft is obtained from the ipsilateral iliac crest. Alternatively, the use of acromial spine autograft has been described.<ref name=":12" /><ref name=":11" /> The side without cortex is the one which will be secured against the glenoid. Two 3.2 mm holes are drilled through the graft (Video). The size of the graft is 25 mm long, 15 mm large and about 10 mm thick. Three sutures are placed, one in each hole, and a third passing through both holes to the posterior side of the graft. One suture is placed in each hole of the graft and are tied so that there are sutures at the leading and trailing ends of the graft. These sutures will be used to shuttle the graft into the glenohumeral joint. Additionally, a third suture is passed through the two holes and exits the posterior aspect of the graft. This suture is helpful in maintaining orientation of the graft during shuttline. Attention is turned to the arthroscopic procedure. The arm is placed in balanced suspension with 20° to 30° of abduction and 20° of forward flexion. Standard three portal access to the glenohumeral joint is established including posterior, anterior, and anterosuperolateral portals. A 7 mm cannula is placed into the latter portal. A standard diagnostic arthroscopy using a 30° arthroscope is performed and the glenohumeral joint is then viewed through the anterosuperolateral portal. Quadrant landmarks of the glenoid at 3, 6, 9 and 12 o’clock are marked with an electrocautery, which is important to help correctly place the bone graft later in the procedure. The anterior - posterior glenoid width measured as the anterior - to - posterior distance between 7:30 and 4:30 on the glenoid face is determined with a calibrated probe. Viewing from a posterior portal, a shaver or electrocautery introduced from the anterosuperolateral portal are used to create a window in rotator interval to allow passage of the bone graft.<ref>Lo IK, Burkhart SS. Arthroscopic coracoplasty through the rotator interval. Arthroscopy 2003;19:667-671</ref> Care is taken to preserve the medial sling of the biceps during this step. The arthroscope is returned to the anterosuperolateral portal for visualization of the posterior capsulolabral structures. The posteroinferior labrum is resected off the posterior glenoid neck from 6 to 10 o’clock for a right shoulder using a motorized shaver in the posterior soft point portal. After resecting the posterior inferior labrum, the posterior glenoid is prepared to be flat. The space between the posterior labrum and the posterior glenoid margin is enlarged to receive the bone graft. Traction maneuvers with the shaver lift the fibers of the infraspinatus obliquely away from the glenoid allowing excellent visualization of the posteroinferior glenoid. Occasionally, a 70° arthroscope is necessary to adequately visualize this area. The capsule is released from the glenoid until the infraspinatus fibers can be seen and so that the open space between the glenoid and the capsule is sufficient to allow the introduction of a 10 mm thick bone graft. The posterior glenoid neck is decorticated with a shaver or burr to create a flat surface suitable to graft incorporation. Particular attention is paid during this procedure to prevent suprascapular nerve injury by avoiding working greater than 14 mm medial to the glenoid.<ref>Bigliani LU, Dalsey RM, McCann PD, April EW. An anatomical study of the suprascapular nerve. Arthroscopy. 1990;6(4):301-5</ref> The knowledge of the precise length of the burr can help the surgeon to avoid technical errors. A spinal needle is inserted at 7 o’clock to determine the proper angle of approach for a posterolateral working portal. The skin incision for the anterior portal is enlarged to accommodate passage the bone graft. Via the anterior portal, the graft is passed through the rotator interval in an anterior to posterior direction. This is achieved by means of utilizing the previous sutures in a shuttling technique (Movie). The leading suture of the graft is delivered into the glenohumeral joint through the anterior portal and retrieved out the posterior portal. Pulling this suture shuttles the graft into the joint. Additionally, a Kocher clamp is used to grasp the graft and assist in delivering the graft. Once the graft lies inside of the joint, alternating tension on the three sutures orients the graft. Graspers can also be used to manipulate the graft into the interval between the posteroinferior glenoid and the capsule. The graft is placed at the posteroinferior aspect of the glenoid (between 6 and 9 o’clock for a right shoulder and between 3 and 6 o’clock for a left shoulder), the cancellous side facing the posterior glenoid. This “free hand” step is the most challenging part of the procedure. In our experience when the graft is introduced in the fossa between the glenoid and the capsule, it become sufficiently stable which the need to hold it in place. Once the bone graft lies flush to the glenoid or slightly overhanging out the glenoid, a spinal needle is used to obtain an angle of approach directly perpendicular to the prepared holes and parallel to the glenoid surface. One or two small punctures are usually necessary to address both tunnels. Then a small 4.5 mm cannula is used to place two 1.2 mm K-wires, one in each hole, and a 3.2 mm cannulated drill is used to overdrill the K-wires through the graft and glenoid. Before removing the drill, particular care is paid to maintaining the K-wires in place. The posterior to anterior K-wires be bicortical but care must be taken to avoid excessive penetration which could injury the anterior neurovascular structures or lung.<ref>Slattery SC, Jobe CM, Watkins B. Posterior to anterior transglenoid pins: anatomy at risk. Arthroscopy. 1998 Apr;14(3):285-8</ref> The length of the screws is determined adding the thickness of the graft and the diameter of the glenoid. Two 4.5 mm cannulated screws are then passed over the K-wires with enough compression to secure the graft (Movie). Once the graft is appropriately placed with strong fixation, both K-wires are removed. If the bone graft is prominent, a burr is used to create a smooth congruent arch with the glenoid. Two to three double-loaded anchors are then inserted through the posterior portal along the posterior glenoid rim starting from inferior to superior. The sutures are passed antegrade or retrograde through the capsule without major capsular shift or plication as the bone graft mainly achieves the stability. This procedure closes the capsule to the native glenoid and thus renders the bone block extracapsular (Movie). This step is necessary to protect the humeral articular cartilage from a direct contact with the bone graft. After portal closure, a sterile bulky dressing is applied and postoperative radiographs are obtained. This technique provides excellent visualization of the glenohumeral joint and is accomplished with less damage to the rotator cuff and posterior deltoid compared to traditional open approaches. The results are generally good.<ref>Barth J, Grosclaude S, Lädermann A, Denard PJ, Graveleau N, Walch G. Arthroscopic Posterior Bone Graft for Posterior Instability: The Transrotator Interval Sparing Cuff Technique. Techniques in Shoulder & Elbow Surgery 2011;12(3):67-71</ref>

[[File:Arthroscopic Posterior Bone Block.mp4|thumb|Video 15. Arthroscopic Posterior Bone Block Through Rotator Interval]]

====Glenoid (Scott) osteotomy====
In rare circumstances, patients with increased glenoid retroversion may require correction with a posterior glenoid osteotomy. Scott osteotomy (posterior opening wedge osteotomy) is typically considered in patients with more than 25 degrees of retroversion.<ref>Scott DJJ: Treatment of recurrent posterior dislocations of the shoulder by glenoplasty. Report of three cases. J Bone Joint Surg Am. 1967;49:471-6.</ref> This is typically considered only in revision settings.<ref>Wirth MA, Seltzer DG, Rockwood CA., Jr. Recurrent posterior glenohumeral dislocation associated with increased retroversion of the glenoid. A case report. Clin Orthop Relat Res. 1994;(308):98-101</ref> Graichen et al.<ref name=":13">Graichen H, Koydl P, Zichner L. Effectiveness of glenoid osteotomy in atraumatic posterior instability of the shoulder associated with excessive retroversion and flatness of the glenoid. Int Orthop. 1999;23:95-99.</ref> reported good or excellent results in 81% of 32 patients undergoing posterior glenoid osteotomy, with the best results in patients with atraumatic instability. However, 25% of patients developed postoperative osteoarthritis, highlighting that this procedure should be only considered in select circumstances.<ref name=":13" /><ref>Lacheta L, Singh TSP, Hovsepian JM, Braun S, Imhoff AB, Pogorzelski J. Posterior open wedge glenoid osteotomy provides reliable results in young patients with increased glenoid retroversion and posterior shoulder instability. Knee Surg Sports Traumatol Arthrosc. 2019;27:299-304.</ref>

A posterior opening wedge osteotomy is performed through a posterior approach with the incision typically located in the posterior axillary fold. An osteotomy is completed at the posteromedial neck of the glenoid leaving the anterior cortex intact for stability. A wedge of bone graft (either autograft or allograft) in then inserted to provide the predetermined amount of correction. The graft is then secured with either screws or plate and screws. Press fit grafting techniques have also been described.

[[File:Image48-113.jpg|thumb|Figure 27. Scott Osteotomy]]

[[File:Image49-115.jpg|thumb|Figure 28. Postoperative X-ray of a Glenoid Osteotomy According to Scott]]

===Locked Dislocations, Static Posterior Dislocation or Glenoid Dysplasia===
Locked dislocation may require open treatment via subscapularis transfer or tenodesis, humeral head allograft reconstruction, or shoulder arthroplasty in severe cases.<ref name=":8" /><ref>Finkelstein JA, Waddell JP, O’Driscoll SW, Vincent G. Acute posterior fracture dislocations of the shoulder treated with the Neer modification of the McLaughlin procedure. J Orthop Trauma. 1995;9:190-193</ref><ref>Wooten C, Klika B, Schleck CD, Harmsen WS, Sperling JW, Cofield RH. Anatomic shoulder arthroplasty as treatment for locked posterior dislocation of the shoulder. J Bone Joint Surg Am. 2014;96:e19</ref><ref>Schliemann B, Muder D, Gessmann J, Schildhauer TA, Seybold D. Locked posterior shoulder dislocation: treatment options and clinical outcomes. Arch Orthop Trauma Surg 2011;131(8):1127–1134</ref>

Figure: mettre reverse AWA

===Derotational Osteotomy===
Derotational osteotomy of the humerus has been suggested as a procedure for younger patients with significant humeral head depression. The necessary criteria are a healthy articular cartilage, a humeral head defect involving < 40% of the articular surface, and a patient who is able to participate in an active rehabilitation programme.<ref>Keppler P, Holz U, Thielemann FW, Meinig R. Locked posterior dislocation of the shoulder: treatment using rotational osteotomy of the humerus. J Orthop Trauma 1994;8:286–292.</ref><ref name=":14">Ziran B, Nourbakhsh A. Proximal humerus derotational osteotomy for internal rotation instability after locked posterior shoulder dislocation: early experience in four patients. Patient Saf Surg 2015;9:15</ref> This technique is a viable option for younger age groups since it can facilitate rehabilitation by providing immediate stability.<ref name=":14" />

[[File:Image50-117.jpg|thumb|Figure 29. Derotational Osteotomy]]

===Shoulder Arthroplasty===

Arthroplasty is a viable option in patients with a large humeral head defect and less bone reserve after locked posterior dislocation of the shoulder. If the defect is larger than 45% to 50% of the articular surface and if the glenoid cavity is intact in a chronic dislocation aged > 6 months, hemiarthroplasty is recommended.<ref>Page AE, Meinhard BP, Schulz E, Toledano B. Bilateral posterior fracture-dislocation of the shoulders: management by bilateral shoulder hemiarthroplasties. J Orthop Trauma 1995;9(6):526–529</ref><ref>Hawkins RJ. Unrecognised dislocations of the shoulder. Inst Course Lect 1985;34:258–263</ref> When concomitant glenoid damage or significant glenoid arthritis is present, total shoulder arthroplasty should be preferred.<ref>Checchia SL, Santos PD, Miyazaki AN. Surgical treatment of acute and chronic posterior fracture-dislocation of the shoulder. J Shoulder Elbow Surg 1998;7(1):53–65</ref><ref>Pritchett JW, Clark JM. Prosthetic replacement for chronic unreduced dislocations of the shoulder. Clin Orthop Relat Res 1987;(216):89–93</ref> Reverse shoulder arthroplasty compared to anatomic has the advantage to solve the problem of instability at the same time.

[[File:Glenoid dysplasie AWA.mp4|thumb|Video 16. Reverse shoulder arthroplasty for glenoid dysplasia]]

===Arthrodesis===
Rare case of glenoid dysplasia can beneficiate from glenohumeral arthrodesis. Please refer to [[Arthrodesis|Glenohumeral Arthritis/ Arthrodesis section]].

=Postoperative Rehabilitation=
Postoperatively patients are placed into a neutral rotation splint, position that decreases stress on the posterior capsule (Figure 30). Immobilization is carried out for 6 to 8 weeks after surgery. Passive range of motion and active assist range of motion can then begin under the supervision of a physical therapist. Physiotherapy is focused on strengthening of the subscapularis that will maintain the humeral head anteriorly, posterior deltoid, and the periscapular stabilizers through resisted external rotation exercises.<ref name=":3" /> The aim is to improve the neuromuscular control of the shoulder joint and to regain dynamic muscular stability. Strengthening typically begins during the third postoperative month. Return to sports should be decided on a case-by-case basis but usually return is restricted until 6 months out from surgery.

[[File:Image51-119.jpg|thumb|Figure 30. Post-traumatic or postoperative immobilization into a neutral rotation splint.]]

=Complications=
Complications are specific to patient subsets and the technique of stabilization used. Chronic shoulder pain, allograft collapse, avascular necrosis, non-union, stiffness, omarthrosis and recurrent instability can be seen.<ref>Sperling JW, Pring M, Antuna SA, Cofield RH. Shoulder arthroplasty for locked posterior dislocation of the shoulder. J Shoulder Elbow Surg 2004;13(5):522–527</ref><ref name=":6" /> Patients with recalcitrant epileptic seizures are more prone to redislocation.

==References==
{{Reflist}}
<references />

Relevant quotes: Relevant quotes

2022-01-29T09:30:13Z

Alexandre.laedermann:

=Anatomy=
An anomaly is not an abnormality. Diversity does not signify sickness ''Georges Canguilhem''

Know the normal before examining for the abnormal ''William Osler''

Humans are variable ''William Osler''

Minima cura si maxima vis - Take care of small things if you want to obtain the greatest results ''Academia de los Linces'' (1603)

The role of the infinitely small is infinitely large ''Louis Pasteur''

Do not look to things that you don’t want to find

=Behaviour=
Don's act superior ''William Osler''

Respect your colleagues ''William Osler''

Never listen to tales or slander a colleague/Never listen to a patient's criticism of another doctor ''William Osler''

Silence is the best weapon against slander ''William Osler''

Silence is power ''William Osler''

Speak only when you have something to say ''William Osler''

=Complications/errors=
The one who does not operate, who lies, and who does not follow his patients does not have complications

Good surgeons operate well: great surgeons know how to manage their own complications

Errors cannot be avoided ''William Osler''

Do not congratulate yourself for saving a patient from a trouble inflicted by you

=Conflict of interest=
Do not sacrifice mental independence ''William Osler''

The commercial promotion of drugs is lamentable ''William Osler''

=Cost/Value-Based Healthcare=
New equipment and new procedures may improve medical care, but seldom decrease the cost ''Mark M Ravitch'' (1919-1989)

It is the surgeon who benefits more from elective surgery

=Diagnosis=
Uncertainty is the rule in medicine ''William Osler''

=Education/teaching=
Intellectual laziness is a vice ''William Osler''

Believe nobody, question everything

If I have seen further it is by standing on the shoulders of giants ''Sir Isaac Newton'' Letter to Robert Hooke (5 February 1676)

Do not expect much from others ''William Osler''

We are influenced by those we admire ''William Osler''

A well-trained doctor is a valuable asset ''William Osler''

Medical common sense is rare ''William Osler''

The practical outcome of medical training is to help others ''William Osler''

The path of medical education follows the evolution of knowledge ''William Osler''

The teacher still has a lot to learn ''William Osler''

The surgical resident is like a mushroom: kept in the dark, fed shit, and expected to grow.

=Efficiency=

Resolve not to waste time ''William Osler''

Do first what has to be done ''William Osler''

or

I never put off till tomorrow what I can possibly do - the day after ''Oscar Wilde''

=Health=
To be in good health means being able to fall sick and recover ''Canguilhem''

Soap, water, and common sense are the best disinfectants ''William Osler''

Too much drugs mean they are all insufficient ''William Osler''

=Knowledge/Learning=
Knowledge is power ''Francis Bacon''

Knowing what to do provides imperturbability ''William Osler''

A student should be a citizen of the world ''William Osler''

Never lose sight of your goal ''William Osler''

Learning is lifelong/Education is a life course ''William Osler''

Medicine is a difficult art to acquire ''William Osler''

Each case has a lesson/Learn from each patient ''William Osler''

Learn from your errors/Learn from your mistakes ''William Osler''

To know that you do not know is the best. To pretend to know when you do not know is a disease ''Lao-tzu'' Chinese philosopher (604 BC - 531 BC)

Pretending to know is a conceit ''William Osler''

It is not because things are difficult that we do not dare, it is because we do not dare that they are difficult ''Lucius Annaeus Seneca''

=Medical errors=
A man must be big enough to admit his mistakes, smart enough to profit from them, and strong enough to correct them ''John C Maxwell''

Experience is merely the name men gave to their mistakes ''Oscar Wilde''

=Medication/Drugs/Prescription=
Sola dosis facit venenum -The dose makes the poison ''Paracelsus'' (1493-1541)

Patients can get well without antibiotics ''Mark M Ravitch'' (1910-1989)

Most men die of their remedies, not of their disease ''Molière'' (1622-1673)

Extreme remedies are very appropriate for extreme diseases ''Hyppocrates'' (460-377 BC)

=Retirement=
The old should remember that they represent the past, and that the young represent the future ''William J Mayo'' (1861-1939)

=Results/Persistence=
Great works are performed not by strength but by perseverance ''Samuel Johnson''

Perfection is obtained by little effort ''Arab saying''

Perfection is not attainable, but if we chase perfection we can catch excellence ''Vince Lombardi''

Perfection is to be cultivated ''William Osler''

The enemy of good is better

Does absence of proof of efficacy provide proof of the absence of efficacy? ''John Marshall''

The first report of any new operation is rarely unfavorable ''Mark M Ravitch'' (1910-1989)

=Science=
Believe those who are seeking the truth; doubt those who find it ''André Gide''

In science, the credit goes to the man who convinces the world, not to the man the idea first occurs ''William Osler''

Every scientific truth is met initially by skepticism ''William Osler''

General acceptance of truth takes time ''William Osler''

Scientific education facilitates clinical work ''William Osler''

Simplicity is the ultimate sophistication ''Leonardo Da Vinci''

=Second opinion=
The more the doctors, the sadder the prognosis ''William Osler''

If two people agree, one of them is not a doctor ''Unknown''

=Statistics=
There are three kinds of lies: lies, damned lies, and statistics ''Mark Twain''

I only believe in statistics that I doctored myself ''Winston S. Churchill'' Former British Prime Minister

=Indication/Plan/Planning=
Doing something is sometimes worse than doing nothing ''Gail Waldby''

It is difficult to make the asymptomatic patient feel better ''Stanley O Hoerr'' (1909-1990)

The greatest triumph of surgery today… lies in finding ways for avoiding surgery ''Robert Tuttle Morris'' (1857-1945)

The most difficult thing is to do nothing ''Norman M Rich''

It takes five years to learn when to operate and twenty years to learn when not to ''Unknown''

You can always amend a big plan, but you can never expand a little one ''Harry S. Truman'' Former U.S. President

Plans are of little importance, but planning is essential ''Winston Churchill'' Former British Prime Minister

The feasibility of an operation is not the best indication for its performance ''Henry Cohen'' (1900-1977)

Never be the first but never be the last to accept change ''Angus B McLachlin'' (1908-1987)

=Teamwork=
Alone we can do so little, together we can do so much ''Helen Keller''

=Treatment=
“First the word, then the plant, lastly the knife” ''Aesculapius'' of Thassaly (1200 BC)

Care for the patient, not the disease/Put the patient before the disease ''William Osler''

The physician is only nature's assistant ''Galen''

Do not mess around with mother nature ''Jonathan Meakins''

=Surgery=
The simpler the procedure, the better the results ''Charles FM Saint'' (1886, 1973)

If it looks good, it might work. If it does not look good, it will never work ''William Silen''

If everything is going right you’ve done something wrong

A poor workman blames his tool

Blood brain barrier (BBB): the screen between the surgeon and anaesthetics

All bleeding eventually ceases ''Guy de Chauliac'' (1300-1368)

There are 4 degrees of intra-operative hemorrhage: 1. “Why did I get involved in this operation?” 2. “Why did I become a surgeon?” 3. “Why did I study to become a doctor?” 4. “Why was I born?” ''Alexander A Artemiev''

When in doubt drain Robert ''Lawson Tait'' (1845-1899)

The incision must be as long as necessary and as short as possible ''Theodore Kocher'' (1841-1917)

Big surgeon - big incision – small activity

Relevant quotes: Relevant quotes

2021-12-29T17:49:52Z

Alexandre.laedermann: /* Treatment */ The physician is only nature's assistant ''Galen''

=Anatomy=
An anomaly is not an abnormality. Diversity does not signify sickness ''Georges Canguilhem''

Know the normal before examining for the abnormal ''William Osler''

Humans are variable ''William Osler''

Minima cura si maxima vis - ''Academia de los Linces'' (1603)

The role of the infinitely small is infinitely large ''Louis Pasteur''

=Behaviour=
Don's act superior ''William Osler''

Respect your colleagues ''William Osler''

Never listen to tales or slander a colleague/Never listen to a patient's criticism of another doctor ''William Osler''

Silence is the best weapon against slander ''William Osler''

Silence is power ''William Osler''

Speak only when you have something to say ''William Osler''

=Conflict of interest=
Do not sacrifice mental independence ''William Osler''

The commercial promotion of drugs is lamentable ''William Osler''

=Diagnosis=
Uncertainty is the rule in medicine ''William Osler''

Errors cannot be avoided ''William Osler''

=Education/teaching=
Intellectual laziness is a vice ''William Osler''

If I have seen further it is by standing on the shoulders of giants ''Sir Isaac Newton'' Letter to Robert Hooke (5 February 1676)

Do not expect much from others ''William Osler''

We are influenced by those we admire ''William Osler''

A well-trained doctor is a valuable asset ''William Osler''

Medical common sense is rare ''William Osler''

The practical outcome of medical training is to help others ''William Osler''

The path of medical education follows the evolution of knowledge ''William Osler''

The teacher still has a lot to learn ''William Osler''

=Efficiency=

Resolve not to waste time ''William Osler''

Do first what has to be done ''William Osler''

or

I never put off till tomorrow what I can possibly do - the day after ''Oscar Wilde''

=Health=
To be in good health means being able to fall sick and recover ''Canguilhem''

Soap, water, and common sense are the best disinfectants ''William Osler''

Too man drugs mean they are all insufficient ''William Osler''

=Knowledge/Learning=
Knowledge is power ''Francis Bacon''

Knowing what to do provides imperturbability ''William Osler''

A student should be a citizen of the world ''William Osler''

Never lose sight of your goal ''William Osler''

Learning is lifelong/Education is a life course ''William Osler''

Medicine is a difficult art to acquire ''William Osler''

Each case has a lesson/Learn from each patient ''William Osler''

Learn from your errors/Learn from your mistakes ''William Osler''

To know that you do not know is the best. To pretend to know when you do not know is a disease ''Lao-tzu'' Chinese philosopher (604 BC - 531 BC)

Pretending to know is a conceit ''William Osler''

It is not because things are difficult that we do not dare, it is because we do not dare that they are difficult ''Lucius Annaeus Seneca''

=Medical errors=
A man must be big enough to admit his mistakes, smart enough to profit from them, and strong enough to correct them ''John C Maxwell''

Experience is merely the name men gave to their mistakes ''Oscar Wilde''

=Medication/Drugs/Prescription=
Sola dosis facit venenum -The dose makes the poison ''Paracelsus'' (1493-1541)

=Results/Persistence=
Great works are performed not by strength but by perseverance ''Samuel Johnson''

Perfection is obtained by little effort ''Arab saying''

Perfection is not attainable, but if we chase perfection we can catch excellence ''Vince Lombardi''

Perfection is to be cultivated ''William Osler''

=Science=
Believe those who are seeking the truth; doubt those who find it ''André Gide''

In science, the credit goes to the man who convinces the world, not to the man the idea first occurs ''William Osler''

Every scientific truth is met initially by skepticism ''William Osler''

General acceptance of truth takes time ''William Osler''

Scientific education facilitates clinical work ''William Osler''

Simplicity is the ultimate sophistication ''Leonardo Da Vinci''

=Second opinion=
The more the doctors, the sadder the prognosis ''William Osler''

If two people agree, one of them is not a doctor ''Unknown''

=Statistics=
There are three kinds of lies: lies, damned lies, and statistics ''Mark Twain''

I only believe in statistics that I doctored myself ''Winston S. Churchill'' Former British Prime Minister

=Surgical indication/Plan/Planning=
Doing something is sometimes worse than doing nothing ''Gail Waldby''

The greatest triumph of surgery today… lies in finding ways for avoiding surgery ''Robert Tuttle Morris'' (1857-1945)

The most difficult thing is to do nothing ''Norman M Rich''

It takes five years to learn when to operate and twenty years to learn when not to ''Unknown''

You can always amend a big plan, but you can never expand a little one ''Harry S. Truman'' Former U.S. President

Plans are of little importance, but planning is essential ''Winston Churchill'' Former British Prime Minister

=Teamwork=
Alone we can do so little, together we can do so much ''Helen Keller''

=Treatment=
“First the word, then the plant, lastly the knife” ''Aesculapius'' of Thassaly (1200 BC)

Care for the patient, not the disease/Put the patient before the disease ''William Osler''

The physician is only nature's assistant ''Galen''

Relevant quotes: Relevant quotes

2021-12-29T13:53:56Z

Alexandre.laedermann:

=Anatomy=
An anomaly is not an abnormality. Diversity does not signify sickness ''Georges Canguilhem''

Know the normal before examining for the abnormal ''William Osler''

Humans are variable ''William Osler''

Minima cura si maxima vis - ''Academia de los Linces'' (1603)

The role of the infinitely small is infinitely large ''Louis Pasteur''

=Behaviour=
Don's act superior ''William Osler''

Respect your colleagues ''William Osler''

Never listen to tales or slander a colleague/Never listen to a patient's criticism of another doctor ''William Osler''

Silence is the best weapon against slander ''William Osler''

Silence is power ''William Osler''

Speak only when you have something to say ''William Osler''

=Conflict of interest=
Do not sacrifice mental independence ''William Osler''

The commercial promotion of drugs is lamentable ''William Osler''

=Diagnosis=
Uncertainty is the rule in medicine ''William Osler''

Errors cannot be avoided ''William Osler''

=Education/teaching=
Intellectual laziness is a vice ''William Osler''

If I have seen further it is by standing on the shoulders of giants ''Sir Isaac Newton'' Letter to Robert Hooke (5 February 1676)

Do not expect much from others ''William Osler''

We are influenced by those we admire ''William Osler''

A well-trained doctor is a valuable asset ''William Osler''

Medical common sense is rare ''William Osler''

The practical outcome of medical training is to help others ''William Osler''

The path of medical education follows the evolution of knowledge ''William Osler''

The teacher still has a lot to learn ''William Osler''

=Efficiency=

Resolve not to waste time ''William Osler''

Do first what has to be done ''William Osler''

or

I never put off till tomorrow what I can possibly do - the day after ''Oscar Wilde''

=Health=
To be in good health means being able to fall sick and recover ''Canguilhem''

Soap, water, and common sense are the best disinfectants ''William Osler''

Too man drugs mean they are all insufficient ''William Osler''

=Knowledge/Learning=
Knowledge is power ''Francis Bacon''

Knowing what to do provides imperturbability ''William Osler''

A student should be a citizen of the world ''William Osler''

Never lose sight of your goal ''William Osler''

Learning is lifelong/Education is a life course ''William Osler''

Medicine is a difficult art to acquire ''William Osler''

Each case has a lesson/Learn from each patient ''William Osler''

Learn from your errors/Learn from your mistakes ''William Osler''

To know that you do not know is the best. To pretend to know when you do not know is a disease ''Lao-tzu'' Chinese philosopher (604 BC - 531 BC)

Pretending to know is a conceit ''William Osler''

It is not because things are difficult that we do not dare, it is because we do not dare that they are difficult ''Lucius Annaeus Seneca''

=Medical errors=
A man must be big enough to admit his mistakes, smart enough to profit from them, and strong enough to correct them ''John C Maxwell''

Experience is merely the name men gave to their mistakes ''Oscar Wilde''

=Medication/Drugs/Prescription=
Sola dosis facit venenum -The dose makes the poison ''Paracelsus'' (1493-1541)

=Results/Persistence=
Great works are performed not by strength but by perseverance ''Samuel Johnson''

Perfection is obtained by little effort ''Arab saying''

Perfection is not attainable, but if we chase perfection we can catch excellence ''Vince Lombardi''

Perfection is to be cultivated ''William Osler''

=Science=
Believe those who are seeking the truth; doubt those who find it ''André Gide''

In science, the credit goes to the man who convinces the world, not to the man the idea first occurs ''William Osler''

Every scientific truth is met initially by skepticism ''William Osler''

General acceptance of truth takes time ''William Osler''

Scientific education facilitates clinical work ''William Osler''

Simplicity is the ultimate sophistication ''Leonardo Da Vinci''

=Second opinion=
The more the doctors, the sadder the prognosis ''William Osler''

If two people agree, one of them is not a doctor ''Unknown''

=Statistics=
There are three kinds of lies: lies, damned lies, and statistics ''Mark Twain''

I only believe in statistics that I doctored myself ''Winston S. Churchill'' Former British Prime Minister

=Surgical indication/Plan/Planning=
Doing something is sometimes worse than doing nothing ''Gail Waldby''

The greatest triumph of surgery today… lies in finding ways for avoiding surgery ''Robert Tuttle Morris'' (1857-1945)

The most difficult thing is to do nothing ''Norman M Rich''

It takes five years to learn when to operate and twenty years to learn when not to ''Unknown''

You can always amend a big plan, but you can never expand a little one ''Harry S. Truman'' Former U.S. President

Plans are of little importance, but planning is essential ''Winston Churchill'' Former British Prime Minister

=Teamwork=
Alone we can do so little, together we can do so much ''Helen Keller''

=Treatment=
“First the word, then the plant, lastly the knife” ''Aesculapius'' of Thassaly (1200 BC)

Care for the patient, not the disease/Put the patient before the disease ''William Osler''

Relevant quotes: Relevant quotes

2021-12-29T13:53:13Z

Alexandre.laedermann: /* Surgical indication/plan/planning */

=Anatomy=
An anomaly is not an abnormality. Diversity does not signify sickness ''Georges Canguilhem''

Know the normal before examining for the abnormal ''William Osler''

Humans are variable ''William Osler''

Minima cura si maxima vis - ''Academia de los Linces'' (1603)

The role of the infinitely small is infinitely large ''Louis Pasteur''

=Behaviour=
Don's act superior ''William Osler''

Respect your colleagues ''William Osler''

Never listen to tales or slander a colleague/Never listen to a patient's criticism of another doctor ''William Osler''

Silence is the best weapon against slander ''William Osler''

Silence is power ''William Osler''

Speak only when you have something to say ''William Osler''

=Conflict of interest=
Do not sacrifice mental independence ''William Osler''

The commercial promotion of drugs is lamentable ''William Osler''

=Diagnosis=
Uncertainty is the rule in medicine ''William Osler''

Errors cannot be avoided ''William Osler''

=Education/teaching=
Intellectual laziness is a vice ''William Osler''

If I have seen further it is by standing on the shoulders of giants ''Sir Isaac Newton'' Letter to Robert Hooke (5 February 1676)

Do not expect much from others ''William Osler''

We are influenced by those we admire ''William Osler''

A well-trained doctor is a valuable asset ''William Osler''

Medical common sense is rare ''William Osler''

The practical outcome of medical training is to help others ''William Osler''

The path of medical education follows the evolution of knowledge ''William Osler''

The teacher still has a lot to learn ''William Osler''

=Efficiency=

Resolve not to waste time ''William Osler''

Do first what has to be done ''William Osler''

or

I never put off till tomorrow what I can possibly do - the day after ''Oscar Wilde''

=Health=
To be in good health means being able to fall sick and recover ''Canguilhem''

Soap, water, and common sense are the best disinfectants ''William Osler''

Too man drugs mean they are all insufficient ''William Osler''

=Knowledge/Learning=
Knowledge is power ''Francis Bacon''

Knowing what to do provides imperturbability ''William Osler''

A student should be a citizen of the world ''William Osler''

Never lose sight of your goal ''William Osler''

Learning is lifelong/Education is a life course ''William Osler''

Medicine is a difficult art to acquire ''William Osler''

Each case has a lesson/Learn from each patient ''William Osler''

Learn from your errors/Learn from your mistakes ''William Osler''

To know that you do not know is the best. To pretend to know when you do not know is a disease ''Lao-tzu'' Chinese philosopher (604 BC - 531 BC)

Pretending to know is a conceit ''William Osler''

It is not because things are difficult that we do not dare, it is because we do not dare that they are difficult ''Lucius Annaeus Seneca''

=Medical errors=
A man must be big enough to admit his mistakes, smart enough to profit from them, and strong enough to correct them ''John C Maxwell''

Experience is merely the name men gave to their mistakes ''Oscar Wilde''

=Medication/Drugs/Prescription=
Sola dosis facit venenum -The dose makes the poison ''Paracelsus'' (1493-1541)

=Results/Persistence=
Great works are performed not by strength but by perseverance ''Samuel Johnson''

Perfection is obtained by little effort ''Arab saying''

Perfection is not attainable, but if we chase perfection we can catch excellence ''Vince Lombardi''

Perfection is to be cultivated ''William Osler''

=Science=
Believe those who are seeking the truth; doubt those who find it ''André Gide''

In science, the credit goes to the man who convinces the world, not to the man the idea first occurs ''William Osler''

Every scientific truth is met initially by skepticism ''William Osler''

General acceptance of truth takes time ''William Osler''

Scientific education facilitates clinical work ''William Osler''

Simplicity is the ultimate sophistication ''Leonardo Da Vinci''

=Second opinion=
The more the doctors, the sadder the prognosis ''William Osler''

If two people agree, one of them is not a doctor ''Unknown''

=Statistics=
There are three kinds of lies: lies, damned lies, and statistics ''Mark Twain''

I only believe in statistics that I doctored myself ''Winston S. Churchill'' Former British Prime Minister

=Surgical indication/Plan/Planning=
Doing something is sometimes worse than doing nothing ''Gail Waldby''

The greatest triumph of surgery today… lies in finding ways for avoiding surgery ''Robert Tuttle Morris'' (1857-1945)

The most difficult thing is to do nothing ''Norman M Rich''

It takes five years to learn when to operate and twenty years to learn when not to ''Unknown''

You can always amend a big plan, but you can never expand a little one ''Harry S. Truman'' Former U.S. President

Plans are of little importance, but planning is essential ''Winston Churchill'' Former British Prime Minister

=Teamwork=
Alone we can do so little, together we can do so much ''Helen Keller''

=Treatment=
“First the word, then the plant, lastly the knife” ''Aesculapius'' of Thassaly (1200 BC)

Care for the patient, not the disease/Put the patient before the disease ''William Osler''

Relevant quotes: Relevant quotes

2021-12-29T13:52:36Z

Alexandre.laedermann:

=Anatomy=
An anomaly is not an abnormality. Diversity does not signify sickness ''Georges Canguilhem''

Know the normal before examining for the abnormal ''William Osler''

Humans are variable ''William Osler''

Minima cura si maxima vis - ''Academia de los Linces'' (1603)

The role of the infinitely small is infinitely large ''Louis Pasteur''

=Behaviour=
Don's act superior ''William Osler''

Respect your colleagues ''William Osler''

Never listen to tales or slander a colleague/Never listen to a patient's criticism of another doctor ''William Osler''

Silence is the best weapon against slander ''William Osler''

Silence is power ''William Osler''

Speak only when you have something to say ''William Osler''

=Conflict of interest=
Do not sacrifice mental independence ''William Osler''

The commercial promotion of drugs is lamentable ''William Osler''

=Diagnosis=
Uncertainty is the rule in medicine ''William Osler''

Errors cannot be avoided ''William Osler''

=Education/teaching=
Intellectual laziness is a vice ''William Osler''

If I have seen further it is by standing on the shoulders of giants ''Sir Isaac Newton'' Letter to Robert Hooke (5 February 1676)

Do not expect much from others ''William Osler''

We are influenced by those we admire ''William Osler''

A well-trained doctor is a valuable asset ''William Osler''

Medical common sense is rare ''William Osler''

The practical outcome of medical training is to help others ''William Osler''

The path of medical education follows the evolution of knowledge ''William Osler''

The teacher still has a lot to learn ''William Osler''

=Efficiency=

Resolve not to waste time ''William Osler''

Do first what has to be done ''William Osler''

or

I never put off till tomorrow what I can possibly do - the day after ''Oscar Wilde''

=Health=
To be in good health means being able to fall sick and recover ''Canguilhem''

Soap, water, and common sense are the best disinfectants ''William Osler''

Too man drugs mean they are all insufficient ''William Osler''

=Knowledge/Learning=
Knowledge is power ''Francis Bacon''

Knowing what to do provides imperturbability ''William Osler''

A student should be a citizen of the world ''William Osler''

Never lose sight of your goal ''William Osler''

Learning is lifelong/Education is a life course ''William Osler''

Medicine is a difficult art to acquire ''William Osler''

Each case has a lesson/Learn from each patient ''William Osler''

Learn from your errors/Learn from your mistakes ''William Osler''

To know that you do not know is the best. To pretend to know when you do not know is a disease ''Lao-tzu'' Chinese philosopher (604 BC - 531 BC)

Pretending to know is a conceit ''William Osler''

It is not because things are difficult that we do not dare, it is because we do not dare that they are difficult ''Lucius Annaeus Seneca''

=Medical errors=
A man must be big enough to admit his mistakes, smart enough to profit from them, and strong enough to correct them ''John C Maxwell''

Experience is merely the name men gave to their mistakes ''Oscar Wilde''

=Medication/Drugs/Prescription=
Sola dosis facit venenum -The dose makes the poison ''Paracelsus'' (1493-1541)

=Results/Persistence=
Great works are performed not by strength but by perseverance ''Samuel Johnson''

Perfection is obtained by little effort ''Arab saying''

Perfection is not attainable, but if we chase perfection we can catch excellence ''Vince Lombardi''

Perfection is to be cultivated ''William Osler''

=Science=
Believe those who are seeking the truth; doubt those who find it ''André Gide''

In science, the credit goes to the man who convinces the world, not to the man the idea first occurs ''William Osler''

Every scientific truth is met initially by skepticism ''William Osler''

General acceptance of truth takes time ''William Osler''

Scientific education facilitates clinical work ''William Osler''

Simplicity is the ultimate sophistication ''Leonardo Da Vinci''

=Second opinion=
The more the doctors, the sadder the prognosis ''William Osler''

If two people agree, one of them is not a doctor ''Unknown''

=Statistics=
There are three kinds of lies: lies, damned lies, and statistics ''Mark Twain''

I only believe in statistics that I doctored myself ''Winston S. Churchill'' Former British Prime Minister

=Surgical indication/plan/planning=
Doing something is sometimes worse than doing nothing ''Gail Waldby''

The greatest triumph of surgery today… lies in finding ways for avoiding surgery ''Robert Tuttle Morris'' (1857-1945)

The most difficult thing is to do nothing ''Norman M Rich''

It takes five years to learn when to operate and twenty years to learn when not to ''Unknown''

You can always amend a big plan, but you can never expand a little one ''Harry S. Truman'' Former U.S. President

Plans are of little importance, but planning is essential ''Winston Churchill'' Former British Prime Minister

=Teamwork=
Alone we can do so little, together we can do so much ''Helen Keller''

=Treatment=
“First the word, then the plant, lastly the knife” ''Aesculapius'' of Thassaly (1200 BC)

Care for the patient, not the disease/Put the patient before the disease ''William Osler''

Main Page

2021-12-29T11:52:40Z

Alexandre.laedermann:

==Welcome to wikiBeemed==
Please complete the Open encyclopedia

==Find articles per category==
{| class="wikitable"
!<big>Shoulder</big>
!<big>Spine</big>
!<big>Hip</big>
!<big>Knee</big>
|-
|[[File:SHOULDER.png|thumb|link=:Category:Shoulder|alt=|center|150x150px]]
|[[File:SPINE.png|thumb|link=:Category:Spine|alt=|center|150x150px]]
|[[File:HIP.png|thumb|link=:Category:Hip|alt=|center|150x150px]]
|[[File:KNEE.png|thumb|alt=|center|150x150px]]
|-
!<big>Foot & Ankle</big>
!<big>Hand</big>
!<big>Rheumatology</big>
!<big>Sports Medicine</big>
|-
|[[File:Foot & Ankle.png|thumb|link=:Category:Foot|alt=|center|150x150px]]
|[[File:HAND.png|thumb|alt=|center|150x150px]]
|[[File:RHUMATOLOGY.png|thumb|alt=|center|150x150px]]
|[[File:SPORTSMED 2.png|thumb|alt=|center|150x150px]]
|-
!<big>Elbow</big>
|
|
|
|-
|[[File:ELBOW.png|thumb|link=:Category:Elbow|alt=|center|150x150px]]
|
|
|
|}
 

==Find eCourse/eLibrary to obtain CME points==
===eLibrary===
*[[Shoulder:Proximal Humeral Fracture|Proximal Humeral Fracture]]

==Aphorisms & Quotations==
*[[Relevant quotes: Relevant quotes|Relevant quotes]]

==Getting started==

*[https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:FAQ MediaWiki FAQ]
*[https://lists.wikimedia.org/mailman/listinfo/mediawiki-announce MediaWiki release mailing list]
*[https://www.mediawiki.org/wiki/Special:MyLanguage/Localisation#Translation_resources Localise MediaWiki for your language]
*[https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Combating_spam Learn how to combat spam on your wiki]

Relevant quotes: Relevant quotes

2021-12-29T11:47:50Z

Alexandre.laedermann: Updated quotes

=André Gide=
Believe those who are seeking the truth; doubt those who find it.

=William Osler=
Perfection is to be cultivated

Intellectual laziness is a vice

Pretending to know is a conceit

Knowing what to do provides imperturbability

Do not expect much from others

We are influenced by those we admire

Don's act superior

Respect your colleagues

Never listen to tales or slander a colleague/Never listen to a patient's criticism of another doctor

Silence is the best weapon against slander

Silence is power

Speak only when you have something to say

Resolve not to waste time

Do first what has to be done

Care for the patient, not the disease/Put the patient before the disease

Uncertainty is the rule in medicine

Errors cannot be avoid

A well-trained doctor is a valuable asset

Conflict of interest: Do not sacrifice mental independence

The commercial promotion of drugs is lamentable

Know the normal before examining for the abnormal

Medical common sense is rare

Humans are variable

Second opinion: The more the doctors, the sadder the prognosis

Soap, water, and common sense are the best disinfectants

Too man drugs mean they are all insufficient

A student should be a citizen of the world

Never lose sight of your goal

Education is a life course

Learning is lifelong

Medicine is a difficult art to acquire

The practical outcome of medical training is to help others

The path of medical education follows the evolution of knowledge

The teacher still has a lot to learn

Scientific education facilitates clinical work

Each case has a lesson

Learn from each patient

Learn from your errors/Learn from your mistakes

Every scientific truth is met initially by skepticism

General acceptance of truth takes time

=Oscar Wilde=
I never put off till tomorrow what I can possibly do - the day after

Relevant quotes: Relevant quotes

2021-12-29T11:33:02Z

Alexandre.laedermann:

=André Gide=
Believe those who are seeking the truth; doubt those who find it.

=William Osler=
Perfection is to be cultivated

Intellectual laziness is a vice

Pretending to know is a conceit

Knowing what to do provides imperturbability

Do not expect much from others

We are influenced by those we admire

Don's act superior

Respect your colleagues

Never listen to tales or slander a colleague/Never listen to a patient's criticism of another doctor

Silence is the best weapon against slander

Silence is power

Speak only when you have something to say

Resolve not to waste time

Do first what has to be done

Care for the patient, not the disease/Put the patient before the disease

Uncertainty is the rule in medicine

Errors cannot be avoid

A well-trained doctor is a valuable asset

Conflict of interest: Do not sacrifice mental independence

The commercial promotion of drugs is lamentable

Know the normal before examining for the abnormal

Medical common sense is rare

Humans are variable

Second opinion: The more the doctors, the sadder the prognosis

Soap, water, and common sense are the best disinfectants

Too man drugs mean they are all insufficient

A student should be a citizen of the world

Never lose sight of your goal

Education is a life course

Learning is lifelong

Medicine is a difficult art to acquire

The practical outcome of medical training is to help others

The path of medical education follows the evolution of knowledge

The teacher still has a lot to learn

Scientific education facilitates clinical work

Each case has a lesson

Learn from each patient

Learn from your errors/Learn from your mistakes

=Oscar Wilde=
I never put off till tomorrow what I can possibly do - the day after

Relevant quotes: Relevant quotes

2021-12-28T09:23:39Z

Alexandre.laedermann:

=André Gide=
Believe those who are seeking the truth; doubt those who find it.

Relevant quotes: Relevant quotes

2021-12-28T09:23:03Z

Alexandre.laedermann: Created page with "André Gide Believe those who are seeking the truth; doubt those who find it."

André Gide
Believe those who are seeking the truth; doubt those who find it.

Main Page

2021-12-28T09:21:52Z

Alexandre.laedermann: /* Quotes */

==Welcome to wikiBeemed==
Please complete the Open encyclopedia

==Find articles per category==
{| class="wikitable"
!<big>Shoulder</big>
!<big>Spine</big>
!<big>Hip</big>
!<big>Knee</big>
|-
|[[File:SHOULDER.png|thumb|link=:Category:Shoulder|alt=|center|150x150px]]
|[[File:SPINE.png|thumb|link=:Category:Spine|alt=|center|150x150px]]
|[[File:HIP.png|thumb|link=:Category:Hip|alt=|center|150x150px]]
|[[File:KNEE.png|thumb|alt=|center|150x150px]]
|-
!<big>Foot & Ankle</big>
!<big>Hand</big>
!<big>Rheumatology</big>
!<big>Sports Medicine</big>
|-
|[[File:Foot & Ankle.png|thumb|link=:Category:Foot|alt=|center|150x150px]]
|[[File:HAND.png|thumb|alt=|center|150x150px]]
|[[File:RHUMATOLOGY.png|thumb|alt=|center|150x150px]]
|[[File:SPORTSMED 2.png|thumb|alt=|center|150x150px]]
|-
!<big>Elbow</big>
|
|
|
|-
|[[File:ELBOW.png|thumb|link=:Category:Elbow|alt=|center|150x150px]]
|
|
|
|}
 

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Main Page

2021-12-28T09:20:38Z

Alexandre.laedermann: /* Quotes */

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{| class="wikitable"
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|[[File:SHOULDER.png|thumb|link=:Category:Shoulder|alt=|center|150x150px]]
|[[File:SPINE.png|thumb|link=:Category:Spine|alt=|center|150x150px]]
|[[File:HIP.png|thumb|link=:Category:Hip|alt=|center|150x150px]]
|[[File:KNEE.png|thumb|alt=|center|150x150px]]
|-
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!<big>Sports Medicine</big>
|-
|[[File:Foot & Ankle.png|thumb|link=:Category:Foot|alt=|center|150x150px]]
|[[File:HAND.png|thumb|alt=|center|150x150px]]
|[[File:RHUMATOLOGY.png|thumb|alt=|center|150x150px]]
|[[File:SPORTSMED 2.png|thumb|alt=|center|150x150px]]
|-
!<big>Elbow</big>
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2021-12-28T09:17:53Z

Alexandre.laedermann: add chapter

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|[[File:SPINE.png|thumb|link=:Category:Spine|alt=|center|150x150px]]
|[[File:HIP.png|thumb|link=:Category:Hip|alt=|center|150x150px]]
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|-
!<big>Foot & Ankle</big>
!<big>Hand</big>
!<big>Rheumatology</big>
!<big>Sports Medicine</big>
|-
|[[File:Foot & Ankle.png|thumb|link=:Category:Foot|alt=|center|150x150px]]
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Anteroinferior Glenohumeral Instability

2021-09-26T06:05:46Z

Alexandre.laedermann: /* Dynamic Anterior Stabilization (DAS) */

==Bullet points==

*One of most common shoulder injuries, 1.7% annual rate in general population.

*High recurrence rate that correlates with age at dislocation, up to 80-90% in teenagers (90% chance for recurrence in age <20).

*The stability of the glenohumeral joint depends on soft tissue stabilizers, bone morphology and dynamic stabilizers such as the rotator cuff and long head of the biceps tendon.

*Osseous lesions, either humeral or glenoid, are identified in 95.0%. The risk of failure of arthroscopic treatment is higher if not addressed. A glenoid bony defect of >20-25% is considered "critical" and is biomechanically highly unstable and require bony procedure to restore bone loss (Latarjet, Bristow, other sources of autograft or allograft).

*A Malgaigne (Hill Sachs) defect is a chondral impaction injury in the posterosuperior humeral head secondary to contact with the glenoid rim. It is present in 80% of traumatic dislocations and 25% of traumatic subluxations.

*Axillary nerve injury is most often a transient neurapraxia of the axillary nerve and is present in up to 5% of patients.

*Incidence of associated rotator cuff tears increase with age of 40 (30% at 40, 80% at 60).

*Static glenohumeral stabilizers are the bone, the ligaments, the capsule, the labrum, and the negative pressure. The dynamic ones are the rotator cuff and long head of biceps tendon.

*The labrum contributes to 50% of additional glenoid depth.

*Anterior static shoulder stability with arm in 90 degrees of abduction and external rotation is provided by the anterior band of inferior glenohumeral ligament (main restraint).

*The middle glenohumeral ligament provides static restraint with arm in 45 degrees of abduction and external rotation.

*The superior glenohumeral ligament provides static restraint with arm at the side.

*The physical examination demonstrates instability if the apprehension test is positive, multidirectional hyperlaxity when the external rotation at side is equal or above 85 degrees, and a pathological laxity of the inferior glenohumeral ligament if the hyperabduction test is positive.

*Three views plain radiographs, including true anteroposterior of the glenohumeral joint, scapular Y (scapular lateral), and Velpeau axillary views are the mainstay of imaging in the setting of acute traumatic anterior instability. Plain radiographs including anteroposterior in neutral, internal and external rotations, scapular Y and Bernageau views are obtained for recurrent instability. Magnetic resonance imaging (MRI) arthrogram is useful to assess for labral or rotator cuff tears, computed tomography (CT) for bone loss assessment.

*Conservative treatment after the first traumatic anterior dislocation is recommended for patients who are not actively engaged in sports, above the age of 30 years old, with a low functional demand, with an associated humeral fracture, or for the athlete with an in-season shoulder dislocation.

*Rehabilitation consist of strengthening of dynamic stabilizers (rotator cuff and periscapular musculature), exercises for proprioception and other specific treatments if apprehension persists.

*Surgical treatment included Bankart repair, capsular plication +/- soft tissue procedures (such as remplissage or dynamic anterior stabilization (DAS) if < 20% bone loss.

*If bone loss ≥ 20%, bone reconstruction with Latarjet, Bristow or free bone block transfers such as Eden-Hybinette is recommended.

==Key words==
Anterior glenohumeral instability; anatomy; humerus; scapula; ligaments; shoulder dislocation; subluxation; reduction; bone loss; Malgaigne; Hill-Sachs; Bankart; capsular shift; remplissage; dynamic anterior stabilization (DAS); Latarjet; Bristow; free bone block transfer; Eden-Hybinette; complication; recurrences; therapeutic implications.

==History==
The first recorded depictions of shoulder reduction are ancient.<ref>Iqbal S, Jacobs U, Akhtar A, Macfarlane RJ, Waseem M. A history of shoulder surgery. Open Orthop J 2013;7:305-9.</ref>

Egyptian hieroglyphs dated 3000 years earlier, pictorially depict a leverage method of shoulder manipulation. They have been followed by the Greeks and Romans. Around 400 BC, Hippocrates, the father of Western medicine, introduced the traction method to reduce the shoulder.
<ref>Hussein MK. Kocher's method is 3,000 years old. J Bone Joint Surg Br 1968;50:669-71.</ref><ref>Celsus A. De Medicina.</ref><ref>Hippocrates. Corpus Hippocraticum—De articulis.</ref>

In 1855, Malgaigne was the first one to describe the humeral bone loss also called Hill-Sachs lesion.<ref>Malgaigne J. Traité des fractures et des luxations. Paris: J.-B. Baillière; 1855.</ref>

In the 1890s, the understanding of the unstable shoulder was elucidated by the work of two French researchers, Broca and Hartman who introduced the concept of capsulolabral damage following dislocations as possible cause of recurrent instability. Notably, most of the findings considered current hallmarks of shoulder instability, including Bankart lesion, bony Bankart, Kim lesion, as well as anterior and posterior labral periosteal sleeve avulsions and glenoid avulsions of glenohumeral ligaments, were described in their papers decades before the eponymous figures to whom they are now commonly assigned depicted them.<ref>Broca A, Hartmann H. Contribution à l'étude des luxations de l'épaule (luxations anciennes et luxations récidivantes). Bull Soc Anat 1890;4:416-23.</ref>

In 1906, Perthes in Germany and a few years later, Bankart in the UK ascertained that the detachment of the labrum caused instability of the shoulder and emphasized reattachment of the labrum to stabilize the joint.<ref>Perthes G. Ueber Operationen beihabitueller Schulterluxation. Dtsch Z Chir 1906;85:199–227.</ref><ref>Bankart AS. Recurrent or Habitual Dislocation of the Shoulder-Joint. British medical journal 1923;2:1132-3.</ref>

Current free bone grafting techniques are based on the initial descriptions by Eden in 1918 and Hybinette in 1932 using autologous iliac crest.<ref>Eden R. Zur Operation der habituellen Schulterluxation unter Mitteilung eines neuen Verfahrens bei Abriss am inneren Pfannenrande. Dsch Z Chir 1918;144:269.</ref><ref>Hybinette S. De la transplantation d’un fragment osseux pour remédier aux luxations récidivantes de l’épaule. Acta Chir Scand 1932:411-45.</ref>

Due to donor site morbidity with autologous iliac crest bone grafting techniques, different auto- and allogeneic bone materials have been evaluated as alternatives. Open and arthroscopic approaches using distal clavicle, femoral head, distal tibial allografts or coracoid process are currently used. The first coracoid process transplant was probably realized by the German surgeon Noeske in 1921.<ref>Anonymous. Zentralbl Chir 1924;43:2402.</ref>

Nowadays, two most popular bony procedures included the Latarjet and its variant, the Bristow.<ref name=":1">Latarjet M. Treatment of recurrent dislocation of the shoulder. Lyon Chir 1954;49:994-7.</ref><ref name=":2">Helfet AJ. Coracoid transplantation for recurring dislocation of the shoulder. J Bone Joint Surg Br 1958;40-B:198-202.</ref>

==Anecdote==
(unpublished data, courtesy of Gilles Walch) At the beginning of the 1950s, Albert Trillat, the head of the orthopedic surgical clinic at the Edouard Herriot Hospital in Lyon (France) and also the promoter of the "no-touch technique", reported combination of an anterior labro-ligamentous complex reinsertion when feasible with a reduction of a so-called coraco-glenoid outlet by means of a coracoid osteoclasy and nail fixation (Figures).<ref>Trillat A. Traitement de la luxation récidivante de l'épaule. Considérations techniques. Lyon Chir 1954:986-93.</ref>
[[File:1562526202257-lg.jpg|thumb|500x500px|Postoperative anteroposterior X-ray of a right Trillat.|alt=|left]]
[[File:1562526204072-lg.jpg|alt=|none|thumb|500x500px|The illustrations demonstrate the effect of the procedure that reduce the coraco-glenoid outlet and lower the subscapularis. Courtesy of Gilles Walch.]]
Another surgeon, Michel Latarjet, who was mainly active in the field of thoracic surgery, visited Dr. Trillat to learn the aforementioned technique. When Latarjet supposedly tried to reproduce the Trillat procedure, he carried an involuntary complete coracoid osteotomy. Thenceforth, not knowing what to do with the bony fragment, he fixed it to the anterior glenoid through the subscapularis using a screw. From this mishap was born the operation which now bears his name.<ref name=":1" />

==Anatomical Considerations==
The glenohumeral joint has six degrees of freedom with minimal bony constraint that provides a large functional range of motion. It thus renders this diarthrodial joint particularly vulnerable to instability. The glenohumeral joint is stabilized by dynamic and static structures. The dynamic stabilizers include the rotator cuff, the long head of the biceps, and the deltoid. The static stabilizers of the joint include the capsule, the glenohumeral ligaments, the labrum, the negative pressure within the joint capsule, and the bony congruity of the joint. The superior glenohumeral ligament functions primarily to resist inferior translation and external rotation of the humeral head in the adducted arm. The middle glenohumeral ligament functions primarily to resist external rotation from 0 degree to 90 degrees and provides anterior stability to the moderately abducted shoulder. The inferior glenohumeral ligament is composed of two bands; anterior and posterior, and the intervening capsule. The primary function of the anterior band of the inferior glenohumeral ligament is to resist anteroinferior translation.<ref name=":3">Burkart AC, Debski RE. Anatomy and function of the glenohumeral ligaments in anterior shoulder instability. Clin Orthop Relat Res 2002:32-9.</ref>

==Prevalence==
The glenohumeral joint is the most commonly dislocated large joint of the body, affecting approximately 1.7% of the general population.<ref>Romeo AA, Cohen BS, Carreira DS. Traumatic anterior shoulder instability. Orthop Clin North Am 2001;32:399-409.</ref>

In greater than 90% of cases, the instability is anterior, has a traumatic origin, and occurs in young athletes involved in contact sports.<ref>Goss TP. Anterior glenohumeral instability. Orthopedics 1988;11:87-95.</ref><ref>Owens BD, Agel J, Mountcastle SB, Cameron KL, Nelson BJ. Incidence of glenohumeral instability in collegiate athletics. Am J Sports Med 2009;37:1750-4.</ref>

Ongoing sports participation in this population is associated with a high recurrence rate.<ref>Owens BD, Dickens JF, Kilcoyne KG, Rue JP. Management of mid-season traumatic anterior shoulder instability in athletes. J Am Acad Orthop Surg 2012;20:518-26.</ref>

==Pathoanatomy and biomechanics==
Anterior shoulder instability usually occurs with an anteriorly directed force applied to an abducted and externally rotated arm, or from a direct blow. During an anterior dislocation, many of the passive and active stabilizers may be damaged. The glenoid labrum, the glenohumeral ligaments, and the glenohumeral joint capsule, representing the soft tissue passive stabilizers will be injured; an avulsion of the anterior labrum, the classic Bankart lesion (Figure) or its variations (glenolabral articular disruption (GLAD), Perthes, anterior labroligamentous periosteal sleeve avulsion (ALPSA)) is almost invariably present,11,22,23 although it does not produce instability in isolation.<ref>Bankart AS. Recurrent or Habitual Dislocation of the Shoulder-Joint. British medical journal 1923;2:1132-3.</ref><ref>Neviaser TJ. The anterior labroligamentous periosteal sleeve avulsion lesion: a cause of anterior instability of the shoulder. Arthroscopy 1993;9:17-21.</ref><ref>Neviaser TJ. The GLAD lesion: another cause of anterior shoulder pain. Arthroscopy 1993;9:22-3.</ref><ref>Speer KP, Deng X, Borrero S, Torzilli PA, Altchek DA, Warren RF. Biomechanical evaluation of a simulated Bankart lesion. J Bone Joint Surg Am 1994;76:1819-26.</ref>
[[File:1562526629855-lg.jpg|thumb|600x600px|A) Coronal T2 MRI views of a right shoulder. The white arrow points a Bankart lesion. B) Arthroscopic view of the same lesion from a posterior portal.|alt=]]
The anteroinferior glenohumeral ligaments and the capsule can be detached from the glenoid rim, and a plastic deformation of the glenohumeral ligaments or an HAGL lesion (Figure) are other common features.<ref>Wolf EM, Cheng JC, Dickson K. Humeral avulsion of glenohumeral ligaments as a cause of anterior shoulder instability. Arthroscopy 1995;11:600-7.</ref>
[[File:1562526631138-lg.jpg|thumb|761x761px|Coronal T2 MRI views of a right shoulder. The white arrow points a HAGL lesion. A retensioning of the inferior glenohumeral ligament (capsular shift according to Neer) will be inefficient.|alt=]]
The plastic deformation of these structures becomes progressively more severe with subsequent episodes.<ref>Bigliani LU, Pollock RG, Soslowsky LJ, Flatow EL, Pawluk RJ, Mow VC. Tensile properties of the inferior glenohumeral ligament. J Orthop Res 1992;10:187-97.</ref><ref>Habermeyer P, Gleyze P, Rickert M. Evolution of lesions of the labrum-ligament complex in posttraumatic anterior shoulder instability: a prospective study. J Shoulder Elbow Surg 1999;8:66-74.</ref><ref>Urayama M, Itoi E, Sashi R, Minagawa H, Sato K. Capsular elongation in shoulders with recurrent anterior dislocation. Quantitative assessment with magnetic resonance arthrography. Am J Sports Med 2003;31:64-7.</ref>

The middle glenohumeral ligament functions to limit both anterior and posterior translations of the arm at 45 degrees of abduction and 45 degrees of external rotation whereas the inferior glenohumeral ligament resists translation of the arm in greater degrees of abduction.<ref name=":3" />

In addition to progressive soft tissue injury, recurrent dislocations can facilitate cartilage and bony injuries. Bony lesions are frequent in recurrent cases and may include defects of the glenoid (bony Bankart or beveling of the anterior glenoid resulting in loss of glenoid concavity), impaction of the posterolateral humeral head (Malgaigne lesion), or even coracoid or proximal humerus fractures (Figures).<ref>Griffith JF, Antonio GE, Yung PS, Wong EM, Yu AB, Ahuja AT, Chan KM. Prevalence, pattern, and spectrum of glenoid bone loss in anterior shoulder dislocation: CT analysis of 218 patients. AJR American journal of roentgenology 2008;190:1247-54.</ref><ref>Buscayret F, Edwards TB, Szabo I, Adeleine P, Coudane H, Walch G. Glenohumeral arthrosis in anterior instability before and after surgical treatment: incidence and contributing factors. Am J Sports Med 2004;32:1165-72.</ref><ref>Edwards TB, Boulahia A, Walch G. Radiographic analysis of bone defects in chronic anterior shoulder instability. Arthroscopy 2003;19:732-9.</ref>

[[File:Media2-53.mov|alt=Arthroscopy of a right shoulder with a humeral cartilage lesion after one traumatic episode of glenohumeral dislocation. Posterior viewing portal.|thumb|Arthroscopy of a right shoulder with a humeral cartilage lesion after one traumatic episode of glenohumeral dislocation. Posterior viewing portal. ]]

[[File:Media3-56.mov|alt=Arthroscopy of a right shoulder with a glenoid cartilage lesion after one traumatic episode of glenohumeral dislocation. Posterior viewing portal.|thumb|Arthroscopy of a right shoulder with a glenoid cartilage lesion after one traumatic episode of glenohumeral dislocation. Posterior viewing portal.]]

[[File:1562527520975-lg.jpg|thumb|600x600px|A) Sagittal view of a CT arthrogram of a left shoulder demonstrates a significant Bankart fracture (white arrow) that produces an “inverted-pear” glenoid. B) Plain anteroposterior radiograph reveals an anteroinferior glenohumeral dislocation with an “engaged” Malgaigne (Hill-Sachs) lesion of the humerus.|alt=]]

Given that the average glenoid diameter is about 24 mm, a 6 mm-wide or larger fragment of the glenoid will typically equate to a 25% or more of the articular surface and is considered a large bony fragment.<ref name=":4">Burkhart SS, De Beer JF. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs: significance of the inverted-pear glenoid and the humeral engaging Hill-Sachs lesion. Arthroscopy 2000;16:677-94.</ref><ref>Burkhart SS, Debeer JF, Tehrany AM, Parten PM. Quantifying glenoid bone loss arthroscopically in shoulder instability. Arthroscopy 2002;18:488-91.</ref>

Such significant glenoid bone loss can be viewed arthroscopically as an inverted pear configuration. All Malgaigne lesions are by definition engaging lesions (since it has engaged at least once). Thus, the notion of “engaging” versus “non-engaging” can lead to significant confusion. Some have proposed that the important lesions are those that engage in the 90-90 position.

Finally, the active restraint, mainly a lesion of the rotator cuff above the age of 40, will complete this complex situation.<ref name=":5">Antonio GE, Griffith JF, Yu AB, Yung PS, Chan KM, Ahuja AT. First-time shoulder dislocation: High prevalence of labral injury and age-related differences revealed by MR arthrography. JMRI 2007;26:983-91.</ref><ref>Itoi E, Tabata S. Rotator cuff tears in anterior dislocation of the shoulder. Int orthop 1992;16:240-4.</ref>

The glenohumeral joint is stabilized by a so-called “concavity compression” principle with the rotator cuff pulling the humeral head into the glenoid concavity and therefore ensuring stability through counteracting decentering translational forces.<ref>Lazarus MD, Sidles JA, Harryman DT, 2nd, Matsen FA, 3rd. Effect of a chondral-labral defect on glenoid concavity and glenohumeral stability. A cadaveric model. J Bone Joint Surg Am 1996;78:94-102.</ref><ref>Matsen FA, 3rd, Harryman DT, 2nd, Sidles JA. Mechanics of glenohumeral instability. Clinics in sports medicine 1991;10:783-8.</ref><ref>Yamamoto A, Takagishi K, Osawa T, Yanagawa T, Nakajima D, Shitara H, Kobayashi T. Prevalence and risk factors of a rotator cuff tear in the general population. J Shoulder Elbow Surg 2010;19:116-20.</ref>

==Natural History and Risk Factors of Dislocation or Recurrences==
To understand the natural history of instability and its importance for the appropriate management of this pathology, the following questions should be answered: What happens in the shoulder after the first dislocation? Which structures suffer damage? Who are the patients at higher risk of recurrence? How does the disease evolve without treatment? Will surgical treatment avoid future negative outcomes and prevent degenerative joint disease? Who should we treat and when?<ref>Carpinteiro EP, Barros AA. Natural History of Anterior Shoulder Instability. Open Orthop J. 2017 Aug 31;11:909-918.</ref>

80% of anterior-inferior dislocations occur in young patients. Recurrent instability is common and multiple dislocations are the rule. Instability is influenced by a large number of variables, including age of onset, activity profile, number of episodes,delay between first episode and surgical treatment. The different risks factors are:

-Young males (up to 100% of recurrence),<ref name=":6">Postacchini F, Gumina S, Cinotti G. Anterior shoulder dislocation in adolescents. J Shoulder Elbow Surg 2000;9:470-4.</ref><ref name=":7">Hovelius L, Augustini BG, Fredin H, Johansson O, Norlin R, Thorling J. Primary anterior dislocation of the shoulder in young patients. A ten-year prospective study. J Bone Joint Surg Am 1996;78:1677-84.</ref>

-Practice of contact sports, forced overhead activity,

-Sport practice at a competitive level,<ref name=":8">Balg F, Boileau P. The instability severity index score. A simple pre-operative score to select patients for arthroscopic or open shoulder stabilisation. J Bone Joint Surg Br 2007;89:1470-7.</ref>

-Bony impairment,

-Concomitant hyperlaxity.<ref>Habermeyer P, Jung D, Ebert T. [Treatment strategy in first traumatic anterior dislocation of the shoulder. Plea for a multi-stage concept of preventive initial management]. Der Unfallchirurg 1998;101:328-41.</ref>

==Classification==
Instability can be classified as primary or recurrent. The latter can be further classified as dislocation, subluxation, apprehension, or an unstable painful shoulder. In frank dislocation, the articular surfaced of the joint are completely separated. Subluxation is defined as symptomatic translation of the humeral head on the glenoid without complete separation of the articular surfaces. Apprehension is classically defined by fear of imminent dislocation in the 90-90 position. This could correspond to an instability phenomena or a persistent fear after a successful glenohumeral stabilization (please refer to Apprehension chapter).<ref name=":9">Haller S, Cunningham G, Laedermann A, Hofmeister J, Van De Ville D, Lovblad KO, Hoffmeyer P. Shoulder apprehension impacts large-scale functional brain networks. AJNR American journal of neuroradiology 2014;35:691-7.</ref>

The unstable painful shoulder presents as pain only (as opposed to a sense of instability) during an apprehension maneuver at clinical examination.<ref name=":10">Boileau P, Zumstein M, Balg F, Penington S, Bicknell RT. The unstable painful shoulder (UPS) as a cause of pain from unrecognized anteroinferior instability in the young athlete. J Shoulder Elbow Surg 2011;20:98-106.</ref><ref name=":11">Patte D, Bernageau J, Rodineau J, Gardes JC. [Unstable painful shoulders (author's transl)]. Rev Chir Orthop Reparatrice Appar Mot 1980;66:157-65.</ref>

The majority of these patients has a history of trauma, but simply do not report a clear history of trauma. Careful preoperative and/or arthroscopic examination will show that the majority of these patients also has evidence of instability (i.e. labral tear, glenoid fracture, or Malgaigne (Hill-Sachs) lesion)

Five types of traumatic anterior dislocation have been described. The subcoracoid dislocation has an antero-inferior direction and is the most common. Other types, including subglenoid, subclavicular, retroperitoneal, and intrathoracic are rare and usually associated with severe trauma.<ref>Patel MR, Pardee ML, Singerman RC. Intrathoracic Dislocation of the Head of the Humerus. J Bone Joint Surg Am 1963;45:1712-4.</ref><ref>Wirth MA, Jensen KL, Agarwal A, Curtis RJ, Rockwood CA, Jr. Fracture-dislocation of the proximal part of the humerus with retroperitoneal displacement of the humeral head. A case report. J Bone Joint Surg Am 1997;79:763-6.</ref>

Osseous defects of the anterior glenoid rim can be classified into three types according to their pathomorphology. In particular, acute (type I) and chronic glenoid rim defects (type II and III) are differentiated, which are provoked either by an acute glenoid fracture or recurrent shoulder dislocations with subsequent erosion of the glenoid rim. Type I lesions are further divided into bony Bankart lesions (type Ia), solitary glenoid rim fractures (type Ib) and multifragmented glenoid rim fractures (type Ic). In most cases, type I glenoid defects can sufficiently be reconstructed by mobilization and anatomical refixation of the fragment.

In cases of complex multifragmented glenoid rim fractures (type Ic), however, it may be necessary to resect the fragments and augment the glenoid defect. Type II defects include chronic fragment-type of lesions that are characterized by an extra-anatomically consolidated or pseudarthrotic fragment of insufficient dimensions for a defect reconstruction due to resorption processes. A bony glenoid augmentation may be indicated, depending on the dimensions of the glenoid defect and the remaining fragment. Erosion-type of defects (type III) are predominantly observed in patients with recurrent anterior shoulder dislocations. These usually develop on the basis of a glenoid fracture with subsequent resorption of the fragment, or as a result of chronic abrasion of the anterior glenoid rim. If the bone loss adopts substantial dimensions, mere soft-tissue stabilization procedures are not sufficient in re-establishing stability.

==Clinical Presentation and Essential Physical Examination==
The history should document age, hand dominance, occupation, participation in sporting activities, initial mechanism of the injury, the position of the arm (extension, abduction, and external rotation favors anterior dislocation), how long the shoulder stays out, the method of reduction, the number of recurrences (frank dislocation vs subluxation), and the effectiveness of a previous nonoperative or operative treatment. The diagnosis of recurrent traumatic anterior glenohumeral instability is usually made easily on the basis of the history, radiographs, and a positive apprehension sign. However, when collision athletes are seen, care should be taken because they may not experience clear dislocation or subluxation and only complain of pain or weakness.

A comprehensive physical examination is essential. The aim is to define the direction of instability, the presence of an associated pathologic hyperlaxity, and to exclude neurological and rotator cuff impairment. Passive and active glenohumeral range of motion should be assessed. Rotator cuff examination includes strength tests such as belly-press, bear hug, Jobe tests and strength in external rotation against resistance (please refer to Rotator Cuff Pathology/Rotator cuff complete lesion). Tests for anterior and superior labral lesions are not systematically performed as they have a poor sensitivity and specificity.<ref>Cook C, Beaty S, Kissenberth MJ, Siffri P, Pill SG, Hawkins RJ. Diagnostic accuracy of five orthopedic clinical tests for diagnosis of superior labrum anterior posterior (SLAP) lesions. J Shoulder Elbow Surg 2012;21:13-22.</ref>

The neurovascular status of the upper extremity is assessed, particularly with regard to the axillary nerve since there is a high incidence of injury to this nerve with traumatic instability (Figure).
[[File:1562529745788-lg.jpg|thumb|600x600px|A) A 54-year-old patient sustained a fracture dislocation of the right shoulder. At clinical examination, no peripheral pulse was palpated. B) During open reduction, the axillary artery (white arrows) was found kinked around the fractured humeral head.|alt=|border]]
Laxity is a normal, physiologic and asymptomatic finding, that corresponds to translation of the humeral head in any direction to the glenoid.<ref>Gerber C, Terrier F, Ganz R. The Trillat procedure for recurrent anterior instability of the shoulder. J Bone Joint Surg Br 1988;70:130-4.</ref>

Laxity is assessed with the sulcus sign, anterior-posterior drawer, hyperabduction tests, and external rotation elbow at side. The two former tests are only qualitative and are not routinely performed by the authors. Hyperlaxity is constitutional, multidirectional, bilateral and asymptomatic. Hyperlaxity of the shoulder is probably best defined as external rotation elbow at the side equal or greater than 85 degrees.<ref>Walch G, Agostini JY, Levigne C, Nove-Josserand L. [Recurrent anterior and multidirectional instability of the shoulder]. Rev Chir Orthop Reparatrice Appar Mot 1995;81:682-90.</ref>

This non-pathological finding is a risk factor for instability but does not by itself demand treatment unless there is clear pathological laxity. Pathological laxity of the inferior glenohumeral ligament is observed when passive abduction in neutral rotation in the glenohumeral joint is above 105 degrees, there is apprehension above 90 degrees of abduction, or if a difference of more than 20 degrees between the two shoulders is noted.<ref>Gagey OJ, Gagey N. The hyperabduction test. J Bone Joint Surg Br 2001;83:69-74.</ref><ref name="HoveliusRahme2016Primary">Hovelius L, Rahme H. Primary anterior dislocation of the shoulder: long-term prognosis at the age of 40 years or younger. Knee Surg Sports Traumatol Arthrosc 2016;24:330-42.</ref>

For apprehension the patient is initially invited to demonstrate his or her functional problem to the examiner (no-touch examination). This examination alone, coupled with a good history, often provides the information needed. However, if the direction of the instability remains unclear, the apprehension (crank) test, an abducted and externally rotated position suggestive of anterior instability is performed. Fear of dislocation or a feeling of anterior pain is considered positive for damage to the anterior capsulolabral complex, which should be relieved with posterior translation of the humerus (relocation maneuver). To summarize, the physical examination demonstrates instability if the apprehension test is positive, multidirectional hyperlaxity when the external rotation at side is equal or above 85 degrees, and a pathological laxity of the inferior glenohumeral ligament if the hyperabduction test is positive.

==Apprehension==
Apprehension can be difficult to diagnose pre- or post-operatively, as it seems more complex than a pure mechanical problem of the shoulder. Although clinical definition seems to be well established, its underlying pathologic mechanism remains unclear. This may explain the wide reported range (3% to 51%) of patients with ongoing apprehension or who will avoid any shoulder movement after an open or arthroscopic stabilization, despite a clinically stable joint.<ref name="HoveliusRahme2016Primary" /><ref>Hovelius L, Vikerfors O, Olofsson A, Svensson O, Rahme H. Bristow-Latarjet and Bankart: a comparative study of shoulder stabilization in 185 shoulders during a seventeen-year follow-up. J Shoulder Elbow Surg 2011;20:1095-101.</ref><ref name=":14">Lädermann A, Lubbeke A, Stern R, Cunningham G, Bellotti V, Gazielly DF. Risk factors for dislocation arthropathy after Latarjet procedure: a long-term study. International orthopaedics 2013;37:1093-8.</ref>

Failure to recognize and adequately address this issue may result in poor outcome and lead to unnecessary surgery or even revision. Furthermore, identifying this condition may allow establishing adequately targeted rehabilitation programs.

===Definition===
An important aspect to incorporate in dislocation management is apprehension, defined as anxiety and motor resistance in patients with a history of anterior glenohumeral instability. Clinically, apprehension sign is defined as fear of imminent dislocation when placing the arm in abduction and external rotation, and should be distinct from mere pain which can be related to inflammation, stiffness and other shoulder pathologies.<ref>Jobe FW, Kvitne RS, Giangarra CE. Shoulder pain in the overhand or throwing athlete. The relationship of anterior instability and rotator cuff impingement. Orthop Rev 1989;18:963-75.</ref><ref>Rowe CR, Zarins B. Recurrent transient subluxation of the shoulder. The Journal of bone and joint surgery American volume 1981;63:863-72.</ref>

Proprioception, as defined by Charles Scott Sherrington, is the sense of the relative position of neighboring parts of the body and strength of effort being employed during movement.<ref>Sherrington C. The Integrative Action of the Nervous System. New York: Charles Scribner's Sons; 1906.</ref>

It is distinct from exteroception, by which one perceives the outside world, and interoception, by which one perceives pain, hunger, or the movement of internal organs. The brain integrates information from proprioception and from the vestibular system into its overall sense of body position, movement, and acceleration. Kinesthesia refers either to the brain's integration of proprioceptive or vestibular inputs.

===“Localization” of Apprehension===
The pathogenesis of apprehension is not fully understood. Theoretically, apprehension could be related to:

1) Brain changes induced by dislocations<ref name=":9" /><ref>Cunningham G, Zanchi D, Emmert K, Kopel R, Van De Ville D, Lädermann A, Haller S, Hoffmeyer P. Neural Correlates of Clinical Scores in Patients with Anterior Shoulder Apprehension. Medicine and science in sports and exercise 2015;47:2612-20.</ref><ref name=":15">Zanchi D, Cunningham G, Lädermann A, Ozturk M, Hoffmeyer P, Haller S. Structural white matter and functional connectivity alterations in patients with shoulder apprehension. Sci Rep 2017;7:42327.</ref><ref name=":16">Zanchi D, Cunningham G, Lädermann A, Ozturk M, Hoffmeyer P, Haller S. Brain activity in the right-frontal pole and lateral occipital cortex predicts successful post-operatory outcome after surgery for anterior glenoumeral instability. Sci Rep 2017;7:498.</ref>

2) Peripheral neuromuscular lesions consecutive to dislocation affecting proprioception<ref name=":17">Atef A, El-Tantawy A, Gad H, Hefeda M. Prevalence of associated injuries after anterior shoulder dislocation: a prospective study. International orthopaedics 2015.</ref>

3) Persistent mechanical instability consisting in micro-motion<ref name=":19">Lädermann A, Denard PJ, Tirefort J, Kolo FC, Chagué S, Cunningham G, Charbonnier C. Does surgery for instability of the shoulder truly stabilize the glenohumeral joint?: A prospective comparative cohort study. Medicine (Baltimore) 2016;95:e4369.</ref>
[[File:1562540576908-lg.jpg|center|thumb|600x600px|Apprehension may be related to (A) central nervous system sequelae, (B) peripheral neurological, muscular or capsular/ligamentous lesions consecutively to dislocation, or (C) mechanical instability as micromovements. Reproduced from Lädermann et al., with permission.]]

====Brain====
Fear, anxiety and anticipation of situations that could lead to a dislocation are essential cognitive processes in shoulder apprehension. Functional magnetic resonance imaging (fMRI) measures brain activity by detecting changes associated with blood flow.<ref>Logothetis NK, Pauls J, Augath M, Trinath T, Oeltermann A. Neurophysiological investigation of the basis of the fMRI signal. Nature 2001;412:150-7.</ref>

When exploring neuronal connections and cerebral changes induced by shoulder dislocation, research revealed that several cerebral areas are modified, representing the different aspects of shoulder apprehension. Specific reorganizations are found in apprehension-related functional connectivity of the primary sensory-motor areas (motor resistance), dorsolateral prefrontal cortex (cognitive control of motor behavior), and the dorsal anterior cingulate cortex/dorsomedial prefrontal cortex and anterior insula (anxiety and emotional regulation) (Figure).<ref name=":9" />
[[File:1562542592373-lg.gif|center|thumb|450x450px|Patients vs control participants had a significantly (P < .05 corrected) higher task-correlated functional connectivity in two almost mirror symmetric components. Reproduced from Haller et al., with permission.]]
 Those regions are involved in the cognitive control of motor behavior. Hence, there is motor control anticipation and muscular resistance (protective reflex mechanism), in order to avoid shoulder movement that could lead to dislocation.<ref>Cieslik EC, Zilles K, Caspers S, et al. Is there "one" DLPFC in cognitive action control? Evidence for heterogeneity from co-activation-based parcellation. Cereb Cortex 2013;23:2677-89.</ref>

Fractional anisotropy, representing white matter integrity, is increased in the left internal capsule and partially in the thalamus in patients compared to healthy controls. Fractional anisotropy correlated positively with pain visual analog scale (VAS) scores (p < .05) and negatively with simple shoulder test (SST) scores (p < .05).<ref name=":15" />

This suggests an abnormal increased axonal integrity and therefore pathological structural plasticity due to the over-connection of white matter fibers in the motor pathway. These structural alterations affect several dimensions of shoulder apprehension as pain perception and performance in daily life.

Shoulder stabilization could allow the brain to partially “recover”. Patients with shoulder apprehension underwent clinical and functional magnetic resonance imaging (fMRI) examination before and one year after shoulder stabilization surgery. Clinical examination showed a significant improvement in postoperative shoulder function compared with preoperative. Coherently, results showed decreased activation in the left pre-motor cortex postoperatively, demonstrating that stabilization surgery induced improvements both at the physical and at the brain level, one year postoperatively (Figure 9). Most interestingly, right–frontal pole and right-occipital cortex activity is associated with good outcome in shoulder performance.<ref name=":16" />
[[File:1562542592786-lg.gif|center|thumb|400x400px|Task related General Linear Model (GLM) shows higher activation in baseline vs. follow-up for apprehension videos vs. control videos, representing partial brain healing. Reproduced from Zanchi et al., with permission.]]

====Peripheral Neuromuscular Lesion====
During a traumatic dislocation, there are a disruption of the shoulder tendinomuscular (in 10% of cases) and peripheral nerve lesions (in 14% of cases).<ref>Robinson CM, Shur N, Sharpe T, Ray A, Murray IR. Injuries associated with traumatic anterior glenohumeral dislocations. J Bone Joint Surg Am 2012;94:18-26.</ref>

However, this does not account for subclinical neurologic damage that may be much more preponderant. Capsuligamentous structures surrounding the glenohumeral joint are richly innervated with proprioceptors and therefore play an important sensorimotor role in addition to their primary mechanical stabilizising function. Thus, when considering the extensive and frequent damage to these structures after shoulder dislocation (Figure), there is bound to be an important loss in glenohumeral proprioception.<ref name=":5" /><ref name=":17" />

The latter plays a significant role in stabilization of a normal healthy shoulder and after any shoulder injury by contributing to motor control.<ref name=":18">Fyhr C, Gustavsson L, Wassinger C, Sole G. The effects of shoulder injury on kinaesthesia: a systematic review and meta-analysis. Man Ther 2015;20:28-37.</ref>
[[File:1562542594443-lg.jpg|center|thumb|600x600px|Arthroscopic view of a left shoulder through a posterior portal. This patient has sustained more than 50 subluxations. The axillary nerve is clearly identifiable (white asterisk). There is no more capsule or inferior glenohumeral ligament, and the subscapularis muscle is hardly recognizable. Reproduced from Lädermann et al., <ref>Lädermann A, Benchouk S, Denard P. Traumatic Anterior Shoulder Instability: General concepts & proper management. In: Park J, ed. Sports Injuries to the Shoulder and Elbow. Berlin Heidelberg: Springer-Verlag; 2015</ref> with permission.]]
Surgical stabilization has been shown to help proper healing of these structures and thus restoring proprioception of the glenohumeral joint.<ref>Myers JB, Lephart SM. Sensorimotor deficits contributing to glenohumeral instability. Clin Orthop Relat Res 2002:98-104.</ref>

====Glenohumeral Joint====
The third etiologic factor for apprehension is persistent micro-motion in the glenohumeral joint despite a clinically stable shoulder, satisfactory radiographic results, and no new episode of subluxation or dislocation. Shoulder dislocation causes damage to the capsuloligamentous complex in 52% of the cases, and the glenoid labrum in 73% of the cases.<ref>Liavaag S, Stiris MG, Svenningsen S, Enger M, Pripp AH, Brox JI. Capsular lesions with glenohumeral ligament injuries in patients with primary shoulder dislocation: magnetic resonance imaging and magnetic resonance arthrography evaluation. Scandinavian journal of medicine & science in sports 2011;21:e291-7.</ref><ref name=":5" />

The plastic deformation of these structures becomes progressively worse with subsequent episodes.The plastic deformation of these structures becomes progressively worse with subsequent episodes. In addition to progressive soft tissue injury, recurrent dislocations induce bony lesions, which may involve the glenoid (bony Bankart), the posterolateral humeral head (Malgaine), or both. Severity of apprehension, quantified as the moment at which it appears during the course of abduction and external rotation, seems to be correlated to the extent of bone loss. Capsular redundancy has also been recognized as a risk factor for ongoing apprehension after surgical stabilization and Ropars et al. found a significantly decreased apprehension in patients with associated capsulorraphy to Latarjet procedures, compared with patients with Latarjet and no capsular reconstruction.<ref name=":12">Ropars M, Cretual A, Kaila R, Bonan I, Herve A, Thomazeau H. Diagnosis and treatment of anteroinferior capsular redundancy associated with anterior shoulder instability using an open Latarjet procedure and capsulorrhaphy. Knee Surg Sports Traumatol Arthrosc 2016;24:3756-64.</ref>

However, these changes may be very subtle and therefore not detectable on standard clinical magnetic resonance imaging in neutral position. This has been described by Patte et al. in non-operated patients and popularized under the name of "unstable painful shoulder".<ref name=":11" /><ref name=":10" />

This micro-motion may yet still be present after surgical stabilization. Shoulder stabilization may thus only prevent new episodes of dislocation, rather than actually truly stabilizing the shoulder.<ref>Singer GC, Kirkland PM, Emery RJ. Coracoid transposition for recurrent anterior instability of the shoulder. A 20-year follow-up study. J Bone Joint Surg Br 1995;77:73-6.</ref><ref>Lädermann A, Tirefort J, Zanchi D, Haller S, Charbonnier C, Cunningham G. Shoulder Apprehension: a Multifactorial Approach. EFORT Open Rev. 2018 24;3(10):550-557</ref>

A study described glenohumeral translation in patients with traumatic anteroinferior instability and subsequently analyzed the effect of glenohumeral stabilization on this translation. For all movements, the authors recorded humeral head position of the contralateral and ipsilateral shoulders in relation to the glenoid center pre- and 1 year post-operatively. They observed an anterior translation of the humeral head (Figure), especially during flexion and abduction movements (p < .05 and p < .05, respectively). One year after surgery, all patients had a clinically stable shoulder and none presented with a new episode of dislocation or subluxation.

However, anterior translation of the humeral head was not significantly reduced and remained close to preoperative values confirming that shoulder stabilization does not stabilize the shoulder but uniquely prevents further dislocation. These findings have several important implications. First, it may explain residual pain, apprehension, and impossibility to return to sport at the same level as reported in other studies. Second, persistent abnormal motion between the glenoid and the humeral head might be the underlying cause of dislocation arthropathy that is observed with a prevalence of 36%. Repeated sliding of the humeral head against the glenoid associated with degenerative changes of cartilage properties and decreased biological healing potential related to aging, could lead to a vicious circle of extensive cartilage damage.<ref name=":19" />
[[File:1562542595262-lg.jpg|center|thumb|600x600px|(A) Abduction simulation obtained from shoulder’s CT reconstruction and optical motion capture, (B) and (C) show a zoom in the shoulder (front and top views). In image (C), we clearly observe an anterior translation (arrow) of the humeral head center (pink sphere) with respect to the glenoid center (white sphere). Note that the clavicle is not shown for clarity. Reproduced from Lädermann et al.,<ref name=":19" /> with permission.]]
 

==Scores==

===Single Assessment Numeric Evaluation (SANE)-instability score===
A modified Single Assessment Numeric Evaluation (SANE) score specific to shoulder instability, the SANE-instability score, has been developed.<ref name=":0">Lädermann A, Denard PJ, Collin P, Mohamed Ibrahim M, Bothorel H, Chiu JC. Single Assessment Numeric Evaluation for instability as an alternative to the Rowe score. J Shoulder Elbow Surg. 2020;S1058-2746(20)30686-8</ref> The SANE-instability score (100 points) is assessed with a single question: “What is the overall percent value of your shoulder if a completely stable shoulder represents 100%?” A high correlation between the Rowe and SANE-instability scores for shoulder instability has been found before and after treatment, as well as for different patient age groups and treatment types. This score is easy to collect and use because it can be collected in the office or remotely, thereby saving considerable time and potentially improving compliance.<ref name=":0" />

===Rowe===
The 1978 Rowe score is calculated with the 3 following items: stability (50 points), motion (20 points), and function (30 points).<ref>Rowe CR, Patel D, Southmayd WW. The Bankart procedure: a long-term end-result study. J Bone Joint Surg Am. 1978; 60: 1-16</ref>

===Walch-Duplay===
This subsection does not exist. You can ask for it to be created, but consider checking the search results below to see whether the topic is already covered.

===WOSI===
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===ISIS===
Boileau et al. proposed a simple 10-point scale scoring system (instability severity index score (ISIS)) based on factors derived from a pre-operative questionnaire, physical examination, and anteroposterior radiographs to determine the risk of treatment failure following isolated arthroscopic Bankart repair (Table). In this model an ISIS of 3 or less was associated with a 5% rate of recurrence, an ISIS of 4 to 6 was associated with a 10% rate of recurrence, and an ISIS over 6 was associated with a 70% rate of recurrence. Although it has imperfections, this score, validated since, has merit to easily remind the clinician of factors that are important to consider when evaluating a patient.<ref name=":8" /><ref>Rouleau DM, Hebert-Davies J, Djahangiri A, Godbout V, Pelet S, Balg F. Validation of the instability shoulder index score in a multicenter reliability study in 114 consecutive cases. Am J Sports Med 2013;41:278-82.</ref>

'''''Table: The instability severity index score is based on a pre-operative questionnaire, clinical examination, and radiographs.'''''
[[File:1562543299662-lg.jpg|center|thumb|899x899px|Figure. 12 * AP, anteroposterior]]
 

==Essential Radiology==
Radiographic evaluation is based on whether the dislocation is acute or chronic.

===Acute Dislocation===
Three views plain radiographs, including true anteroposterior of the glenohumeral joint, scapular Y (scapular lateral), and Velpeau axillary views are the mainstay of imaging in the setting of traumatic anterior instability.<ref>Bloom MH, Obata WG. Diagnosis of posterior dislocation of the shoulder with use of Velpeau axillary and angle-up roentgenographic views. J Bone Joint Surg Am 1967;49:943-9.</ref>

The latter view is crucial to obtain, as the two first alone do not allowed to exclude a dislocation. The goal is to confirm the direction of dislocation and to evaluate associated lesions. One reduced, further imaging studies in the setting of an associated fracture (computed tomography (CT)), suspicion of rotator cuff injury (ultrasonography or magnetic resonance imaging (MRI)), or vascular impairment (injected CT) may be warranted.

===Preoperative Planning in Case of Recurrent Dislocation===
The first step is to analyze, if available, plan radiographs with the shoulder out of joint to confirm the direction of instability. Plain radiographs including anteroposterior in neutral, internal and external rotations, scapular Y and Bernageau views are then obtained.<ref>Bernageau J, Patte D, Debeyre J, Ferrane J. [Value of the glenoid profile in recurrent luxations of the shoulder]. Rev Chir Orthop Reparatrice Appar Mot 1976;62:142–7.</ref>

Bone loss, static instability, post-dislocation arthropathy, and coracoid non-union (if a Latarjet or a Bristow procedures are planned) have to be estimated. Magnetic resonance imaging (MRI) arthrogram is useful to assess for soft tissue such as an anterior labral tear (Figure). 
[[File:1562543301909-lg.jpg|center|thumb|600x600px|Coronal T1 SPIR magnetic resonance imaging (MRI) of a right shoulder showing disruption of the anteroinferior glenoid labrum. B]]
Associated intra-articular pathology such as SLAP, HAGL, and rotator cuff lesions or a paralabral cyst are also assessed (Figure).

The evaluation is completed by a 3D computed tomography arthrogram in the setting of recurrent instability in which there is primary concern for bone loss. The extent of both glenoid bone loss and Hill-Sachs lesions are best assessed by computed tomography scan and are used to determine the need for a bony procedure as opposed to arthroscopic Bankart repair (Figures).
[[File:1562543901744-lg.jpg|center|thumb|600x600px|A) Sagittal view of a CT arthrogram of a left shoulder demonstrates a significant Bankart fracture that produces an “inverted-pear” glenoid. B) Plain anteroposterior radiograph reveals an anteroinferior glenohumeral dislocation with an “engaged” Malgaigne (Hill-Sachs) lesion of the humerus.]]
 
[[File:1562544592047-lg.jpg|center|thumb|600x600px|Axial computed tomography (CT) arthrogram view showing a large Malgaigne lesion.]]
 

==Treatments==
===Clinical Practice Guideline===
The goal of this section is to provide clinicians with recommendations based on the best available evidence; to inform clinicians of when there is no evidence; and finally, to help clinicians deliver the best health care possible.

The degree, nature and combination of injuries induced by traumatic glenohumeral instability are highly variable. Damage to the bony and soft tissue stabilizers of the shoulder, as well as neurologic impairment, must be detected and analyzed in order to provide the patient with the most adequate treatment option. This new knowledge should be applied to rehabilitation therapy and surgical stabilization techniques. As the current stabilization techniques do not seem to prevent residual glenohumeral micro-motion, it remains to be determined which factors help to minimize this phenomenon, whether it is, the increase in the anteroposterior diameter of the glenoid with a bone graft, the sling effect provided by the conjoined tendon or the long head of the biceps, the capsulorraphy, the repaired labrum or the remplissage.<ref>Lädermann A, Bohm E, Tay E, Scheibel M. Bone-mediated anteroinferior glenohumeral instability : Current concepts. Der Orthopade 2018.</ref><ref name=":13">Collin P, Lädermann A. Dynamic Anterior Stabilization Using the Long Head of the Biceps for Anteroinferior Glenohumeral Instability. Arthrosc Tech 2018;7:e39-e44.</ref><ref>Young AA, Maia R, Berhouet J, Walch G. Open Latarjet procedure for management of bone loss in anterior instability of the glenohumeral joint. J Shoulder Elbow Surg 2011;20:S61-9.</ref><ref name=":12" />

===Methods of Reduction===
Around 400 BC, Hippocrates, the father of Western medicine, introduced the traction method to reduce the shoulder. The patient lay supine whilst the physician standing on the patient's affected side held the arm and applied traction. The stockinged foot of the physician placed in the axilla served as counter traction. This technique was detailed in the Hippocratic Corpus, and as it remained the primary medical text for centuries so did the method. Similar technique of reduction was re-introduced in the 1870 as a painless technique by Theodor Kocher, but is now obsolete because of the likelihood of serious complications.<ref>Kocher E. Eine neue Reductionsmethode für Schulterverrenkung. Berlin Klin 1870;7:101-5.</ref>

===Conservative (Nonoperative) Treatment===
Heading towards a better understanding of the complex and multifactorial origins of glenohumeral instability and apprehension, postoperative management may in turn also be improved, notably in challenging cases of patients with persistent apprehension, despite a clinically stable shoulder. Knowing that shoulder apprehension could be the result of ongoing cerebral abnormalities or residual micro-motion may avoid costly series of onerous investigations, useless physiotherapy sessions or even re-operations. Furthermore, this perspective offers a new angle of a therapeutic approach that differs from conventional manual rehabilitation methods centered on the glenohumeral joint itself. If persistent apprehension or micro-motion is detected, growing research evidence supports the use of a multidisciplinary approach including:

1) A "reafferentation" (reconveying and connecting the neurological peripheral input to the cortex)89 of the shoulder particularly focused on proprioceptive work,69 which has been proved to lead to superior neuromuscular control than strengthening alone.<ref>Horvat JC. [Reconstruction of the spinal cord and its motor connections using embryonal nervous tissue transplantation and peripheral nerve autotransplantation. A study in the adult rat]. Neurochirurgie 1991;37:303-11.</ref><ref>Salles JI, Velasques B, Cossich V, Nicoliche E, Ribeiro P, Amaral MV, Motta G. Strength training and shoulder proprioception. J Athl Train 2015;50:277-80.</ref><ref name=":18" />

2) A biofeedback therapy where the patient directly visualizes his abnormal response to a negative stimulus on fMRI or electroencephalogram, and can thereby actively correct it. This treatment modality has already shown to improve shoulder control and performance in various settings.<ref>deCharms RC, Maeda F, Glover GH, Ludlow D, Pauly JM, Soneji D, Gabrieli JD, Mackey SC. Control over brain activation and pain learned by using real-time functional MRI. Proceedings of the National Academy of Sciences of the United States of America 2005;102:18626-31.</ref><ref>Antunes A, Carnide F, Matias R. Real-time kinematic biofeedback improves scapulothoracic control and performance during scapular-focused exercises: A single-blind randomized controlled laboratory study. Hum Mov Sci 2016;48:44-53.</ref><ref>Huang HY, Lin JJ, Guo YL, Wang WT, Chen YJ. EMG biofeedback effectiveness to alter muscle activity pattern and scapular kinematics in subjects with and without shoulder impingement. J Electromyogr Kinesiol 2013;23:267-74.</ref>

3) A cognitive behavioral approach to decondition this pathological residual apprehension by making them realize residual apprehension does not necessarily lead to recurrent instability with gradual exposition that has already shown successful results in the treatment of kinesiophobia,94-96 a condition based on a re-injury fear-avoidance model initially described in low-back pain,97 further popularized in sports medicine98 and various upper limb conditions.<ref>Das De S, Vranceanu AM, Ring DC. Contribution of kinesophobia and catastrophic thinking to upper-extremity-specific disability. J Bone Joint Surg Am 2013;95:76-81.</ref>

4) Electric stimulation of hypoactive rotator cuff and periscapular muscles.<ref>Moroder P, Minkus M, Bohm E, Danzinger V, Gerhardt C, Scheibel M. Use of shoulder pacemaker for treatment of functional shoulder instability: Proof of concept. Obere Extrem 2017;12:103-8.</ref>

===Treatment of Acute First Traumatic Dislocations===
The first step, whenever possible, is to obtain a complete set of radiographs before attempting a reduction. This will allow an assessment of the type of dislocation and associated bone injuries. Attempting to reduce a fracture dislocation can have troublesome clinical and legal consequences (Figure).
[[File:1562546209492-lg.jpg|center|thumb|600x600px|A) An anteroposterior plain radiograph of a left shoulder shows an anterior dislocation with a nondisplaced humeral neck fracture on the prereduction radiographs. B) Radiographs after attempting a closed reduction without adequate muscle relaxation reveal displacement of the fracture with the humeral head remaining anteriorly.]]
Exceptions are an impossibility to have reasonably fast access to radiology or a patient with neurological impairment. Because of the possible association of nerve injuries and, to a lesser extent, vascular injuries (Figure), an essential part of the physical examination is an assessment of the neurovascular status of the upper extremity before reduction.<ref>de Laat EA, Visser CP, Coene LN, Pahlplatz PV, Tavy DL. Nerve lesions in primary shoulder dislocations and humeral neck fractures. A prospective clinical and EMG study. J Bone Joint Surg Br 1994;76:381-3.</ref><ref>Brown FW, Navigato WJ. Rupture of the axillary artery and brachial plexus palsy associated with anterior dislocation of the shoulder. Report of a case with successful vascular repair. Clin Orthop Relat Res 1968;60:195-9.</ref>
[[File:1562529745788-lg.jpg|center|thumb|600x600px|A) A 54-year-old patient sustained a fracture dislocation of the right shoulder. At clinical examination, no peripheral pulse was palpated. B) During open reduction, the axillary artery (white arrows) was found kinked around the fractured humeral head.]]
They are numerus appropriate methods of reduction that have been described. The second step is to use the technique of closed reduction which is mastered by the doctor who will perform the maneuver. The glenohumeral joint should be reduced as gently and expeditiously as possible. In the case of fracture dislocation, the reduction is best performed under general anesthesia to have adequate muscle relaxation. After reducing the dislocation, plain radiographs are obtained to verify the adequacy of the reduction.

Results concerning conservative treatment are still debatable. A stable shoulder is obtained at ten years in only half of patients with conservative treatment.<ref name=":7" />

However, recurrence rate is highly dependent on age and activity of the patient; studies have reported a 72% to 95% recurrence in patients under 20 years of age, and 70% to 82% recurrence between the ages of 20 and 30 years, and only 30% in those over 30 years of age.<ref>te Slaa RL, Brand R, Marti RK. A prospective arthroscopic study of acute first-time anterior shoulder dislocation in the young: a five-year follow-up study. J Shoulder Elbow Surg 2003;12:529-34.</ref><ref name=":6" /><ref>Robinson CM, Howes J, Murdoch H, Will E, Graham C. Functional outcome and risk of recurrent instability after primary traumatic anterior shoulder dislocation in young patients. J Bone Joint Surg Am 2006;88:2326-36.</ref>

Many patients above the age of 30 would consequently undergo unnecessary surgery if proposed after the first dislocation. Conservative treatment after the first traumatic anterior dislocation may be thus recommended for patients who are not actively engaged in sports, above the age of 30 years old, with a low functional demand, with an associated humeral fracture, or for the athlete with an in-season shoulder dislocation. For the latter situation, athletes are allowed to attempt to return to competition provided there is enough time left in the season to permit adequate rehabilitation with progression to sport-specific drills.

Rehabilitation, including return of range of motion and strengthening of dynamic stabilizers may facilitate return to sport within several weeks. Motion-limiting braces that prevent extreme shoulder abduction, extension, and external rotation are often prescribed as it may reduce the risk of recurrence. However, such braces are not well-tolerated in patients who must complete certain overhead tasks such as throwing. Moreover, a second in-season shoulder dislocation should lead to removal from sport and proceeding with stabilization so as to avoid further glenohumeral damage.

A number of studies have compared nonoperative treatment and arthroscopic stabilization. Overall, these studies report a sevenfold reduction in the risk of recurrent instability after arthroscopic stabilization, when compared with nonoperative treatment for the first-time dislocator.<ref>Murray IR, Ahmed I, White NJ, Robinson CM. Traumatic anterior shoulder instability in the athlete. Scandinavian journal of medicine & science in sports 2013;23:387-405.</ref>

A Cochrane review concluded that early surgical intervention is warranted in young adults aged less than 30 years engaged in highly demanding physical activities.<ref>Handoll HH, Almaiyah MA, Rangan A. Surgical versus non-surgical treatment for acute anterior shoulder dislocation. The Cochrane database of systematic reviews 2004:CD004325</ref>

Consequently, for patients who are actively engaging in a collision or contact or overhead sport, who risk their life in case a new dislocation (e.g. firemen, proponents of extreme sports like base jumping, and climbing), with associated static anterior subluxation, an interposed tissue or a nonconcentric reduction, or patients with rotator cuff avulsion, conservative measures are usually inadequate and prompt surgery is indicated.

===Surgical (Operative) Treatment===
Recurrent dislocation is not trivial. Each episode creates new lesions and increases the risk of developing dislocation arthropathy. The concept of early operative surgical management of the first-time dislocator has consequently been introduced to address the high recurrence rate in the young athletic population. Surgery should be proposed, as having the ultimate aim to achieve a pain-free stable shoulder while preserving range of motion. The surgical approach is based on the extent of bone loss and patient-specific risk factors for recurrence.

====Soft tissue procedures====
=====Bankart and Associate Repairs=====
The aim of a Bankart repair is to restore anatomy by reattaching the labrum to the glenoid (Figure) and tighten the inferior glenohumeral ligament by shifting from inferior to superior. Several technical factors are also important to success. It is important to place anchors at the margin of the articular surface (as opposed to the glenoid neck) to allow recreation of the labral bumper. The surgeon must be sure to obtain a proper inferior to superior shift of the capsule (Neer’s modification). Although this surgery can be performed in an open manner, the advantage of an arthroscopic approach is that it preserves the subscapularis and allows assessment of associated pathology. The literature demonstrates that patients with low risk of recurrence will benefit from either an anatomic open or arthroscopic repair with an acceptable rate of recurrence.<ref>Harris JD, Gupta AK, Mall NA, Abrams GD, McCormick FM, Cole BJ, Bach BR Jr, Romeo AA, Verma NN. Long-term outcomes after Bankart shoulder stabilization. Arthroscopy 2013;29:920-33.</ref>
[[File:1562546210935-lg.jpg|center|thumb|600x600px|Illustration of a Bankart repair (sagittal view of a right shoulder). Courtesy of Gilles Walch.]]

HAGL (Humeral Avulsion of the Glenohumeral Ligaments) lesions are uncommon causes of anterior instability. There are 3 variants of HAGL lesions: 1. Avulsion from bone 2. Capsular split 3. Combined bone avulsion and capsular split. These lesions can be addressed by repair or more easily by a Latarjet.

=====Remplissage=====
Remplissage has been described by Connoly and may be used as an adjunct to arthroscopic Bankart repair in the setting a of large Malgaigne (Hill-Sachs) lesion with glenoid bone loss of <25%.<ref>Connoly J. Humeral head defects associated with shoulder dislocations. American Academy of Orthopaedic Surgeons Instructional course lectures: Mosby; 1972:42-54.</ref>

This technique consists of a posterior capsulodesis and infraspinatus tenodesis that fills the Malgaigne lesion. The purpose is to render the Malgaigne lesion extra-capsular, avoiding its engagement. Wolf et al. and Boileau et al. presented encouraging mid- to long-term results of arthroscopic remplissage and concomitant anterior Bankart repair.<ref name=":20">Boileau P, O'Shea K, Vargas P, Pinedo M, Old J, Zumstein M. Anatomical and functional results after arthroscopic Hill-Sachs remplissage. J Bone Joint Surg Am 2012;94:618-26.</ref><ref name=":21">Wolf EM, Arianjam A. Hill-Sachs remplissage, an arthroscopic solution for the engaging Hill-Sachs lesion: 2- to 10-year follow-up and incidence of recurrence. J Shoulder Elbow Surg 2014;23:814-20.</ref>

Surgical Technique
The arthroscope can typically remain in the posterior portal because the 70 degrees angle enhances appropriate visualization. Depending on patient anatomy, the arthroscope can be switched to the anterolateral portal to obtain another view of the defect. A spinal needle is centered over the Malgaigne (Hill-Sachs) lesion, and an accessory posterolateral portal is created 2 fingerbreadths lateral to the posterior viewing portal to allow orthogonal insertion of suture anchors. The use of a cannula is optional. A shaver is used to abrade the Malgaigne (Hill-Sachs) lesion. Two anchors are inserted in the valley of the defect adjacent to the articular margin, 1 superior and 1 inferior. If used, the cannula is at this point retracted into the subdeltoid space. A curved penetrating grasper is used to retrieve the inferior anchor suture, followed by a straight penetrating grasper for the superior anchor suture. The humeral head is reduced, and the inferior sutures are tied in mattress fashion in the subdeltoid space, followed by the superior sutures, to complete the remplissage.

=====Subscapularis Tendon Augmentation or Capsular Reconstruction=====
When traditional arthroscopic Bankart repair is not possible due to severe capsulolabral deficiency, different types of open or arthroscopic subscapularis tendon augmentation or capsular reconstruction have been described.<ref name=":27">Denard PJ, Narbona P, Lädermann A, Burkhart SS. Bankart augmentation for capsulolabral deficiency using a split subscapularis tendon flap. Arthroscopy 2011;27:1135-41.</ref><ref>Maiotti M, Massoni C, Russo R, Schroter S, Zanini A, Bianchedi D. Arthroscopic Subscapularis Augmentation of Bankart Repair in Chronic Anterior Shoulder Instability With Bone Loss Less Than 25% and Capsular Deficiency: Clinical Multicenter Study. Arthroscopy 2016.</ref><ref>Maiotti M, Russo R, Zanini A, Schroter S, Massoni C, Bianchedi D. Arthroscopic Bankart repair and subscapularis augmentation: an alternative technique treating anterior shoulder instability with bone loss. J Shoulder Elbow Surg 2016;25:898-906.</ref><ref>Russo R, Della Rotonda G, Cautiero F, Ciccarelli M, Maiotti M, Massoni C, Di Pietto F, Zappia M. Arthroscopic Bankart repair asciated with subscapularis augmentation (ASA) versus open Latarjet to treat recurrent anterior shoulder instability with moderate glenoid bone loss: clinical comparison of two series. Musculoskelet Surg 2016.</ref>

[[File:1562546211256-lg.jpg|center|thumb|609x609px|Bankart augmentation with split subscapularis tendon transfer. (A) A flap of the posterior portion of the superior half of the subscapularis tendon is created. (B) The subscapularis flap is mobilized in a trapdoor fashion such that the capsular surface of the subscapularis tendon is reflected from medial to lateral as a separate lamina while the outer surface is left unaltered. Note, arrows in (A) and (B) point to the free margin of the subscapularis tendon flap. (C) The subscapularis flap undergoes tenodesis to the anterior glenoid suture anchors to augment capsulolabral deficiency. Reproduced from Denard et al.,<ref name=":27" /> with permission.|alt=]]

Surgical technique
A standard diagnostic arthroscopy is performed with a 30 degrees arthroscope, viewing through a posterior portal with a pump maintaining pressure of 50 mm Hg. The labrum is inspected in its entirety. An anterior portal is established just above the lateral half of the subscapularis and medial to the sling of the biceps, by use of an 18-gauge spinal needle with an outside-in technique. An anterosuperolateral portal is similarly established off the anterolateral border of the acromion. This portal should be placed so that it provides a 45 degrees angle of approach to the superior glenoid. The arthroscope is placed in the anterosuperolateral portal, and the anterior labrum is more thoroughly inspected. The remaining capsulolabral sleeve is dissected from the glenoid neck with an arthroscopic elevator until the subscapularis muscle is visible deep to the cleft. A 2- to 3-mm strip of articular cartilage is removed along the glenoid rim with a ring curette, creating an enhanced bone bed for capsulolabral repair. A capsulolabral repair is performed inferiorly with whatever good tissue remains. An anteroinferior anchor is placed. After placement of this anchor, if there is insufficient capsulolabral tissue to create the desired “bumper” along the anterior glenoid rim, the surgeon must consider various reconstructive options, including a split subscapularis tendon flap.

=====Augmentation With Split Subscapularis Flap=====
To augment the capsulolabral deficiency, a flap of the posterior portion of the superior half of the subscapularis tendon is mobilized and undergoes tenodesis to the anterior glenoid. This flap is created in a “trapdoor” fashion such that the capsular surface of the subscapularis tendon is reflected from medial to lateral as a separate lamina while the outer surface in left unaltered. By use of arthroscopic scissors introduced through the anterior portal, a longitudinal incision through one-half the thickness of the subscapularis is created in the superior half of the tendon (Figure).
[[File:1562547676763-lg.jpg|center|thumb|600x600px|Left shoulder, anterosuperolateral viewing portal, showing creation of a split subscapularis flap to augment a Bankart repair in the setting of capsulolabral deficiency. The flap is created with arthroscopic scissors introduced through an anterior portal. Suture is also seen from an inferior Bankart repair (arrow). (SSc, subscapularis tendon.). Reproduced from Denard et al.<ref name=":27" />, with permission.]]

Care is taken not to violate the full thickness of the subscapularis. The subscapularis flap dissection progresses from medial to lateral until the leading medial edge of the flap is mobile enough to reach the anterior glenoid. After mobilization of the subscapularis tendon flap, additional suture anchors are placed on the previously prepared glenoid strip at the 3-o'clock and 4-o'clock positions. Sutures from the anchor are passed through the subscapularis flap and tied as described previously. This completes the augmentation with a split subscapularis tendon flap (Figure).

[[File:1562547677981-lg.jpg|center|thumb|1071x1071px|Left shoulder, anterosuperolateral viewing portal, showing completed arthroscopic Bankart repair augmented with a split subscapularis flap in the setting of capsulolabral deficiency. (A) Completed repair showing restoration of anterior soft tissue by use of the split subscapularis tendon (SSc) flap. (B) The split between the subscapularis (arrow) is visualized anterior to the flap that has undergone tenodesis. (G, glenoid; H, humeral head.). Reproduced from Denard et al.,<ref name=":27" /> with permission.]]

Postoperatively, the patient's extremity is placed in a sling for 6 weeks. At the end of six weeks, stretching exercises are commenced with full forward flexion allowed and external rotation to half that of the contralateral shoulder. The goal is to achieve half the external rotation of the normal side at three months postoperatively. Strengthening is delayed until four months postoperatively because this is usually a last-resort salvage procedure. Return to full activities is delayed until one year postoperatively.

=====Dynamic Anterior Stabilization (DAS)=====
[[File:DAS long.mov|thumb|Surgical Technique]]

Dynamic anterior stabilization transfers the long head of the biceps to the anterior glenoid margin, thereby creating a “sling effect” (Figure).
[[File:1562547677283-lg.jpg|center|thumb|700x700px|(A) Native shoulder. (B) Latarjet procedure. The coracoid graft including the conjoint tendon is secured to the anterior glenoid by means of two 4.5-mm screws. (C) Dynamic anterior stabilization. The long head of the biceps is transferred to the anterior glenoid margin. Reproduced from Collin et al.,<ref name=":13" /> with permission.]]
 The dynamic anterior stabilization technique provides decreased anterior glenohumeral translation in cases of Bankart lesions with limited anterior bone loss (<20%)<ref>Mehl J, Otto A, Imhoff FB, Murphy M, Dyrna F, Obopilwe E, Cote M, Lädermann A, Collin P, Beitzel K, Mazzocca AD. Dynamic Anterior Shoulder Stabilization With the Long Head of the Biceps Tendon: A Biomechanical Study. Am J Sports Med. 2019 May;47(6):1441-1450.</ref>

In comparison with isolated Bankart repair, it is able to stop the anterior translation less anterior and therefore reduces the risk of a conflict between the humeral head and the anterior margin of the glenoid. It is also easier and safer than arthroscopic Latarjet. Moreover, it does not require screws nor traction of the coracoid process, and should consequently reduce the risks of neurologic damage. Furthermore, the procedure can be performed with only 3 small incisions (Video), as it does not require coracoid transfer, which eliminates risks of nerve dissection, graft overhang and cortical resorption, hence reducing the probability for dislocation arthroplasty. Lastly, the pectoralis minor remains intact, which would avoid scapular dyskinesis. The potential drawbacks of the dynamic anterior stabilization are that it relies on the long head of biceps tendon, which has smaller diameter than the conjoint tendon and could therefore have a weaker “sling effect” than that of the standard Latarjet. Also, there are, like in the Latarjet procedure, the risks of biceps pain, and secondary iatrogenic factors. Furthermore, in cases with larger bone defects (≥ 20 %) there is a relevant posterior and inferior shift of the humeral head in relation to the glenoid, when the arm is brought in the ABER position.(reference to be completed) Indications and limitations are yet to be defined. MRI scans showed that the transposed long head of the biceps successfully healed to the glenoid rim and remained intact at the 6- and 12-month follow-ups in patients who underwent dynamic anterior stabilization for the treatment of chronic anteroinferior glenohumeral instability with bipolar and/or SLAP II lesions with limited (<13.5%) to subcritical (13.5%—25%) glenoid bone loss.<ref name=":28">de Campos Azevedo C, Ângelo AC. All-Suture Anchor Dynamic Anterior Stabilization Produced Successful Healing of the Biceps Tendon: A Report of 3 Cases. JBJS Case Connect. 2021:17;11(1)</ref> However, it is recommended that future studies are carried out with a more long-term follow-up.

Preoperative Patient Positioning
The operation, illustrated in the video, is performed in the semi-beach chair position under general anesthesia with an interscalene block. An examination under anesthesia is performed before prepping and draping the arm.

Initial Exposure and Portal Placement
An intra-articular approach is used through a standard posterior portal (soft spot), a standard diagnostic arthroscopy is performed with a 30-degree arthroscope and a pump maintaining pressure at 60 mm Hg. Antero-lateral and anterior portals are then established by an outside-in technique using a spinal needle as a guide. The rotator interval is opened, and the internal structures (glenoid defects, humeral defects, etc.) are further assessed with a probe.

Anterior Glenoid Preparation
From a lateral viewing portal, the labrum, if necessary, is detached from the glenoid, and a suture is passed around the labrum and pulled through the posterior portal to increase access for preparation of the anterior glenoid (Figure). The glenoid neck is cleaned from soft tissues at around 3 o’clock with a burr.

[[File:1562549774413-lg.jpg|center|thumb|600x600px|Intra-articular view of a right shoulder, anterolateral viewing portal. A suture is passed around the detached labrum and pulled through the posterior portal to increase access for preparation of the anterior glenoid. ∗ indicates the labrum, the black arrows the access to the glenoid neck, and HH the humeral head. Reproduced from Collin et al.,<ref name=":13" /> with permission.]]

Addressing the Long Head of Biceps and Subscapularis Split
The long head of biceps is then tenotomized and the biciptal groove is opened laterally and distally to avoid detaching the subscapularis (Figure).
[[File:1562549775232-lg.jpg|center|thumb|600x600px|Retrocoracoid space of a right shoulder, anterolateral viewing portal. After LHB tenotomy, the bicipital sheath (black arrows) is opened laterally and the LHB (∗) is found. (CT, conjoint tendon; LHB, long head of the biceps.). Reproduced from Collin et al.,<ref name=":13" /> with permission.]]
The biceps is then exteriorized, and secured 20 mm from the proximal tendon. From a lateral viewing portal the subscapularis is exposed on three sides, together with the lateral margin of the conjoint tendon. Three options exist to create a split in the middle of the subscapularis above the junction of the superior two-thirds used in the standard Latarjet procedure: From a lateral viewing portal, either a switching stick (Wissinger Rod) can be passed across the glenohumeral joint through a posterior approach at the level of the inferior glenoid (Figure), an outside-in approach can be used or simply by passing through the subscapularis muscle with a suture passer, by grabbing the sutures that secure the biceps and pulling the biceps through the tendon.

[[File:1562549776269-lg.jpg|center|thumb|600x600px|Intraoperative view of a right shoulder with passage of the switching stick (∗) across the glenohumeral joint at the level of the inferior glenoid to the subscapularis. (HH, humeral head). Reproduced from Collin et al.,<ref name=":13" /> with permission.]]

The switching stick is now found in the retrocoracoid space and maintained lateral to the conjoint tendon to avoid damaging the nerve plexus. The probe is then introduced through the anterior portal to complete the split.

Long Head of Biceps Tenodesis to Anterior Glenoid
A drill is then used to prepare a hole at 3 o'clock from anterior to posterior within the neck of the glenoid, 2.0 cm deep, depending on the length of the interference screw. The LHB tendon is then passed through the subscapularis split into the pre-drilled hole, to establish the “sling effect”, and fixed using a tenodesis screw (Figure).

[[File:1562549775588-lg.jpg|center|thumb|600x600px|Intraoperative view of a right shoulder through the subscapularis split, anterolateral viewing portal. The long head of the biceps tendon (black arrow) is fixed using a tenodesis screw (∗) to establish the “sling effect”. Reproduced from Collin et al.<ref name=":13" />, with permission.]]

Alternatively, the biceps may be managed without exteriorization, as shown in the linked video.[https://www.vumedi.com/video/all-suture-anchor-double-double-pulley-dynamic-anterior-stabilization/] When choosing this technical variant, two all-suture anchors (double loaded with sutures) must me placed on the glenoid rim and each of the respective eight suture limbs must be passed through the biceps before the tenotomy is completed; a double-pulley technique is used to shuttle the biceps through the subscapularis tendon split to the anteroinferior glenoid; the biceps is fixed to the glenoid with a total of four knots (Figure).

[[File:Figure 4 jpeg.jpg|none|thumb|959x959px|Representation of the posterior portal arthroscopic view of the trans-subscapular transposition of the long head of the biceps using the double double-pulley on a right shoulder in the beach chair position. A) Two knots of the double double-pulley are tied after all suture limbs were passed through the long head of the biceps (LHB) tendon; B) the remaining 4 opposing suture limbs are pulled and the LHB tendon reaches the anteroinferior glenoid rim after passing through the subscapularis tendon (SC) split; C) the dashed line represents the final course of the LHB tendon through and anteriorly to the subscapularis tendon. The opposing 4 suture limbs will each be used to obtain an additional 2 knots to reinforce the fixation of the LHB to the glenoid rim. Reproduced from de Campos Azevedo and Ângelo<ref name=":28" />, with permission.]]

Labral Repair
With the arthroscope through the posterior portal, a standard Bankart repair is performed using 2-3 suture anchors. The anchors are placed on the glenoid rim at 3, 4, and 5 o’clock to enable the retention of the capsulo-ligamentous structures and to re-establish the labral damper effect (Video and Figure).
[[File:1562549775598-lg.jpg|center|thumb|600x600px|Intra-articular view through the posterior portal. Associated capsulolabral repair using 2 to 3 anchors recreates normal articular concavity (bumper effect). The anchors are placed on the glenoid rim between 3 and 6 o'clock, depending on the lesion. ∗ indicates the labrum. Reproduced from Collin et al.,<ref name=":13" /> with permission.]]

Postoperative Rehabilitation
Patients are instructed to wear a simple sling for 10 days encouraging rest and reducing the risk of post-operative hematoma formation. Rehabilitation with self-mobilization in elevation and external rotation is allowed from day 0. At 10 days, activities of daily living are allowed and self-mobilization in elevation and external rotation continued. Return to low-risk sports (eg, jogging, cycling, and swimming) is allowed at 6 weeks, and high-risk (throwing and collision) sports at 3 months only after satisfactory clinical and radiographic evaluations confirm satisfactory healing of the coracoid graft. Initially, no physiotherapy is recommended.

====Bony procedures====
In the setting of glenoid bone loss ≥20% of the glenoid diameter an arthroscopic Bankart repair has an unacceptably high rate of recurrence. Burkhart and DeBeer reported a 4% recurrence rate for arthroscopic Bankart repair when glenoid bone loss was <25%. However, with glenoid bone loss ≥25%, the recurrence rate was 67% with an arthroscopic approach. They subsequently recommended a bony procedure procedure in the population with substantial glenoid bone loss.<ref name=":4" />

Treatment is based on patient factors and associated pathology as previously discussed. In general, for patients under the age of 30, primary stabilization following a first traumatic anterior instability episode is offered. Such patients are counseled on the natural history or anterior instability and the potential for subsequent injury. For the majority of patients over the age of 30, nonoperative treatment is advised with standard sling immobilization for three weeks followed by progressive strengthening and return to activities. For such patients with persistent weakness or recurrent instability a magnetic resonance imaging (MRI) or MRI arthrogram is obtained to evaluate for an associated rotator cuff tear and stabilization is performed.

In consideration of the current literature, the following indications for osseous reconstruction procedures of the glenoid concavity can be recommended: - Substantial erosion-type defects (type IIIb), which constitute the instability-associated main pathology. - Chronic fragment-type defects (type II), where the glenoid area and concavity cannot be reconstructed by mobilization and refixation of the fragment. - In the rare patient with an acute, non-reconstructible, multifragmented glenoid fracture (type Ic). - In cases of revision surgery, e.g. after failed soft-tissue stabilization, a glenoid augmentation procedure is recommended also for smaller bony defects (type IIIa).

=====Open Latarjet=====
In 1954, Latarjet reported a coracoid transfer procedure in which the inferior aspect of the coracoid was secured to the anterior glenoid. The excellent stability of this procedure is obtained by a triple effect first proposed by Patte:<ref>Patte D, Debeyre J. Luxations récidivantes de l’épaule. Tech Chir Orthop Paris: Encycl Med Chir 1980:44–52.</ref>

1) the sling effect of the conjoint tendon when the arm is abducted and externally rotated, 2), the ‘‘bony effect’’ that increases or restore the glenoid anteroposterior diameter (Figure), and 3) the retensionning of inferior capsule to the stump of coracoacromial ligament, rending the coracoid extra-articular.
{| class="wikitable"
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![[File:1562549774884-lg.jpg|center|thumb|412x412px]]A
![[File:1562549775216-lg.jpg|center|thumb|300x300px]]B
!
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''Illustration of the three effects A) the sling effect, B) the bony effect and C) the retensioning of the capsule. Courtesy of Gilles Walch.'' 

When the arm is at an end-range position, the sling effect contributes 76-77% at different loads and the capsule the remaining 23-24% to the stabilization of the humeral head. At the mid-range position of the arm, the sling effect facilitates 51-62% and the bone block 38-49% of the stability. The sling effect, therefore, seems to constitute the number one stabilizing mechanism of the Latarjet procedure at both, the mid- and end-range of motion. The internal-external range of motion is thereby not significantly impaired.<ref>Yamamoto N, Muraki T, An KN, Sperling JW, Cofield RH, Itoi E, Walch G, Steinmann SP. The stabilizing mechanism of the Latarjet procedure: a cadaveric study. J Bone Joint Surg Am 2013;95:1390-7.</ref>

The Latarjet procedure is associated with a very low recurrence rate even in the setting of substantial glenoid bone loss and has become the gold standard of treatment in such settings. In addition, this non-anatomic method of anterior glenohumeral stabilization has progressively expanded and is actually the primary technique of choice for many European surgeons, as it prevents recurrent anterior instability in approximately 95 to 99% of cases. This procedure is also favored by some as a first choice in many contact athletes.<ref>Joshi MA, Young AA, Balestro JC, Walch G. The Latarjet-Patte procedure for recurrent anterior shoulder instability in contact athletes. Clinics in sports medicine 2013;32:731-9.</ref>

[[File:1562549775732-lg.jpg|center|thumb|600x600px|Illustration of a partial remodelling after an anteroposterior 2.5 cm tricortical iliac crest bone block. Antero-posterior (A) and Neer (B) view of a right shoulder after iliac crest bone block. Observe on 3 years computer tomography (CT) scan follow-up, the anteroposterior diameter of the glenoid remains supraphysiologic, explaining the efficiency of this open procedure.]]
Surgical technique (Video)
[[File:1563403564475-lg.mp4|center|thumb|300x300px|Video]]

Patient preparation
The patient is positioned in a classical, 40 degrees, beach chair position, preferably under a combination of general anesthesia and locoregional interscalene block to maximize the patient and the surgeon’s comfort. A single prophylactic antibiotic dose is highly recommended, as infectious complications are not uncommon in the proximity of the axilla. The upper limb is draped freely to allow manipulation of the shoulder and placed on an arm board. The operative site, including the sternoclavicular joint medially, is covered with iodine incise drape.

Incision
The incision is performed under the tip of the coracoid process extending 4 to 5 cm distally.
[[File:Gfaddw .png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The tip of the coracoid process is palpated, and the incision is performed under the tip of the coracoid process extending 4 to 5 cm distally.]]
The dissection begins at the level of the Mohrenheim fossa, a triangular region just inferior to the clavicle, between the deltoid and pectoralis major muscles which do not contain neurovascular structures. The deltopectoral interval is then opened bluntly with two Richardson retractors, letting the cephalic vein medially.
[[File:Figure 2da a.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The dissection begins at the level of the Mohrenheim fossa, a triangular region just inferior to the clavicle, between the deltoid and pectoralis major muscles, which do not contain neurovascular structures. The deltopectoral interval is then opened bluntly with two Richardson retractors.]]
The Gelpi retractor is placed deep in the approach, while the cephalic vein is retracted laterally. The whole coracoid process with the insertion of pectoralis minor, coracoacromial ligament, and the conjoined tendon (CT) is exposed by placing the Hohmann retractor on its tip.
[[File:Figure 3d a aw.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The whole coracoid process with the insertion of pectoralis minor, coracoacromial, and the CT is exposed by placing the Hohmann retractor on its tip.]]
The pectoralis minor is released from the coracoid process with electrocautery while the arm is internally rotated and adducted.
[[File:Figure 4d ada .png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. Pectoralis minor (blue arrow) is released from the coracoid process (CP) while the arm is in adduction and internal rotation. CT – conjoined tendon.]]
The upper limb is abducted and fully externally rotated to improve the coracoacromial ligament visualization, which is then released approximately 1.5 cm laterally from its attachment.
[[File:Figure 5da ada .png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The coracoacromial ligament (white arrow) is released 1.5 cm laterally from its attachment on the coracoid process (CP). The arm is abducted and externally rotated for 90° to improve its visualization. CT – conjoined tendon.]]
Coracoid graft harvest and preparation
A 90° angled saw blade is used to perform a coracoid process osteotomy at its base as far back as possible but still just anterior to the coracoclavicular ligament, starting superomedialy and proceeding inferolateraly.
[[File:Figure 64v q.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. A 90° angled saw blade is used for coracoid osteotomy, which is performed at the base of the coracoid process (CP) as far back as possible, however still in front of the coracoclavicular ligaments. CT – conjoined tendon.]]
When the coracoid process gets loose, a chisel is meticulously used to complete the osteotomy.
[[File:Figure 7dqwq qd.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The coracoid osteotomy is meticulously finished with a chisel. CP – coracoid process. ]]
The coracoid process is rotated for 180° while being held with a grasper. It is attentively released until the muscle belly is uncovered in order to be easily and safely manipulated. The coracoid process should not be placed outside the surgical field to avoid tension in musculocutaneous nerve neuropraxia. Its undersurface is flattened and slightly decorticated with a saw blade to create a healthy bleeding surface that will precisely conform to the later prepared anterior glenoid.
[[File:Figure 8q q .png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The undersurface of the coracoid process (CP) is flattened and slightly decorticated with a saw blade to create a healthy bleeding surface that will precisely conform to the later prepared anterior glenoid.]]
The two 4 mm holes for screw fixation are drilled equally distant from the base and the tip, 1 cm apart and 8-9 mm laterally from the insertion of the coracoacromial.
[[File:Figure 9das as.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. Two 4 mm holes for screw fixation are predrilled perpendicularly and centrally in the coracoid graft, 1 cm apart, and 8-9 mm laterally from the insertion of the coracoacromial. ]]
It is essential that the holes are drilled perpendicularly to the surface and centrally to the graft. There are two options for labral fixation, either by transosseous coracoid fixation or by fixation with anchors at the later medial coracoid-glenoid edge. If the surgeon chooses the transosseous coracoid fixation, two holes for later labral fixation are predrilled with a K-wire on the lateral coracoid process bony rim where the coracoacromial inserts, but so that they are placed bellow it and do not pass it. A non-resorbable suture is shuttled through each of them. The coracoid process is retracted medially with the pectoralis major muscle.

Glenoid exposure and preparation
The arm is placed in abduction and external rotation and the subscapularis split between the upper 2/3 and lower 1/3 of the subscapularis is performed by sharply introducing horizontally placed scissors towards the anterior glenoid neck.
[[File:Figure 10Ada s.png|none|thumb|Left upper extremity of a patient placed in a semi beach-chair position. The arm is placed in abduction and external rotation. ]]
[[File:Figure 10Bdaads a.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The subscapularis split between the upper 2/3 and lower 1/3 of the subscapularis (SSc) is performed by sharply introducing horizontally placed scissors through the subscapularis muscle towards the anterior glenoid neck. Then they are rotated for 90°.]]
Then, they are rotated for 90°. Their blades are extended to widen the split, while a Hohmann retractor is placed between the blades on the medial side of anterior glenoid neck. The division is additionally increased with a No. 15 blade.
[[File:Figure 11A.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position.The blades of the scissors are extended to widen the split, while a Hohmann retractor is placed between the blades on the medial side of the AGN. AGN – anterior glenoid neck.]]
[[File:Figure 11B.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The split is additionally increased with a No. 15 blade. SSc - Subscapularis, * - anterior capsule.]]
The superior and inferior parts of the subscapularis are held apart by two Gelpi retractors, one placed superficially and one deeper, while a Hohmann retractor is placed on the inferior aspect of the glenoid neck. The glenohumeral joint's exact location is exposed by reducing the anteriorly dislocated humeral head, and a vertical incision is performed.
[[File:Figure 12.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The exact location of the glenohumeral joint is exposed by reducing the anteriorly dislocated humeral head, and a vertical incision is performed in an inferior to a superior direction to protect the axillary nerve. * – anterior capsule.]]
A Trillat instrument is introduced in the joint to slightly posteriorly subluxate the humeral head to get a better view of the anterior labrum, and a wide glenoid retractor is exchanged with the Hohmann retractor on the medial side of the anterior glenoid to improve the visualization of the anterior glenoid. The labrum is horizontally released at the level of 3 o'clock position, and the release is extended inferiorly until the 5 o'clock position. Two non-resorbable sutures are passed through the superior and inferior half of the released labrum for later labral reconstruction.
[[File:Figure 13.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The labrum is horizontally released at the level of 3 o'clock position, and the release is extended inferiorly until the 5 o'clock position. A resorbable suture is passed through the superior half of the released labrum (white arrow). Afterward, another suture is passed through the inferior half of the released labrum for later labral reconstruction. ]]
A curved osteotome is used to slightly decorticate the anterior glenoid neck from 3 o'clock to 5 o'clock position to a healthy and bleeding flat bone bed.
[[File:Figure 14.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. A curved osteotome is used to lightly decorticate the AGN from 3 to 5 o'clock position to a healthy and bleeding flat bone bed. AGN – anterior glenoid neck.]]
The inferior hole aimed less than 10° away from the glenoid articular surface is predrilled with a 2.75 mm cannulated drill in the anterior glenoid neck, located 8-9 mm from the anterior glenoid.
[[File:Figure 15.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The inferior pilot hole aimed less than 10° away from the glenoid articular surface is drilled first with a K-wire and then with a 2.75 mm cannulated drill in the AGN, located 8 mm from the anterior glenoid. AGN – anterior glenoid neck. G – glenoid.]]
When drilling, it is important to stay as parallel as possible to the glenoid surface, as an angle exceeding ten degrees in the axial plane puts the suprascapular nerve at high risk of lesion at its course on the posterior glenoid rim (Figure).<ref name=":23">Lädermann A, Denard PJ, Burkhart SS. Injury of the suprascapular nerve during Latarjet procedure: an anatomic study. Arthroscopy 2012;28:316-21.</ref>[[File:1562551669419-lg.jpg|center|thumb|591x591px|A) The suprascapular nerve passes through the scapular notch beneath the transverse scapular ligament to enter the supraspinatus fossa and provide motor innervation to the supraspinatus muscle. The nerve then courses distally around the base of the scapular spine (spinoglenoid notch) to enter the infraspinatus fossa and provide motor innervation to the infraspinatus muscle. B) The infraspinatus branches of the suprascapular nerve are at risk during screw placement for Latarjet reconstruction. Reproduced from Lädermann et al., with permission.]]

Coracoid Positioning and Fixation

The coracoid process is retrieved and the two sutures that were previously placed through the labrum are inserted through the two predrilled graft holes if the transosseous labral fixation is underway. The coracoid process is placed at the prepared anterior glenoid neck surface. A K-wire is passed through the lower predrilled coracoid and glenoid hole to position the coracoid process on the anterior glenoid neck. The screw length is measured, and the screw is introduced for preliminary fixation.
[[File:Figure 16.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. The coracoid process (CP) is placed at the prepared AGN surface. First, the inferior screw is introduced for preliminary fixation of the coracoid process so that the graft can still slightly rotate around the screw. CT – conjoined tendon.]]
A thin Darrach retractor is used to place the superior part of the coracoid process flush with the glenoid face. Afterward, the superior hole is drilled with a 2.75 mm cannulated drill in the anterior glenoid neck, the length is measured, and the screw is introduced but not fully tightened.
[[File:Figure 17.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. A Darrach (D) is used to place the superior part of the coracoid process flush with the glenoid face. The superior hole is drilled with a 2.75 mm cannulated drill in the AGN, the length is measured, and the screw is introduced but not fully tightened. CP – coracoid process, white arrow – coracoacromial ligament.]]
The anterior labrum is fixed on the coracoid process by tightening the knots of the sutures passing through the labrum.
[[File:Figure 18A.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. Reattachment of the labrum (white arrow) on the coracoid process (CP) remains to be done. The labral reattachment (white arrow) has been performed ]]
[[File:Figure 18B.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. Reattachment of the labrum (white arrow) on the coracoid process (CP) remains to be done. G – glenoid.]]
Then the coracoid is fully fixed by completely tightening the two partially threaded 4.0 mm cancellous screws. This accomplishes an excellent compression between the coracoid process and the anterior glenoid neck due to the lag-by-design technique. If, however, the surgeon an anchor technique, around two anchors are placed at the medial coracoid-glenoid edge, and fixation of the labrum is performed.

Capsulo-labral reconstruction
Finally, the anterior capsule is reconstructed by the imbrication of the coracoacromial ligament with a resorbable suture. While the operated arm is held in external rotation to avoid the postoperative rotational deficit, the humeral head is reduced posteriorly in the center of the glenoid during adduction, slight anterior forward flexion, and a posterior level push.
[[File:Figure 19A.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. Humeral head is anteriorly dislocated.]]
[[File:Figure 19B.png|none|thumb|Left shoulder of a patient placed in a semi beach-chair position. Finally, the anterior capsule (white arrow) is reconstructed by the imbrication of the coracoacromial ligament (CA) with a resorbable suture. It is crucial that during the reconstruction, the arm is placed in adduction, anterior forward flexion, and external rotation and that the anteriorly dislocated humeral head is reduced. ]]
Only then, an adequate capsular tension is expected. The wound is copiously irrigated.

Closure
The wound is copiously irrigated. The lateral tendinous part of the subscapularis is repaired with a non-resorbable suture. A standard layered closure is performed.

=====Arthroscopic Latarjet=====
Surgical Technique
Operations are performed in the usual semi-beach chair position under general anesthesia with an interscalenic block or catheter. Arthroscopic Latarjet are carried out using a total of 5 portals (posterior, anterolateral, anterior, suicide, and superior to access the superior coracoid (Figure 34).
[[File:1562552295999-lg.jpg|center|thumb|600x600px|A) Anterior view, B) posterior view. The modified 5 portals are used for the arthroscopic Latarjet. AL anterolateral, A anterior, S superior, Su suicide portal, P posterior portal. Reproduced from Cunningham et al., with permission.]]
 Intra-articular approach is carried out through the standard “soft spot” posterior portal. The rotator interval is opened, and the internal structures (glenoid defects, humeral defects, HAGL, etc.) are further assessed with the probe. To provide a healthy bed for graft healing, the glenoid neck is abraded between 2 and 5 o’clock with a burr. A release of the subscapularis on 270 degrees and of the lateral side of conjoint tendon are then performed. The two subscapularis nerves and the axillary nerve are only located and not dissected as this may lead to neurological lesions. From a lateral viewing portal, a switching stick is inserted through the posterior approach, passed across the glenohumeral joint at the level of the glenoid defect and then advanced through subscapularis to establish the level of split. From the suicide portal, a modified cannulated subscapularis splitter is advanced on the switching stick to facilitate the split.

The probe is then introduced through the anterior portal to complete the split. The latter is thus done before coracoid osteotomy consequently protecting the plexus. At this point, with the scope in the anterior portal, the coracoid is prepared and then osteotomized with osteotome rather than a burr, in order to keep maximum graft length. The graft is extracted through the suicide portal and prepared outside, as inside debridement and trimming might be less accurate and puts the plexus at risk. The coracoid is then secured on the coracoid positioning cannula and positioned on the glenoid neck flush with the glenoid border. Two long K-wires are inserted through the coracoid positioning cannula, and the glenoid is drilled with a 3.2-mm drill bit. The length of the definitive screw is directly read from the depth gauge on the drill. The fixation is obtained with two 4.5-mm cannulated malleolar screws (Figure).

[[File:1562552292659-lg.jpg|center|thumb|600x600px|A) arthroscopic view and B) postoperative anteroposterior x-ray of a left Latarjet procedure. * indicates the graft fixed on the anterior glenoid. Reproduced from Lädermann et al., with permission.]]

=====Open Bristow=====
Independently of Latarjet, Helfet reported in 1958 a slightly different procedure named after his master, Bristow, where the coracoid with conjoined tendon attached was pressed against the anterior glenoid by suturing it to a slit in the subscapularis tendon instead of a screw.<ref name=":2" />

Despite the frequent synonymous labeling as “Bristow-Latarjet” coracoid transfer, the techniques remain distinct and non-equivalent reconstructive procedures. When differentiating between the coracoid transfer techniques, the stabilizing effect by the Bristow technique is inferior to that of the Latarjet procedure in cases of substantial glenoid bone loss due to the difference in coracoid graft size but also due to the direction of the conjoint tendon (Figure).<ref>Giles JW, Degen RM, Johnson JA, Athwal GS. The Bristow and Latarjet procedures: why these techniques should not be considered synonymous. J Bone Joint Surg Am 2014;96:1340-8.</ref>

[[File:1562552295240-lg.jpg|center|thumb|600x600px|Direction of the conjoint tendon in A) Latarjet and B) Bristow procedure (courtesy of George Athwal). Note that the conjoint tendon (blue arrow) during Latarjet has to go around the inferior subscapularis (dark blue). Contrarily, the conjoint tendon exits directly through the split during Bristow procedure. * indicates the origin of the conjoint tendon. Reproduced from Lädermann et al., with permission.]]

Surgical technique
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=====Arthroscopic Bristow=====
[[File:1562553238652-lg.mp4|center|thumb|600x600px|Video]]

Coracoid Preparation, Drilling, and Osteotomy
The arthroscope is initially maintained in the posterior viewing portal. By use of electrocautery through the anterolateral portal, the rotator interval is opened and the subscapularis is followed medially to the coracoid. During this time, the arm should be internally rotated to relax the subscapularis. The coracoid is dissected and the coracoacromial ligament is released. The anterior portal is established just medial to the coracoid, and the pectoralis minor is released. The undersurface of the coracoid is flattened with a motorized rasp through the anterolateral portal. The coracoid is drilled with a coracoid drill guide, a polydioxanone suture is passed through the bone tunnel, and the coracoid peg button is shuttled in place. Through the anterolateral portal, the coracoid undergoes osteotomy 1.5 to 2.0 cm from its tip.

Glenoid Preparation and Anchor Insertion
The labrum is released from the anterior glenoid neck, and a polydioxanone suture is placed through the labrum at the 5-o'clock position. The anterior glenoid neck is abraded to a flat surface using a motorized rasp and a suture anchor inserted at the 3-o'clock position to be used later for the Bankart repair.

Subscapularis Splitting and Axillary Nerve Protection
By use of switching sticks, the arthroscope is transferred to the northwest portal, the anterior glenoid neck preparation is confirmed, and a short half-pipe cannula is placed through the posterior portal. The glenoid drill guide is inserted over the cannula and placed flush with the glenoid face at the 5-o'clock position. A switching stick retracts the labrum and subscapularis through the west portal, and the glenoid tunnel is drilled from posterior with a 2.8-mm K-wire (the outer sleeve is left in place to facilitate the cortical-button transfer later). The posterior subscapularis spreader replaces the glenoid drill guide and is pushed through the subscapularis muscle along with the 5-o'clock position, at the inferior one-third junction of the subscapularis. An anterior bursectomy is performed through the south portal to identify the “3 sisters” (anterior humeral circumflex vasculature), which are followed to the “2 brothers” (musculocutaneous and axillary nerves). The nerves are carefully protected with a nerve retractor, and the tip of the posterior spreader is slowly opened within the subscapularis muscle. The tendon is split from medial to lateral while the capsule is being preserved, and the anterior subscapularis spreader is inserted through the east portal with its tip medial to the posterior spreader.

Coracoid Transfer and Fixation
By use of a suture retriever through the posterior sleeve, the cortical button and coracoid bone block are transferred through the subscapularis muscle and lie flush with the anterior glenoid neck. This fixation is made using 2 round, 6.5-mm, slightly convex titanium buttons, connecting with a loop of continuous suture, forming 4 parallel strands. The glenoid cortical button is slid over the 4 white suture strands, a sliding-locking Nice knot is tied, and the button is advanced onto the posterior glenoid neck. A specific suture tensioner is used to increase bone compression to 100 N.

Bankart Repair
Using the previously placed glenoid anchor, we complete the labral repair, placing the bone block in an extra-articular position. Additional anchors can be inserted depending on the clinical situation and patient anatomy. The tensioning device is removed posteriorly, and 3 surgeon's knots are tied to complete the coracoid fixation.

=====Eden-Hybinette and Other Free Bone Block Transfers=====
Aiming to reduce donor site morbidity associated with the harvesting of autologous bone blocks, autografts of the iliac crest and distal clavicle and allograft of femoral head and distal tibia have been evaluated (Figure).<ref>Mascarenhas R, Raleigh E, McRae S, Leiter J, Saltzman B, MacDonald PB. Iliac crest allograft glenoid reconstruction for recurrent anterior shoulder instability in athletes: Surgical technique and results. International journal of shoulder surgery 2014;8:127-32.</ref><ref name=":24">Provencher MT, Ghodadra N, LeClere L, Solomon DJ, Romeo AA. Anatomic osteochondral glenoid reconstruction for recurrent glenohumeral instability with glenoid deficiency using a distal tibia allograft. Arthroscopy 2009;25:446-52.</ref><ref>Weng PW, Shen HC, Lee HH, Wu SS, Lee CH. Open reconstruction of large bony glenoid erosion with allogeneic bone graft for recurrent anterior shoulder dislocation. Am J Sports Med 2009;37:1792-7.</ref><ref>Zhao J, Huangfu X, Yang X, Xie G, Xu C. Arthroscopic glenoid bone grafting with nonrigid fixation for anterior shoulder instability: 52 patients with 2- to 5-year follow-up. Am J Sports Med 2014;42:831-9.</ref>

Anatomically, iliac crest bone blocks offer the possibility of a nearly unrestricted graft size, but also the coracoid process was found to be a sufficient graft source to re-establish the anatomy for most glenoid defect cases.<ref>Bueno RS, Ikemoto RY, Nascimento LG, Almeida LH, Strose E, Murachovsky J. Correlation of coracoid thickness and glenoid width: an anatomic morphometric analysis. Am J Sports Med 2012;40:1664-7.</ref>

Provencher et al. described the use of an osteochondral tibia allograft with the advantages of a cartilaginous interface, improved graft availability and an excellent glenoid articular conformity.<ref name=":24" />

Radiologically, successful bony consolidation and a remodeling process of the allografts have been observed, as described for autologous glenoid reconstruction. However, a slightly higher recurrence rates of 0-22% were observed.

[[File:1562555338099-lg.jpg|center|thumb|600x600px|Illustration and arthroscopic intra-operative view of a left anatomic and intra-articular iliac crest bone grafting technique with graft fixation by two bio-compression screws. Reproduced from Lädermann et al., with permission.]]

Surgical Technique
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=====Trillat=====
[[File:Capture d’écran 2020-01-28 à 22.02.11.png|thumb|Native situation]]

[[File:Capture d’écran 2020-01-28 à 22.02.54.png|thumb|Illustration of a shoulder after Trillat procedure]]

[[File:Capture d’écran 2020-01-28 à 22.03.20.png|thumb|Effect of the Trillat procedure with the arm in abduction-external rotation]]

==Rehabilitation==

===Non-Operative Treatment of Acute First Traumatic Dislocations===
Although positioning the arm in external rotation has been recommended, it has now clearly been demonstrated that immobilization of the shoulder in internal rotation after primary, traumatic anterior shoulder dislocation is sufficient.<ref>Vavken P, Sadoghi P, Quidde J, Lucas R, Delaney R, Mueller AM, Rosso C, Valderrabano V. Immobilization in internal or external rotation does not change recurrence rates after traumatic anterior shoulder dislocation. J Shoulder Elbow Surg 2013.</ref><ref>Itoi E, Hatakeyama Y, Sato T, Kido T, Minagawa H, Yamamoto N, Wakabayashi I, Nozaka K. Immobilization in external rotation after shoulder dislocation reduces the risk of recurrence. A randomized controlled trial. J Bone Joint Surg Am 2007;89:2124-31.</ref><ref>Braun C, McRobert CJ. Conservative management following closed reduction of traumatic anterior dislocation of the shoulder. Cochrane Database Syst Rev. 2019 May 10;5:CD004962.</ref>

There is conflicting evidence regarding the length of immobilization required after dislocation but three weeks is typically recommended, followed by physical therapy for strengthening of the rotator cuff and scapular stabilizers. Range of motion of the elbow, wrist, and hand are permitted immediately. Then, closed-chain exercises facilitate rotator cuff function to enhance joint stability and stimulate muscular coactivation and proprioception.<ref>Jaggi A, Lambert S. Rehabilitation for shoulder instability. Br J Sports Med 2010;44:333-40.</ref>

For throwing athletes, a program is initiated and advanced, beginning at three months. A full return to sports is typically permitted at five to six months.

===Rehabilitation Protocol After Bankart and Remplissage Stabilization===
The shoulder is immobilized for four weeks using a sling. Passive and assisted-active exercises are then initiated for forward flexion and external rotation. After six weeks, patients begin strengthening exercises of the rotator cuff and scapular stabilizers. For patients with a remplissage strengthening is delayed until twelve weeks postoperative. Patients are permitted to practice noncontact sports as soon as they recover their range of motion. Full return to throwing or contact sports is usually allowed after six months according to each individual’s functional recovery.

===Rehabilitation Protocol After Dynamic Anterior Stabilization===
Patients are instructed to wear a simple sling for 10 days encouraging rest and reducing the risk of post-operative hematoma formation. Rehabilitation with self-mobilization in elevation and external rotation is allowed from day 0. At 10 days, activities of daily living are allowed and self-mobilization in elevation and external rotation continued. Return to low-risk sports (eg, jogging, cycling, and swimming) is allowed at 6 weeks, and high-risk (throwing and collision) sports at 3 months. Initially, no physiotherapy is recommended.<ref name=":13" />

===Rehabilitation Protocol After Latarjet Reconstruction===
The shoulder is immobilized for ten days using a sling. The patient is asked to stretch in flexion and external rotation at least five times per day. No physical therapy is prescribed. The patient is not allowed to carry with his operated arm or to flex the elbow against resistance during the first six weeks. Activities of daily living are encouraged as comfort permits. At six weeks, non-contact sports are allowed. Return to contact sports is usually possible after three months assuming confirmation of bony union of the coracoid graft.

==Results and Complications==

===Soft tissue procedures (Bankart, Remplissage)===
Arthroscopic Bankart stabilization with use of suture anchors offers the advantage of being minimally invasive, allows assessment of associated pathology, and allows the surgeon to restore anatomy while reattaching the labral lesion and retensionning the glenohumeral ligament. While the short-term outcome of Bankart has been excellent, mid-term reported results show higher rates of recurrent of instability. According to the meta-analysis by Hobby et al., recurrence (dislocation and subluxation) after arthroscopic Bankart repair with suture anchors varies between 0 to 29.6%, with a mean of 8.9%.<ref>Hobby J, Griffin D, Dunbar M, Boileau P. Is arthroscopic surgery for stabilisation of chronic shoulder instability as effective as open surgery? A systematic review and meta-analysis of 62 studies including 3044 arthroscopic operations. J Bone Joint Surg Br 2007;89:1188-96.</ref>

This rate of course varies with patient factors, particularly the amount of bony deficiency. Preoperatively, pitfalls are consequently to underestimate risk factors for recurrence for this surgery. In adolescent contact athletes undergoing arthroscopic labral repair, the overall recurrence rate is 51%. Rugby players who undergo primary arthroscopic shoulder stabilization aged <16 years have 2.2 times the risk of developing a further instability episode when compared to athletes aged ≥16 years at the time of index surgery, with a recurrence rate of 93%.<ref>Torrance E, Clarke CJ, Monga P, Funk L, Walton MJ. Recurrence After Arthroscopic Labral Repair for Traumatic Anterior Instability in Adolescent Rugby and Contact Athletes. Am J Sports Med 2018;46:2969-74.</ref>

Bankart repair combined with Malgaigne (Hill-Sachs) remplissage for large defects of the posterosuperior aspect of the humeral head may be an elegant approach in case of isolated humeral defect. Reported results are promising with a high rate of healing of the posterior aspect of the capsule and the infraspinatus tendon into the humeral defect, and a moderate loss of external rotation with the arm at the side. Moreover, most patients were able to return to sport including those involving overhead activities, around 70% at the same level.<ref name=":20" /><ref name=":21" />

The Malgaigne remplissage is believed to be a posterior capsulotenodesis that acts as a checkrein diminishing anterior humeral head translation and reducing the risk of postoperative redislocation. However, some authors have observed that according to the location of the impaction fracture, the procedure actually corresponds to a capsulomyodesis including the teres minor muscle, rather than a capsolutenodesis as classically described (Figure).
[[File:1562556949052-lg.jpg|center|thumb|600x600px|Posterior view of a right shoulder specimen after rotator cuff repair and Malgaigne (Hill-Sachs) remplissage (three lower knots). Note the proximity of the superior knot to the infraspinatus muscle (black arrow). The two inferior knots perforate the teres minor muscle (white arrow) realizing a capsulomyodesis.]]
 Concerns about remplissage may include the potential muscle lesion to the external rotators, increased cost, and increased difficulty and operative time. Yet, beyond a slight loss in postoperative external rotation, there is no documented additional complication to remplissage.

===Open Bone Block Procedures===
Open anatomical bone grafting procedures show very good clinical mid- to long-term results. With this procedure return to sports activities is possible for at least 83% of patients regardless of the size of glenoid defect. In a study of 107 patients, Lädermann et al. reported a mean postoperative Walch-Duplay score of 93, good or excellent results in 97% of cases, and 95% of patients very satisfied or satisfied with their outcome.<ref name=":14" />

However, complications exist both in the short- and long-term. A systematic review of 30 studies with a total of 1658 coracoid transfers, also including more recent surgeries with shorter follow-up periods, reported a low recurrence rate of 6.0%. The arthropathy rates is also reduced to 17-36% compared to the original procedures. A systematic review of 30 studies, comprising a total of 1658 open coracoid transfers, recorded graft non-union or postoperative graft migration (10.1%), hardware complications (6.5%), instability (6.0%), graft osteolysis (1.6%), infection (1.5%), nerve palsy (1.2%), intraoperative fractures (1.1%) and hematoma (0.7%) with a revision surgery conducted in 4.9% of the cases. Hardware problems were identified as the most frequent reason for revision surgery. In addition to failure of stabilization, hardware or graft malpositioning and respective screw breakage, loosening or migration is attended with a high risk for soft tissue as well as articular surface damage.<ref name=":22">Butt U, Charalambous CP. Arthroscopic coracoid transfer in the treatment of recurrent shoulder instability: a systematic review of early results. Arthroscopy 2013;29:774-9.</ref>

Regarding the postoperative muscle function, a significant strength deficit of the internal and external rotators was observed in comparison to the contralateral, unaffected shoulder.<ref>Caubere A, Lami D, Boileau P, Parratte S, Ollivier M, Argenson JN. Is the subscapularis normal after the open Latarjet procedure? An isokinetic and magnetic resonance imaging evaluation. J Shoulder Elbow Surg 2017;26:1775-81.</ref>

Risk of neurological impairment of the musculocutaneous nerve can be reduced by gently manipulating the coracoid process during preparation and avoiding an excessive medial dissection.<ref>Clavert P, Lutz JC, Wolfram-Gabel R, Kempf JF, Kahn JL. Relationships of the musculocutaneous nerve and the coracobrachialis during coracoid abutment procedure (Latarjet procedure). Surgical and radiologic anatomy : SRA 2009;31:49-53.</ref>

The suprascapular nerve is at risk posteriorly during screw insertion and can be protected by parallel placement of the screws within 10 degrees of the glenoid surface in the axial plane (Figures).<ref name=":23" />
[[File:1562556944819-lg.jpg|center|thumb|500x500px|The infraspinatus branches of the suprascapular nerve are at risk during screw placement for Latarjet reconstruction when a divergence of more than 10 degrees between the screws and the glenoid surface in the axial plane is noted. Photograph showing intimate proximity between screws placed for Latarjet procedure and suprascapular nerve. Reproduced from Lädermann et al., with permission.]]
[[File:1562556938948-lg.jpg|center|thumb|459x459px|Schema of screw and spinoglenoid notch orientation. (A) Axial view. The medial-to-lateral orientation was recorded by measuring the angle of the screws (α 1 angle) and of the spinoglenoid notch wire (β1 angle) relative to the glenoid plane. (B) Sagittal view. The superior-to-inferior orientation was determined by measuring the angle of the screws (α2 angle) and the spinoglenoid notch (β2 angle) perpendicular to the glenoid. (CG, coracoid graft; G, glenoid; HH, humeral head; SN, suprascapular nerve.). Reproduced from Lädermann et al., with permission.]]
[[File:1562556945397-lg.jpg|center|thumb|600x600px|Axial (A) and anteroposterior (B) plain radiographs of a left shoulder. The two screws diverge from the plane of the glenoid, pointing in direction of the spinoglenoid notch. A magnification (C) of the axial view demonstrates poor contact (white arrow) between the glenoid and the graft (delimited by red dotted line). Parallel screws would have led to better contact and a lower risk of suprascapular nerve injury]]
 

===Arthroscopic Bone Block Procedures===
Similarly, very good short-term results are achieved after arthroscopic glenoid rim reconstruction without events of postoperative redislocation and the advantage of subscapularis muscle preservation.<ref name=":25">Anderl W, Pauzenberger L, Laky B, Kriegleder B, Heuberer PR. Arthroscopic Implant-Free Bone Grafting for Shoulder Instability With Glenoid Bone Loss: Clinical and Radiological Outcome at a Minimum 2-Year Follow-up. Am J Sports Med 2016;44:1137-45.</ref><ref name=":26">Kraus N, Amphansap T, Gerhardt C, Scheibel M. Arthroscopic anatomic glenoid reconstruction using an autologous iliac crest bone grafting technique. J Shoulder Elbow Surg 2014;23:1700-8.</ref>

At present, however, merely short-term results of the arthroscopic techniques are published and only by the pioneers of these techniques. Following the arthroscopic coracoid transfer techniques, recurrence rates of 0-2% were observed after short- to mid-term follow-up investigations.<ref>Boileau P, Thélu CÉ, Mercier N, Ohl X, Houghton-Clemmey R, Carles M, Trojani C. Arthroscopic Bristow-Latarjet combined with bankart repair restores shoulder stability in patients with glenoid bone loss. Clin Orthop Relat Res 2014;472:2413-24.</ref><ref>Dumont GD, Fogerty S, Rosso C, Lafosse L. The arthroscopic latarjet procedure for anterior shoulder instability: 5-year minimum follow-up. Am J Sports Med 2014;42:2560-6.</ref><ref>Zhu YM, Jiang C, Song G, Lu Y, Li F. Arthroscopic Latarjet Procedure With Anterior Capsular Reconstruction: Clinical Outcome and Radiologic Evaluation With a Minimum 2-Year Follow-Up. Arthroscopy 2017.</ref>

The arthroscopic approach is, however, quite challenging and requires a lengthy learning curve. When directly comparing the arthroscopic and open techniques, a similar functional outcome and patient satisfaction were achieved, but screw placement inaccuracy, persistent apprehension, recurrence rate and complications were higher for the arthroscopic approach.<ref>Cunningham G, Benchouk S, Kherad O, Lädermann A. Comparison of arthroscopic and open Latarjet with a learning curve analysis. Knee Surg Sports Traumatol Arthrosc 2016;24:540-5.</ref>

A slightly reduced percentage of graft non-union or postoperative graft migration (8.1%), hardware problems (2.3%), instability (1.7%) and nerve injury (0.6%) was recorded, while the rate of osteolysis (4.1%) increased. Conversion to an open approach had to be conducted in 3.5% of the surgeries. However, a smaller number of cases conducted by fewer surgeons is available for evaluation of the arthroscopic approach. Larger case numbers by different surgeons and long-term results are therefore required to validate these first positive outcomes.<ref name=":22" />

===Remodeling of the Graft With Bone Block Procedure===
Regardless of the bone grafting technique employed, whether an implant-free or screw-based fixation method, a remodeling process according to Wolff’s law is observed with successful reconstruction of the anatomical pear-shaped glenoid configuration. Approximately 60% of the entire coracoid graft has been observed to undergo osteolysis. The superficial part of the proximal coracoid is predominantly affected, while the deep portion of the distal coracoid aspect showed the least osteolysis and best osseous union.<ref>Di Giacomo G, Costantini A, de Gasperis N, De Vita A, Lin BK, Francone M, Rojas Beccaglia MA, Mastantuono M. Coracoid graft osteolysis after the Latarjet procedure for anteroinferior shoulder instability: a computed tomography scan study of twenty-six patients. J Shoulder Elbow Surg 2011;20:989-95.</ref>

For the free bone grafting procedures, a partial extra-articular resorption of the initially oversized glenoid reconstruction may lead to restoration of the anatomic glenoid configuration over time in terms of a remodeling process (Figure).<ref>Moroder P, Hirzinger C, Lederer S, Matis N, Hitzl W, Tauber M, Resch H, Auffarth A. Restoration of anterior glenoid bone defects in posttraumatic recurrent anterior shoulder instability using the J-bone graft shows anatomic graft remodeling. Am J Sports Med 2012;40:1544-50.</ref><ref name=":26" />
[[File:1562557690817-lg.jpg|center|thumb|600x600px|Three-dimensional computer tomography reconstruction displaying an erosion-type defect (type III) before surgery (Figure 45 a), immediately after reconstruction using a free iliac crest autograft (Figure 45 b) and one year postoperatively (Figure 45 c) after completion of the remodeling with restoration of the anatomical glenoid configuration. Reproduced from Lädermann et al., with permission.]]
===Complication due to harvesting process of the iliac crest===
In comparison to the coracoid transfer procedure, free bone grafting techniques offer the advantage with potentially less severe complications. Complications of autologous bone grafting are predominantly associated with the harvesting process of the iliac crest bone block including pain, hypoesthesia and hematoma observed in 0-13% of the patients. Attempting to reduce donor site morbidity, current studies are evaluating the use of allogeneic bone material as an alternative to autografts. Further complications reported after open autologous iliac crest bone grafting comprise hardware failure (0-4%), shoulder hematoma (0-4%), subscapularis insufficiency (0-3%), graft fracture (0-2%), infection (0-2%) and adhesive capsulitis (0-2%).<ref>Auffarth A, Schauer J, Matis N, Kofler B, Hitzl W, Resch H. The J-bone graft for anatomical glenoid reconstruction in recurrent posttraumatic anterior shoulder dislocation. Am J Sports Med 2008;36:638-47.</ref><ref>Deml C, Kaiser P, van Leeuwen WF, Zitterl M, Euler SA. The J-Shaped Bone Graft for Anatomic Glenoid Reconstruction: A 10-Year Clinical Follow-up and Computed Tomography-Osteoabsorptiometry Study. Am J Sports Med 2016;44:2778-83.</ref><ref>Scheibel M, Nikulka C, Dick A, Schroeder RJ, Gerber Popp A, Haas NP. Autogenous bone grafting for chronic anteroinferior glenoid defects via a complete subscapularis tenotomy approach. Arch Orthop Trauma Surg 2008;128:1317-25.</ref><ref>Steffen V, Hertel R. Rim reconstruction with autogenous iliac crest for anterior glenoid deficiency: forty-three instability cases followed for 5-19 years. J Shoulder Elbow Surg 2013;22:550-9.</ref><ref>Warner JJ, Gill TJ, O'Hollerhan J D, Pathare N, Millett PJ. Anatomical glenoid reconstruction for recurrent anterior glenohumeral instability with glenoid deficiency using an autogenous tricortical iliac crest bone graft. Am J Sports Med 2006;34:205-12.</ref>

An investigation of 6449 patients reported an overall donor site morbidity rate of 19.4% after iliac crest bone harvesting including infections, chronic pain, fractures and nerve injuries at the harvesting site.<ref>Dimitriou R, Mataliotakis GI, Angoules AG, Kanakaris NK, Giannoudis PV. Complications following autologous bone graft harvesting from the iliac crest and using the RIA: a systematic review. Injury 2011;42 Suppl 2:S3-15.</ref>

The currently published studies evaluating arthroscopic autologous iliac crest bone grafting reported a singular case of donor site morbidity and one case of graft fracture in the 30 patients treated.<ref name=":25" /><ref name=":26" />

===Dislocation arthropathy===
Another complication is the development of dislocation arthropathy with a rate similar to other type of procedures (Figure).<ref>Hovelius LK, Sandstrom BC, Rosmark DL, Saebo M, Sundgren KH, Malmqvist BG. Long-term results with the Bankart and Bristow-Latarjet procedures: recurrent shoulder instability and arthropathy. J Shoulder Elbow Surg 2001;10:445-52.</ref>
[[File:1562557685456-lg.jpg|center|thumb|300x300px|Illustration of the three stage of dislocation arthropathy according to Samilson. Courtesy of Gilles Walch.]]
Even if the development of dislocation arthropathy is concerning (around 30%) (Figure), it is rather associated with the disease rather than to the surgery itself.
[[File:1562557685288-lg.jpg|center|thumb|600x600px|A) Anteroposterior plain radiographs of a left shoulder in a 32 year-old woman presenting with recurrent dislocations. Dislocation arthropathy Samilson B is obvious. B) CT scan of the same shoulder demonstrates significant glenoid and humeral bone loss.]]
While the precise cause is unknown, surgery in patients older than 40 years of age, a prolonged period between the initial dislocation and surgery and a lateral overhang of the transferred coracoid process in relation to the glenoid rim have been identified as risk factors. Contrarily, hyperlaxity was observed to be a protective factor against development of a dislocation arthropathy, which may be explained by the lower glenohumeral contact pressures.<ref name=":14" />

===Pull-out===
Anchor (Bankart repair) or screw (Latarjet, Bristow, free graft transfer) pull-out may happen (Figure).
[[File:1562557690266-lg.jpg|center|thumb|600x600px|A) Radiographs of a left shoulder ten days after a Latarjet reconstruction. The patient has been allowed to remove sling but not to do sport. B) The patient ignored the recommendation and was immediately jogging. He returned five hours after the last examination. Controlled radiographs revealed pullout of the graft due to contraction of the short head of the biceps on the coracoid graft.]]
 

==What would Codman have thought about this?==
The role of the supraspinatus in dislocation...

CHAPTER IX
THE ROLE OF THE SUPRASPINATUS IN DISLOCATIONS AND FRACTURES OF THE SHOULDER JOINT

THIS chapter does not aim to be an exhaustive treatise on fractures and dislocations of the shoulder, although a very large number of articles have been studied in order to compile it. During the summer of 1928, Dr. T. W. Stevenson reviewed the literature for me, with especial effort to find to what extent the bursa and the short rotators had been referred to. At about the same time, I took advantage of the service of the Library Bureau of the American College of Surgeons, with the request that they find for me all the references they could concerning rupture of the supraspinatus tendon. After a careful search they were unable to find any articles whatever which were devoted to the subject, although occasionally they found references to rupture or avulsion of the tendons in cases of dislocation on which operations had been done.
So far as I know there is no record in the literature of what I call the "Pivotal- Paradox," described on page 43. I, myself, did not understand this paradox when I started to write the book, and only gradually puzzled out its meaning and significance. Certainly none of the authors, who have written on dislocations and fractures in this region, seem aware of the facts that in complete elevation of the arm almost no rotation can occur and that the extent of rotation diminishes as the arm is elevated. The lack of this knowledge of normal functions seems to me to render most of the previous explanations of the mechanism of dislocations and fractures in this region nearly worthless, for several important deductions can be made by the use of these facts. I have consequently eliminated much that I had previously written about the opinions of authorities.
In complete elevation there is only one possible geometric relation of the two units, i.e., the head of the humerus and its tuberosities, with the scapula and its processes. No matter in what degree of rotation you start to raise your arm and no matter in what plane you raise it, the capacity for rotation will be less and less as the arm ascends until, in complete elevation, tuberosities and processes will be locked in a fixed position. In this fixed position the articular head of the humerus will be shown by X-ray in the antero-posterior view, to face nearly outward, and in the lateral view to face somewhat forward, i.e., it actually faces obliquely outward and forward, exactly reversed from its anatomic position. The axis of the condyles of the lower end of the humerus becomes antero-posterior, with the internal condyle pointing forward. The humerus has rotated inward 90° and has become inverted. You may say that the angle between the shaft and the axis of the neck gained 45° by inversion and then 45° by external rotation, or you may say, if you please, it first gained 45° by internal rotation and then another 45° by inversion. Do not proceed with this chapter until you are sure that you have understood this paragraph, even if it is necessary for you to take a humerus in your hand.
The reader must bear in mind that this pivotal position may be assumed by extension of the scapula on the humerus as well as by extension of the humerus on the scapula. For instance, the arm may be in this position when a boxer delivers a telling punch, "putting his body into it." However, the true pivotal position implies that the clavicle is elevated and carried backward to its extreme limit when the arm is elevated to its extreme degree. In other words, the scapula and humerus may move into their share of the pivotal position without the clavicle rising (subordinate pivotal positions), but the arm, to attain complete elevation and the true pivotal position, must be raised to the side of the head.
The scapulo-humeral joint will lock in different positions according to the degree of rotation of the humerus, in a very queer way. (See Figs. 25 and 26.) There can be very little scapulo-humeral abduction with the humerus in full internal rotation; i.e., when the forearm is behind the back, even if clavicle is raised. Starting with your clavicle held down, try elevation of your arm in either internal or external rotation, and then compare the extent of motion when you start with it raised. You will see why authors have differed so much in their estimates of the degree of motion possible in the scapulohumeral joint. To get the maximum you must perform elevation in internal rotation in the sagittal plane or external rotation in the coronal plane; you cannot interchange. These motions cannot be estimated by putting the scapula of a cadaver in a vise, because in life they vary with the relative positions of humerus, scapula and clavicle.
It is as if the secondary humeral joint, limited by the acromion and coracoid, were built with two long sloping sides meeting at an angle above the head, so that when the arm is raised in any plane it eventually comes to rest in the trough formed at the angle of the coronal and sagittal planes and cannot rotate any more. Nature's command is: "Make any combination of elevation and rotation within this enclosure which you wish, but if you exceed these normal limits, you may dislocate or fracture your humerus."

A logical conclusion from these facts is that in whatever way a forward or lateral fall occurs, no strain will come on the scapulohumeral structures until they assume this locked position in complete elevation, provided rotation of the humerus is unhindered as the arm is being elevated. In other words, when the arm is being elevated in mid-rotation in the sagittal plane and arrives at a little above a horizontal position, if inward rotation be prevented, some structure must give, provided the fall continues in this plane. This is exactly reversed in the case of falls in the coronal plane, for when outward rotation is prevented, some break in bone or soft parts must occur. The latter example is the usual one in dislocation and fracture of the head of the humerus.
Let us imagine the same forces applied in another way, i.e., by leverage on the arm when the body is in a fixed position, for mechanically it is the same problem whether the falling patient exerts force on the outstretched arm, or the fixed patient has the same force applied to the arm. Let us imagine the arm thrust into a pipe and force applied to that pipe as in the following diagrams, by lifting its free end up from the plane of the paper- (Fig. 53.)
In making an effort to remember the combinations of rotation and elevation of the arm which may or may not be made, a simple formula is this: evolution has fitted the human animal to fall directly forward on his face with his arm and forearm in almost any position in relation to his body, but, once he has fallen, his arm and forearm cannot be brought much behind the plane of his body in the position in which he lies on his face on the ground, without in some way raising his body.
We may learn a good deal about the shoulder joint from watching the maneuvers of a wrestler endeavoring to turn his opponent from a face-downward position. These maneuvers are essentially the same as those represented in the diagrams above, that is, they depend on getting the flexed forearm in such a position that a little more leverage would break or dislocate the humerus, unless the prone wrestler does permit his body to be raised. Of all the possible positions in which his forearm and arm can be pulled backward, that in which the arm lies at the side will show the greatest backward mobility, i.e., "dorsal flexion."
In lateral falls, when the abducted arm is held behind the plane of the body, the same dislocating or breaking strains that the wrestler endeavors to secure may be produced, the force being supplied by gravity. Moreover, falls will be more violent and sudden, and perhaps catch the muscles when relaxed, instead of having the opposing muscles offer resistance by the voluntary tension which the prone wrestler can assume.

FIGURE 53. LEVERAGES CAUSING ANTERIOR AND POSTERIOR DISLOCATIONS
In interpreting this plate the reader must imagine the arm thrust into a pipe, and he must suppose that the patient's body remains in ironlike rigidity while the outer end of the pipe is raised directly upward from the plane of the paper. Provided the body remained rigid and the tube were raised in this manner, a dislocation of the head of the humerus or fracture must occur. Typical backward or subacromial dislocation would occur in Figures 2, 6 and 7, while subcoracoid dislocation would occur in the other positions.

As in simple frontal falls, so in simple dorsal falls no dislocation of the shoulder will occur, if the arms are free, for we may lie on our backs with our arms in any position anterior to the coronal plane of the body. Even when the dorsal fall occurs with the forearm behind the back or behind the head, dislocation is unlikely.
Thus we reach the conclusion that only headlong, lateral, or semi-lateral, sudden falls can produce the forced elevation combined with prevention of rotation which is necessary to cause anterior luxation of the shoulder joint.
It is possible to conjecture, from a more detailed study of the questions just considered, which forms of dislocation, or varied locations of the lines of fracture, will occur in the shoulder if the lines of force are known. For instance, it is safe to say that only the results of forces applied as in Cuts 2, 6 and 7, in Fig. 53, may result in subacromial dislocation, while all of the others produce subglenoid dislocation.
To express the writer's belief in another way: anterior dislocations of the humeral head occur after the arm has reached the fixed "pivotal position," or more often by prevention of rotation when the arm is at least above the level of the shoulder and the extent of possible rotation therefore greatly diminished; subacromial displacements occur when the arm is below the level of the shoulder and is rotated internally.
This belief is founded not only on the facts already mentioned, but on two others. The first is the remarkable ability of the arm to rotate quickly. Any one who has done any wrestling will remember how elusive were his opponent's arms, unless his elbows were bent, and how easily they slipped out of his grasp as he endeavored to obtain a "shoulder lock." The second is the utter unreliability of the histories given by patients of falls "on the shoulder." The reader is again referred to p. 10. Patients with these injuries almost always say that they struck their shoulders and do not realize that they fell with their arms elevated, i.e., raised to fend off the ground. The inertia of the body is so great as compared to that of the arm, that even in a sudden fall the arm may be thrust forward or outward before the body reaches the ground. A man must already be hugging something, as a football, under his arm in order to fall on his shoulder.
The fact that the arm rotates readily in a safe direction as it is instinctively raised (i.e., raised in relation to the scapula, although pointing downward) during a fall, means that subconsciously the arm will usually reach the relatively safe pivotal position. Meantime the palm meets the ground and the force becomes disseminated to the various ligaments, muscles and bones of hand, wrist, elbow, shoulder and back, each in turn breaking the fall until the final bony lock in the pivotal position brings the stress to a limit. Even then the pec-toralis, the teres major and latissimus, and finally the clavicle, may still further disseminate the stresses. But notice that in this elevated position the lines of force of these muscles converge toward the glenoid, so that they are not, in this position, functioning as rotators as they do when the arm is at the side. The higher the axis of the humerus the more their power is exerted toward the face of the glenoid in their effort to avert the leverage of the shaft from gaining a fulcrum on the acromial edge. However, while they are in use in fending off the ground, the pectoralis and latissimus are acting also as strong internal rotators. This is the period of danger (Fig. 55), for the pivotal position, once reached, means safety, unless the downward factor in the fall is great. When the arm is in the pivotal position, the broad tendon of the latissimus actually covers the unprotected axillary portion of the capsule and tends to prevent the head from dislocating, although the pull of this muscle is in the main downward. In this position the long head of the triceps, the teres major and the latissimus actually form a support for the lower half of the capsule.

FIGURE 54. ACTION OF PECTORALIS MAJOR IN DISLOCATION
This diagram pertains to the discussion of whether the pectoralis major and latissimus dorsi should be regarded as furnishing a fulcrum in case of fracture of the upper end of the humerus. The contention is made that the pull of these muscles not only does not act as a fulcrum, but to some extent relieves the strain on the surgical neck, by pulling the tuberosities away from the true fulcrum which is the acromion. If these muscles acted as a fulcrum, the power would be applied on the glenoid and would immediately rotate the whole scapula, so that the acromion would become a fulcrum. The writer holds that in such accidents there can be no disruptive force in the region of the head of the humerus unless the acromion does act as a fulcrum.
The diagram further illustrates the fact that the power of the supraspinatus is applied in such a manner as to restrain dislocation, but that in forced elevation of the arm the upper edge of the glenoid acts as a wedge driven in between two points of application of strain. This idea is amplified in Plate IX.

Many authors have contended that besides the obvious bony fulcrums which occur, there may be others momentarily maintained by contracted muscles, which may lead to fracture or dislocation. Perhaps this is true, but I have been able to work out few such mechanical positions. For instance, the lever formed by the humerus when the arm is in the anatomic position, the pectoralis and latis-simus contracted, and outward force applied at the elbow, may be considered either to have its fulcrum on the glenoid or to apply power there, with the pectoralis, etc., as a fulcrum. The latter might be the proper way to consider the problem if fracture occurred in the long arm of the lever, distal to these muscular attachments. It seems more logical to me to regard the applications of muscle pulls as forces acting on the obvious bony fulcrums. However, there can be no doubt that when these muscles are contracted they would tend to prevent outward rotation of the humerus.

FIGURE 55. TRAJECTORY OF CENTER OF GRAVITY
The center of gravity of a person in falling necessarily always has a trajectory formed by the momentum with which he falls forward, combined with that with which he falls downward, and that which is exerted in relation to the median plane. The writer contends that in most instances, dislocations and fractures in the region of the upper end of the humerus take place when the trajectory meets the ground at or posterior to the point of impaction of the elbow, and also internal to this point. If the trajectory came far anterior to the point of the elbow, the arm would be folded to the side, or if it came far posterior to the point of the elbow, the arm would extend harmlessly beside the head. If it came near the median plane or to the opposite side of it, the arm would slip outward into the hammock position. It therefore seems highly probable that most of these fractures happen when the arm is internally rotated by the pectoralis, etc., and the fall is of such a sudden and violent character that the humerus does not have time to rotate.
If the vertical factor in the trajectory were great so that the patient was falling nearly straight, head downward, fracture or dislocation in the pivotal position would occur. The writer believes that in every case there is acromio-humeral contact, and therefore always a subordinate pivotal position (see Fig. 25).

I am not in sympathy with the view of those authors who hold that the contracted pectoralis and latissimus act as a fulcrum to promote dislocation or fracture of the head of the humerus. I think the reverse is true, so far as their adductor action is concerned, for I am convinced that this action merely tends to prevent dislocation, since the force is applied to the long arm of the lever distal to the true fulcrum which is the acromion.
Lack of space prevents elaboration of the following additional reasons which support this conviction.

The directions of the majority of the fibers of the pectoralis
major suggest that -their contraction would bring the head toward
the glenoid from the very start of elevation, i.e., they would directly
oppose dislocation.
In other words, the lower fibers of the pectoralis are inserted higher on the humerus than the upper fibers; thus all fibers of the muscle tend to pull in a line away from the acromion as a fulcrum while the arm is being raised.
The combined power of the adductors would not be enough to break the humerus, if both ends of the latter were fixed. Therefore, their power would not be enough to act as a fulcrum for a fracture in the short arm of the lever, although it might be sufficient in the long arm.
Even if the power on the long arm of the lever'acting through the muscles as a fulcrum, became applied to the glenoid and to the supraspinatus and other opposing muscles, the result would merely tip the scapula so as to apply the acromion as a fulcrum.
Until the acromion became a fulcrum no disruptive force could take place between the scapula and humerus.
If the humerus touched the acromion at all and the pectoralis, etc., applied their power exactly opposite this point, the leverage exerted on the glenoid would not be changed in any way; nor would it be changed much if the point of application were moved a little away from the neutral point on the long arm of the lever. However, that slight change would diminish rather than enhance the tendency to dislocation.
The X-ray shows close apposition of acromion and humerus, when the arms are akimbo, in the salute position and in complete elevation.
The acromion is always the fulcrum, although in the above positions different parts of the acromial edge come in contact with different parts of the circumference of the humeral head. (Fig. 25.)
Although I believe that the pull of the pectoralis and latissimus actually help to prevent dislocation by their action as adductors, I am strongly of the opinion that as internal rotators they actually help to promote dislocation. The reasons may be briefly stated a& follows: On account of the position of insertions of their tendons, to be adductors, they first have to be internal rotators. As adductors they do their best to fend off the ground until the last possible moment when the acromion has begun to be a fulcrum. Meanwhile, as internal rotators, they are drawing the arm into a subordinate pivotal position and thus prevent external rotation, which is the only method of escape for the arm if it must rise in the coronal plane. Thus we can conceive of their having power enough to keep the humerus internally rotated until it is too late for it to turn, although we cannot conceive of their being able to act as direct adductors strongly enough to withstand the falling weight of the body. If, in any case, they instinctively relax in time for rotation to occur, the arm will rise to the side of the head and no harm will have been done. Occasionally, however, the relaxation is too late, or vice versa, the violence is too sudden, and the arm will be caught in internal rotation in or near the coronal plane. It will then be too late for the adductors to relax in order to let rotation occur and thus permit the arm to ascend by the head.
The nearer the bent arm, in internal rotation, lies to the sagittal plane the safer it will be; the nearer the externally rotated arm lies to the coronal plane the safer it will be and vice versa. As a matter of fact, in healthy youth it is astounding how rapidly this instinctive rotation will occur. The football player may be hurled headlong by impact with other players in such a way that his body may be twisting laterally as it falls, yet his outstretched arms fend off the ground just long enough to prevent his breaking his neck, and in spite of the sudden, twisting violence, rotation at the last moment usually avoids dislocation of the shoulder.
Yet occasionally the resultant of all the forces of the fall makes the trajectory of the center of gravity strike posterior to the point of the elbow and to its inner side, while the humerus is internally rotated, and anterior dislocation will occur.
If the reader wishes to go into this in more detail he may force his mind to project a combination of Figures 26 and 55. It is difficult enough to visualize the normal workings of the shoulder joint, but it is still more difficult to foretell the results, on this beautifully adjusted apparatus, of a fall downstairs. Yet I think these general principles usually apply.
On the supposition that our conclusion that the humerus must obtain a fulcrum on the acromion in order to exert a disruptive force to produce dislocation is correct, let us consider what occurs in the inner unit of the shoulder, Figure 8, Chapter I.
The fulcrum on the edge of the acromion obtains its skeletal support, whatever the position of the arm, directly through the clavicle to the sternum. As has been said, not only is upward dislocation of the acromio-clavicular joint prevented by the fact that the clavicular portion of it is superior, but by the strong coraco-clavicular ligaments. Thus the clavicle in any position furnishes a strong radius through which the pressure on the fulcrum is firmly sustained. Moreover, the S shape of the clavicle has been shown to not only withstand great pressure in a line between its two ends, but to have great elasticity when the pressure is released.
I wish to accent again three characteristics of the scapulohumeral joint.

The capsule is necessarily loose.
The upper half is muscular and strong; the lower half is fibrous and weak.
Since the humerus can rotate many degrees (probably 100+) without moving the scapula, any one of the short rotators may receive the chief burden of the strain according to the degree of rotation when the acromion becomes the fulcrum. The following remarks will be based on the supposition that the supraspinatus is uppermost, as in Fig. 9, but would apply equally well when any of the other rotators were directly opposed to the force moving the elbow.
As the elbow rises upward not only is the supraspinatus contracted but the upper edge of the glenoid becomes a wedge in the reentrant angle, between the articular cartilage and inner surface of the supraspinatus. This accounts for the frequency with which fracture of the tuberosity accompanies dislocation. In most cases not only the facet on the tuberosity for the supraspinatus will be carried away, but also a concavo-convex piece of bone comprised of the greater tuberosity and part of the lesser, and extending down to the point where the humerus touches the acromion, and including even the bicipital groove as a whole with its tendon intact. (See Plate IX.)
If the force goes no further we shall have a false dislocation, for the lower part of the capsule being loose and there being no support above, the head will glide over the lower edge of the glenoid and fall into the lower part of the capsule, stretching it downward. Correspondingly, the dislocation will be at once reduced as the arm falls to the side, for it will not be pushed through a hole in the capsule and thus have an impediment to easy reduction.

PLATE IX. FRATURES OF THE TUBEROSITY AND FALSE DISLOCATION
The mechanism of fracture of the greater tuberosity and its relation to false and true dislocations.
a. The pivotal position.
6. When leverage is exerted against the acromion as a fulcrum, the biceps tendon guides the upper edge of the glenoid to enter the sulcus as a wedge, thus tending to chip off the tuberosities. This wedge is not a point but the curved edge of the fibrocartilage backed by the rim of the glenoid.
c. The inferior extremity of the fragment is therefore at the point of impaction of the acromion. The biceps tendon, tuberosity and subacromial bursa remain in their normal relations. A false dislocation of the head may then occur without rupturing the lower part of the capsule because tension is relieved by the rent in the upper portion. The lower part of the capsule, which is normally capacious, will be merely carried beneath the glenoid, as the arm descends.
d. The same lesion with the muscles depicted. A portion of the subscapularis still remains attached to the lesser tuberosity, but most of the greater tuberosity, and part of the lesser, remain in Continuity with the fragment.
e-f. Schematic drawings to illustrate the difference between a false and a true dislocation. False dislocation must necessarily be accompanied by rupture of the upper portion of the capsule, together with fracture of the greater tuberosity or rupture of the tendons. There is no structure except possibly the biceps tendon likely to interfere with its replacement, but in a case of true dislocation where the lower part of the capsule alone gives way, the sides of the capsular rent would tend to become tight around the neck of the bone, when efforts are made at reduction. In the worst cases where the two forms are combined an operation is required.
It seems as if some cases must occur in which the biceps tendon would be freed because the line of fracture might extend down the groove and the tendon would thus be separated from the greater tuberosity, and lie between the fragments. I think it usually remains in contact with both fragments if it is not evulsed from the glenoid by the same violence, in which case it retracts into the groove.

This I believe to be the mechanism in most cases of fracture of the tuberosity, whether the accompanying dislocation is recognized or not. On the other hand, both the bone and the supraspinatus attachment may hold in whole or in part, and be stretched down over the glenoid, until the lower portion of the capsule is tensed and torn and permits the head to slip through it and remain subglenoid, with the torn capsule tense on each side of the surgical neck. This will be the ordinary uncomplicated true dislocation.
Violent falls may produce a combination, first wedging off the tuberosity and then driving the head through the lower capsule.
Other variations may be:
1. Instead of the whole tuberosity being wedged off, the supraspinatus may tear away only the facet of insertion.
2. Evulsion of the supraspinatus at the blue line may occur.
3. Rupture of the supraspinatus may take place just above the palisades.
4. Very rarely a lip may be pried away from the lower edge of the glenoid instead of having the capsular attachment give way. I suspect that this is more apt to occur when the forearm is very much rotated internally and the arm is akimbo.
5. Rupture of the long head of the biceps may accompany true or false dislocation, or any of the above variations.
In general, in types 1, 2 and 3, we may expect additional tearing either toward the side of the infraspinatus or toward the side of the subscapularis, according to the degree of rotation of the humerus on the scapula at the time of the fall.
These are the very obvious lesions which may occur, but I believe the most common complication to be the " rim rents " described in Chapter V, which occur not only with dislocation, but in many cases where these structures are just able to resist dislocation, although the synovia becomes separated from the articular margin and a few inner fibers of the tendon are torn.
Another factor which may resist dislocation remains to be considered—the atmospheric pressure which holds the bursal surfaces together. In the typical false dislocation with fracture of the tuberosity, I do not believe that the relations of roof and floor of the bursa are destroyed. Until air is let into the bursa the surfaces tend to remain in contact. Many a time I have demonstrated this on the operating table. The same is true of the joint. To test in actual pounds the degree of pull required to separate these surfaces remains for some future observer. I feel confident that many pounds of direct pull would be required in the living to separate either bursa or joint to any great extent unless fluid is present. Even when the bursa is opened one cannot pull the joint surfaces apart without undue force unless the supraspinatus is torn, when they fall apart as soon as the air enters. The surface area of the bursa and that of the joint must be very nearly the same, roughly two inches in diameter, each. In X-ray tests one must remember that the cartilages do not show and that the presence of fluid permits separation.
A thorough understanding of what has been said in the preceding pages of this chapter is so important that a summary seems necessary at this point.
1. In spite of the usual histories which patients give of striking on the shoulder, the cause of dislocations or fractures is rarely, if ever, direct, but is usually a backward or downward (i.e., backward and downward in relation to the body as the patient falls) force, acting in the pivotal position, or in a subordinated pivotal position, through the humerus as a lever, with the acromion as a fulcrum, and the weight represented below by the lower portion of the capsule supported by the triceps, latissimus and teres major, and above by the resistance of the supra- and infra-spinatus, the long head of the biceps, and the atmospheric pressure in joint and bursa.
2. During a fall, unless the elbow is maintained in flexion, rotation of the humerus readily occurs; but since no lateral motion at the elbow is possible, fixation of a flexed forearm in a given position may greatly alter the direction of force applied at the shoulder, so that dislocation might occur at a point in elevation short of the pivotal position, but usually above the horizontal. For example, a lateral fall in the coronal plane when the humerus is held in internal or mid-rotation, in such a manner that external rotation is prevented (as by contraction of the pectoralis major), or a somewhat headlong fall in the sagittal plane while internal rotation of the forearm is prevented, might result in fracture or dislocation.
3. It is very unlikely that forward dislocation ever takes place unless the fall is at least somewhat headlong, i.e., one in which the elbow strikes a point anterior to the trajectory of the center of gravity.
4. In most instances subglenoid dislocation must be at first momentarily erect. The descent of the arm into the sling position, in which we usually find it, will be in internal rotation with the head of the humerus still displaced below and anterior to the glenoid, with the subscapularis relaxed and the other short rotators stretched over the glenoid. The long head of the triceps will be between the teres major below and the minor above, and the articular surface of the humerus will face backward on the origin of the long head of the triceps.
5. It seems probable that backward or subacromial dislocation never takes place from forces operating on the arm when it is being elevated, but must occur below the horizontal when the humerus is only abducted to a sufficient degree to permit the flexed forearm to be forced backward behind the body in internal rotation. Vice versa, anterior dislocation usually occurs only when the arm is above the horizontal, although theoretically, if the elbow were at the side and the humerus were rotated outward by the flexed forearm, anterior dislocation might occur from a sudden lateral fall which forced the forearm in external rotation behind the body. This would be a very unnatural way to fall, however.
If we accept the above explanation of the mechanics of dislocation, we may proceed to speculate on the reasons why fracture instead of dislocation often occurs from exactly similar falls. Age seems to be the determining factor, but this factor may be subdivided into two secondary ones, i.e., the relative tensile strength of the structures at different ages, and the relative mobility of the bones in youth and in age.
Assuming stress in the pivotal position:
In early youth the humerus ascends high under the acromion, and as the epiphyseal line is relatively the weakest point, epiphyseal separation will probably occur.
As a rule, in youth and manhood after union of the epiphyses, tendon and muscle and bone are strong relatively to the lower portion of the capsule, so that dislocation will take place. If any fracture occurs it will usually be at the greater tuberosity. Occasionally it will occur at the surgical neck.
In old age the trabecular structure about the base of the tuberosities will be weak; therefore, comminuted fracture will readily occur. If the bone holds, dislocation will usually be accompanied by rupture of the supraspinatus, for the muscles and tendons will be weak and cannot disseminate the force.
The second factor, i.e., the extent to which the head of the humerus may pass beneath the acromion, is also important in determining the seats of fracture in youth and in age.
In childhood the tip of the acromion is soft and cartilaginous, and thus the stress on the bony portion of -the acromion would be met at about the epiphyseal line, although the head of the bone passes far beneath the cartilaginous acromion.

FIGURE 56. EPIPHYSES OF A CHILD'S SHOULDER BONES
Outline drawing from X-ray of child with both arms elevated. By use of a dotted line the figure on the left is made to appear as an anterior view while that on the right appears as a posterior. At this age the tip of the acromion is pure cartilage and does not appear in the film. Notice that the head of the humerus passes beneath the acromion just far enough so that the bony portion of the acromion would gain a point of impact very close to the epiphyseal line. The cartilaginous tip would bend and the breaking force would occur at the epiphyseal junction.
This figure also shows that the line of epiphyseal union of the coracoid is at its base. I have never recognized a separation of this epiphysis. My work has been such that I have seen comparatively few injured children, but I think that it is quite possible that this lesion does occur, and may be detected by characteristic symptoms. It is certainly one of those conditions which we should expect on purely mechanical grounds.

In youth the tuberosity also passes far beneath the acromial edge, and this will bring the fulcrum to bear low down on the surgical neck, just above the attachment of the powerful pectoralis major. Usually dislocation will occur with or without fracture of the tuberosity. Occasionally the surgical neck will give way at the fulcrum.
In the stiff, aged joint, the tuberosity will barely pass beneath the acromion, and impact of the latter will come at the point just below the tuberosities, where the cancellated bone is weak, so that comminuted, intracapsular fracture will usually occur.
It is likely that there may be some changes in the exact lines of these comminuted fractures according to the degree of rotation which the humerus attains at the time of fracture. That is, the acromion will be applied at quite different points on the tuberosity in external and in internal rotation.
Other factors may be important also. For instance, the rapidity of the application of force; the degrees of contraction of the various muscles; congenital or habitual variations in the structure or position of the bones and of other tissues; the weight of the body; many minor circumstances or unusual combinations of any of the above factors. However, the point I wish to make is that the pivotal position is to the human arm in its varied activities as his earth is to the fox. The elusive arm must be driven to its pivotal position to be caught, or tricked by preventing rotation on the way. With continued effort we may always dig the fox out, and with continued backward force we may always break or dislocate the head of the humerus,, although the human arm is as clever in evasive rotation as the fox is in doubling.
There are many other points on which a consideration of the "Pivotal Paradox" is enlightening and which are worthy of study, for a thorough understanding of the mechanics of dislocations must be of help in their diagnosis and treatment. However, it will require many studies by many people before practical experience will cease to be our guide. Whether the deductions I have made above prove to be right or wrong, the following practical facts support them and are confirmed by all writers and by each surgeon in his own experience.
The causes of anterior dislocations are usually headlong or lateral falls with the arms thrust forward to fend off the ground.
The same kinds of falls may also produce the following lesions of the upper end of the humerus:

(1) Separation of the humeral epiphysis.
(2) Fracture of the surgical neck.
(3) Fracture of the tuberosities.
(4) Fracture of the anatomic neck.
(5) Comminuted fractures in which the typical form consists of four fragments; i.e., the two tuberosities, the anatomic head, and the shaft. (See Fig. 60.)

Any of these forms may be complicated by concomitant dislocation of the articular head, whether or not it remains attached to the shaft.
The fractures will be discussed in the next chapter and dislocations in the remainder of this one. However, the two subjects are inseparable and one should realize that both fracture and dislocation occur in many cases which are classed as either lesion. I am inclined to think that a combination is the rule, especially in cases of fracture of the tuberosities, and that many supposedly simple fractures are accompanied by false dislocation of the head which immediately becomes spontaneously reduced. Previous dislocation is evident in cases of complete separation at the anatomic neck in which the head remains displaced, but unless the latter is completely separated, it will be dragged back by the tuberosities, which are rarely dislocated because they are sucked back by the bursa and almost invariably remain attached to the short rotators. In other words, these tendons may rupture without the occurrence of any bone lesion, but if one does occur, the tendons remain attached to the fragment. Only small crumbs of the tuberosities ever become really free even in the most comminuted fractures.
The number of shoulder injuries compared to the total number of industrial accidents reported in Massachusetts during eight years is shown in tabular form. This table is not perfectly accurate, so far as the figures on dislocations and fractures are concerned, because it was not arranged for the particular purpose for which I am using it. For instance, all fractures of the clavicle and all fractures of the humerus are included because no distinctions had been made as to the part of the bone injured. It is probable, therefore, that the number of dislocations is fairly exact, but that the number of fractures of the upper end of the humerus is considerably less than the figure given, and probably in every year less than the number of dislocations. Probably many of the cases which were classed as fractures also had dislocations and vice versa. Although there is a striking tendency toward uniformity of the numbers through the different years, the proportion of dislocations to fractures varies somewhat for the above reasons. It is fairly safe to say, however, that about one-fifth of all shoulder injuries occurring in industry are fractures or dislocations of the upper end of the humerus. It is likely that if we could get similar statistics from the population not engaged in industry, fractures would be more common than dislocations, because fractures in this region usually occur in elderly people. Unfortunately, there can as yet be no statistics to determine how often the supraspinatus is injured as a complication of these so-called major (?) injuries, nor what proportion it forms of the other injuries which are unclassified. I believe that it costs our community more than all the other lesions together, not only because it is so common as the major lesion in fractures and dislocations, but because there are many unrecognized minor cases.

The shoulder is the most frequently dislocated joint in the body. This fact is quite properly generally ascribed to its relative instability. Dislocation of the humerus occurred 108 times in 528 cases of dislocation reported by Eliason, and it has been stated by various authors that forty to sixty per cent of all dislocations are of the shoulder. Many shoulders are probably dislocated and immediately reduced by the patient or his companions as they lift him after a fall, without knowledge that dislocation has occurred.
Dislocations of the head of the humerus have been classified in several ways, although for practical purposes only two classes are of importance, i.e., the forward or subcoracoid, and the backward or subacromial forms. As the latter are rare, "dislocation of the shoulder" usually refers to the former.

The first four varieties in the table are essentially the same. If the tear of the capsule and stretching of the muscle bellies away from their beds-are extensive, the dislocated head can be moved easily from a subglenoid to a subcoracoid or to even a subclavicular position. As has been shown, the erect subglenoid position probably occurs in every case momentarily, as the patient falls with the upraised arm, although depression and internal rotation at once ensue from muscular contraction, causing the arm to assume the position at the side in which we usually find it. Very rarely does the erect phase last long enough to be classified!
Subspinous is merely an extreme degree of subacromial dislocation. It occurs when the infraspinatus has been badly torn from its bed so that a large space under the spine of the scapula accommodates the displaced head. Upward dislocation implies an accompanying fracture of the acromion and is nothing more than a curiosity in extremely severe accidents. I have never seen it.

DIAGNOSIS OF ANTERIOR DISLOCATION

In simple subcoracoid dislocation of the humerus, the well-known signs are as follows:

History of a trauma to the shoulder in which something was felt to give way and a severe, acute, nauseating pain was experienced.
Active and passive movements are limited and painful.
The forearm is held flexed and internally rotated.
The elbow is away from the side and cannot be completely adducted, thus causing the long axis of the shaft to incline upward and inward.
Patient stands inclined to the affected side so as to bring the axis of the humerus to a vertical position.
Measuring from the acromion to external epicondyle, the upper arm appears lengthened.
The anterior axillary fold (on the affected side) is lower.
The shoulder is flattened.
The acromial process is prominent.
The head is palpable under the coracoid.
A soft crepitus can be elicited while manipulating the shoulder.
In other words, the facts to be learned from the history, inspection, palpation, motions and mensuration, plus the aid of the X-ray, will usually make the diagnosis beyond doubt. In fact, the diagnosis is generally so obvious that we must be on our guard not to overlook concomitant injuries and complications. While examining the patient one should take especial note of the circulation of the arm, and of the sensitivity of the skin over the arm and shoulder. The power of the deltoid, rhomboids, clavicular part of the pectoralis major, supraspinatus and infraspinatus, etc., should be carefully noted with a view to detecting paralysis. When the case is typical, the eleven signs are exceedingly plain, but this does not mean that when they are absent there is no dislocation.

It is very important for the reader to understand that all of the above signs, except the first and the last, fail when the articular head has been replaced on the tuberosity, which has itself been displaced into the glenoid. At this point the reader should refer to the history of Case 71, page 288, and study the accompanying diagrams. Our mistakes in diagnosis will occur in these cases where the head of the humerus can hardly be said to be out of place, but is certainly not in place, for the short rotators with the evulsed facets lie between it and the glenoid. (Fig. 58 and Case 115, p. 389.)
The second symptom was absent in Case 115 because the nerves were paralyzed or so retracted as not to be influenced when the arm was moved. The replacement of the head to nearly its normal position had completely removed the third to tenth symptoms and even the eleventh symptom, in this particular case, was absent or very difficult to detect.
Of course, such cases of pseudo-reduction are not common, but they occur now and then, so that we must never fail to bear in mind that cases of dislocation which are not quite satisfactory may become extremely unsatisfactory, if the supraspinatus or other short rotators are torn, or have dragged the facets toward the glenoid.
Treatment. The main therapeutic principles are: reduction, fixation and gradual return to function.
Reduction in most cases can be obtained by the Kocher or by the Astley Cooper traction methods. These procedures are too well known to describe in this text. The Kocher method is most generally used because much less force needs to be exerted, and hence less trauma should occur during the reduction. However, as Kocher himself said in his original article, it does not always work and it is sometimes necessary to use the Astley Cooper method.
Much has been said concerning the optimum position in which to maintain reduction. This would seem to suggest that the ideal position had not been found. Some modern authors, notably Stevens, are of the opinion that the arm should be put up in abduction and external rotation.
A simple way of obtaining abduction and external rotation is to put the patient in recumbency, and fasten the hand to the head of the bed. A suitable ambulatory splint can be used, or both methods in conjunction. A splint maintaining abduction and external rotation is cumbersome, and attracts a great deal of attention. The ordinary airplane splint abducts, but internally rotates the arm. Abduction and external rotation put the patient in the position of a traffic officer stopping a line of cars. The writer does not advocate this abduction treatment, and prefers not to fix the arm at all.
The advocates for maintaining the arm in the sling position after reduction, contend that the torn capsule heals better because it is relaxed. This seems reasonable, unless the rent is longitudinal, in which case its edges would be approximated better in abduction. It has never been determined positively whether rents in the capsule are usually longitudinal or transverse. Some writers claim that the capsule is torn from the forward edge of the glenoid, and my opinion is that this is the usual condition, for this only means the tearing of the pillars which form the opening of the bursa subscapularis. More observations of cases where death has occurred from the same accident as that which dislocated the limb are much needed. If we knew in general how the capsule is usually torn, the answer to the question of whether to maintain adduction or abduction would be much more plain.
The writer believes that at present there is too great a tendency to confine the arm after reduction. It would seem more logical to let the patient use his arm a little—even to urge him to do so, in order that debris and blood clot may work out of the joint capsule into the areolar tissue, where they would be readily absorbed. If the capsule were emptied of the blood clot, it would seem that it would be more likely to have its edges fuse together again without leaving any distortion or undue irregularity. On the other hand, I believe that motion should not be forced for fear of tearing edges which are beginning to unite. For those who think this policy too radical, it would be safer to treat most cases in the sling position than in the abducted one, unless the surgeon were very well versed in the study of the shoulder joint. I think stooping exercises should be begun at once and continued daily in any case. We should use fixation only for comfort, and this means very little, for one may be sure that if there is severe pain after reduction some complication exists.

Prognosis. It would seem an easy thing to make a prognosis in cases of dislocation, but as will be seen shortly, complications are frequent, often unrecognized, and greatly modify the period of disability. A fair prognosis in uncomplicated cases would seem to be a return to normal function in from four to eight weeks. However, complications are, I am sure, more frequent than is generally realized.

FIGURE 57
X-rays of the case alluded to in the text in which the articular head had become displaced beneath the deltoid and was excised through a sabre-cut incision. This patient recovered with a useful arm, and was able to play excellent golf for many years afterwards. Undoubtedly fracture and dislocation occurred at the same time, and the head was left behind in the erect phase of dislocation, when the arm came to the side. The articular surface remained in nearly the position which it occupies in normal elevation. It seems possible that if this fact is recognized in similar cases, reduction might be accomplished by again placing the shaft in elevation, opposing the raw surface of the articular head to that of the tuberosity, and holding them together while the arm is brought to the side in the coronal plane.
Figure a, before operation.
Figure b, a few months after operation. The acromion, which had been sawed across for the sabre-cut incision, has been wired about two steel pegs.
Figure c, taken nineteen years later, when the patient was eighty. There had been no trouble from the wire or pegs in the intervening years. At this time motion in the joint still persisted, but "was very limited in degree. However, it was sufficient to permit a slight amount of abduction and rotation, which permitted him to use his arm freely for ordinary purposes. Although this operation was successful in restoring a fair degree of usefulness, if I were obliged to operate again for such a condition I should not remove the articular head, and would endeavor to reconstruct a normal joint, perhaps employing Dr. Nicola's suggestion of anchoring the articular head by means of the biceps tendon. Before incising, I should hyperelevate the arm in internal rotation in order to appose the fractured surfaces.

Gubler, in a study of insurance records of 252 workmen's compensation cases, states that recovery occurred in 94.1% of the cases after an average of thirty-eight days of treatment. Another investigator, Kuttner, reports a far different experience. He was able to trace fifty-four uncomplicated cases from among 168 treated during the previous five years. Only seven (13%) had regained full use of the limb without loss of strength or motion. In fourteen (26%) the range of motion was complete, but the strength was reduced one-half or more. The remaining thirty-two (61%) had some loss of motion, which in twenty-six amounted to inability to raise the elbow laterally above the level of the shoulder. He states that all of these cases were uncomplicated (which we doubt), and had been treated in the hospital by immobilization for a week, followed by massage and mechanotherapy for two to three months. Goebel reports similar unfavorable results on twenty-four patients. Twelve had full function, but subjective complaints. Twelve had limitation of motion. Lexer reports forty cases; ten with complete restoration, fifteen with some limitation, fifteen with pain and loss of strength.
These reports are self-explanatory, and coincide with my observation of results obtained in general hospitals. The conclusion is that most of these patients received other injuries at the time of the accident or during treatment. I believe that uncomplicated cases tend to recover in about four weeks, unless interfered with by injudicious treatment, such as prolonged fixation.

Complications. Injuries to other structures about the joint are common and students should be most thoroughly warned of this fact. It is not so much that these complicating lesions are difficult to detect at the time of the first treatment, but that they are not suspected. It is a fact that these complicating lesions do often exist and do maintain disability and pain long after the joint itself has returned to normal, yet there is no organized effort of our profession to correct this condition. Industrial cases may be labelled malingerers, psychoneurotics, hysterics, or cases of traumatic neuroses, because of this prolonged disability with few detected physical signs. The five common complications of dislocation are the following:

Fracture of tuberosities.
Avulsion of the facets, or rupture of the tendons.
Fracture of the glenoid rim of the scapula.
Injury to the brachial plexus.
Rupture of the axillary artery or of other vessels.
Fracture of the greater tuberosity has hitherto been thought to be by far the most common injury accompanying dislocation. Graessner found the greater tuberosity broken twenty-four times in forty-eight dislocations, but in many of them the fragment was only a small scale of bone, indicating an avulsion of the tendon. Delbet found it in twenty-two out of one hundred and ten cases. Dollinger in five out of thirty-nine. Goebel twenty in forty-three cases. Schlaepfer found it eight times in one hundred and twenty cases, or 7.4%. Gubler reports it in eighteen out of two hundred and fifty-two cases, or 7.1%. Gubler also reports ten cases of other bone injury, and ten of nerve injury in his series. In my opinion, many of the cases where only a small facet is torn away should be classed with supraspinatus injuries rather than with fractures of the tuberosity, because they result in free communication between the joint and the bursa.
The bone injuries are generally easy to diagnose if looked for. The typical signs of fracture, especially ecchymosis down the arm along the biceps, are usually present and the X-ray is of great assistance. The real difficulty is too great a tendency to treat the major abnormality, the dislocation, and to overlook very important, but less obvious, injuries. Sometimes failure to recognize complications is due to careless X-ray examination, but more often to the inexperience of the doctor who first treats the patient. Rupture or avulsion of tendons attached to the tuberosities should be suspected when the films are negative.
The injuries to nerves and arteries will be considered in Chapter XI.

REFERENCES OF AUTHORITIES TO THE ROLE OF THE SUPEASPINATUS
IN DISLOCATION

Little is to be found in the literature to confirm my beliefs or to explain why the short rotators come to be so frequently injured. Only a few writers have realized the frequency of such injuries, and I do not think that any" of them have appreciated the significance of the fact that the bursa and joint are thus put into communication.
Stimson says that the supraspinatus is sometimes, probably often, torn from its attachment to the humerus, and the same is true in less degree of the infraspinatus, and occasionally even of the teres minor. He states also that avulsion of the tuberosities may take the place of laceration of the tendons. Preston says that injury to the capsule is not infrequently accompanied by injury to the tendons which overlie and reinforce it, and when the violence producing the luxation is great, there may be a destruction of tendon continuity.
Stevens gives an excellent description of shoulder dislocation with especial reference to the short rotators. According to him, an anterior dislocation is an impossibility without putting a strain upon the tendons of the supraspinatus, infraspinatus and teres minor. With the humeral head in subcoracoid dislocation, the distance from origin to insertion of the supraspinatus is greatly increased, and in addition the tendon is angled over the rim of the empty glenoid. Similarly the posterior rotators are pulled over the posterior rim of the glenoid, and are almost always injured. "We may," he says, "assume that in every case of dislocation of the humerus, and especially in anterior dislocation, there is an injury to the tendon of the supraspinatus, and that often it is ruptured."
Very few other authors even allude to this tendon.
The following cases as well as the above quotations from the literature support the assertion that the facet of the supraspinatus may be torn off in dislocation.

CASE REPORTS

No. 12. Mr. A. F. K. Age 45. Massachusetts General Hospital No. 174082 W. S., Jan. 23, 1911.
A subcoracoid dislocation of four months' duration. Open reduction of dislocation. Supraspinatus was found retracted with facet of insertion. Heavy silk sutures to unite it with tuberosity. Feb. 24; 1912: An excellent functional result, but scar is ugly.

No. 22. Mr. J. H. D. Age 69. Massachusetts General Hospital No. 182238, April 22, 1912.
Five weeks ago fell, injuring right shoulder. Reduced by M.D. Went back to work. One week ago dislocated it again when drunk. I made an unsuccessful attempt at reduction in the Accident Room, and then carried the patient under ether to the operating room, and through the usual incision for the bursa I opened directly into the joint. A defect corresponding to the facet of the supraspinatus was found, the supraspinatus being retracted under the acromion. There was no piece of loose bone corresponding to the defect, although the whole joint was carefully searched. It must therefore be assumed that the loose piece had been absorbed. The dislocation was reduced, supraspinatus reinforced with silk and the wound closed. Two years later he wrote me: " I can do quite a lot with it, only when I reach overhead it gives way and causes some pain."

No. 71. Mrs. E. C. Age 68. On June 10, 1921, fell downstairs, broke left wrist and dislocated left shoulder. Ether was given by the local doctor, and he supposed he had reduced the dislocation. She consulted me on August 9, 1921, and after taking X-rays, I reported to the physician who had sent her to me that I thought that the shoulder joint had been reduced. The accompanying X-ray seemed to me to show that the bone was in place. I know now that this appearance is deceptive. In such cases as this, the tuberosity has been retracted into the glenoid and the head of the humerus rides on it. Therefore, there is not very much change of contour in the position of the shoulder, because the total amount of bony substance between the tip of the shoulder and the glenoid is the same, although the position of the tuberosity is reversed and lies in the glenoid. The following is an account of the operation which I did on April 5, 1922, nearly a year after the injury.
Sabre-cut incision. Prominent anterior mass proved to be head of humerus minus the tuberosity. The tuberosity had been retracted by the posterior short rotators and lay partly in the glenoid cavity and partly overlapping its posterior margin. The biceps tendon was displaced so as to lie between the head of the bone and the glenoid. It was excised. The retracted tuberosity was also excised. The synovial and tendinous capsule of the joint was completely gone, except at the anterior edge, namely, the portion formed by the subscapularis tendon. A good, practical result was obtained, i.e., a movable, painless, weak shoulder, lacking power in abduction, but more useful than a painful joint.

It is my belief that in most of these cases of dislocation where the X-ray shows a portion of the tuberosity to be absent, careful pictures will show its presence in the glenoid or just below the glenoid. The capsule forms a pouch below the glenoid and this pouch catches the smaller fragments if they have become loose. The cases are deceptive because a reasonable amount of motion may be found within the first few weeks and the position of the head is so nearly normal that it is not realized that the head does not actually touch the glenoid.

FIGURE 58. THE USUAL CAUSE OF FAILURE TO REDUCE A DISLOCATION
Mrs. E. C.— X-ray (a) before the local doctor attempted reduction. The fragments of tuberosities may be seen external to the lower edge of the glenoid. The head of the bone is displaced far beneath the coracoid process; the form of dislocation might be classified as subclavicular. It is probable that in this case there was both a true and a false dislocation. After reduction (b) the tuberosities seem to be absent, though indications of their fragments are shown near the lower edge of the glenoid. I have operated upon a number of other similar cases (e.g., Nos. 5 and 92), so that I have formed the opinion that when the X-ray after reduction shows the absence of the tuberosity, radical operation is indicated, even if the X-ray does not demonstrate the fragments. It is my belief that this form of displacement accounts for the great majority of instances, which the authors quoted in this chapter speak of, as unsatisfactory results.

Case 115, to be reported later, was also an illustration of this condition. Two of the most alert industrial surgeons whom I know were fooled by the superficial appearance in this case, and I, myself, did not recognize it on my first visit. Even Stevens, whom I regard as having been particularly well informed about conditions in the shoulder, shows in his illustration, "Fig. 4," what I believe to be a case of this kind. He speaks of the fragments as having disappeared behind the head of the humerus. In cases showing X-rays similar to this, I would recommend exploration through the routine incision of the bursa. If it is obvious that the fragment has retracted into the glenoid, I recommend enlarging the incision to a "sabre-cut," and making an attempt to suture the structures in their normal position.
Before leaving the subject of anterior dislocation, I should like to italicize the following paragraph:
I believe that after the reduction of every case of dislocation of the humerus, the patient should be allowed to recover from the anaesthetic and be urged to move his arm freely, before any bandaging is applied. All motions may be safely performed except abduction in external rotation, and even this may be done with due care and using extension at the same time. If we find paralysis of any of the muscles, areas of skin anaesthesia, undue axillary swelling, gritting sensation in the joint, or a tendency for the joint to slip out of place, the patient should be at once hospitalized and consultation obtained.

(The author here advises the reader to study the next chapter on fractures and then to return to the remainder of this chapter, which discusses some of the more unusual forms of dislocation.)

FIGURE 58
(c) Explanation. Erect dislocation, as usual, preceded the subcoracoid position. The fragments of tuberosity, still held together by the musculo-tendinous cuff, slipped down on the glenoid, while the head was dislocated below and the arm fell to the side. Reduction was attempted and seemed successful, but the head of the humerus merely became superimposed on the fragments so that it seemed that the dislocation had been reduced, and the contour of the swollen shoulder became nearly normal. The biceps tendon was carried with the fragments on to the glenoid. In Case 115 there was scarcely any fracture except at the facets of insertion; the whole musculo-tendinous cuff had dropped back on the glenoid. In most cases the retracted tuberosities are held on the glenoid by the short rotators, as this man holds his hat on the further side of the tree. The biceps tendon may (Case 115) or may not (Case 71) be torn in such cases.

Subacromial dislocation is rare. I can only recall one case in private practice. This was in a young man who was a personal friend. It is twenty years since I reduced his dislocation, immediately after the accident, and the shoulder has given him no trouble since. Probably most of these subacromial or subspinous cases run as smooth a course, but occasionally, as in the following instance, one proves to need operation.

No. 33. Mrs. C. B. Age 38. Massachusetts General Hospital No. 184814 W. S., Sept. 7, 1912.
A case of recurrent subspinous dislocation which had remained unreduced for three months. "Sabre-cut" incision, the joint carefully inspected and cleaned of old granulations and detritus. None of the short rotators had been ruptured. Dislocation reduced and acromion wired in place. April 17, 1914, she writes, "I am thankful to say my shoulder is all right. It does not seem to be as strong as the other one, otherwise it is fine."

This is the type of case in which the "sabre-cut" incision is particularly applicable, in fact, it is almost indispensable if one wishes to obtain a satisfactory cleaning out of the glenoid. In all these operations for old dislocations I have found the glenoid to be filled with old granulations and detritus. Satisfactory reduction could not have been done without thorough cleaning of the cartilaginous surface.
The second case is an illustration of what I believe to be the usual mechanism of subacromial dislocation. She gave the history that seven years previously the first dislocation had occurred, during a convulsion while she was in labor. Six months later she dislocated it again while " closing a door behind her." The last time it was dislocated by "turning quickly around in her chair."
In the case first mentioned, the young man sustained his injury while being thrown from a sitting posture on a toboggan which had struck a rock. He was thrown in the air—presumably still holding the railing of the toboggan. This might produce the same effect of internally rotating the arm, as in closing a door behind the back.

OLD DISLOCATIONS

Speed considers a dislocation as old and irreducible after three months. The obstacles to reduction are the same as for a simple dislocation plus such secondary changes as:

Cicatricial contraction from healing scars in the capsule and adhesions to surrounding structures.
Displaced bone fragments, osteophytic outgrowths, callus, etc.
Muscles shortened and atrophied.
Synovial space obliterated
One can readily understand the difficulty of reducing an old dislocation if he will study the specimens to be seen in anatomic museums. The remarkable attempts of nature to derive some utility from a dislocated shoulder joint make reduction most difficult. At the point where the humeral head lies against the scapula, a tremendous bony proliferation takes place, and inevitably ankylosis or pseudoarthrosis results. The glenoid becomes atrophied and filled with fibrous tissue.
The varying combinations of pain, deformity, and limitation of motion which these patients present have incited surgeons to attempt relief. Every surgeon of large experience htts probably made a few attempts to help such patients, but before long finds that they form a class of cases in which he can be generous to his younger colleagues, who also in time learn by experience. As a matter of fact, these are serious cases and demand expert care, although this is not attainable at present, for there are no such experts, so far as I am aware.
There are five general lines of treatment from which we may choose.

(1) To leave nature to do the best she can.
(2) To attempt bloodless reduction under an anaesthetic.
(3) To attempt open reduction.
(4) To resect the head of the humerus.
(5) To perform arthrodesis.

Andrews concluded that an attempt at reduction by manipulation is extremely dangerous. In his words, "The bloodless method has a gory trail of accidents." He finds fifty cases of hemorrhage, mostly fatal, up to 1905. An interesting one was reported by J. C. Warren, in whose case a large aneurysmal tumor arose after attempts at reduction. The subclavian was tied and recovery ensued.
If a new joint can be produced at all, it should be possible to do it by the "sabre-cut" incision, for all the structures of the joint are readily visible and accessible. I have encountered two chief difficulties. One has been the fusion of the retracted tendons and tuberosities with the glenoid alluded to in Case No. 71. If many months have passed, there is little left of the cartilaginous surface of the glenoid when the debris has been removed from it. However, this is not the chief obstacle—the real one being the absence of any synovial membrane to prevent adhesions of the cartilaginous head in its new bed. If the cartilaginous head is not too badly destroyed and seems likely to function, I should advise completing the attempt to make a new joint, but if the head has been eroded and there is no synovia left to surround it, adhesions will surely take place, and almost no motion will be secured. An irritable, painful joint with only a few degrees of mobility will result. In such a case, I think that one should deliberately perform excision or arthrodesis. The method of arthroplasty recently suggested by Dr. Laurence Jones of Kansas City offers a most hopeful solution of this problem.

RECURRENT OR HABITUAL DISLOCATION OF THE SHOULDER JOINT

Recurrent dislocation is not a common lesion, but it has interested a large number of investigators. Speed says that this lesion is peculiar to athletes and epileptics. This is more than a witticism, but not entirely true. Almost every author has put forward a somewhat different theory as to the cause of recurrent dislocation, and Speed has gathered together the most important ones. They are:

Defect in the head of the humerus acquired at first dislocation, or perhaps congenital.
Defect in the glenoid—acquired fracture of the edge, or congenital shallowness.
Rupture of the insertions of the external rotators of the head of the humerus.
Avulsion of tuberosities with or without rupture of the rotators.
Detachment of capsule from anterior lip of glenoid.
Enlarged joint from relaxed capsule following tears which have been given insufficient time for strong cicatrization, or repeated stretching without tears.
A seventh theory may be added. Since the shoulder joint is not a real joint, and is dependent for its integrity on a very complicated neuro-muscular cooperation, the essential feature in some of these interesting cases may be a failure of this cooperation. Reference to Plate I will show how easily incoordinated pulls from two opposing muscles might result in instability of the head on its fulcrum. Rupture or stretching of the tendon of the latissimus might thus make the joint unstable in the pivotal position. Certainly from an X-ray point of view the bony structures in most of these cases are normal.
The slight support furnished the joint by the bony structures has been considered, and it would seem more reasonable to suspect a defect in the major supporting structures, the muscles and their tendons, than in the bony structure. The importance of the supra-spinatus and of the other short rotators has been emphasized, and it has been noted with what frequency their continuity is broken in ordinary dislocations. More authors have found occasion to mention lesions of the short rotators and tuberosities in recurrent dislocations than in simple dislocations, because the majority of the former cases are treated surgically, so that more opportunity is afforded for observation.
Considerable evidence is given in favor of each of the causes listed by Speed and probably any one of them could well account for a recurrent dislocation. Hildebrand found two cases of fracture of the anterior rim of the glenoid with laceration of the capsule, in which he obtained good results by reshaping and deepening the glenoid. In an X-ray study of twenty-one cases in Hildebrand's clinic in Berlin, Pilz found definite bony defects in the humeral head in fifteen, de Fourmestraux found a deformity of the head in four out of eighty cases. Henderson reported no bone injury found by X-ray in many cases. We have seen several cases in which no abnormality could be found with careful X-ray examination.
According to Stevens recurrent dislocations at the shoulder joint are always due to more or less tearing of the supraspinatus, infraspinatus, teres minor, and more rarely of the subscapularis, and their subsequent repair by scar tissue in a position of stretch. No definite cases to prove this were given.
Thomas concludes that habitual dislocation is due to a traumatic, cicatricial, anterior, hernial pouch of the capsule. The most constant lesion which he found was a tear in the anterior and lower part of the capsule. In an experimental luxation of the shoulder on a cadaver, he placed the head in complete subcoracoid dislocation, and found the supraspinatus, infraspinatus and teres minor not torn or greatly stretched. However, any assumption that such lesions do not occur in the living is unwarranted, for the conditions are so different. In such experiments lax atonic tissues replace the living contractile muscles, and the force is gradually and gently applied as compared to the sudden smashing force acting in the living. A force suddenly applied against active muscles would have much greater rupturing power than a much greater force evenly applied against dead muscles.
One of the earliest mentions of the role of the supraspinatus was by Duchenne, who wrote: "Recurrent dislocation cannot occur with a normal supraspinatus." Yet I do not entirely agree with this great authority, for in none of my cases of habitual dislocation have I demonstrated such a rupture, and in two I actually did demonstrate that there was no rupture. Furthermore, I have never seen habitual dislocation complicate a case of ruptured supraspinatus.
Speed states that the head of the humerus twists out of the glenoid through the inferior portion of the capsule, and he believes that to permit this dislocation there must be a great strain on the supraspinatus tendon, or even a tear in it.
It is in the treatment of these recurrent cases that the greatest variations of opinion are to be found. Almost every author has contributed a different technique. The surprising thing is that so many varied methods should produce such uniformly excellent results as are claimed for them, yet the number of methods suggests that none is highly successful. The essential points of some of these methods of treatment will be briefly given with their results, when obtainable. Many of the reports are based upon too few cases followed for too brief a period. It is noticeable that few authors have reported later series in a second paper, and this suggests that the late results and greater experience have not supported them in their early statements.

Treatment.

Two general principles of treatment have been applied to habitual dislocation. They are:

Prevention—control primary dislocation, and allow healing of capsule.
Reconstruction.
A. Suspending head of humerus from above.
B. Support from below.
1. Reefing.
2. Bone operation on glenoid.
C. Combinations of above.
D. Use of the long head of the biceps as a round ligament.
A shearing-off of the attachment of the capsule to the fibrocartilage of the glenoid is described by Bankart as the cause of recurrent dislocation. The defect is permanent and his operation aims to repair the rent. His incision runs from above the clavicle downward and outward over the coracoid for about five inches. The deltoid and pectoralis major are separated, not cut, and the coracoid divided and driven downward with the muscles attached. The subscapularis tendon is divided and the capsule sutured to the glenoidal labium. The subscapularis and coracoid are sutured in place. Four weeks of rest is followed by active and passive motion. Four successful cases are reported.
Carrell, who gives the above classification of treatment, uses an ingenious combination of A. and B. An anterior incision exposes the long head of the biceps. The tendon is sectioned at its lowest level, and reflected from its sheath to where it emerges from the capsule. The distal end of the muscle is attached to the short head. To the free tendon is attached a piece of fascia about six inches long. A posterior incision running down four inches from the acromion separates the deltoid and exposes the teres minor. The fascia is passed under the neck, weaving in and out of the capsule. It emerges just above the teres minor and is passed through a drill hole in the acromion. The arm is immobilized at the side and motion begun in three weeks. Good results are reported in four cases. One wonders whether the posterior incision can be made without injury to the circumflex nerve. Recently Fowler has suggested a modification of this suspension operation. The biceps tendon is not interfered with, but a strip of fascia lata is passed through the capsule below the neck and anchored, both on the acromion and on the coracoid.
A bone transplant was placed by Eden under the raised periosteum of the neck of the scapula so that one-half to one centimeter stuck out in front of the joint. He also reefed the capsule and kept the arm abducted for three weeks.
Henderson's tenosuspension operation has been popular in America, but as seen by the discussion following Fowler's paper, it cannot be a thoroughly satisfactory procedure. Keller uses a crucial plication of the capsule through a posterior incision. Loeffler places a band of fascia from the greater tuberosity of the humerus to the acromion. Mandl used Finsterer's operation with success. The head of the humerus is held back by a band on the anterior surface of the joint, taking the place of the normal joint capsule. The band is composed of "part of the coraco-brachialis and part of the biceps." Oudard divides the subscapularis and overlaps it so as to shorten it about three centimeters. The tip of the coracoid is cut and a bone graft three to four centimeters long is inserted between base and tip. The coracoid may be slit and one-half slid down so as to lengthen the coracoid three centimeters. Nine cases were treated successfully. Six additional cases are reported. Perkins devised an operation in 1906 for suture of the torn capsule and reports good results. A restraining ligament was made by Plummer and Potts using a fascial strip from the greater tuberosity to the acromion. They report two cases with good results. Nine cases of recurring dislocation were treated in a year by Riviere, who pleated the capsule by placing interrupted sutures through the subscapu-laris. Landes uses a fascia lata cord or several silk sutures and suspends the head of the humerus by passing this cord through a drill hole and slinging it over the clavicle just lateral to the coracoid. Selig, who considers atrophy or rupture of the external rotators the main cause of habitual dislocation, makes an incision through the supraspinatus fossa, separates the trapezius fibers, and shortens the supraspinatus tendon by plication.
It is Sever's belief that the subscapularis and supraspinatus prevent dislocation when the arm is elevated by opposing the pectoralis major, which adducts and draws the humerus forward, and pulls the upper part of the humerus inward and downward. He says that in all operations for recurrence, the good comes from cutting the pectoralis major and shortening the subscapularis. No results are stated. He notes that repair of the infraspinatus and supraspinatus can also be done at the same time. Other authors, notably Allis, have also held similar views.
The operation advocated by Speed is done through an incision just below the coracoid and extending down four inches. The pectoralis major is divided one and one-half inches from its insertion into the humerus, and the axillary structures put aside. The edge of the glenoid is next palpated, after which, a drill hole one inch deep is made diagonally into the neck of the scapula. A bone transplant from the tibia is driven in with three-fourths inch projecting. This is supposed to prevent the head of the humerus from slipping out forward into anterior dislocation, at the same time not interfering with the normal range of motion.
A heavy silk ligature reenforces the anterior part of the capsule in the operation of Spitzy. A curved incision exposes the deltoid insertion, which is cut and retracted. A heavy silk ligature is passed around the surgical neck and tied in front. The ends are left long so that they can pass upward anterior to the capsule, and be tied over the coracoid. The capsule is then folded over the ligature and sewed, thus shortening the capsule. The deltoid is re-attached, and after a rest period of four weeks exercise is begun.
Thomas was an exponent of the capsule pleating operation. He used a posterior axillary incision, and took a reef in the capsule. He claimed exceedingly good results, as do the others. He performed capsulorrhaphy on eighteen epileptics suffering from recurrent dislocation. Twelve cases were successful, for a time at least. A capsule pleat and fascial transplant across the front of the joint is performed by Valtancoli, who reports eighty-six per cent cures.
It would seem that a patient stands some chance of cure by any of these methods. Therefore, it would be to the patient's advantage to choose the simplest, since his chances of recovery are as good as if he had the most complicated one. It is interesting to speculate why such a diversity of treatments should produce so uniform a result. It may be explained by the temporary or permanent limitation of joint function consequent to the operation. Some of the above procedures have as an object the limitation of motion, and all of them probably do limit motion. The trauma of the instrumentation, the bleeding and exudate, and the placing of sutures result in the formation of scar tissue. In addition the arm is immobilized for a time. Fixation and a sensitive scar produce pain on motion, and a certain mental impression which results in a patient's using his arm in a very gingerly way for a long time. Actual limitation or voluntary limitation are important reasons why the arm is not soon again moved into extreme elevation. It is highly probable that the late results of all these methods would not be entirely satisfactory.
Some authors have advocated and devised external apparatus to check abduction within a safe limit. These hobbles are a nuisance and offer no cure, but do prevent dislocation. The lesion is annoying and causes so much disability that many of these cases beg for operation. The treatment should be suited to the type of lesion and to the habits of the individual patient. Bony defects should be repaired or modified by plastic methods. Nicola's operation seems to be applicable, whatever the cause.
The writer has on two occasions done negative exploratory operations for this condition by opening the bursa but without entering the joint. The following case may be of interest to those who believe that deformities of the head of the bone may be the cause of recurrent dislocation, for in this patient a thorough exploration was done.

Case No. 24. Mr. K. N. Age 26. Massachusetts General Hospital No. 182833 E. S., May 22, 1912.

A large, powerful young man. First injury six months before while wrestling. Repeated dislocations after slight muscular efforts since then. "Sabre-cut" incision, supraspinatus divided and joint explored. The capsule was found to be torn, especially the portions at the lower and inner edge of the glenoid. A sort of hernia of the synovial membrane existed, which evidently made a pouch for the head when dislocated. A plastic repair was done on this part of the capsule. Part of the articular surface was missing, as if it had been broken off and absorbed. The patient was seen by me about a year after the operation, and at that time had a perfect result. I have not been able to trace him since.

This particular condition of axillary tearing of the capsule has been described by Thomas of Philadelphia, and considered by him to be the most common lesion in shoulder injuries. I have little doubt that it is a factor common to all recurrent dislocations. One cannot imagine dislocations occurring without a tear of the capsule of the joint. In all these cases the pillars of capsule which bound the opening of the bursa subscapularis must be more or less torn to enable the head of the humerus to lie in the subcoracoid position.
I have seen numerous cases of habitual dislocation, but owing to my lack of faith in any particular technique I have done few operations. I have been content to teach the patient about the mechanism of dislocation and explain to him that he cannot dislocate his arm without combining rotation and abduction. He may abduct the arm as much as he is able to do so in internal rotation in the coronal plane with impunity. These cases are usually in young men, and as has been said before, in athletes or in epileptics. Athletes may avoid dislocation by giving up those forms of athletics which tend to produce it. I have known two young men, who were my personal friends, both of whom were subject to this annoying difficulty. Both patients eventually outgrew it or changed their habits so that it did not occur. One of them, for instance, had to give up boxing because the arm would at times dislocate if he gave a forward blow. In doing this, the relation of scapula and humerus are practically the same as when they are in the pivotal position. He was a skillful athlete at other forms of amusement. It seems to me that for this type of patient it is better to change habits than to submit to operation.
In the cases of epileptics, it is imperative that the patient should wear an apparatus which prevents the combination of external rotation and abduction or should be operated upon. It has not been my fortune to have the care of any such cases. Should I be compelled to operate for this condition, I should at present choose the operation of Nicola. I here reprint some remarks made by Dr. Nicola at the discussion of Dr. Fowler's paper.
"For three years I have been using my own operation, which does not utilize any foreign material. It is done through one incision, the convalescence is short, and so far as I know there have been no recurrences on operations done by me as well as by about thirty other operators. It seems to me that it is getting more and more difficult for the student of orthopedics to decide which type of operation to use. In the end the operation that will become most popular is the one that is very simple to perform and can be done most frequently on almost any type of dislocation, no matter what the pathologic changes are (bony defects, muscle tears or capsular tears) ; and, finally, it is a matter of convalescence. In the operation which I have been doing, the line of incision begins just above the coracoid process and extends down and out in the line of the fibers of the deltoid. In my original description I stated that this should come between the pectoralis major and the deltoid, but I find that it is easy to approach it merely by going through the lines of the fibers of the deltoid. Before cutting the tendon, one should be sure to put transfixion sutures in both ends because frequently the arm may extend and the lower segment of the biceps tendon will slip behind the pectoralis and cause great anxiety. After the tendon is divided, a hole is drilled through the head of the humerus. I usually go anywhere along the bicipital groove and point the drill so that it comes out at the upper end of the angle of the head. The tendon is passed through the head and is sutured on itself, so that there is no muscle loss and the tendon has a tendency to restrict the movement and, therefore, keeps the head in the glenoid cavity. Some of the men have used this operation for fracture of the surgical neclc of the humerus when there has been downward displacement of the head into the axilla, and there they replace the head in position and drill a hole so that they maintain the head in position."
This operation appeals to me as more likely to fulfill the conditions required than any of the others. Fowler's operation also seems to me a rational procedure, but not so simple as Nicola's.
Extract from a personal letter from Dr. Nicola, June 6, 1930: "The cases reported in the reprint which you received, together with the rest, have been followed over a period of two years. The boxer has been back in the ring and has won two semifinal contests with no recurrence of dislocation. Case No. 3, which was an epileptic, was killed in an auto accident eight months after the operation. Through friendship with the coroner, I was able to examine the tendon of the long head of the biceps with special reference to the point which you made in your letter. I found that instead of thinning out of the long head of the biceps which extended to the glenoid cavity, the tendon above the humerus was thickened about the size of the little finger."
Extract from personal letter from Dr. Nicola, June 6, 1932: "I have personally done twenty-four of these operations with one hundred per cent cures. I have not heard of any recurrences from the various men who are associated with me at the Hospital for the Ruptured and Crippled. I hope that you will soon find an opportunity to operate upon such a case and to convince yourself that this operation is very simple to perform. I am now doing it through a two and one-half inch incision taken just below the clavicle on the inner side of the coracoid process and extending downward through the fibers of the deltoid muscle. The hole through the head of the humerus is made with a one-fourth inch gauge, instead of a drill. This facilitates matters considerably."
This operation I am sure could be readily done through my routine bursal incision which separates the deltoid fibers directly over the bicipital groove.

INFANTILE DISLOCATION OF THE SHOULDER

Lesions of the bursa or of the supraspinatus tendon in childhood apparently do not occur, at least they have never fallen within my experience. However, a not very infrequent lesion in childhood, namely, birth palsy complicated by dislocation of the shoulder, sometimes causes confusion in the diagnosis of shoulder lesions in later years. We see the shoulder deformed from a lesion which occurred at or soon after birth.
There has been much discussion as to whether the term congenital dislocation of the shoulder joint should ever be used. It seems very probable that a large number of so-called congenital subluxations, if not a majority of the published cases, were instances of obstetric palsy in which the dislocation remained after the paralysis had recovered. Infantile dislocation may be discussed under three headings, according to whether it existed before birth, occurred at birth or resulted soon after from paralysis caused at birth.

(1) Abnormality of development—true congenital dislocation. The existence of such a clinical entity has been questioned, but it has been established without any doubt, although it must be very rare. R. W. Smith of Dublin, in 1839, was the first to bring this condition before the profession. He published an account of three cases in the Dublin Journal of that year. Two of these were males, age 20. The dislocation was subcoracoid. The muscles about the shoulder were wasted. One patient had club foot. The third case was an insane woman, age 29, in whom the condition was bilateral.
At post-mortem examination there were facets just under the cora-coid, with a displacement of the capsule anteriorly to enclose the joint. The head of the humerus was flattened, and the acromion and coracoid elongated and hooked downward. In all the cases abduction was limited. Eleven years later Smith published two additional cases. In 1841 Guerin presented two cases and demonstrated a symmelian foetus which showed this abnormality on both sides. Since these reports, numerous cases have appeared in the literature. Grieg analyzed the cases of fifty-eight authors in the Edinburgh Medical Journal of 1923. He makes the following statement. "So far I have only found twelve cases reported to date in which evidence brought before the profession fails to justify any other conclusion than that they are cases of true primary congenital dislocation of the shoulder."

(2) Dislocation produced by obstetric manipulation or during birth. This group is open to criticism because proof of its existence is not satisfactory. T. T. Thomas was firmly of the opinion that traumatic dislocation not only occurs, but is the primary factor with regard to paralysis. He believed that paralysis is secondary to a rent in the capsule due to a traumatic dislocation. Taylor, writing in 1921, states that neither he nor any of three obstetricians of a large Lying-in Hospital had ever seen a case of Erb's palsy in which the subluxation preceded paralysis. In 1866 Loignan wrote a thesis for a Paris doctorate on the subject. He found that he could not dislocate the shoulder by manipulation. The constant lesion which occurred, if sufficient force were used, was a fracture of the humeral shaft through the soft bone under the epiphysis. Other investigators, notably Sever, have been unable to produce traumatic dislocation or rupture of the capsule by manipulation in infant cadavers. The writer feels that dislocation occurring at birth is so rare as to be negligible in diagnosis.

(3) Acquired subluxation due to injury of the plexus. Obstetric paralysis was first described by Smellie in 1768. He thought the condition was due to prolonged pressure on the arm while the child was in the pelvis. It was brought before the profession, however, by Duchenne, who in 1872 described four cases in infants and believed it to be due to pressure on the nerve trunks. Erb described the palsy in adults in 1874. Since that time it has been known as Erb-Duchenne paralysis. Erb believed it to be due to pressure on the fifth cervical root, known as Erb's point. Fieux opposed this view and adopted the theory that traction is responsible. He demonstrated on infant cadavers the fact that when the head is forcibly drawn away from the shoulder, the fifth cervical root is torn just proximal to its junction with the sixth nerve. With more force, the latter nerve may also be torn. Only the muscles of the upper arm are paralyzed. The palsy is usually flaccid.
Infants with Erb's palsy present a typical history and appearance. There is usually a difficult birth where traction on the head has been made under ether relaxation. The arm hangs limp and vertically at the side, the elbow is extended and the forearm pro-nated. There is inability to abduct, elevate, outwardly rotate, or supinate. There is extreme internal rotation so that the palm often faces outward. After a short time, there is wasting from disuse, and flattening of the shoulder soon appears. Passive motions' are free at first, but the healthy muscles soon contract and produce limitation of motion—notably of external rotation. The muscles paralyzed are the deltoid, supra- and infra-spinatus, teres minor, biceps, brachialis and brachioradialis. There is no sensory disturbance.
Clark, Taylor and Prout estimated one case of palsy in 2,000 births. Most cases of birth palsy show some luxation of the head of the humerus. Fairbanks saw twenty-eight subluxations in thirty-seven cases of palsy, or seventy-six per cent; Thomas reported nine in twelve. Taylor has reported sixty-eight cases, forty-six of which showed subluxation. He has never seen the condition in patients less than six weeks old. Of those patients who had palsy, who were more than six weeks old, seventy-seven per cent showed subluxation. In 109 X-ray studies reported by Sever in 1916, sixty-four or fifty-nine per cent showed subluxation. The ages in this series varied from one day to eighteen years.
It should be noted that this form of dislocation is posterior, while the first two forms are anterior or inferior.

Mechanism of Posterior Subluxation. The appearance of the arm soon undergoes a change from the flaccid condition which follows the immediate injury for a few weeks after birth. The upper arm is brought forward and adducted by contraction of the well muscles. The elbow is usually a little flexed, the pronated forearm passing downward and inward across the front of the body. Abduction is checked before the arm comes to a right angle. Backward motion is usually impossible and external rotation is markedly limited. With the elbow at the side, it is often impossible to rotate the humerus out sufficiently to bring the forearm into the forward plane. The bones of the affected side—the humerus, scapula and clavicle—are smaller than those on the opposite side. This is an important point in the diagnosis of late cases. The front of the shoulder is flattened, while there is a fullness behind, below the acromion, due to the head of the humerus. The muscles which tend to prevent posterior dislocation are the teres minor, supraspinatus, infraspinatus, and posterior part of the deltoid. The pectoralis major, the teres major and latissimus dorsi are rarely even partially paralyzed and rotate the humerus strongly inward. The subscapularis acts as a powerful internal rotator. These muscles become contracted while the paralyzed ones are stretched. The teres major and latissimus dorsi exert traction downward and posteriorly. The anterior portion of the capsule becomes shortened secondarily. Since the arm is held in an internally rotated position, there is a constant jstrain on the neck of the humerus, tending to twist it backward. In the plastic young bone, this twisting occurs and the plane of the head of the bone to the shaft may be changed ten or fifteen degrees. The dislocation is not truly posterior—it is rather a rotation of the head than a dislocation, so that the articular portion is rotated backward and the side of the head lies on the glenoid without having escaped from its capsule.
During the first year nothing can be seen in the way of bony deformity in the X-ray, except possibly a slight posterior subluxation and relatively small size of the head compared to that of the other side. As the child grows older, the subluxation increases. There is increased outward displacement and elevation of the scapula. The acromion and coracoid become hooked downward in front of the head of the humerus. The clavicle is shortened and its curves are more marked than in the normal. The coracoid process is usually elongated. The glenoid becomes shallow. These changes of the bones occur while the paralysis exists, and even if the paralysis clears up, they persist.

Treatment. In early cases the arm may be held in abduction, elevation, external rotation and supination by a light wire splint. Sever, however, prefers to let the child use the hand and arm freely with the risk of contractures. Passive motion and massage are carried out at frequent intervals. Operation is deferred until the child is three or four years of age. Once contractures have developed, it is best to cut the contracted muscles. Manipulation is of little value because of the tendency to recurrence, unless the paralyzed muscles have regained their tone. Sever has described his operation at length in a paper read before the Section on Orthopedic Surgery of the American Medical Association, 1925. He cuts the pectoralis and subscapularis tendons and removes one-half inch to three-quarters inch of the tip of the coracoid with its muscle attachments. If necessary he removes the hooked acromion to allow reduction. The arm is put up in a light splint in abduction, elevation, external rotation and supination. Muscle reeducation by active and passive motion is begun after eight to ten days. The splint is worn night and day for three months, but is removed daily for exercises.

Prognosis. This depends largely on the recovery of the paralyzed muscles in early cases. If the child is seen early, contractures and subluxation may be minimized by passive motion until the nerves have regenerated. In late cases, however, where contractures have developed and there is no tendency of the nerves to regenerate, operation has to be resorted to and gives a good, hut not brilliant, functional result. Sever records partial recovery in 297 of 394 cases which were operated upon. After operation there is great difficulty in inwardly rotating the arm. He states that this may be eventually overcome, however.
I have had very little personal experience in these cases, but the following case taught me such an important lesson that an account of it is presented in the hope that it may stimulate some one to follow up a series of such cases in which operations had been done in childhood.

CASE 70.
A strong boy, age 14, was referred to me for trouble with his shoulder, with the story that he had had difficulty since he was a baby, and that while he was a very strong, active boy otherwise, he was greatly handicapped by his shrunken, weak, deformed right arm. The diagnosis in the case puzzled me a good deal at first, for there was no paralysis, and the X-ray simply showed a rather small and deformed humeral head and glenoid cavity. In spite of this, by palpation, it was easy to feel that the head of the humerus was posterior to the glenoid under the acromion. Both the coracoid and the acromion were hooked down in an unnatural manner, which was easy to understand when one recognized the true character of the lesion, for the acromion process had nothing beneath it and was not performing its normal function. All parts of the shoulder, including the bones, were smaller than those of the opposite side. There was practically no motion in the scapulo-humeral joint and the arm was held in internal rotation. An extraordinary amount of compensatory mobility had developed in the motion of the scapula on the chest wall— not only in flexion and extension, but in abduction and adduction.
It was clearly a case of birth palsy in which the bones had remained out of place after the muscular paralyses had recovered, and therefore the patient now only suffered from the consequence of the luxation.
I operated on June 16, 1921, through a "sabre-cut" incision, and to my surprise, found that the cartilaginous surfaces of the glenoid and of the head of the humerus had remained in nearly a normal condition, although they had been separated for so many years. The capsule was stretched and distorted, but not disrupted. The cartilaginous surface of the glenoid was rather puckered and the articular head of the humerus was small and rather misshapen, although less so than one would think from the appearance in the X-ray, which of course showed the surface of the bony centers of the epiphysis and not the cartilage. The contraction of the subscapularis and pectoralis major was so great that I had to divide their tendons in order to get the head of the bone in place. The coracoid process was so deformed that I had to excise about two-thirds of it subperiosteal^ in order to reduce the humerus. The "sabre-cut" incision, of course, mobilized the acromion. After reducing the head of the bone, I was able to put four silk sutures "a-distance" to reunite the cut ends of the subscapularis. I did not attempt to correct the torsion of the neck, although it caused some eversion of the arm when the head of the bone was in place. The whole wound was sutured, and the patient was put up in plaster in semi-abduction and semi-external rotation.
It was most remarkable to watch the boy's convalescence. There was a good surgical recovery, but the miraculous part was to see the promptness with which the bones and muscles tended to grow into normal condition. Within six months he had nearly normal use of his shoulder, and the condition of the muscles had greatly improved.
As the patient lived in another city I lost track of him about six months after the operation and did not see him again for ten years, when I looked him up in preparation for this book. It is fortunate that I did so, for the lesson which I learned was important and may be of help to others.
During the ten years that had passed, the boy had become a man of twenty-four, whose occupation was in moving buildings. He did much of the manual labor himself. When he came into my office he looked strong and vigorous, and I had to ask him which shoulder was the bad one. Then my disappointment came.
A skillfully made movable pad inside his coat concealed the small size of his right shoulder. His vigorous handshake and well-developed forearm gave no hint of the practically ankylosed joint which was displayed when he removed his clothes. On closer examination I found both coracoid and acromion clutching down on the head of the bone like crooked fingers grasping it and holding it fixed. It appeared as if the acromion process had bent downward from the point where I had divided it and had become fixed in this position.
After a time the explanation occurred to me. At fourteen, the acromion and coracoid are cartilaginous epiphyses, for they have not yet ossified. After my operation, although the head of the humerus was in place, it was small and underdeveloped because of imperfect function for fourteen years. Consequently the cartilaginous acromion and coracoid became bent down over it, grasped it, and then, at about twenty, turned to bone and held it fixed. I did not at the time of the operation realize that the greater part of the acromion does not unite with the spinous process until about twenty. I think now that if I had insisted that this boy should have slept with his arm elevated until he was twenty, and had kept up appropriate exercises, he might have obtained a more perfect shoulder. It is not a great hardship to form the habit of sleeping with the arm in the hammock position. Many people do this by preference. He had been able to hold his arm in this position when I last saw him six months after the operation. Later the strength of the divided internal rotators returned and tended to rotate the arm to its old position, and also to resist elevation in external rotation. The head of the bone being small, the cartilaginous acromion slowly yielded to fit over its convexity. I think that it is highly probable that if the late results of other operations which have been done for these cases were critically examined, the same disappointing condition might be found in later years. Operations should not be undertaken on these cases unless the parents are warned that the patient should be under the surgeon's care until his epiphyses are united; i.e., when the patient is about twenty. I am inclined to think that nature's results at the end of ten years would compare very favorably with those of surgeons.

ACROMIO-CLAVICULAR DISLOCATION

A brief consideration of lesions of the acromio-clavicular joint seems advisable, although strictly speaking, neither the subacromial bursa nor the supraspinatus tendon are involved. One must remember that the coraco-acromial ligament intervenes between these structures. When this joint is dislocated the coraco-acromial ligament goes intact with the scapula. In severe cases the coraco-clavicular ligaments (conoid and trapezoid) are torn.
Mechanism. The acromio-clavicular joint, itself, is weak, but the conjunction of the two bones derives its strength from the conoid and trapezoid ligaments which are attached to the coracoid process of the scapula. Upward dislocation of the clavicle is favored by the upward and outward slope of the joint. The clavicular facet looks downward, outward, and backward. Dislocation is almost always caused by direct violence. A blow on the back of the acromion or a fall on the tip of the shoulder drives the acromion downward, inward, and forward, and the clavicle with the coracoid process as a fulcrum is torn away.
Dislocation is classed as complete or incomplete according to whether or not the facets clear each other. The ligaments of the joint itself are more or less torn, even in incomplete dislocation, but the conoid and trapezoid ligaments are usually torn in complete dislocation.
Diagnosis. The diagnosis is to be made from the history of trauma, pain and disability. The outer end of the clavicle is prominent and movable, and can be readily reduced, but reduction is hard to maintain if the coraco-clavicular ligaments are ruptured.
Treatment. Upward, outward, and backward traction on the scapula is indicated and can be applied by various braces or by recumbency. The most favored method is the clavicular cross. A T-shaped splint is applied to the back, and the shoulders strapped to the cross arms.
Open reduction and fixation are occasionally necessary. Several operations have been devised, most of them using fascial strips. Representative among these may be cited Bunnell's ingenious method. He threads a cord of fascia through holes in the acromion and clavicle, and places a loop under the coracoid process.
Prognosis. If the reduction can be maintained, the chances are good that a patient will regain function in the course of several months, but soreness and some pain may persist for years. Arthritic changes may take place. I personally have never found it necessary to operate on acromio-clavicular dislocation, but in extreme cases I should recommend Bunnell's operation.

ACROMIO-CLAVICULAR ARTHRITIS

In contrast to the mechanism of the scapulo-humeral articulation, that of the acromio-clavicular joint is typical of the kind in which arthritis is prone to occur. It is a hinge joint with a very limited degree of motion. For its size, when in action, it carries an immense burden of weight. For instance, as one pushes open a heavy door, this little joint has to bear the equivalent weight of almost the^ whole power exerted. The same is true of the joint on the sternal end of the clavicle, but that joint has a much larger surface area. In laboring men who carry or lift heavy burdens, spurring from arthritis of the acromio-clavicular joint is so common as to form almost as normal a tissue as the great calluses in their hands. In many of the older individuals, the rims of new-formed bone actually fuse, so that the joint becomes obliterated. These changes may progress with very little pain and discomfort to the individual, or they may be accompanied by the usual signs of arthritis, which occasionally are so severe that they incapacitate the patient.
The acromio-clavicular joint holds an exposed position on the shoulder, and falling objects not infrequently strike the joint directly—perhaps breaking some of the small bony lips, causing hemorrhage about or in the joint. Such cases may be laid up for months on account of the local tenderness when they attempt to use the arm. I find it very difficult, in giving an opinion on compensation cases, to state when such individuals should be expected to return to work. The X-ray appearance is far from being a criterion. A man may have a very ragged and hypertrophied-looking joint and yet be conscious of no symptoms. Another man with barely perceptible changes may have much local tenderness. On the whole, it is surprising how well these laboring men are able to bear acromioclavicular arthritis. The diagnosis of these lesions rests entirely on the readily ascertained facts of localized swelling and tenderness, supported by the X-ray evidence of lipping of the joint. Confusion in diagnosis only arises when one allows one's self to center his attention on this joint and to ignore other really more important lesions. Never forget that this condition may attract your attention too readily, and by its presence conceal a lesion of the supraspinatus which is far more serious. Acromio-clavicular arthritis must be judged by the degree of symptoms, not by its X-ray appearance, for often there is much lipping of the edges of these joints and yet no symptoms at all.
Treatment. As a rule, these cases respond well to rest. A few weeks' confinement of the arm in a sling soon after a bruise on one of these joints is all that should be attempted. I am convinced that complete fixation of this joint is unfortunate. I do think that rest is very important in acute stages. Patients who have had prolonged symptoms have usually had either prolonged energetic treatment or prolonged fixation.
In a few subacute and prolonged cases, I have cut into the joint with the same idea that one has in cases of periostitis, where one incises to cause relief of tension. As a rule, however, I believe that simple rest is the only form of treatment which is important. The usual physiotherapy methods may be of some use, but my personal experience with them has been little.
Remember that the acromio-clavicular joint is not in immediate anatomic relation with the subacromial bursa. The coraco-acromial ligament intervenes. Therefore, acromio-clavicular arthritis does not prevent rotation or abduction in the scapulo-humeral joint, except in extreme positions. If these motions are not present, do not blame the acromio-clavicular joint entirely, even if it is swollen and tender.
Arthritic changes in this joint commonly occur after luxation or subluxation, and soreness may continue many months and sometimes a few years after such accidents. Men who do their own work generally continue at it in spite of this protracted soreness, but employees are apt to find their shoulders too sore to permit labor, if their compensation is paid. Thus this little lesion may be the cause of their never working again, for it is a commonplace that a year of loafing is a serious matter for an elderly laborer. Surgical obliteration of the joint should be considered, in some cases at least, as a mental stimulant. It is not an important joint.

BIBLIOGRAPHY

BANKART, A. S. B. Recurrent or habitual dislocation of the shoulder joint.
Brit. M. J. 1923. 2. 1182-1133. BUNNELL, S. Fascial graft for dislocation of acromio-clavicular joint.
Surg. Gyn. and Obst. 1928. 46. 563-564. CARRELL, W. B. Habitual dislocation of the shoulder.
J. A. M. A. 1927. 89. 948-952. DELBET, P. Des luxations anciennes et irreductibles de l'epaule.
Arch. Gen. de Med. 1893. ser. 7. vol. 81. 19-39. DOLI.INGER, J. Die Veralteten traumatischen Verrenkungen der Schulter; des
Ellenbogens und der Hufte.
Ergebnisse der Chir. und Orthop. 1911. 3. 83-194. DOI.LINGER, J. Das anatomische Hinderniss der Reposition bei veralteten sub-
coracoidealen Schulterverrenkungen und meine Methode zur blutigen Reposition dieser Verrenkung.
Deut. Zeit. fur Chir. 1902-03. 66. 819-335. DUCHENNE, G. B. Physiologie des mouvements.
Paris. J.-B. Bailliere et Fils. 1867. pp. 7-17. EDEN, R. T. Habitual dislocation of shoulder.
Zentralbl. f. Chir. 1920. 47. 1002. ELIASON, E. T. Nelson's System of Surg. vol. 3. p. 292-293. FIEUX, see Bibl., Chap. XI. FINSTERER, H. Zur Frage nach der zweckmassigsten Behandlung der habituellen
Schulter luxation.
Wien. Med. Woch. 1924. 74. 1232-1237. FOURMESTRAUX, J. DE. Les luxations recidivantes de l'epaule; pathogenie; traite-
ment.
Arch. Med.-Chir. de Province. 1920. 10. 18-26. FOWLER, E. B. A new operation for recurrent dislocation of the shoulder.
J. A. M. A. 1932. 98. 476-478. GERSTER, A. G. Subcoracoid dislocation of the humerus; paralysis of the serratus
magnus; arthrotomy.
Med. News, Phila. 1884. 44. 423. GOEBEL, W. Zur Prognose der traumatischen Schultergelenksluxation.
Zeit. fur Artzl. Fortbildung. 1909. 6. 347-855. GRASSNER, R. Die Briiche des grossen Oberarmhockers.
Veroff. aus dem Gebiete des Milit.-Sanitat. 1906. 85. 180-198. GRATZ AND ROBINSON. Am. J. Surg. XV. 1932. 71. January. GUBLER, H. Zur Prognose der Schultergelenksluxationem.
Schweiz. Med. Woch. 1922. 52. 960-964.
Abst. J. A. M. A. 1922. 79. 1964. HENDERSON, M. S. "Tenosuspension" for habitual dislocation of the shoulder.
Surg. Gyn. and Obst. 1926. 43. 18-25. HILDEBRAND. Zur operativen Behandlung der habituellen Schulterluxation.
Arch, fur Klin. Chir. 1902. 66. 360-364.
KELLER, W. L. Treatment of chronic recurrent dislocation of the shoulder by
crucial capsular plication.
Ann. Surg. 1925. 81. 143-148. KOCHER, THEODORE. Eine neue Reductionsmethode fiir Schulterverrenkung.
Berl. Klin. Wchnschr. 1870. 7. 101-105.
Bull. Soc. Med. de la Suisse Rom. Lausanne. 1873. 7. 819-330. 3 pi. KUTTNER. Zur Prognose der traumatischen Luxation.
Zentralbl. fur Chir. 1908. 35. Beilage p. 155-157. LANDES, T. L. Recurring dislocation of the shoulder joint.
Brit. Med. J. 1921. 2. 321-822.
LEXER, K. Nachuntersuchungen von traumatischern Schultergelenksluxation. Beitr. zur Klin. Chir. 1910. 70. 221-235.
LOEFFLER, F. Die Behandlung der habituellen Schulterluxation durch Bildung
eines extraartikularen Hemmungsbandes.
Zbl. fur Chir. 1920. 47. 324-326. MANDL, F. Bemerkungen zur Operation der habituellen Schulterluxation.
Deut. Zeitschr. fur Chir. 1925. 191. 108-120. NICOLA, T. Recurrent anterior dislocation of the shoulder; a new operation.
J. Bone and Joint Surg. 1929. 11. 128-182.
NICOLA, T. Recurrent dislocation of the shoulder; its treatment by transplantation of the long head of the biceps. Amer. J. Surg. 1929. 6. 815.
NICOLA, T. Operation for relief of recurrent dislocation with presentation of
patients.
Amer. J. Surg. 1931. 11. 119-121. OUDARD. La luxation recidivante de F6paule (varied ante>o-interne).
J. de Chir. 1924. 23. 13-25.
Abst. J. A. M. A. 1924. 82. 1004. OUDAFD. La luxation recidivante de l'6paule (variete ante>o-interne).
Presse Med. 1928. 86. 201-202. PERKINS, G. Discussion on the painful shoulder.
Proc. Roy. Soc. Med. (Sect. Orthop.) 1929. 22. 20-80. PERTHES. Munch. Med. Woch. 1905. H, 10. s. 481. PERTHES, G. Results of surgerv in habitual dislocation of humerus.
Dtsch. Ztschr. f. Chir. 192*5. 194. 1-24. Also J. A. M. A. 1926. 86. 589.
PILZ, W. Zur RHntgenuntersuchung der habituellen Schulterverrenkung. Arch, fur Klin. Chir. 1925. 135. 1-22. Abst. J. A. M. A. 1925. 85. 75. Also Zbl. Chir. Soc. 22, s. 1390. 1928.
PLUMMER, W. W. & POTTS, F. N. Two cases of recurrent anterior dislocation of the shoulder. J. Bone and Joint Surg. 1925. 7. 190-198.
PRESTON, M. E. Fractures and dislocations. C. V. Mosby Co., St. Louis. 1915. p. 11-108.
RIVIERE, G. Capsulorrhapie de l'articulation de l'£paule pour luxation recidivante. Lvon Chir. 1918. 15. 437-439. Abst. J. A. M. A. 1919. 72. 612.
SCHI.AEPFER, K. Uncomplicated dislocations of the shoulder; their rational treatment and late results. Amer. J. Med. Sc. 1924. 167. 244-255.
SELIO, R. Die bei der habituellen Schulterluxation gebrauchlichen Operations methoden von anatomischen Grundsatzen aus betrachtet. Was leistet der Musculus supraspinatus. Deut. Zeit. fur Chir. 1915. 132. 581-588.
SEVER, J. W. The rational treatment of fractures of the upper end of the humerus. Report of end results. J. A. M. A. 1923. 80. 1603-1608.
SEVER, J. W. Recurrent dislocation of the shoulder joint. Mechanical consideration of its treatment. J. A. M. A. 1921. 925-927.
SINZ, P. Inaugural-Dissertation. Erlangen. 1982.
SPEED, K. Recurrent anterior dislocation at the shoulder. Operative cure by bone graft. Surg. Gyn. and Obst. 1927. 44. 468-477.
SPEED, K. Fractures and dislocations.
Lea and Febiger, Phila. 1916. p. 857-440.
SPITZY, H. Stabilization of the shoulder joint for habitual dislocation.
Surg. Gyn. and Obst. 1928. 46. 256-257. STEVENS, J. H. The action of the short rotators on the normal abduction of the
arm, with a consideration of their action in some cases of subacromial bursitis
and allied conditions.
Amer. J. Med. Sc. 1909. 138. 870-884. STEVENS, J. H. Dislocation of the shoulder.
Ann. Surg. 1926. 83. 84-103. STEVENS, J. H. Fractures of the upper end of the humerus.
Ann. Surg. 1919. 69. 147-160. STIMSON, L. A. Fractures and dislocations.
Lea and Febiger, Phila. 1917. TAYLOR, R. T. Fracture dislocation of the shoulder. Arch. Surg. 1928. 17. 475-483. THOMAS, T. T. Habitual or recurrent dislocation of the shoulder. Etiology and
pathology.
Amer. J. Med. Sc. 1909. 137. 229-246.
J. A. M. A. 85. No. 16, s. 1202. 1925. TREVES, F. Surgical applied anatomy.
Lea and Febiger, Phila. 5th ed. VALTANCOLI, G. Sulla lussazione abituale di spalla.
Chir. d. Organi di Movimento. 1924. 9. 131-140. WARREN, J. C. Am. J. Med. Sci. 1846. XI. WILSON, P. D. & COCHRANE, W. A. Fractures and dislocations.
Lippincott & Co. 1925. p. 59-153.

NOTE—Sinz (1932) gives a very extensive Bibliography. He recommends a bone transplant to the glenoid (after Perthes or Eden) but apparently was unaware of the work of Nicola.

==References==
<references />

File:DAS long.mov

2021-09-26T06:05:12Z

Alexandre.laedermann:

Surgical Technique

Shoulder:Glenohumeral Arthritis/Reverse Shoulder Arthroplasty

2021-09-10T10:34:11Z

Alexandre.laedermann: /* Subscapularis Repair */

==Bullet Points==

*Indications for reverse shoulder arthroplasty expended. Weight-bearing patients, preoperative deltoid or acromial impairment, in certain circumstances, are not an absolute contraindication to reverse shoulder arthroplasty.

*Deltopectoral, anterosuperior (transdeltoid), and deltoid and subscapularis sparing approaches are currently used. Transacromial approach has been abandoned.

*Adequate deltoid tension obtained through restoration of humeral and arm length is one of the keys for postoperative function and prevention of instability following reverse shoulder arthroplasty. With a classic Grammont prosthesis postoperative humeral lengthening is approximately 2 mm and arm lengthening is approximately 24 mm.

*Subclinical neurologic lesions after Medial Glenoid/Medial Humerus Design are a frequent with consequence of lengthening with a drastically increasing prevalence above 40 mm of arm lengthening. Lateralized designs seem to be protective. Arm lengthening should be controlled with 0 to 2 cm being a reasonable goal to avoid postoperative neurological impairment.

*Medial Glenoid/Medial Humerus 155 degrees neck-shaft angle designs are progressively replaced by lateralized and lower neck-shaft angle (145-135 degrees) designs that theoretically attain, compared to traditional Grammont-type prosthesis, an optimal compromise in range of motion and soft tissue tension.

*Anterior forward flexion and Constant scores after reverse shoulder arthroplasty plateau at 6 months postoperative whereas internal and external rotation continue to improve up to 2 years postoperative. Several preoperative factors are correlated with postoperative range of motion.

*Previously, complications have been reported to affect 19% to 68% of patients and include acromial fracture, haematoma, infection, instability, mechanical baseplate failure, neurological injury, periprosthetic fracture and scapular notching. The rate of postoperative complications has dramatically decreased.

*The launch of a variety of reverse shoulder arthroplasty designs on the market has introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

==Key words==
Reverse total shoulder arthroplasty; prosthesis; postoperative function; humerus and arm length; deltoid impairment; muscle insufficiency; complications; indications, contraindications; impingement; humeral lateralization; glenoid; neck-shaft angle; function; range of motion; active forward flexion; predicting factors; results; clinical outcomes; weight-bearing joint; wheelchair; crutches.

==History==
Paul Grammont was born on April 1940 in Salins-les-Bains, in the northeastern part of France. He began medical studies in Lyon. Very quickly he became interested in surgery, and more specifically in orthopaedic surgery. He first became the fellow and then assistant of Professor Albert Trillat. He became a Professor of Orthopaedic Surgery and Traumatology in 1974 at the age of 34. He then moved to Dijon (France) where he became the Chairman of the Orthopaedic Department of the University Hospital. While he had few laboratory resources, he began many of his biomechanical shoulder experiments in his own garage. Grammont was creative: besides developing the reverse shoulder prosthesis,<ref>Grammont PM, Latfay, J, Deries X. [In French] Etude et réalisation d’une nouvelle prothèse d’épaule. Rhumatologie 1987;39: 407-418</ref> he also developed an early patellofemoral prosthesis<ref>Renard JF, Grammont P. [In French] La prothe`se autocentrique de rotule: technique et re´sultats apre`s 7 ans de recul. Rhumatologie.
1989;41:241–245.</ref> and one of the first nails with a self-advancing mechanism designed to lengthen long bones like the tibia and the femur (Albizia nail).<ref>Guichet JM, Grammont PM, Trouilloud P. [A nail for progressive lengthening. An animal experiment with a 2-year follow-up]. Chirurgie. 1992;118(6-7):405-410</ref> Paul Grammont died in Lyon the 30 March 2013.

==Anecdotes==
This subsection does not exist. You can ask for it to be created, but consider checking the search results below to see whether the topic is already covered.

==Human Development==
During evolution the permanently orthograde posture has freed the human shoulder girdle of its quadruped functions. The anterior limbs became the upper limbs with the characteristics of a non-weight-bearing joint. Major bony and muscular adaptations occurred.<ref>Baulot, E. Sirveaux, F. Boileau, P. Grammont's idea: The story of Paul Grammont's functional surgery concept and the development of the reverse principle. Clin Orthop Relat Res. 2011 Sep;469(9):2425-31</ref> The scapulohumeral complex underwent drastic changes to facilitate prehension, leading to major bony and muscular modifications. A relative atrophy of the supraspinatus muscle occurred, as illustrated by a decrease in the scapular index.<ref>Inman, VT. Saunders, M. Abbott, MC. Observations on the function of the shoulder joint. J Bone Joint Surg Br 1944;26(1):1-30</ref><ref>Pearl, R., and Schultz, F.: Human Biology: A Record of Research. Edited, Baltimore, Warwick and York Inc Publishers, 1930</ref> The decrease in the effectiveness of the latter muscle was at the same time compensated for by the increase in size, mass, and lateral extension of the acromion process. The progressive distal migration of the point of insertion of the deltoid muscle and lateralization of the acromion indicate the more dominant position occupied by the deltoid with strengthening in particular of the middle deltoid abduction component.<ref name=":27">Grammont, P. M.: Place de l’ostéotomie de l’épine de l’omoplate avec translation, rotation, élévation de l’acromion dans les ruptures chroniques de la coiffe des rotateurs. Lyon Chir 1979;55:327–329</ref>

The glenohumeral joint is highly mobile and relatively unconstrained. Stability of the joint relies upon concavity-compression whereby the rotator cuff exerts a compressive force of the humeral head upon the glenoid. In the absence of concavity-compression, the unopposed contraction of the deltoid creates a force vector that displaces the head superiorly rather than in abduction. Depending on the type of rotator cuff lesion, a patient may present with pseudoparalysis.

To compensate the loss of function of the rotator cuff, several options have been proposed; the most reasonable, whenever possible, is to repair the rotator cuff. Good results are obtained in the vast majority of the cases with healing of the rotator cuff on the tuberosities. In some circumstances, rotator cuff repair is however contraindicated or technically impossible.

For instance, a rotator cuff insufficiency associated with pain and pseudoparalysis remains a challenging condition. It is extremely difficult, if not impossible, to obtain a functionally good result with a conventional prosthetic arthroplasty in this situation, where only a “limited goals surgery” is appropriate, a concept introduced by Neer.<ref>Neer, C. S., 2nd; Craig, E. V.; and Fukuda, H.: Cuff-tear arthropathy. J Bone Joint Surg Am 1983;65(9):1232-44</ref> Effectively, hemiarthroplasty provides satisfactory pain relief but poor motion,<ref>Sanchez-Sotelo, J.; Cofield, R. H.; and Rowland, C. M.: Shoulder hemiarthroplasty for glenohumeral arthritis associated with severe rotator cuff deficiency. J Bone Joint Surg Am 2001;83(12):1814-22</ref> whereas total anatomic shoulder arthroplasty is complicated with early loosening of the glenoid component.<ref>Barrett, W. P.; Franklin, J. L.; Jackins, S. E.; Wyss, C. R.; and Matsen, F. A., 3rd: Total shoulder arthroplasty. J Bone Joint Surg Am 1987;69(6):865-72</ref>

In order to provide active forward elevation above 90 degrees, the abduction role of the deltoid has to be increased. This can be obtained by several mechanisms, such as an osteotomy of the scapular spine<ref name=":27" /> or more commonly by medializing the center of rotation the glenohumeral joint.<ref>Grammont, P. M.; Bourgon, J.; and Pelzer, P.: Study of a Mechanical Model for a Shoulder Total Prosthesis: Realization of a Prototype. In ECAM de Lyon. Edited, Dijon, Université Dijon, 1981</ref> The concept of functional surgery is born from the latter option: whereas no effective anatomic solution exists, restoration of function has to be proposed through a novel morphology.

The first-generation of reverse shoulder arthroplasty has been implanted in Germany and France.<ref>Gérard, Y.; Leblanc, J. P.; and Rousseau, B.: A complete shoulder prosthesis. Chirurgie 1973;99:655–663</ref><ref>Kolbel, R., and Friedebold, G.: [Shoulder joint replacement]. Arch Orthop Unfallchir 1973;76(1):31-9</ref> However, early loosening and mechanical complications forced to abandon their use. Nevertheless, successive improvements imagined by Grammont followed and, in 1991, a reverse shoulder arthroplasty called the “Delta III” has been developed.<ref name=":36">Baulot, E.; Chabernaud, D.; and Grammont, P. M.: [Results of Grammont's inverted prosthesis in omarthritis associated with major cuff destruction. Apropos of 16 cases]. Acta Orthop Belg 1995;61(Suppl 1):112-9</ref> The two major innovations were a large metal hemisphere with no neck on the glenoid side, and a small humeral polyethylene cup (covering less than half of the hemisphere), oriented with a nonanatomic inclination of 155 degree.

==Biomechanics==

#REDIRECT [[https://wiki.beemed.com/view/Shoulder:Biomechanics]<nowiki>]</nowiki>

Reverse shoulder arthroplasty, often used in multiply operated patients with distorted anatomy, imparts physiological and biomechanical changes that may increase the potential for complications.<ref name=":5">Farshad M, Gerber C. Reverse total shoulder arthroplasty-from the most to the least common complication. Int Orthop. 2010 Dec;34(8):1075-82</ref>

First, the arthroplasty position medializes and lowers the glenohumeral center of rotation, thereby increasing the lever of the deltoid muscle (Medial Glenoid/Medial Humerus Design). Deltoid tension, increased by the lowered center of rotation, increases muscle fiber recruitment of the anterior and posterior deltoid that compensates for a deficient rotator cuff (Figure). The medialization increased the deltoid moment arm up to 20%, and an inferior move increased the efficacy of the deltoid up to 30%.<ref>Terrier A, Reist A, Merlini F, Farron A. Simulated joint and muscle forces in reversed and anatomic shoulder prostheses. J Bone Joint Surg Br 2008;90:751-6.</ref>

[[File:Muscle recruitment.jpg|thumb|center|(A) Native shoulder. The center of rotation is in the humeral head, and the level of arm of deltoid does not allow deltoid recruitment. (B) Bony increased-offset reverse shoulder arthroplasty with lateral glenoid/medial humerus design. As in native shoulders, the bony lateralization of the center of rotation decreases recruitment of the deltoid for rotation. (C) Grammont reverse shoulder arthroplasty with humeral lateralization with a medial glenoid/lateral humerus design. Medialization of the center of rotation and humeral lateralization allows important deltoid recruitment. Reproduced from Collin et al.,<ref name=":6">Collin P, Liu X, Denard PJ, Gain S, Nowak A, Lädermann A. Standard versus bony increased-offset reverse shoulder arthroplasty: a retrospective comparative cohort study. J Shoulder Elbow Surg. 2018;27(1):59-64</ref> with permission.]]

Second, to provide an inherently stable reverse shoulder arthroplasty, the weight bearing part is convex and the supported part concave (reversal of the ball and socket). The fixed nature of the glenosphere places torsional forces on the humerus that may affect humeral component instability.<ref name=":37">Melis B, DeFranco M, Lädermann A, Molé D, Favard L, Nérot C, Maynou C, Walch G. An evaluation of the radiological changes around the Grammont reverse geometry shoulder arthroplasty after eight to 12 years. J Bone Joint Surg Br. 2011 Sep;93(9):1240-6</ref> The native spinning joint becomes a hinge joint, new configuration that leads to various impingements’ types and locations.

Third, the semi-constrained nature of the prosthesis restores glenohumeral stability which provides the stable fulcrum which is essential for active anterior elevation.

Finally, lengthening of the arm which provides space for range of motion of the proximal humerus,<ref name=":32">Lädermann A, Edwards TB, Walch G. Arm lengthening after reverse shoulder arthroplasty: a review. Int orthop 2014;38:991-1000</ref> enhances stability, and re-tensions the deltoid. The latter factor is critical due to the semi-constrained design of the prosthesis. The increase in compressive force between the humeral and glenoid components has a stabilizing effect.<ref>Gagey O, Hue E. Mechanics of the deltoid muscle. A new approach. Clin Orthop Relat Res 2000:250-7</ref> Under such tension, the reverse glenoid component provides the stable fulcrum essential for shoulder anterior elevation and prosthesis stability.<ref name=":28">Boileau P, Watkinson DJ, Hatzidakis AM, Balg F. Grammont reverse prosthesis: design, rationale, and biomechanics. J Shoulder Elbow Surg 2005;14:147S-61S</ref> This tension is determined by arm length.

===Arm Lengthening===
Failure to adequately tension the deltoid may result in prosthetic instability and poor function which are the most common clinically significant complications following reverse shoulder arthroplasty. On the other hand, other complications following reverse shoulder arthroplasty can be related to excessive deltoid tension such as neurological lesions, fractures of the acromion, or fixed abduction of the arm.<ref name=":28" /><ref>Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. Neer Award 2005: The Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg 2006;15:527-40</ref> Adequate deltoid tension is thus accepted as a key to prosthetic function and stability.<ref name=":28" /><ref name=":32" />

The glenosphere has to be implanted on the lower part of the glenoid to avoid notching and to improve rotation at 90 degrees of abduction.<ref>De Biase CF, Ziveri G, Delcogliano M, de Caro F, Gumina S, Borroni M, Castagna A, Postacchini R.The use of an eccentric glenosphere compared with a concentric glenosphere in reverse total shoulder arthroplasty: two-year minimum follow-up results. Int Orthop. 2013 Oct;37(10):1949-55</ref><ref name=":3">Lädermann A, Tay E, Collin P, Piotton S, Chiu CH, Michelet A, Charbonnier C. Effect of critical shoulder angle, glenoid lateralization, and humeral inclination on range of movement in reverse shoulder arthroplasty. Bone Joint Res. 2019;8(8):378-386</ref><ref>Lévigne C, Garret J, Boileau P, Alami G, Favard L, Walch G. Scapular notching in reverse shoulder arthroplasty: is it important to avoid it and how? Clin Orthop Relat Res. 2011 Sep;469(9):2512-20</ref><ref name=":37" /><ref name=":38">Mizuno N, Denard PJ, Raiss P, Walch G. The clinical and radiographical results of reverse total shoulder arthroplasty with eccentric glenosphere. Int Orthop. 2012 Aug;36(8):1647-53</ref><ref name=":39">Nyffeler RW, Werner CM, Gerber C. Biomechanical relevance of glenoid component positioning in the reverse Delta III total shoulder prosthesis. J Shoulder Elbow Surg 2005;14:524-8.</ref> The type of glenosphere (size, eccentricity) allowed the adjustment of arm length by several millimeters (about 1% of arm length). Consequently, the key factors for arm length are the height of the stem, type of stem, polyethylene thickness and the use of an augment or spacer. Collectively, these factors allow arm lengthening by up to several centimeters (about 10% of arm length).<ref name=":32" /> The tension is thus determined by arm length. The latter is dependent of 1) the position of the glenosphere in the frontal plane (Figure), 2) the size of the glenosphere, 3) the use of an eccentric or inferiorly tilted glenosphere, 4) the use of a spacer, 5) the thickness of the polyethylene, 6) the height of humeral cut and stem implantation (Figure 3)<ref name=":29">Lädermann A, Walch G, Lubbeke A, Drake GN, Melis B, Bacle G, Collin P, Edwards TB, Sirveaux F. Influence of arm lengthening in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2012 Mar;21(3):336-41</ref> and prosthetic design (Figure).

[[File:Image2-19.jpg|thumb|center|Influence of position of glenosphere in vertical plane. (A) A rather high implantation of the baseplate or the use of a non-eccentric glenosphere does not allow proper deltoid re-tensioning. (B) The use of an eccentric glenosphere or a low position of the glenosphere in the vertical plane allows satisfactory deltoid re-tensioning,<ref name=":29" /> with permission]]

[[File:Image3-21.jpg|thumb|center|Influence of the humeral cut on arm length. (A) Preoperative status with a lack of deltoid tension. (B-C) An aggressive humeral cut results in a low implantation of the stem with a lack of deltoid tension. (D-E) A minimal humeral cut leads to a high implantation of the prosthetic stem with adequate deltoid tension. From: Lädermann et al., with permission,<ref name=":29" /> with permission]]

[[File:Image4-23.jpg|thumb|center|The neck-shaft angle is one of the biggest variabilities between different prosthesis designs. A steeper or more anatomic neck-shaft angle (Grammont-type 155 degrees vs. 145 degrees and 135 degrees designs) leads to a decrease in the acromiohumeral distance. For every 10 degrees decrease the acromiohumeral distance shortens by approximately 3 mm. In other words, between a 155 degrees and a 135 degrees configuration, arm lengthening varies by about 10 mm.]]

From a clinical perspective lengthening of the arm and humerus, distalization angle, acromio-prosthesis distance (Figures) have been used as surrogates for deltoid tension since they intuitively correlate with deltoid tension and they have been correlated with functional outcome and risk of postoperative instability.<ref>Boutsiadis A, Lenoir H, Denard PJ, Panisset JC, Brossard P, Delsol P, Guichard F, Barth J. The lateralization and distalization shoulder angles are important determinants of clinical outcomes in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2018 Jul;27(7):1226-1234</ref><ref name=":30">Lädermann A, Williams MD, Melis B, Hoffmeyer P, Walch G. Objective evaluation of lengthening in reverse shoulder arthroplasty.J Shoulder Elbow Surg. 2009 Jul-Aug;18(4):588-95</ref><ref name=":29" /> Most of these factors nowadays can easily be evaluated thank to navigation software.<ref name=":40">Iannotti JP, Walker K, Rodriguez E, Patterson TE, Jun BJ, Ricchetti ET. Accuracy of 3-Dimensional Planning, Implant Templating, and Patient-Specific Instrumentation in Anatomic Total Shoulder Arthroplasty. J Bone Joint Surg Am. 2019 Mar 6;101(5):446-457</ref><ref name=":41">Walch G, Vezeridis PS, Boileau P, Deransart P, Chaoui J. Three-dimensional planning and use of patient-specific guides improve glenoid component position: an in vitro study. J Shoulder Elbow Surg. 2015 Feb;24(2):302-9</ref>

[[File:Figure3.jpg|thumb|center|The epicondylar line (EL) is defined between the most lateral part of the medial and lateral epicondyle. Another line, the diaphyseal axis (DI), is determined by a line drawn in the centre of the proximal medullary canal. Intersection between the epicondylar line and the diaphyseal axis represent the point C. Intersection between the diaphyseal axis and top of the humeral head is named H. The point A is located at the intersection between the diaphyseal axis and a perpendicular line passing through the most lateral and inferior point of the acromion. A, C, and H are represented by small white points, large white points corresponding to centimeter marker stuck on the skin of the arm. A, acromion; C, condyles; H, head; EL, epicondylar line; DI, diaphyseal axis; preop, preoperative; contro, controlateral; EF, enlargement factor, <ref name=":30" /> with permission]]

[[File:DLA 1 blinded.png|thumb|center|The distalization shoulder angle (DSA) angle is formed by a line connecting the most lateral border of the acromion and the superior glenoid tubercle and a line connecting the superior glenoid tubercle and the most superior border of the greater tuberosity. In this case, it is measured at 61 degrees.]]

===Lateralization in Reverse Shoulder Arthroplasty===
The basic biomechanical principles of the Grammont reverse shoulder arthroplasty are a medialization of the glenohumeral center of rotation, the use of a larger ball on the glenoid component, and a lowering of the humerus. These principles increase the deltoid lever arm and provide a space for unrestricted range of motion of the proximal humerus and a stable fulcrum essential for active elevation and stability.<ref name=":28" /> However, many complications, such as limited postoperative range of motion or impingement that could be attributed to the medialized glenoid design, have been reported in the literature.<ref name=":1">Gerber C, Pennington SD, Nyffeler RW. Reverse total shoulder arthroplasty. J Am Acad Orthop Surg 2009;17:284-95</ref> To address these problems, several authors have proposed a change in the design of the Grammont prosthesis, promoting an increased bony or metallic glenoid offset.<ref name=":31">Boileau P, Moineau G, Roussanne Y, O'Shea K. Bony increased-offset reversed shoulder arthroplasty: minimizing scapular impingement while maximizing glenoid fixation. Clin Orthop Relat Res 2011;469:2558-67</ref><ref name=":13">Gutierrez S, Levy JC, Frankle MA, Cuff D, Keller TS, Pupello DR, Lee WE 3rd. Evaluation of abduction range of motion and avoidance of inferior scapular impingement in a reverse shoulder model. J Shoulder Elbow Surg 2008;17:608-15</ref> Different methods to measure glenoid lateralization have been proposed.<ref>Frankle MA, Teramoto A, Luo ZP, Levy JC, Pupello D. Glenoid morphology in reverse shoulder arthroplasty: classification and surgical implications. J Shoulder Elbow Surg 2009;18:874-85</ref><ref name=":8">Jobin CM, Brown GD, Bahu MJ, Gardner TR, Bigliani LU, Levine WN, Ahmad CS. Reverse total shoulder arthroplasty for cuff tear arthropathy: the clinical effect of deltoid lengthening and center of rotation medialization. J Shoulder Elbow Surg 2012;21:1269-77</ref>

====Definitions====
It is important to understand the differences between humeral or glenoid lateralization. These factors can be used to predict range of motion and vary based on prosthesis and technical factors. Humeral lateralization is defined as the distance from the center of the polyethylene cup, and the lateral part of the greater tuberosity (Figure). It can be estimated by the lateralization shoulder angle (Figure).

[[File:Image5-25.jpg|thumb|center|3D distances corresponded to the radius of spheres. Offset of the sphere were centered on the center of the polyethylene cup (pivot point) and of the bony glenoid center (GC) for humeral (A) and global offset (B), respectively, and included the lateral part of the greater tuberosity. ]]

[[File:LSA.png|thumb|center|The lateralization shoulder angle is formed by a line connecting the superior glenoid tubercle and the most lateral border of the acromion and a line connecting the most lateral border of the acromion and the most lateral border of the greater tuberosity. In this case, it is measured at 77 degrees.]]

It depends upon glenoid wearing, reaming and grafting, contact of the baseplate with the glenoid, the offset of the glenosphere and/or baseplate, the glenosphere diameter and tilt, the level of the humeral cut, the humeral neck-shaft angle, the humeral prosthetic design, the use of a spacer, the polyethylene thickness (humeral polyethylene socket offset), and the remaining proximal and lateral humeral bone stock.

At the other end of the spectrum, failure to adequately restore bone or prosthetic humeral lateralization may result in loss of humeral contour,<ref>Chacon A, Virani N, Shannon R, Levy JC, Pupello D, Frankle M. Revision arthroplasty with use of a reverse shoulder prosthesis-allograft composite. J Bone Joint Surg Am. 2009 Jan;91(1):119-27</ref> and deltoid shape curve and thus deltoid retensionning, and could lead to prosthetic instability and poor postoperative function.<ref name=":29" /><ref name=":30" />

===Neck-shaft angle===
More anatomic neck-shaft angles decrease the rate of scapular notching and improve postoperative range of motion.<ref name=":3" /><ref name=":11" />

The launch of this variety of designs on the market has introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

===Range of motion after reverse shoulder arthroplasty: which combinations of humeral stem and glenosphere work the best?===
Reproduced from Lädermann et al., with permission.<ref>Lädermann A, Collin P, Denard PJ. Range of motion after reverse shoulder arthroplasty: Which combinations of humeral stem and glenosphere work the best? Obere Extremität 2020 doi:10.1007/s11678-020-00599-5</ref>
====Introduction====
The initial reverse shoulder arthroplasty design was excellent at restoring forward flexion but had several design-related complications including bony impingement and scapular notching,<ref name=":11">Lädermann A, Denard PJ, Collin P, Zbinden O, Chiu JC, Boileau P, Olivier F, Walch G. Effect of humeral stem and glenosphere designs on range of motion and muscle length in reverse shoulder arthroplasty. Int Orthop. 2020;44(3):519-30</ref><ref name=":37" /> instability,<ref>Chae J, Siljander M, Wiater JM. Instability in Reverse Total Shoulder Arthroplasty. J Am Acad Orthop Surg 2018;26:587-596</ref> acromial fractures,<ref name=":18">Haidamous G, Lädermann A, Frankle M, Gorman A, Denard PJ. The risk of postoperative scapular spine fracture following reverse shoulder arthroplasty is increased with an onlay humeral stem. J Shoulder Elbow Surg. 2020;9:S1058-2746(20)30337-2.</ref> limited range of motion (particularly internal and external rotation),<ref name=":10">Denard PJ, Lädermann A, Haidamous G, Hartzler R, Parsons BO, Lederman ES, Tokish JM. Radiographic Parameters Associated With Excellent Versus Poor Range Of Motion Outcomes Following Reverse Shoulder Arthroplasty. Shoulder & Elbow 2020;9:1758573220936234.</ref><ref>Lädermann A, Denard PJ, Tirefort J, Collin P, Nowak A, Schwitzguebel A J-P. Subscapularis- and deltoid-sparing vs traditional deltopectoral approach in reverse shoulder arthroplasty: a prospective case-control study. J Orthop Surg Res 2017;12:112</ref> and humeral stem loosening.<ref name=":37" /><ref>Lädermann A, Schwitzguebel AJ, Edwards TB, Godeneche A, Favard L, Walch G, Sirveaux F, Boileau P, Gerber C. Glenoid loosening and migration in reverse shoulder arthroplasty. Bone Joint J. 2019;101-B:461-469</ref> Many of these have been attributed to the initial Grammont design which featured a medialized glenosphere and 155 degrees straight stem (Medial Glenoid/Medial Humerus Design).<ref name=":1" />

A variety of changes in prosthetic design have been proposed to address these issues either on the humeral side or on the glenoid side, the goal being to decrease scapular notching, maximize efficiency of the remaining rotator cuff, improve stability and improve range of motion. On the glenoid side authors have promoted increased lateralization either with bone or metal.<ref name=":31" /><ref name=":4">Gutiérrez S, Comiskey CA 4th, Luo ZP, Pupello DR, Frankle MA. Range of impingement-free abduction and adduction deficit after reverse shoulder arthroplasty. Hierarchy of surgical and implant-design-related factors. J Bone Joint Surg Am . 2008;90(12):2606-15</ref> On the humeral side, a more anatomic humeral inclination (i.e. 145 or 135 degrees) and inlay and onlay systems designs have introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

Therefore, the aim of this chapter is to evaluate the advantages and inconvenience of different reverse shoulder arthroplasty’s designs and to provide recommendations accordingly.

====Glenoid Configuration====
Glenoid configuration has an important effect on postoperative range of motion. The three most important variables are glenoid offset, eccentricity, and glenosphere size. None of these latter parameters influence significantly the measured bone strains at the glenoid near the bone-implant interface.<ref>Pauzenberger L, Dwyer C, Obopilwe E, Nowak MD, Cote M, Romeo AA, Mazzocca AD, Dyrna F. Influence of glenosphere and baseplate parameters on glenoid bone strains in reverse shoulder arthroplasty. BMC musculoskeletal disorders 2019;20(1):587</ref>

=====Glenoid Offset (lateralization)=====
The initial Grammont-style reverse shoulder arthroplasty utilized a glenosphere with a medialized center of rotation. While this design reliably improved forward elevation, the high rate of scapular notching and internal and external rotation deficit observed with this design have been attributed to the medialized glenoid design.<ref name=":1" /><ref>Lawrence C, Williams GR, Namdari S. Influence of Glenosphere Design on Outcomes and Complications of Reverse Arthroplasty: A Systematic Review. Clinics in orthopedic surgery 2016;8:288-297</ref> To address these problems, glenoid lateralization have been proposed to decrease scapular notching, improve soft tissue tension, and increase impingement-free range of motion. The glenoid component is considered as lateralized if lateralization equals or exceeds 5 mm compared to Grammont design.<ref>Werthel JD, Walch G, Vegehan E, Deransart P, Sanchez-Sotelo J, Valenti P. Lateralization in reverse shoulder arthroplasty: a descriptive analysis of different implants in current practice. Int Orthop 2019;43:2349-2360</ref> It is important to note that this lateralization of the center of rotation is relative to the implant designed by Grammont, but still medialized compared to the native glenohumeral joint. Lateralization can be achieved by either the placement of bone medial to the baseplate (bone increase offset reverse shoulder arthroplasty (BIO-RSA))<ref name=":31" /> or with metallic lateralization via the baseplate or glenosphere. While both have been associated with clinical improvement,<ref>Ernstbrunner L, Werthel JD, Wagner E, Hatta T, Sperling JW, Cofield RH. Glenoid bone grafting in primary reverse total shoulder arthroplasty. J Shoulder Elbow Surg 2017;26:1441-1447</ref><ref>Klein SM, Dunning P, Mulieri P, Pupello D, Downes K, Frankle MA. Effects of acquired glenoid bone defects on surgical technique and clinical outcomes in reverse shoulder arthroplasty. J Bone Joint Surg Am 2010;92:1144-1154</ref> metallic lateralization appears to be less subject to displacement, particularly with lateralization beyond 5 mm.<ref>Denard PJ, Lederman E, Parsons BO, Romeo AA. Finite element analysis of glenoid-sided lateralization in reverse shoulder arthroplasty. J Orthop Res 2017;35:1548-1555</ref>

Basic science studies show several benefits of lateralization. In both sawbone<ref name=":13" /> and computer models,<ref name=":4" /><ref name=":21">Kim SJ, Jang SW, Jung KH, Kim YS, Lee SJ, Yoo YS. Analysis of impingement-free range of motion of the glenohumeral joint after reverse total shoulder arthroplasty using three different implant models. Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2019;24:87-94</ref><ref name=":3" /> lateralization improves range of motion in all directions.<ref name=":3" /> Lateralization also leads to improvement in stability.<ref>Ferle M, Pastor MF, Hagenah J, Hurschler C, Smith T. Effect of the humeral neck-shaft angle and glenosphere lateralization on stability of reverse shoulder arthroplasty: a cadaveric study. J Shoulder Elbow Surg 2019;28:966-973</ref>

The question remains how much lateralization is ideal. While clinical evidence is currently lacking, computer modeling suggests that 5 to 10 mm of lateralization relative to the native glenoid is ideal.<ref name=":3" /><ref name=":14">Werner BS, Chaoui J, Walch G. The influence of humeral neck shaft angle and glenoid lateralization on range of motion in reverse shoulder arthroplasty. J Shoulder Elbow Surg 2017;26(10):1726-1731</ref><ref>Gutiérrez S, Greiwe RM, Frankle MA, Siegal S, Lee WE 3rd. Biomechanical comparison of component position and hardware failure in the reverse shoulder prosthesis. J Shoulder Elbow Surg 2007;16:S9-S12</ref> Nevertheless, clinical data to date has not necessarily proved that lateralization improves range of motion<ref name=":6" /> or outcome scores<ref>Helmkamp JK, Bullock GS, Amilo NR, Guerrero EM, Ledbetter LS, Sell TC, Garrigues GE. The clinical and radiographic impact of center of rotation lateralization in reverse shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg, 2018, 27:2099-2107</ref> compared to a traditional reverse shoulder arthroplasty. Greiner et al. performed a randomized controlled trial of 17 Grammont reverse shoulder arthroplasties and 17 BIO-RSAs and reported no difference in Constant scores at 1 year postoperative.<ref>Greiner S, Schmidt C, Herrmann S, Pauly S, Perka C. Clinical performance of lateralized versus non-lateralized reverse shoulder arthroplasty: a prospective randomized study. J Shoulder Elbow Surg, 2015, 24:1397-1404</ref> In a retrospective study, Athwal et al. did not observe substantial range of motion, strength, or outcome scores.<ref name=":22">Athwal GS, MacDermid JC, Reddy KM, Marsh JP, Faber KJ, Drosdowech D. Does bony increased-offset reverse shoulder arthroplasty decrease scapular notching? J Shoulder Elbow Surg, 2015, 24:468-473</ref> The frequency of scapular notching, however, was significantly higher (P=.022) in the reverse shoulder arthroplasty cohort than in the BIO-RSA cohort: 75% versus 40%.<ref name=":22" /> This finding has been also reported by Zitkovsky et al.<ref name=":15">Zitkovsky HS, Carducci MP, Mahendraraj KA, Grubhofer F, Jawa A. Lateralization and Decreased Neck-Shaft Angle Reduces Scapular Notching and Heterotopic Ossification. J Am Acad Orthop Surg. 2020 Apr 8. doi: 10.5435/JAAOS-D-19-00808. Online ahead of print.</ref> At 10 years follow-up, Kennon et al. confirmed that scapular notching rates are significantly higher with medialized components compared to lateralized ones (77% in vs. 47%, P= .013).<ref>Kennon JC, Songy C, Bartels D, Statz J, Cofield RH, Sperling JW, Sanchez-Sotelo J. Primary reverse shoulder arthroplasty: how did medialized and glenoid-based lateralized style prostheses compare at 10 years? J Shoulder Elbow Surg. 2020;29(7S):S23-S31</ref> Notably, all of the these studies utilized a 155 degrees humeral prothesis and thus further comparative studies are required with 135 and/or 145 degrees protheses.

=====Glenosphere Eccentricity=====
Inferior eccentric positioning of the glenosphere can also be used to decrease the adduction deficit and thus reduce scapular notching.<ref name=":21" /><ref name=":7">Lädermann A, Denard PJ, Boileau P, Farron A, Deransart P, Walch G. What is the best glenoid configuration in onlay reverse shoulder arthroplasty? Int Orthop. 2018;42(6):1339-1346</ref> Mizuno et al. previously reported that an inferiorly eccentric glenosphere reduced the severity of scapular notching with a 155 degrees prosthesis,<ref name=":38" /> improving thus postoperative rotations elbow at side.<ref name=":2">Lädermann A, Gueorguiev B, Charbonnier C, Stimec BV, Fasel JH, Zderic I, Hagen J, Walch G. Scapular Notching on Kinematic Simulated Range of Motion After Reverse Shoulder Arthroplasty Is Not the Result of Impingement in Adduction. Medicine (Baltimore). 2015;94(38):e1615</ref> While the differences are small, the eccentric glenosphere provided the greatest ability to limit scapular notching while maximizing range of motion by increasing the subacromial space.<ref name=":7" /><ref name=":3" /> Abduction is effectively positively correlated with acromiohumeral distance (r = 0.93; p < 0.001) which is increased with an eccentric glenosphere.<ref name=":11" /> Rotation in abduction is important to activities of daily living. Interestingly, the latter are impossible in most configurations due to inexistent subacromial space (Figure 9). Postero-inferior eccentricity can improve also extension and could favorize as well internal rotation hand in the back (Figure).

[[File:Figure 1.png|thumb|Rotations rotation at 90 degrees of abduction might be impossible due to inexistent subacromial space. Eccentric positioning of the glenosphere creates subacromial space.]]

[[File:Figure 2 Postero-inferior eccentricity.png|thumb|Postero-inferior eccentricity improves extension. A) Inferior eccentricity alone (yellow arrow) allows 52 degrees of extension. B) 40 degrees of postero-inferior eccentricity (yellow arrow) improves extension to 73 degrees.]]

It is important to note, however, that inferior overhang of the glenosphere can be achieved either by an eccentric glenosphere or by baseplate position. Conversely, an eccentric glenosphere with an improperly positioned superior baseplate will not provide clinical benefit. Thus, the surgeon must be cognizant of both the overhang of the given glenosphere relative to the selected baseplate, as well as any eccentricity in the glenosphere. Furthermore, the benefits of overhang or eccentricity must be weighed against the risks of nerve injury and acromial fracture associated with arm lengthening. The ideal amount of overhang relative to the glenoid appears to be about 2.5 mm based on clinical evidence.<ref name=":10" />

=====Glenosphere size=====
The size of the glenosphere influences theoretically and clinically postoperative range of motion. Lädermann et al. found that a small glenosphere (36 mm) improves external rotation in abduction.<ref name=":7" /> However, with the elbow at side, larger diameter glenospheres have been shown to provide a greater impingement-free arc of motion, and decrease scapular notching in biomechanical studies. Werner et al. reported superior values for extension and external rotation with a 39 mm glenosphere compared to a 36 mm glenosphere mm.<ref name=":14" /> Berhouet et al. demonstrated in a cadaveric study that a 42 mm glenosphere was associated with improved rotational range of motion compared to a 36 mm glenosphere (p <0.05).<ref>Berhouet J, Garaud P, Favard L. Evaluation of the role of glenosphere design and humeral component retroversion in avoiding scapular notching during reverse shoulder arthroplasty.J Shoulder Elbow Surg . 2014;23(2):151-8</ref> Another study comparing functional scores and range of motion differences between two groups of patients, one receiving a 36 mm glenosphere and the other receiving a 44 mm glenosphere, found that patients with the larger glenosphere had a 12 degrees increase in external rotation in adduction compared to those with the smaller glenosphere (p <.001).<ref>Muller AM, Born M, Jung C, Flury M, Kolling C, Schwyzer HK, Audigé L. Glenosphere size in reverse shoulder arthroplasty: is larger better for external rotation and abduction strength? J Shoulder Elbow Surg 2018;27(1):44-52</ref> Similarly, Mollon et al. showed that a 42 mm glenosphere size generated a 15 degree improvement in forward flexion and a 6 degree improvement in external rotation compared to the 38 mm size, with an overall improvement in pain scores.<ref>Mollon B, Mahure SA, Roche CP, Zuckerman JD. Impact of glenosphere size on clinical outcomes after reverse total shoulder arthroplasty: an analysis of 297 shoulders. J Shoulder Elbow Surg. 2016;25(5):763-71</ref> Finally, a study by Haidamous et al. demonstrated that larger glenosphere size and inferior positioning as well as posterior humeral offset are associated with improved postoperative range of motion following reverse shoulder arthroplasty with a 135 degrees humeral component.<ref name=":10" /> Nevertheless, larger glenospheres limit abduction and rotations in abduction and are prone to higher volumetric wear rates and experienced greater polyethylene volume loss.<ref>Haggart J, Newton MD, Hartner S, Ho A, Baker KC, Kurdziel MD, Wiater JM. Neer Award 2017: wear rates of 32-mm and 40-mm glenospheres in a reverse total shoulder arthroplasty wear simulation model. J Shoulder Elbow Surg . 2017;26(11):2029-2037</ref> Additionally, one must consider patient size. Overstuffing can occur. Matsuki et al., for instance, demonstrated that small- and large-stature patients achieved lower improvement in range of motion with an RSA system with only 2 glenosphere sizes (38 and 42) likely because the small patients were overstuffed and the large patients did not have large enough glenospheres and/or lateralization.<ref>Matsuki K, King JJ, Wright TW, Schoch BS. Outcomes of reverse shoulder arthroplasty in small- and large-stature patients. J Shoulder Elbow Surg. 2018;27(5):808-815</ref>

====Humeral Stem Designs====
The primary humeral stem variables include stem geometry, neck-shaft angle, inlay versus onlay configuration, and humeral spacers.

=====Stem geometry=====
Short curved stems were initially developed to facilitate implantation, maintain bone stock, and preserve rotator cuff insertion.<ref>Lädermann A, Chiu JC, Cunningham G, Hervé A, Piotton S, Bothorel H, Collin P. Do short stems influence the cervico-diaphyseal angle and the medullary filling after reverse shoulder arthroplasties? Orthop Traumatol Surg Res. 2020;106(2):241-246</ref> These stems also change humeral offset based on their positioning in the humeral canal. In one study an onlay curve stem lead to a 7-mm increase in humeral offset compared to a traditional inlay straight Grammont prosthesis.<ref name=":12">Lädermann A, Denard PJ, Boileau P, Farron A, Deransart P, Terrier A, Ston J, Walch G. Effect of humeral stem design on humeral position and range of motion in reverse shoulder arthroplasty. Int Orthop. 2015;39(11):2205-13</ref> Curve stems decrease the acromiohumeral distance, which may lead to acromial impingement at small abduction angles.<ref name=":12" /> On the other hand, humeral lateralization can be useful to compensate for medialization in case of bone loss (Figure) and has been theorized to improve the mechanics of the remaining rotator cuff and deltoid musculature.<ref>Parry S, Stachler S, Mahylis J. Lateralization in reverse shoulder arthroplasty: A review. Journal of orthopaedics 2020;22:64-67</ref> Stem design appeared to have also a substantial effect on abduction, as combinations with the straight Grammont stem had greater abduction (73–80%), compared to those with the onlay curved stem (54–69%).<ref name=":11" />

[[File:Managing the eroded glenoid in shoulder arthroplasty Noumea 2019.jpg|thumb|Humeral lateralization can help to restore global lateralization in case of glenoid bone loss. A) Massive glenoid bone loss compensated by glenoid allograft and a straight stem (Lateral Glenoid/Medial Humerus concept). Observe that the central peg hardly reaches the native glenoid. Such construct has a potential for failure (B). Another option would have been to use a smaller glenoid graft and a curved stem (Lateral Glenoid/Lateral Humerus)]]

=====Neck-shaft angle (inclination)=====
The Grammont reverse shoulder arthroplasty was designed as a non-anatomic implant with a relative valgus humeral neck inclination of 155 degrees. Based on the work by Gutierrez et al.,<ref name=":13" /> neck-shaft angle has decreased in modern prosthetic designs to a more varus or anatomic inclination of 145 or 135 degrees.

The neck shaft angle is a major factor influencing length of the arm,<ref name=":37" /> but has little effect on humeral lateralization; by changing inclination from 155 degrees to 135 degrees within an onlay design, humeral offset only increased by about 2 mm.<ref name=":12" />

Theoretically, compared to low neck shaft angle stems, higher inclinations (155 degrees) increased abduction by 100% and external rotation in abduction, regardless of glenosphere designs.<ref name=":12" /><ref name=":3" /> This finding is important as such external rotation is a major factor in the ability to perform activities of daily activities such as hair care and facial grooming. However, a 155 degrees is associated with decreased adduction external rotation at the side<ref name=":12" /><ref>Nelson R, Lowe JT, Lawler SM, Fitzgerald M, Mantell MT, Jawa A. Lateralized Center of Rotation and Lower Neck-Shaft Angle Are Associated With Lower Rates of Scapular Notching and Heterotopic Ossification and Improved Pain for Reverse Shoulder Arthroplasty at 1 Year. Orthopedics. 2018;41(4):230-6</ref><ref name=":14" /> and extension due to medial bony impingement (which also leads to scapular notching).<ref name=":3" /><ref name=":11" /><ref name=":4" /><ref name=":14" /><ref>Oh JH, Shin SJ, McGarry MH, Scott JH, Heckmann N, Lee TQ. Biomechanical effects of humeral neck-shaft angle and subscapularis integrity in reverse total shoulder arthroplasty. J Shoulder Elbow Surg.2014;23(8):1091-8</ref><ref>Virani NA, Cabezas A, Gutiérrez S, Santoni BG, Otto R, Frankle M. Reverse shoulder arthroplasty components and surgical techniques that restore glenohumeral motion. J Shoulder Elbow Surg. 2013;22(2):179-87</ref> Lateralization obtained via a lower neck shaft angle increases adduction, by 357% between a 155 degrees prosthesis compared with a 135 degrees prosthesis. Also, an increase in extension, of 381%, and external rotation elbow at side, of 116%, are observed with a 135 degrees prosthesis.<ref name=":12" /> Such finding are important as external rotation with the elbow at the side and extension led to friction between the scapular pillar and the polyethylene insert. Even if this friction phenomenon does not limit range of motion, it likely contributes to progressive polyethylene wear and scapular notching.<ref name=":2" /> Reducing the neck-shaft angle can, however, have some negative effects on reverse shoulder arthroplasty contact mechanics. The contact area is reduced by 29% for 155 degrees to 145 degrees and by 59% for 155 degrees to 135 degrees. Consequently, there is an increased maximum contact stress by 71% for 155 degrees to 145 degrees and by 286% for 155 to 135 degrees.<ref>Langohr GD, Willing R, Medley JB, Athwal GS, Johnson JA. Contact mechanics of reverse total shoulder arthroplasty during abduction: the effect of neck-shaft angle, humeral cup depth, and glenosphere diameter. J Shoulder Elbow Surg. 2016;25(4):589-97</ref>

Gobezie et al. published the results of a randomized controlled trial comparing humeral inclination of 135 degrees to 155 degrees among patients undergoing reverse shoulder arthroplasty with a neutral glenosphere (no lateralization) and found no significant difference in forward flexion, external rotation, or functional outcomes.<ref name=":16">Gobezie R, Shishani Y, Lederman E, Denard PJ. Can a functional difference be detected in reverse arthroplasty with 135° versus 155° prosthesis for the treatment of rotator cuff arthropathy: a prospective randomized study. J Shoulder Elbow Surg. 2019;28(5):813-8</ref> They and other studies have confirmed that scapular notching is decreased with a 135 degrees prothesis.<ref name=":15" /><ref name=":16" /><ref name=":17">Erickson BJ, Frank RM, Harris JD, Mall N, Romeo AA. The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg. 2015;24(6):988-93</ref> A systematic review of 2222 shoulders comparing 135 degrees and 155 degrees prostheses reported higher rates of scapular notching in the 155 degrees group (16.8% vs. 2.8%), improved external rotation in the 135 degrees group, and no difference in instability of forward flexion between groups.<ref name=":17" />

Lastly, in case of fracture, reverse shoulder arthroplasty with a 135 degrees neck shaft angle is associated with higher tuberosity healing rates compared to 145 degrees or 155 degrees.<ref>O'Sullivan J, Lädermann A, Parsons BO, Werner B, Steinbeck J, Tokish JM, Denard PJ. A systematic review of tuberosity healing and outcomes following reverse shoulder arthroplasty for fracture according to humeral inclination of the prosthesis. J Shoulder Elbow Surg. 2020;29(9):1938-49</ref>

=====Onlay vs Inlay=====
Compared to on inlay design, an onlay humeral design with the same 155 degrees inclination increased humeral offset by 6.6 mm.<ref name=":12" /> Acromiohumeral distance varied by 9.8 mm with the smallest occurring with the onlay 135 degrees model and the largest occurring with a Grammont inlay 155 degrees. Compared to the inlay design, an onlay humeral design with the same 155 degrees inclination decreased the acromioclavicular distance by 4.1 mm. Compared to the onlay 155 degrees model, with the inlay 155 degrees model there was a 10 degree decrease (77.8 to 67.9 degrees) in abduction and a 5 degree (range, −15.3 to −20.2 degrees) increase in adduction.<ref name=":12" />

Clinically, Beltrame et al. conducted a prospective clinical study comparing onlay and inlay steams. They found that onlay design 145 degrees may provide better active external rotation, extension, adduction.<ref>Beltrame A, Di Benedetto P, Cicuto C, Cainero V, Chisoni R, Causero A. Onlay versus Inlay humeral steam in Reverse Shoulder Arthroplasty (RSA): clinical and biomechanical study. Acta Biomed. 2019;90(12-S):54-63</ref> However, there are numerous bias in their study (i.e. different neck shaft angle and stem lateralization) that prevent integration of their results in the present analysis.

In a retrospective comparative radiological study, Haidamous et al. showed similarly that an onlay humeral stem design resulted in a 10 mm increase in distalization compared to an inlay humeral stem, and a 2.5 times (11.9% vs 4.7%) increased risk of scapular spine fracture.<ref name=":18" /> It seems thus that the combination of lateralization and distalization in an onlay system dramatically increases the incidence of scapular spine fractures.

Lengthening of the supraspinatus and infraspinatus is systematically observed with an onlay design. It is greatest using onlay stems (7–30%) and lateralized glenospheres (13–31%).<ref name=":11" /> Subscapularis lengthening is observed for onlay stems combined with lateralized glenospheres (5–9%), while excessive subscapularis shortening is observed for the inlay stem combined with all glenospheres except the lateralized design (> 15%).<ref name=":11" />

=====Polyethylene Insert=====
Since inferior impingement between the polyethylene and the scapula is systematic with the arm at the side, another potential way to limit friction and notching in external rotation is to create a notch in the polyethylene inferiorly between 3 and 9 o’clock as it has been done in some prostheses (e.g., Arrow and SMR). Another solution to increase range of motion is to reduce the depth of the polyethylene inlay. De Wilde et al. found that for every 3-mm decrease in depth of polyethylene cup, ROM increased by 12 degrees.<ref>De Wilde LF, Poncet D, Middernacht B, Ekelund A.Prosthetic overhang is the most effective way to prevent scapular conflict in a reverse total shoulder prosthesis. Acta Orthop 2010 81:719-726</ref>

====Discussion====
The literature is controversial with regard to possibilities of regaining range of motion following reverse shoulder arthroplasty. While prosthetic designs are varied and lead to substantial changes in computer models, many of the theoretical advantages have not been confirmed clinically. Table summarizes implant design considerations to improve range of motion. The optimal compromise in range of motion for a primary reverse shoulder arthroplasty without bone loss could be a Lateral Glenoid/Medial (or Intermediate) Humerus design with a low neck shaft angle (145-135 degrees) and an inlay concept. However, all prosthetic designs should be considered on a case-by-case basis to optimize outcome. Glenoid and humeral prosthetic design has to be chosen depending on pre- and intra-operative factors including patient expectations, bone morphology, soft tissue state such as rotator cuff or nerve, approaches, surgical exposure, etc. It may, for example, not be possible to utilize a large glenosphere in all patients as they may not be appropriate for the anatomy of smaller individuals and might be more challenging technically. As a result, the surgeon must continuously weigh the benefits and possibilities of available implant-related variables regarding patient’s specific conditions. The systematic use of patient-specific instrumentation and navigation as well as preoperative determination of components are obviously the next steps in providing more accurate component positioning and size and thus improving range of motion. Despite the advances made by glenoid lateralization and inferiorization, there remains ample opportunity for continued improvement and innovation in prosthetic design.

=Preoperative planning=

Preoperative planning is mandatory as it allows to improve range of motion.<ref>Kolmodin J, Davidson IU, Jun BJ, Sodhi N, Subhas N, Patterson TE, Li ZM, Iannotti JP, Ricchetti ET. Scapular Notching After Reverse Total Shoulder Arthroplasty: Prediction Using Patient-Specific Osseous Anatomy, Implant Location, and Shoulder Motion. J Bone Joint Surg Am. 2018 Jul 5;100(13):1095-1103</ref> To guarantee the best possible functional results, restoration of the appropriate humeral and arm length, a and free range of motion should be the goal.<ref name=":8" /><ref name=":29" /><ref>Renaud P, Wahab H, Bontoux L, Dauty M, Richard I, Bregeon C. [Total inverted shoulder prosthesis and rotator cuff insufficiency: evaluation and determination of anatomical parameters predictive of good functional outcome in 21 shoulders]. Ann Readapt Med Phys 2001 ;44(5):273-80</ref> Even if the available softwares do not take into account soft tissue (stiffness, fatty infiltration,…), they are already able to plan and analyze lateralization and distalization.<ref name=":40" /><ref name=":41" />

=Indications and Contraindications=
==Indications==
Reverse shoulder arthroplasty is a powerful tool that has opened new barriers, especially for reconstructive shoulder surgery. Traditionally, the ideal candidate has been a patient above 70 years old with symptomatic cuff tear arthropathy. Appropriate candidates now include young patients, who have shown excellent clinical improvement with high implant survivorship of up to 10 years.<ref>Black EM, Roberts SM, Siegel E, Yannopoulos P, Higgins LD, Warner JJ. Reverse shoulder arthroplasty as salvage for failed prior arthroplasty in patients 65 years of age or younger. J Shoulder Elbow Surg 2014;23:1036-42</ref><ref>Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: Results after five to fifteen years. J Shoulder Elbow Surg 2013;22:1199-208</ref><ref>Muh SJ, Streit JJ, Wanner JP, Lenarz CJ, Shishani Y, Rowland DY, Riley C, Nowinski RJ, Edwards TB, Gobezie R. Early follow-up of reverse total shoulder arthroplasty in patients sixty years of age or younger. J Bone Joint Surg Am 2013;95:1877-83</ref><ref>Otto RJ, Clark RE, Frankle MA. Reverse shoulder arthroplasty in patients younger than 55 years: 2- to 12-year follow-up. J Shoulder Elbow Surg 2017;26:792-7</ref><ref>Sershon RA, Van Thiel GS, Lin EC, McGill KC, Cole BJ, Verma NN, Romeo AA, Nicholson GP. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg 2014;23:395-400</ref><ref>Walters JD, Barkoh K, Smith RA, Azar FM, Throckmorton TW. Younger patients report similar activity levels to older patients after reverse total shoulder arthroplasty. J Shoulder Elbow Surg2016;25:1418-24</ref>

Many pathologies that could not be treated previously found a solution through this design, and indications are currently expanding. It is now used for various conditions such as failed total shoulder arthroplasty or hemiarthroplasty, complex proximal humeral fractures and defective fracture union or nonunion, chronic locked dislocation, immunological arthritis with or without associated rotator cuff tears, failed or irreparable massive rotator cuff tears, and tumors.<ref>Smith CD, Guyver P, Bunker TD. Indications for reverse shoulder replacement: A systematic review. J Bone Joint Surg [Br] 2012;94:577-83</ref>
===Acute proximal humerus fracture===
Reverse shoulder arthroplasty is a more reliable treatment than hemiarthroplasty for complex proximal humerus fractures at least in elderly patients because its functional outcomes appear to depend less on tuberosity healing and rotator cuff integrity (Figure).<ref>Lädermann A, Chiu J, Collin P, Piotton S, Nover L, Scheibel M. Hemi- vs reverse shoulder arthroplasty for acute proximal humeral fractures: a systematic review of level I and II studies. Obere Extremität 2019;14:127–35</ref>

[[File:Figure 25 Millon.jpg|thumb|center|Reverse shoulder athroplasty for fracture.
Frontal, axial and lateral Lamy radiographs after a reverse total shoulder implant. Note the lower positioning of the glenoid baseplate, the satisfactory reconstruction of the tuberosities, and the absence of cement at the autograft level.]]

===Malunited/nonunited proximal humerus fracture===
Surgical options to address malunited proximal humerus fractures are determined largely by the existing deformity. They can be categorized broadly as humeral head-preserving techniques (e.g. osteotomies, soft-tissue releases and removal of bony protuberances) or humeral head-sacrificing techniques. Amongst the latter, reverse shoulder arthroplasty proved to be the most reliable.

[[File:Malunion Rickenbach.png|thumb|center|Reverse shoulder arthroplasty for malunion of proximal humeral fracture. A) Anteroposterior radiograph of a malunited proximal humerus fracture; B) post-operative radiograph of the fracture sequelae treated with reverse shoulder arthroplasty.]]

===Glenohumeral Osteoarthritis With Severe Glenoid Bone Loss===
The use of reverse shoulder arthroplasty in patients with severe glenoid bone loss and osteoarthritis is the best option. Excellent results have been reported in patients with osteoarthritis, an intact rotator cuff and substantial glenoid bone loss treated with reverse shoulder arthroplasty with or without bone grafting (Video).

[[File:Glenohumeral Osteoarthritis With Severe Glenoid Bone Loss.mp4|thumb|Fifty-one years old patient with right glenoid dysplasia (C glenoid) and an intact rotator cuff. Computed tomography (CT) scan of the shoulder shows 60 degrees of retroversion. The patient has been treated with combined bony and metallic augmentation. At three months follow-up, range of motion improves and imaging reveals satisfactory glenoid reconstruction.]]

===Chronic Locked Glenohumeral Joint Dislocation===
Chronic locked glenohumeral dislocation can also be treated with reverse shoulder arthroplasty (Figure).<ref>Statz JM, Schoch BS, Sanchez-Sotelo J, Sperling JW, Cofield RH.Shoulder arthroplasty for locked anterior shoulder dislocation: a role for the reversed design. Int Orthop. 2017 Jun;41(6):1227-1234</ref>

[[File:Locked dislocation treated by RSA.png|thumb|Locked dislocation of a right shoulder. On the right, postoperative X-ray.]]

===Rheumatoid Arthritis With or Without Associated Rotator Cuff Tears===
Excellent to satisfactory results have been reported for patients with rheumatoid arthritis treated with reverse shoulder arthroplasty. There is no higher complication rates as compared to reverse shoulder arthroplasty in cuff tear arthropathy.<ref>Cho CH, Kim DH, Song KS. Reverse Shoulder Arthroplasty in Patients with Rheumatoid Arthritis: A Systematic Review. Clin Orthop Surg. 2017 Sep;9(3):325-331</ref>

===Revision Arthroplasty===
Revision surgery after primary shoulder arthroplasty (i.e. hemiarthroplasty, resurfacing or total shoulder arthroplasty) produced high patient satisfaction (Figure). It is, however, associated with higher complication and failure rates compared to reverse shoulder arthroplasty for patients without previous arthroplasty.<ref>Gauci MO, Cavalier M, Gonzalez JF, Holzer N, Baring T, Walch G, Boileau P. Revision of failed shoulder arthroplasty: epidemiology, etiology, and surgical options. J Shoulder Elbow Surg. 2019 Oct 6. pii: S1058-2746(19)30531-2</ref>

[[File:Pitacollo TSA-RSA.jpg|thumb|center|A) Anteroposterior radiograph of a failed anatomic total shoulder arthroplasty; B) Anteroposterior post-operative radiograph after reverse shoulder arthroplasty.]]

===Tumours===
Reverse shoulder arthroplasty is an acceptable option for patients after wide resection of the proximal humerus and rotator cuff tendons for malignant bone tumours. However, a prerequisite for the ability to implant a reverse shoulder arthroplasty in these cases requires preservation of the axillary nerve and deltoid muscle to be successful.<ref>Bonnevialle N, Mansat P, Lebon J, Laffosse JM, Bonnevialle P. Reverse shoulder arthroplasty for malignant tumors of proximal humerus. J Shoulder Elbow Surg. 2015 Jan;24(1):36-44.</ref><ref name=":23" />

==Contraindications==
Absolute contraindications include general factors such as non compliance patients (severe psychiatric/neurologic disability, substance abuse), neuro-arthropathies (Charcot) and high patient morbidity (ASA 4+), and local factors like an uncontrolled active infection and substantial deltoid insufficiency because of the very high probability of recurrent instability and the minimal potential gain in function.<ref name=":23" />

=Clinical Practice Guideline=
The goal of this section is to provide clinicians with recommendations based on the best available evidence; to inform clinicians of when there is no evidence; and finally, to help clinicians deliver the best health care possible.

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=Approaches=
==Introduction==
Reverse shoulder arthroplasty can be performed through several approaches, the deltopectoral and anterosuperior being the most common, each with their advantages and disadvantages. The preparation is standardized for all approaches. The patient lies in the beach chair position with a 60° tilt of the chest, at the lateral extremity of the table, leaving the anterior and posterior sides of the shoulder free from obstruction. The elbow must be free from any support to enable the operating assistant to apply a proximally directed force at the elbow allowing proximal subluxation of the humeral head. The front arm rests on an armrest and is draped free.

==Deltopectoral Approach==
The deltopectoral approach allows increased visibility and accessibility of the humerus, better positioning of the glenoid component, reduced implant loosening and scapular notching, and does not compromise the deltoid, which is the important motor of the shoulder. This approach tenotomises the subscapularis or osteotomizes the lesser tuberosity. Failure (observed in 45% of cases, Collin, unpublished data) and dysfunction of the repaired subscapularis remains a concern after both tenotomy and lesser tuberosity osteotomy despite multiple variations in subscapularis takedown and reattachment techniques. Neurologic atrophy and fatty infiltration of the subscapularis muscle belly have been also reported to causes pain and impaired function.

===Surgical technique===
The deltopectoral approach consisted of a 10 to 15 cm skin incision being made from the coracoid process toward the deltoid insertion. The infraclavicular fossa (Mohrenheim fossa) is found, the cephalic vein identified and the consistent medial branches, which give the appearance of the Mercedes Benz symbol, are ligated. A self-retaining retractor is used to maintain exposure between the deltoid and pectoralis major. The subacromial bursa was resected to allow placement of a Hohmann retractor under the deltoid over the top of the coracoid process. The arm was abducted and internally rotated. The subacromial bursa is resected to allow placement of a Brown-Deltoid retractor.

====Subscapularis Tenotomy====
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====Osteotomy of the Lesser Tuberosity====
The osteotomy is initiated at the bicipital groove with a 2-mm saw blade and then completed with a curved osteotome. An approximately 2.5 cm2 in the coronal plane and 5 mm thick fleck of lesser tuberosity is taken such that the osteotomy entered the joint medially without violating the humeral head.<ref>Giuseffi SA, Wongtriratanachai P, Omae H, Cil A, Zobitz ME, An KN, Sperling JW, Steinmann SP. Biomechanical comparison of lesser tuberosity osteotomy versus subscapularis tenotomy in total shoulder arthroplasty. J Shoulder Elbow Surg 2012;21:1087-95.</ref><ref>Ponce BA, Ahluwalia RS, Mazzocca AD, Gobezie RG, Warner JJ, Millett PJ. Biomechanical and clinical evaluation of a novel lesser tuberosity repair technique in total shoulder arthroplasty. J Bone Joint Surg Am 2005;87(Suppl 2):1-8</ref>

A complete release of the subscapularis tendon is then performed and the tendon is pushed in the subscapularis fossa. A glenoid retractor is placed anteriorly. The humeral head is resected with a guide or a free-handed anatomic cut respecting native humeral head version and inclination.

====Subscapularis Repair====
The healing rate of the subscapularis following reverse shoulder arthroplasty is only 52.6%.<ref name=":0">Collin P, Rol M, Muniandy M, Gain S, Lädermann A, Ode G. Relationship between postoperative integrity of subscapularis tendon and functional outcome in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2021;30;S1058-2746(21)00523-1</ref> Internal rotation function in patients with an intact subscapularis at two years after reverse shoulder arthroplasty is significantly better than in patients with failed or absent tendon repairs. Primary repair of reparable subscapularis tendons during reverse shoulder arthroplasty should be thus strongly considered.<ref name=":0" />

====Lesser Osteotomy Repair====
Before placement of the humeral stem, two holes are created with a 2-mm drill bit in the bicipital groove at the superior and inferior aspects of the lesser tuberosity osteotomy. One hole was created in the metaphysis just medial to the lesser tuberosity osteotomy. The sutures are then passed from lateral to medial by entering the bicipital groove, passing around the humeral stem, and exiting medially (Figure). A racking hitch is positioned to rest in the bicipital groove. The two sutures are passed through the subscapularis just medial to the lesser tuberosity osteotomy. The needle is removed from each construct to leave two superior and two inferior limbs (Figure). Then, one of the superior limbs and one of the inferior limbs were shuttled through the superior racking hitch knot (Figure). The suture limbs are passed through a tensioner to remove slack and to tension the repair (Figure).

{| class="wikitable"
|-
|[[File:Capture d’écran 2020-03-28 à 08.56.41.png|thumb|Passage of the sutures. A suture with a half racking suture on the end is passed from lateral to medial through the inferior two holes, and (B) a separate suture is passed through the superior hole.]]
|[[File:Capture d’écran 2020-03-28 à 08.57.27.png|thumb|Passage of the sutures through the subscapularis and needle removal. The stem is placed so that the sutures pass around the prosthesis. (A) The sutures are passed through the subscapularis tendon, and (B) the wedged ends are cut to provide access to four free limbs.]]
|-
|[[File:Capture d’écran 2020-03-28 à 08.58.02.png|thumb|Passage of the sutures through the knots. (A) One suture limb from each pair is selected and (B) passed through the half racking suture.]]
|[[File:Capture d’écran 2020-03-28 à 08.58.27.png|thumb|Tensioning of the sutures. The suture limbs passed through the half racking suture are tensioned. Tensioning is done under visual inspection.]]
|}

==Anterosuperior (Transdeltoid) Approach==
Molé et al. reported superolateral approach that has the main advantage of better post-operative stability, because the anterior structures, including ligament complexes, are preserved.<ref>Molé D, Wein F, Dézaly C, Valenti P, Sirveaux F. Surgical technique: the anterosuperior approach for reverse shoulder arthroplasty. Clin Orthop Relat Res. 2011 Sep;469(9):2461-8</ref> This approach is different from the transacromial approach originally described by Grammont and Baulot<ref name=":35">Grammont PM, Baulot E. Delta shoulder prosthesis for rotator cuff rupture. Orthopedics 1993;16:65-8</ref> and the anterosuperior approach described by Mackenzie.<ref>Mackenzie D. The antero-superior exposure for total shoulder replacement. Orthop Traumatol 1993;2:71-7</ref> While this technique has shown good results, it involves splitting of the deltoid muscle with the risk of weakening of the anterior deltoid (mechanical or neurologic by damage to the distal branches of axillary nerve) and improper postoperative function.

===Surgical technique===
The skin incision extends from the posterior part of the acromioclavicular joint. It is 9 cm long and runs along the axis of the arm. The surgeon dissociates the anterior deltoid fibers and positions a stop suture on the distal portion of the dissociation to prevent any injury of the axillary nerve. The deltoid muscle fibers are divided to open and excise the subacromial bursa and the anterior deltoid from the anterior edge of the acromion and takes away the proximal attachment of the coracoacromial ligament as one piece. The humeral head osteotomy should be generous to allow optimal exposure of the glenoid. Glenoid exposure is completed, labrum is resected, and peripheral capsular release performed. The inferior labrum is carefully released with a knife while maintaining contact with the bony rim and avoiding electric cautery, considering the proximity of the axillary nerve, which is not visualized. This allows the positioning of a hooked retractor that presses the humeral epiphysis, which is protected by a trial humeral prosthesis. Once the glenoid implant is in place, the surgeon subluxates the humerus superiorly and anteriorly and cuffs the trial humeral stem with a trial insert; the reduction enables the surgeon to test the stability and tension. At the end of surgery, the deltoid is closed using laterolateral sutures.

==Deltoid and Subscapularis Sparing Approach (Subscapularis On)==
Indications for subscapularis-on approach were all types of primary reverse shoulder with an intact subscapularis.

[[File:SSc sparing reduit.mp4|thumb|center|Illustrates a right subscapularis-on RSA with superior glenoid erosion.]]

===Surgical technique===
The skin incision extends from the tip of the coracoid process and runs along the axis of the arm. A deltopectoral approach is performed (please refer to deltopectoral approach). After excision of the bursa, the surgeon explores the cuff through rotator interval. Once an intact subscapularis is confirmed, deep dissection is carried out either through the supraspinatus tear or after detaching it. With the arm held in extension and adduction, two long blunt-tipped Hohmann retractors are placed around the humeral head, allowing clear exposure of the proximal humerus (Figure).

[[File:Fig 2.jpg|thumb|center|Illustration: With the arm held in extension and adduction, two long broad-tipped Hohmann retractors are placed around the humeral head, retracting the subscapularis and the remnant posterior rotator cuff, allowing clear exposure of the humeral head.]]

The humerus is prepared to accommodate a stem. After a retroversion guide placement, the level of the humeral head osteotomy is marked with an electrocautery device (Figure), and a free-hand osteotomy is performed. The humeral head osteotomy should be generous to allow optimal exposure of the glenoid.

[[File:Fig 3.jpg|thumb|center|A 20 degrees retroversion guide is placed and the level of the osteotomy is marked on the humeral head with an electrocautery device.]]

The humeral shaft is then prepared (Figure).

[[File:Fig 4.jpg|thumb|center|Following humeral head removal, preparation of the humeral shaft is completed using only compactors.]]

If the initial osteotomy is too shallow or the inclination is suboptimal, it is then revised to maximize the anatomic fit between the prosthesis and the bone. After preparing the humerus, a trial humeral prosthesis is inserted in humeral canal to protect the humeral epiphysis during glenoid preparation. Cartilage removal, labrum resection, and peripheral capsular release are then completed sequentially. Tight inferior glenohumeral ligaments, which may prevent adequate exposure of the glenoid or post-operative shoulder mobility, are released using an electrocautery device with close contact with the inferior glenoid rim. A forked retractor is then inserted inferiorly to maintain visualization and accessibility to the glenoid (Figure).

[[File:Fig 5.jpg|thumb|center|A forked retractor is placed inferior to the glenoid to maintain visualization and accessibility. The glenoid is prepared according to the recommended surgical technique to obtain neutral inclination and version.]]

This maneuver pushes the humeral epiphysis inferiorly or antero-inferiorly (compared to standard deltopectoral approach in which the humeral head is dislocated posteriorly) for better visualization of the glenoid. The glenoid is prepared according to the recommended surgical technique to obtain neutral inclination and version. Preoperative planning software is used to determine the amount of inferior tilt and whether an augmented baseplate is required. The baseplate is secured onto the glenoid with non-locking and locking peripheral screws. An eccentric 36 or 39 mm glenosphere is used to limit impingement in adduction, extension and external rotation. It is not recommended implanting a larger glenosphere as the excessive lateralization may hinder access to the humerus. The glenosphere is impacted into the baseplate. Once the glenoid implant is in place, the surgeon subluxs the humerus superiorly and anteriorly. A stem is inserted. The shoulder is reduced via gentle traction on the arm and range of motion tested in all planes to ensure stability and confirm the prosthesis moves easily without impingement. The prothesis is then dislocated for final implantation of a definitive polyethylene. Osteophytes are removed and lateral tuberoplasty can be performed to maximize flexibility and avoid bony impingement. The surgical incision measures about 7 to 10 cm (Figure).

[[File:Fig 6 améliorée.jpg|thumb|center|Length of the surgical incision.]]

===Postoperative Rehabilitation===
By using this subscapularis-on approach, patients do not require any immobilization with a sling following the operation. Immediate active motion in all planes is allowed post-operatively.

===Complications===
Tuberosity avulsions that require suture cerclage can bee observed (Figure).

[[File:Figure 8.jpg|thumb|center|A) Example of tuberosity avulsions (black arrows) requiring 3 suture cerclages. B) Tuberosity healing was observed at two-year follow-up. ]]

===Advantages of Subscapularis-on Approach===
There are several reasons why the integrity of the subscapularis tendon should be maintained when performing a reverse shoulder arthroplasty. First, acute muscle lengthening related to the non-anatomic design of the prosthesis plays a role. The muscle lengthening occurs mainly in the supraspinatus (19 mm with a bony increased offset reverse shoulder arthroplasty (BIO-RSA) implant), followed by the upper part of the subscapularis, which accounts for 70% or more of the strength and function of the subscapular muscle-tendon unit. Muscle lengthening could theoretically make reinsertion of the subscapularis more challenging, particularly with lateral offset designs.
Secondly, the inferior part of the subscapularis has no tendon macroscopically; the muscle attaches directly to the bone, making reinsertion difficult. Healing rate is consequently low, at around 55%. Thirdly, the subscapularis is described as being the largest muscle in the rotator cuff and stronger (53% of global strength of the rotator cuff) than the supraspinatus, infraspinatus and teres minor combined.<ref name=":33">Keating JF, Waterworth P, Shaw-Dunn J, Crossan J. The relative strengths of the rotator cuff muscles. A cadaver study. J Bone Joint Surg Br 1993;75:137-40</ref> If a muscle has to be divided, it seems logical to sacrifice the supraspinatus that accounts for only 14% of the global strength.<ref name=":33" /> Fourth, the subscapularis plays a crucial role in anterior elevation. Collin et al. previously demonstrated that the subscapularis is the most important rotator cuff muscle for elevation in native shoulders.<ref>Collin P, Matsumura N, Lädermann A, Denard PJ, Walch G. Relationship between massive chronic rotator cuff tear pattern and loss of active shoulder range of motion. J Shoulder Elbow Surg 2014;23:1195-202</ref>

===Disadvantages of Subscapularis-on Approach===
The main disadvantage of the subscapularis-on technique is limited surgical exposure. Even though specialized jigs were not required for the above-mentioned technique, the development of specifically-designed instrumentation for this procedure seems necessary. Moreover, limited exposure prevents the use of patient-specific surgical guides. Development of less invasive guides or navigation systems may become inevitable in the future. Even if good exposure of the humeral head is achieved, the free-hand humeral osteotomy can be problematic. Subscapularis-on approach is technically challenging in certain cases (e.g. stiff shoulders, small patients) and may not be practical or possible in all circumstances. Intra-operatively, important lateralization (> 5 mm) of the glenoid is impossible, as subsequent exposure of the humerus is insufficient to implant the stem.

=Specific Conditions=
==Reverse Shoulder Arthroplasty in Patients with Preoperative Deltoid Impairment==
===Definition, Causes, and Classification of Deltoid Impairment===
The deltoid is critical for shoulder motion and any pathology involving this muscle is highly detrimental to normal glenohumeral function. It generates over 50% of the force necessary to elevate the arm in scapula plane in a normal shoulder and is the only muscle remaining to provide an abduction moment in patients with massive rotator cuff tears.<ref>Bianchi S, Martinoli C, Abdelwahab IF. Imaging findings of spontaneous detachment of the deltoid muscle as a complication of massive rotator cuff tear. Skeletal radiology 2006;35:410-5</ref> Deltoid impairment is defined as any condition which compromise its physiological function. Such impairment may be permanent or transient and can occur from a variety of conditions.

The deltoid muscle may be shortened upon itself and lose function by disruption of normal length-tension relationships (Figure).

[[File:Image21-57.jpg|thumb|center|Proximal migration of the humeral head leads to a lack of deltoid tension.]]

Effectively, as the Blix curve describes, maintenance of length is required for a muscle to generate adequate tension.<ref>Blix M. Die lange und dle spannung des muskels. Skand Arch Physiol 1891:295-318</ref> Therefore shortening either by proximal migration of the deltoid insertion (rotator cuff arthropathy) or distal migration of the origin (scapular spine fracture) will compromise deltoid function. Proximal migration in particular can be considered a transient cause of deltoid impairment since it can be treated with reverse shoulder arthroplasty. Distal migration, on the other hand, may be permanent or transient depending on the situation.

In the most severe conditions, part or all of the deltoid muscle may be completely absent. Such permanent impairment is rare but may be observed following deltoid muscular flap transfer (for irreparable rotator cuff tears, Figure)<ref>Gazielly D. The deltoid flap procedure. Tech Shoulder Elbow Surg 2000:117–27</ref><ref name=":42">Glanzmann MC, Flury M, Simmen BR. Reverse shoulder arthroplasty as salvage procedure after deltoid muscle flap transfer for irreparable rotator cuff tear: a case report. J Shoulder Elbow Surg 2009;18:e1-2</ref><ref name=":20">Tay AK, Collin P. Irreparable spontaneous deltoid rupture in rotator cuff arthropathy: the use of a reverse total shoulder replacement. J Shoulder Elbow Surg 2011;20:e5-8</ref> or following tumor resection (Figure).

[[File:Image22-59.jpg|thumb|center| Status after a left deltoid muscular flap transfer for irreparable rotator cuff tears. A: Schematic drawing of the surgical technique (with permission of Gazielly D.). B: Frontal magnetic resonance imaging demonstrates absence of the deltoid muscle laterally. C. Clinical photo demonstrating atrophy of the anterior and middle deltoid.]]

[[File:Image23-61.jpg|thumb|center|A: Intraoperative view of a left anterior deltoid resection in the context of proximal humerus neoplasm. Isolation of the anterior deltoid through which an open biopsy had previously been performed. B: Resection of the entire anterior deltoid and proximal humerus. C: Intraoperative view following implantation of a reverse shoulder arthroplasty. D: Postoperative anterior-posterior radiograph.]]

One of the most common forms of deltoid impairment seen clinically is disruption of the muscle origin (without removal of the entire muscle belly). This most commonly occurs in the postsurgical setting after an open rotator cuff repair in which a deltoid split approach is used and part of the deltoid origin is take-down to gain exposure (Figure).<ref>Sher JS, Iannotti JP, Warner JJ, Groff Y, Williams GR. Surgical treatment of postoperative deltoid origin disruption. Clin Orthop Relat Res 1997:93-8</ref>

[[File:Image24-63.jpg|thumb|center|Sequelae of a right open rotator cuff repair involving violation of the deltoid insertion. A: clinical appearance with an anterior deltoid with severe atrophy. B: Anterior-posterior radiograph demonstrating rotator cuff arthropathy. C: Postoperative anterior-posterior view of the reverse shoulder arthroplasty. D and E: Coronal and sagittal views of postoperative anterior forward elevation.]]

Failure of the deltoid to heal back to the acromion can easily be appreciated clinically by a defect to palpation. Additionally, deltoid insertion disruption can occur through chronic attritional rupture as in chronic rotator cuff arthropathy with anterosuperior escape,<ref>Blazar PE, Williams GR, Iannotti JP. Spontaneous detachment of the deltoid muscle origin. J Shoulder Elbow Surg 1998;7:389-92</ref><ref>Morisawa K, Yamashita K, Asami A, Nishikawa H, Watanabe H. Spontaneous rupture of the deltoid muscle associated with massive tearing of the rotator cuff. J Shoulder Elbow Surg 1997;6:556-8</ref> or following trauma (Figure).<ref>Chiba D, Sano H, Nakajo S, Fujii F. Traumatic deltoid rupture caused by seatbelt during a traffic accident: a case report. Journal of orthopaedic surgery 2008;16:127-9</ref><ref>Lin JT, Nagler W. Partial tear of the posterior deltoid muscle in an elderly woman. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine 2003;13:120-1</ref>

[[File:Image25-65.jpg|thumb|center|Evaluation in an acute phase of left posterior deltoid insertion disruption on T2 weighted fat saturated magnetic resonance imaging (MRI) arthrogram sagittal sequences revealed an edema (red arrows) propagating into the muscle.]]

The deltoid muscle may be globally impaired in the setting of persistent denervation,<ref>Wilbourn AJ, Aminoff MJ. AAEM minimonograph 32: the electrodiagnostic examination in patients with radiculopathies. American Association of Electrodiagnostic Medicine. Muscle Nerve 1998:1612-31</ref> grade 3 or 4 fatty infiltration,<ref>Goutallier D, Postel JM, Bernageau J, Lavau L, Voisin MC. Fatty muscle degeneration in cuff ruptures. Pre- and postoperative evaluation by CT scan. Clin Orthop Relat Res 1994:78-83</ref> previous surgical approach, trauma (Figure), post radiation syndrome, or myopathy (myositis, Parkinson, Duchenne muscular dystrophy, etc.).<ref>Moser T, Lecours J, Michaud J, Bureau NJ, Guillin R, Cardinal E. The deltoid, a forgotten muscle of the shoulder. Skeletal radiology 2013;42:1361-75</ref>

[[File:Image29-73.jpg|thumb|Preoperative (A, anterior-posterior and B, lateral scapular views) and post reverse shoulder arthroplasty (C anterior-posterior view) of a right shoulder after a gunshot in a patient that presented post-traumatically with global neurological impairment including the axillary nerve.]]

Once the etiology is determined, the deltoid impairment should be then classified according to its location and extent. Lädermann et al.<ref name=":23">Lädermann A, Walch G, Denard PJ, Collin P, Sirveaux F, Favard L, Edwards TB, Kherad O, Boileau P. Reverse shoulder arthroplasty in patients with pre-operative impairment of the deltoid muscle. The bone & joint journal 2013;95-B:1106-13</ref> proposed a classification for deltoid impairment based on location: type 1 corresponds to an impairment localized anteriorly, type 2 an anterior and middle one, type 3 involves only the middle deltoid, and type 4 is a global impairment (Figure). As discussed subsequently, this classification related to prognosis with type 4 in particular having a poorer function following reverse shoulder arthroplasty.

[[File:Classification atteinte deltoid.jpg|thumb|center|Deltoid impairment based on location: type 1 corresponds to an impairment localized anteriorly, type 2 an anterior and middle one, type 3 involves only the middle deltoid, and type 4 is a global impairment. ]]

====Results====
Glanzmann et al. first published a case report of the results of a reverse shoulder arthroplasty after deltoid muscle flap transfer.<ref name=":42" /> At two years follow-up, the patient was satisfied and had a Constant score of 62 points, suggesting that the entire deltoid may not be necessary for a successful outcome. Tay and Collin also described successful results of a reverse shoulder arthroplasty implanted in the setting of an irreparable rupture of the middle portion of the deltoid muscle.<ref name=":20" /> No intra- or postoperative complication was noticed. At two years follow-up, the patient was pain free, had active anterior elevation of 150 degrees, and the Constant score was 65 points. Gulotta et al. reported in their biomechanical study that scapular plane elevation may still be possible following a reverse shoulder arthroplasty in the setting of anterior deltoid deficiency. When the anterior deltoid is deficient, there is a compensatory increase in the force required by the subscapularis and middle deltoid.<ref>Gulotta LV, Choi D, Marinello P, Wright T, Cordasco FA, Craig EV, Warren RF. Anterior deltoid deficiency in reverse total shoulder replacement: a biomechanical study with cadavers. J Bone Joint Surg Br 2012;94:1666-9</ref> In this condition, surgeons should focus on preserving the subscapularis as much as possible during approach of reverse shoulder arthroplasty. Whatley et al. reported three cases who had postoperative rupture of the anterolateral deltoid following failed mini-open or open rotator cuff repairs. Successful repair of the deltoid was achieved using a transosseous suture repair in all three patients.<ref>Whatley AN, Fowler RL, Warner JJ, Higgins LD. Postoperative rupture of the anterolateral deltoid muscle following reverse total shoulder arthroplasty in patients who have undergone open rotator cuff repair. J Shoulder Elbow Surg 2011;20:114-22</ref> Essilfie et al. presented a case with deltoid failure after anatomical total shoulder arthroplasty revised with reverse shoulder arthroplasty. His ASES score after reverse shoulder arthroplasty was better than historical outcomes for resection arthroplasty and glenohumeral arthrodesis.<ref>Essilfie A, McKnight B, Heckmann N, Rick Hatch GF, 3rd, Omid R. Revision reverse total shoulder arthroplasty in a patient with preoperative deltoid insufficiency: a case report. J Shoulder Elbow Surg 2017;26:e232-e5</ref> Lattisimus dorsi muscle transfer can also provide an augmentation in patients with deltoid insufficiency.<ref name=":43">Dosari M, Hameed S, Mukhtar K, Elmhiregh A. Reverse shoulder arthroplasty for deltoid-deficient shoulder following latissimus dorsi flap transfer. Case report. Int J Surg Case Rep 2017;39:256-9</ref><ref>Goel DP, Ross DC, Drosdowech DS. Rotator cuff tear arthropathy and deltoid avulsion treated with reverse total shoulder arthroplasty and latissimus dorsi transfer: case report and review of the literature. J Shoulder Elbow Surg 2012;21:e1-7</ref> Dosari et al. presented a patient with a history of gunshot injury and loss of most of his shoulder bony and muscular structures. Due to deltoid muscle deficiency, the patient underwent lattisimus dorsi muscle flap followed by reverse shoulder arthroplasty with successful result.<ref name=":43" /> Deltoid reconstruction at the same time of reverse shoulder arthroplasty is also a viable choice as a salvage procedure for patients with deltoid deficiency.<ref name=":25">Marinello PG, Amini MH, Peers S, O'Donnell J, Iannotti JP. Reverse total shoulder arthroplasty with combined deltoid reconstruction in patients with anterior and/or middle deltoid tears. J Shoulder Elbow Surg 2016;25:936-41</ref> Marinello suggested if less than 50% of any part of the anterior or middle deltoid was involved (≤3 cm), reattachment or reconstruction was not needed. If all of the anterior and/or middle deltoid were involved, then reattachment or reconstruction was indicated.<ref name=":25" /> In a multicentered study, Lädermann et al. reviewed 49 patients (49 shoulders) at a mean of 38 ± 30 months postoperative following reverse shoulder arthroplasty in the setting of deltoid impairment.<ref name=":23" /> Postoperative complications occurred in nine (18%) patients, including two postoperative dislocations and two acute postoperative neurological lesions. Five (10%) patients required additional surgery. Active forward elevation and Constant score improved significantly. However, these values are significantly lower for patients suffering from global deltoid impairment (type 4) compared to types 1 through 3. The mean postoperative forward elevation was lower in the setting of global deltoid impairment (70 degrees) compared to partial impairment (127 degrees, 136 degrees and 125 degrees, groups 1-3 respectively) (P=.002). The postoperative Constant score was lower in the setting of global impairment (41) compared to partial impairment (57, 63 and 68, groups 1-3 respectively) (P=.006). Overall, the rate of patient satisfaction was 98% at final follow-up.<ref name=":23" /> Schneeberger et al. retrospectively reviewed the outcome of 19 patients treated with reverse shoulder arthroplasty after failed deltoid flap reconstruction.<ref>Schneeberger AG, Muller TM, Steens W, Thur C. Reverse total shoulder arthroplasty after failed deltoid flap reconstruction. Arch Orthop Trauma Surg 2014;134:317-23</ref> They noticed a high rate of complication (37%), including one instability. Nonetheless, at a mean follow-up of 4.5 years, only two patients had moderate to severe pain, all patients regained anterior active elevation above 90 degrees, and 15 of 19 patients were very satisfied.

It seems that the most important factor for postoperative result is the extent of the lesion, and not its cause. Interestingly, patient satisfaction is high in all publications on reverse shoulder arthroplasty in the setting of deltoid impairment. However, this is likely related to very poor preoperative function and moderate preoperative expectations of this population.

==Acromial Insufficiency==
Pre- or postoperative acromial pathology, which could theoretically compromise deltoid condition and affect the proper function of the prosthesis, is of legitimate concern.

===Preoperative===
Postoperative fractures occur at least in 3% of cases and their causes are numerous. Preoperatively, the acromion may be subject to a congenital or acquired abnormality such as an os acromiale. It can also already be eroded, fragmented or even fractured from the underlying head in case of cuff tear arthropathy (Figure), or osteoporosis-induced insufficiency.

[[File:Image37-89.jpg|thumb|center|Preoperative insufficiency of a left acromion on an anteroposterior view. Note that a large part of the acromion just seems to have disappeared.]]

[[File:Bouvier.jpg|thumb|center|Preoperative spine fracture in a patient suffering from rotator cuff arthropathy with severe Glenoid bone loss.]]

===Postoperative===
It has been suggested that these fractures may be the result of a stress coming from the tip of the superior metaglene fixation screw.<ref name=":34">Crosby LA, Hamilton A, Twiss T. Scapula fractures after reverse total shoulder arthroplasty: classification and treatment. Clin Orthop Relat Res 2011;469:2544-9</ref> Another risk factor is osteoporosis<ref>Otto RJ, Virani NA, Levy JC, Nigro PT, Cuff DJ, Frankle MA. Scapular fractures after reverse shoulder arthroplasty: evaluation of risk factors and the reliability of a proposed classification. J Shoulder Elbow Surg. 2013 Nov;22(11):1514-21</ref><ref name=":24">Schenk P, Aichmair A, Beeler S, Ernstbrunner L, Meyer DC, Gerber C. Acromial Fractures Following Reverse Total Shoulder Arthroplasty: A Cohort Controlled Analysis. Orthopedics. 2020 Jan 1;43(1):15-22</ref> The role of prosthetic design, distalization, global lateralization and Glenoid medicalization is still debated.<ref name=":24" /><ref>Wong MT, Langohr GDG, Athwal GS, Johnson JA. Implant positioning in reverse shoulder arthroplasty has an impact on acromial stresses. J Shoulder Elbow Surg. 2016 Nov;25(11):1889-1895</ref>

Acromial fractures can be classified as avulsion fractures of the anterior acromion (Type I), fractures of the acromion posterior to the acromioclavicular joint (Type II) and fractures of the scapular spine (Type III).<ref name=":34" />

The symptomatology usually appears within the first year with sudden pain and decrease of function. The localization of the former is typically posterior. The fracture is best seen on an axillary lateral view to differentiate acromial fracture from scapular spine fracture (Figure).

[[File:Acromial fracture.png|thumb|center|Postoperative anteroposterior X-ray demonstrate an acromial fracture.]]

The use of positron emission tomography-computed tomography is helpful in diagnosis of non-displaced fractures.

[[File:SPECT CT acromial fracture.png|thumb|center|SPECT CT of a left shoulder after a reverse shoulder arthroplasty. The patient developed pain 6 months after surgery. X-ray did not revealed fracture. SCPECT CT clearly demonstrated a hypersignal on the acromion.]]

Good results have surprisingly been reported in patients with preoperative acquired or congenital acromial pathology or postoperative acromial fracture.<ref>Mottier F, Wall B, Nove-Josserand L, Galoisy Guibal L, Walch G. [Reverse prosthesis and os acromiale or acromion stress fracture]. Rev Chir Orthop Reparatrice Appar Mot 2007;93:133-41</ref> This can be explained by the persistent attachment of the deltoid to the spine of the scapula and clavicle and the more predominant postoperative scapulothoracic motion compared to the glenohumeral one. In case of postoperative acromial or scapular fractures, results are usually disappointing.<ref>Neyton L, Erickson J, Ascione F, Bugelli G, Lunini E, Walch G. Grammont Award 2018: Scapular fractures in reverse shoulder arthroplasty (Grammont style): prevalence, functional, and radiographic results with minimum 5-year follow-up. J Shoulder Elbow Surg. 2019 Feb;28(2):260-267</ref>

The best treatment option for acromial fractures is thus conservative, as it does not lead to major shoulder dysfunction. Outcome of scapular spine fractures are more unpredictable with displacement of the bony support for the entire deltoid, pain and dysfunction. Consequently, some authors recommend open reduction, internal fixation and allograft associated with postoperative immobilization on a 60° abduction splint in order to avoid nonunion and acromiohumeral contact secondary to inferior acromial tilt.<ref name=":34" />

==Latissimus Dorsi Transfert in Combination with the Reverse Shoulder Arthroplasty==
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==Reverse Shoulder Arthroplasty in Weight Bearing Patients==
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=Results=
With a mean anterior forward flexion of 137 degrees and a mean external rotation elbow at the side of 6 degrees, reverse shoulder arthroplasty typically provides satisfactory clinical outcomes for a variety of complex shoulder diagnoses associated with severe pain and limitation of range of motion.<ref name=":26">Wall B, Nove-Josserand L, O'Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am 2007;89:1476-85</ref> However, some patients have had unexpectedly poor functional improvements after reverse shoulder arthroplasty.<ref name=":26" /> Poor postoperative range of motion following reverse shoulder arthroplasty, has been associated with younger age,<ref name=":44">Hartzler RU, Steen BM, Hussey MM, Cusick MC, Cottrell BJ, Clark RE, Frankle MA. Reverse shoulder arthroplasty for massive rotator cuff tear: risk factors for poor functional improvement. J Shoulder Elbow Surg 2015;24:1698-706</ref> gender,<ref name=":45">Schwartz DG, Cottrell BJ, Teusink MJ, Clark RE, Downes KL, Tannenbaum RS, Frankle MA. Factors that predict postoperative motion in patients treated with reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2014 Sep;23(9):1289-95</ref> surgeon experience,<ref>Walch G, Bacle G, Lädermann A, Nové-Josserand L, Smithers CJ. Do the indications, results, and complications of reverse shoulder arthroplasty change with surgeon's experience? J Shoulder Elbow Surg. 2012 Nov;21(11):1470-7</ref> preoperative diagnosis such as posttraumatic arthritis and revision arthroplasty,<ref>Cuff D, Pupello D, Virani N, Levy J, Frankle M. Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency. J Bone Joint Surg Am 2008;90:1244-51.</ref><ref name=":26" /> pre- and intraoperative range of motion or deltoid impairment,<ref name=":23" /><ref name=":45" /> postoperative arm lengthening<ref name=":32" /><ref>Lädermann A, Lubbeke A, Collin P, Edwards TB, Sirveaux F, Walch G. Influence of surgical approach on functional outcome in reverse shoulder arthroplasty. Orthopaedics & traumatology, surgery & research : OTSR 2011;97:579-82</ref><ref name=":30" /> or neurological lesion.<ref name=":44" /><ref name=":46">Lädermann A, Lübbeke A, Mélis B, Stern R, Christofilopoulos P, Bacle G, Walch G. Prevalence of neurologic lesions after total shoulder arthroplasty. J Bone Joint Surg Am 2011;93:1288-93</ref> Surgery of the non-dominant side, lower preoperative range of motion, and lower functional outcome scores preoperatively are predictive of a slower recovery of active anterior forward flexion after reverse shoulder arthroplasty.<ref>Collin P, Matsukawa T, Denard PJ, Gain S, Lädermann A.Pre-operative factors influence the recovery of range of motion following reverse shoulder arthroplasty. Int Orthop. 2017 Oct;41(10):2135-2142</ref>

=Complications=
The first series of reverse shoulder arthroplasty with an at least two years follow-up, confirmed the preliminary results with excellent functional outcome and stable glenoid fixation.<ref name=":36" /> Beck S, Patsalis T, Busch A, Dittrich F, Dudda M, Jäger M, Wegner A. A substantial and durable improvement in the long term has been reported.<ref>Beck S, Patsalis T, Busch A, Dittrich F, Dudda M, Jäger M, Wegner A. Long-term results of the reverse Total Evolutive Shoulder System (TESS). Arch Orthop Trauma Surg. 2019 Aug;139(8):1039-1044</ref><ref>Ernstbrunner L, Rahm S, Suter A, Imam MA, Catanzaro S, Grubhofer F, Gerber C. Salvage reverse total shoulder arthroplasty for failed operative treatment of proximal humeral fractures in patients younger than 60 years: long-term results. J Shoulder Elbow Surg. 2019 Oct 6. pii: S1058-2746(19)30537-3.</ref><ref>van Ochten JHM, van der Pluijm M, Pouw M, Felsch QTM, Heesterbeek P, de Vos MJ. Long - Term survivorship and clinical and radiological follow - up of the primary uncemented Delta III reverse shoulder prosthesis. J Orthop. 2019 Mar 24;16(4):342-346</ref> However, the complexity of this procedure with regards to its singular anatomy and special patient population, is reflected by the large number of reported problems and complications. As defined by Zumstein et al., problems can be defined as intra- or postoperative events that are not likely to affect the patient’s final outcome.<ref name=":19">Zumstein MA1, Pinedo M, Old J, Boileau P. Problems, complications, reoperations, and revisions in reverse total shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg. 2011 Jan;20(1):146-57</ref> This will include hematomas, phlebitis, heterotopic ossification, algodystrophy and will not be part of the treated subjects of this thesis. Complications are defined as any intra- or postoperative events that are likely to have a negative influence on the patient’s final outcome, such as intraoperative cement extravasation, intra- or postoperative fractures, dislocations, infections, neurological lesions, radiographic changes such as glenoid or humeral lucent lines, scapular notching, stress shielding, aseptic loosening, reinterventions (without replacement of the component) or revisions (with replacement of the component).

==Radiological Changes==
This is the most frequently reported complication after reverse shoulder arthroplasty.<ref name=":19" /> Long-term studies reported their prevalence.<ref name=":37" />

===Impingements===
====Scapular Notching====
Scapular notching is the most frequent radiographic change after a reverse shoulder arthroplasty and has been reported as high as 88%.<ref name=":37" /> It was initially described as the result of abutment of the prosthetic metaphysis against the scapular neck with the arm in adduction consequent to humerus medialization. Repetitive contact between polyethylene and bone may result in polyethylene wear debris, chronic inflammation and osteolysis,<ref name=":39" /> radiolucency around the glenoid component,<ref>Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-86</ref> loosening of the glenoid component,<ref>Cazeneuve JF, Cristofari DJ. Delta III reverse shoulder arthroplasty: radiological outcome for acute complex fractures of the proximal humerus in elderly patients. OOrthop Traumatol Surg Res 2009;95:325-9</ref> presence of an inferior bone spur, and ossification in the glenohumeral space.<ref name=":37" />

Scapular notching (Figure) typically occurs within six months after surgery and appears to stabilize in most cases. The use of an anterosuperior approach, a high position of the baseplate on the glenoid and superior tilting have all been associated with higher rates of notching caused by mechanical impingement with the arm in adduction. Eccentric glenospheres with an inferior offset and glenoid components with a more lateral offset (bony or metal) can reduce the risk of notching.<ref name=":11" /><ref name=":3" /> Mizuno et al. analyzed the influence of an eccentric glenosphere in 47 consecutive cases compared with a historical group treated by the same surgeon. The rates of notching were not different but the severity of notching was less when using an eccentric glenosphere.<ref name=":38" /> Other authors have reported a negligible rate of notching when using an inferior offset component.

[[File:Scapular notching.png|thumb|center|Scapular notching. The severe superior glenoid bone loss (left) has not been corrected intraoperatively (middle), resulting in a severe scapular notching of grade 4 according to Sirveaux.]]

Two types of impingement interactions are noted (Figure).

[[File:Image41-97.jpg|thumb|Two types of impingement interactions coexist; it could correspond to a friction of the polyethylene against the bone (Figure A and B). These repetitive frictions might lead with time to progressive bony abrasion. These phenomena are probably the cause of a rapid apparition of scapular notching. They are the results of multiple motions (adduction, rotations, extension) and not the consequence of a simple contact with the pillar in adduction arm at the side as previously believed. Contrarily, some impingements are related to an abutment with no possibilities to either component to continue the movement (Figure C and D). ]]

====Anterior Impingement====
Anterior impingement can also occur in the setting of reverse shoulder arthroplasty. Anterior impingement may specifically jeopardize the clinical outcome and implant survivorship, ranging from limitation in internal rotation to dislocation by decoaptation, or failure.<ref>De Wilde L1, Walch G. Humeral prosthetic failure of reversed total shoulder arthroplasty: a report of three cases. J Shoulder Elbow Surg. 2006 Mar-Apr;15(2):260-4</ref> As the conformation of the joint changes from spinning to hinging in reverse shoulder arthroplasty, implant version of the humeral stem seems to be the most predictive factor for the occurrence anterior scapular notching. Grammont already warned that excessive retroversion led to decreased internal rotation.<ref name=":35" /> The anterior notching mostly occurred in adduction. The best compromise between anterior and posterior notching to favor a functional arc of motion seems to be 20 to 40 degrees of humeral retroversion.<ref>Stephenson DR, Oh JH, McGarry MH, Rick Hatch GF 3rd, Lee TQ. Effect of humeral component version on impingement in reverse total shoulder arthroplasty. J Shoulder Elbow Surg. 2011 Jun;20(4):652-8</ref> On the other hand, glenoid component version doesn’t seem to influence notching in the axial plane.<ref>Favre P, Sussmann PS, Gerber C. The effect of component positioning on intrinsic stability of the reverse shoulder arthroplasty. J Shoulder Elbow Surg 2010;19:550–556</ref>

==Infection==
The incidence of infections after primary reverse shoulder arthroplasty is around 5%,<ref name=":5" /> which is higher than in anatomic shoulder arthroplasty.<ref>Fehringer EV, Mikuls TR, Michaud KD, Henderson WG, O'Dell JR. Shoulder arthroplasties have fewer complications than hip or knee arthroplasties in US veterans. Clin Orthop Relat Res 2010;468:717-22</ref><ref>Seebauer L. Total reverse shoulder arthroplasty: European lessons and future trends. Am J Orthop (Belle Mead NJ). 2007 Dec;36(12 Suppl 1):22-8</ref> Reasons are the large dead space caused by the ball-and-socket configuration, the frequent postoperative hematoma, the extensive surgical dissection, and in some patients the compromised general health and the numerous previous surgeries. The commonly identified low-virulence organisms are Cutibacterium acnes and Staphylococcus epidermidis. Proven and suspected infections should be revised operatively. Acute infection of less than three weeks in a stable arthroplasty should be treated with debridement and antibiotics. Late infections should be treated with arthroplasty removal, debridement and reimplantation.

==Instability==

Dislocation is one of the most common complications after reverse shoulder arthroplasty, with rates as high as 14% which account for almost half of the complications in some series. Intraoperative criteria have been proposed by other authors to assess prosthetic stability. The recommendations are numerous and include 1) a prosthesis implantation in such a way that it is difficult to reduce, 2) the absence of pistoning of the prosthesis when applying axial traction on the arm, 3) stability throughout a full range of motion, 4) passive adduction of the arm with elbow at side, 5) palpation of the tension in the conjoint tendon after reduction with the arm at the side and the elbow extended, 6) no asymmetric subluxation or tilting of the proximal humeral component on the glenosphere during adduction, and 7) free glenohumeral motion without scapula-thoracic motion between 0° to 60° of abduction. Most cases of dislocation occur during the first few months after implantation and are a result of a technical error. Risk factors for dislocation include body mass index > 30, male sex, previous surgery, subscapularis deficiency and high neck shaft angle (155 degrees). The etiology of dislocation is multifactorial. It can occur due to 1) deltoid insufficiency, 2) lack of anterior restraints including subscapularis insufficiency, conjoint tendon weakness, and pectoralis major insufficiency, 3) malpositioning of the components, 4) impingement, and 5) infection. Instability is more frequent in cases of revision arthroplasty. Deltoid insufficiency can be caused by preoperative factors or can result from a postoperative lack of deltoid tension, acromion fracture, polyethylene wear, stem subsidence, or postoperative neurological palsy. Lädermann et al. noted a strong correlation (p < 0.0001) between preoperative humeral length and dislocation. Postoperative shortening of the humerus, as compared to preoperative or contralateral humeral length, was observed in all cases of dislocation.<ref name=":30" /> Subscapularis integrity is important if a 155 degrees is used.<ref>Edwards TB, Williams MD, Labriola JE, Elkousy HA, Gartsman GM, O'Connor DP. Subscapularis insufficiency and the risk of shoulder dislocation after reverse shoulder arthroplasty. J Shoulder Elbow Surg 2009;18:892-6</ref><ref>Cheung EV, Sarkissian EJ, Sox-Harris A, Comer GC, Saleh JR, Diaz R, Costouros JG. Instability after reverse total shoulder replacement. J Shoulder Elbow Surg 2011;20:584-90</ref> Low neck shaft angles (145 and 135 degrees) are more stable designs and subscapularis integrity seems less important to prevent instability.

[[File:Instability.jpg|thumb|center|One month after implantation of a reverse shoulder arthroplasty for a proximal humeral fracture. The X-ray revealed a prosthetic dislocation. Electroneuromyography (ENMG) confirmed a severe axonotmesis of the axillary nerve.]]

==Neurological Lesions==
Lengthening of the arm during reverse shoulder arthroplasty, because of its nonanatomic design and/or maneuver of glenohumeral reduction, may be a major factor responsible for the increased prevalence of neurologic injury. Clinically relevant neurological complications involving the brachial plexus or the axillary nerve, however, are rare following reverse shoulder arthroplasty. A prospective study determined the electrodiagnostic occurrence of peripheral nerve lesions following 155 degrees neck shaft angle reverse shoulder arthroplasty.<ref name=":46" /> If one also takes into account subclinical deterioration of preoperative lesions, 63% of patients in this study had postoperative neurologic lesions. However, only 5% of patients had a lesion that was present beyond 6 months postoperative. The rate of postoperative lesions seems lower using low neck shaft angles.<ref>Lowe JT, Lawler SM, Testa EJ, Jawa A. Lateralization of the glenosphere in reverse shoulder arthroplasty decreases arm lengthening and demonstrates comparable risk of nerve injury compared with anatomic arthroplasty: a prospective cohort study. J Shoulder Elbow Surg. 2018 Oct;27(10):1845-1851</ref> It seems consequently that distalization put the nerve at risk and that lateralization is rather protective for the plexus.

==Glenoid or humeral non- or disassembly==
Glenoid or humeral non- or disassembly, and polyethylene disassociation are minor problems and are mainly due to prosthetic design (Figure).

[[File:Glenoid dissociation.png|thumb|center|Glenoid disassembly. Six weeks postoperative anteroposterior, Neer and axial imaging revealing a disassembly of the glenosphere on the metaglene.]]

==Periprothetic fractures==
===Humerus===
Humeral fractures occurred intra- or postoperatively.

====Intraoperative====
Intraoperatively, they can appear in the metaphyseal area (“controlled fracture” according to Walch) and are related to retractor positioning. Humeral diaphyseal fractures occur intraoperatively in case of an incorrect sizing of the component or excessive external rotation during preparation of the glenoid and release. They usually require the use of a longer implant to bypass the fracture line or an open reduction internal fixation (ORIF).

====Postoperative====
Postoperatively, fractures usually result from trauma (Figure). They can be treated either conservatively if the component is stable or they require revision in cases of unstable components.

[[File:Image47-109.jpg|thumb|center|Postoperative fracture under the stem of the prosthesis that has been treated conservatively.]]

[[File:Image49-113.png|thumb|Patient known for a right reverse shoulder arthroplasty that sustained a fall on the ipsilateral elbow. A transverse supracondylar fracture of the distal humerus is noted on lateral view.]]

==Heterotopic ossification==
Heterotopic ossification after reverse shoulder arthroplasty (Figure) is a relatively common finding of unknown clinical importance.

[[File:Heterotopic ossifications.png|thumb|center|Heterotopic ossification after reverse shoulder arthroplasty ]]

=References=
<references />

Shoulder:Glenohumeral Arthritis/Reverse Shoulder Arthroplasty

2021-09-10T10:33:20Z

Alexandre.laedermann: /* Subscapularis Repair */

==Bullet Points==

*Indications for reverse shoulder arthroplasty expended. Weight-bearing patients, preoperative deltoid or acromial impairment, in certain circumstances, are not an absolute contraindication to reverse shoulder arthroplasty.

*Deltopectoral, anterosuperior (transdeltoid), and deltoid and subscapularis sparing approaches are currently used. Transacromial approach has been abandoned.

*Adequate deltoid tension obtained through restoration of humeral and arm length is one of the keys for postoperative function and prevention of instability following reverse shoulder arthroplasty. With a classic Grammont prosthesis postoperative humeral lengthening is approximately 2 mm and arm lengthening is approximately 24 mm.

*Subclinical neurologic lesions after Medial Glenoid/Medial Humerus Design are a frequent with consequence of lengthening with a drastically increasing prevalence above 40 mm of arm lengthening. Lateralized designs seem to be protective. Arm lengthening should be controlled with 0 to 2 cm being a reasonable goal to avoid postoperative neurological impairment.

*Medial Glenoid/Medial Humerus 155 degrees neck-shaft angle designs are progressively replaced by lateralized and lower neck-shaft angle (145-135 degrees) designs that theoretically attain, compared to traditional Grammont-type prosthesis, an optimal compromise in range of motion and soft tissue tension.

*Anterior forward flexion and Constant scores after reverse shoulder arthroplasty plateau at 6 months postoperative whereas internal and external rotation continue to improve up to 2 years postoperative. Several preoperative factors are correlated with postoperative range of motion.

*Previously, complications have been reported to affect 19% to 68% of patients and include acromial fracture, haematoma, infection, instability, mechanical baseplate failure, neurological injury, periprosthetic fracture and scapular notching. The rate of postoperative complications has dramatically decreased.

*The launch of a variety of reverse shoulder arthroplasty designs on the market has introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

==Key words==
Reverse total shoulder arthroplasty; prosthesis; postoperative function; humerus and arm length; deltoid impairment; muscle insufficiency; complications; indications, contraindications; impingement; humeral lateralization; glenoid; neck-shaft angle; function; range of motion; active forward flexion; predicting factors; results; clinical outcomes; weight-bearing joint; wheelchair; crutches.

==History==
Paul Grammont was born on April 1940 in Salins-les-Bains, in the northeastern part of France. He began medical studies in Lyon. Very quickly he became interested in surgery, and more specifically in orthopaedic surgery. He first became the fellow and then assistant of Professor Albert Trillat. He became a Professor of Orthopaedic Surgery and Traumatology in 1974 at the age of 34. He then moved to Dijon (France) where he became the Chairman of the Orthopaedic Department of the University Hospital. While he had few laboratory resources, he began many of his biomechanical shoulder experiments in his own garage. Grammont was creative: besides developing the reverse shoulder prosthesis,<ref>Grammont PM, Latfay, J, Deries X. [In French] Etude et réalisation d’une nouvelle prothèse d’épaule. Rhumatologie 1987;39: 407-418</ref> he also developed an early patellofemoral prosthesis<ref>Renard JF, Grammont P. [In French] La prothe`se autocentrique de rotule: technique et re´sultats apre`s 7 ans de recul. Rhumatologie.
1989;41:241–245.</ref> and one of the first nails with a self-advancing mechanism designed to lengthen long bones like the tibia and the femur (Albizia nail).<ref>Guichet JM, Grammont PM, Trouilloud P. [A nail for progressive lengthening. An animal experiment with a 2-year follow-up]. Chirurgie. 1992;118(6-7):405-410</ref> Paul Grammont died in Lyon the 30 March 2013.

==Anecdotes==
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==Human Development==
During evolution the permanently orthograde posture has freed the human shoulder girdle of its quadruped functions. The anterior limbs became the upper limbs with the characteristics of a non-weight-bearing joint. Major bony and muscular adaptations occurred.<ref>Baulot, E. Sirveaux, F. Boileau, P. Grammont's idea: The story of Paul Grammont's functional surgery concept and the development of the reverse principle. Clin Orthop Relat Res. 2011 Sep;469(9):2425-31</ref> The scapulohumeral complex underwent drastic changes to facilitate prehension, leading to major bony and muscular modifications. A relative atrophy of the supraspinatus muscle occurred, as illustrated by a decrease in the scapular index.<ref>Inman, VT. Saunders, M. Abbott, MC. Observations on the function of the shoulder joint. J Bone Joint Surg Br 1944;26(1):1-30</ref><ref>Pearl, R., and Schultz, F.: Human Biology: A Record of Research. Edited, Baltimore, Warwick and York Inc Publishers, 1930</ref> The decrease in the effectiveness of the latter muscle was at the same time compensated for by the increase in size, mass, and lateral extension of the acromion process. The progressive distal migration of the point of insertion of the deltoid muscle and lateralization of the acromion indicate the more dominant position occupied by the deltoid with strengthening in particular of the middle deltoid abduction component.<ref name=":27">Grammont, P. M.: Place de l’ostéotomie de l’épine de l’omoplate avec translation, rotation, élévation de l’acromion dans les ruptures chroniques de la coiffe des rotateurs. Lyon Chir 1979;55:327–329</ref>

The glenohumeral joint is highly mobile and relatively unconstrained. Stability of the joint relies upon concavity-compression whereby the rotator cuff exerts a compressive force of the humeral head upon the glenoid. In the absence of concavity-compression, the unopposed contraction of the deltoid creates a force vector that displaces the head superiorly rather than in abduction. Depending on the type of rotator cuff lesion, a patient may present with pseudoparalysis.

To compensate the loss of function of the rotator cuff, several options have been proposed; the most reasonable, whenever possible, is to repair the rotator cuff. Good results are obtained in the vast majority of the cases with healing of the rotator cuff on the tuberosities. In some circumstances, rotator cuff repair is however contraindicated or technically impossible.

For instance, a rotator cuff insufficiency associated with pain and pseudoparalysis remains a challenging condition. It is extremely difficult, if not impossible, to obtain a functionally good result with a conventional prosthetic arthroplasty in this situation, where only a “limited goals surgery” is appropriate, a concept introduced by Neer.<ref>Neer, C. S., 2nd; Craig, E. V.; and Fukuda, H.: Cuff-tear arthropathy. J Bone Joint Surg Am 1983;65(9):1232-44</ref> Effectively, hemiarthroplasty provides satisfactory pain relief but poor motion,<ref>Sanchez-Sotelo, J.; Cofield, R. H.; and Rowland, C. M.: Shoulder hemiarthroplasty for glenohumeral arthritis associated with severe rotator cuff deficiency. J Bone Joint Surg Am 2001;83(12):1814-22</ref> whereas total anatomic shoulder arthroplasty is complicated with early loosening of the glenoid component.<ref>Barrett, W. P.; Franklin, J. L.; Jackins, S. E.; Wyss, C. R.; and Matsen, F. A., 3rd: Total shoulder arthroplasty. J Bone Joint Surg Am 1987;69(6):865-72</ref>

In order to provide active forward elevation above 90 degrees, the abduction role of the deltoid has to be increased. This can be obtained by several mechanisms, such as an osteotomy of the scapular spine<ref name=":27" /> or more commonly by medializing the center of rotation the glenohumeral joint.<ref>Grammont, P. M.; Bourgon, J.; and Pelzer, P.: Study of a Mechanical Model for a Shoulder Total Prosthesis: Realization of a Prototype. In ECAM de Lyon. Edited, Dijon, Université Dijon, 1981</ref> The concept of functional surgery is born from the latter option: whereas no effective anatomic solution exists, restoration of function has to be proposed through a novel morphology.

The first-generation of reverse shoulder arthroplasty has been implanted in Germany and France.<ref>Gérard, Y.; Leblanc, J. P.; and Rousseau, B.: A complete shoulder prosthesis. Chirurgie 1973;99:655–663</ref><ref>Kolbel, R., and Friedebold, G.: [Shoulder joint replacement]. Arch Orthop Unfallchir 1973;76(1):31-9</ref> However, early loosening and mechanical complications forced to abandon their use. Nevertheless, successive improvements imagined by Grammont followed and, in 1991, a reverse shoulder arthroplasty called the “Delta III” has been developed.<ref name=":36">Baulot, E.; Chabernaud, D.; and Grammont, P. M.: [Results of Grammont's inverted prosthesis in omarthritis associated with major cuff destruction. Apropos of 16 cases]. Acta Orthop Belg 1995;61(Suppl 1):112-9</ref> The two major innovations were a large metal hemisphere with no neck on the glenoid side, and a small humeral polyethylene cup (covering less than half of the hemisphere), oriented with a nonanatomic inclination of 155 degree.

==Biomechanics==

#REDIRECT [[https://wiki.beemed.com/view/Shoulder:Biomechanics]<nowiki>]</nowiki>

Reverse shoulder arthroplasty, often used in multiply operated patients with distorted anatomy, imparts physiological and biomechanical changes that may increase the potential for complications.<ref name=":5">Farshad M, Gerber C. Reverse total shoulder arthroplasty-from the most to the least common complication. Int Orthop. 2010 Dec;34(8):1075-82</ref>

First, the arthroplasty position medializes and lowers the glenohumeral center of rotation, thereby increasing the lever of the deltoid muscle (Medial Glenoid/Medial Humerus Design). Deltoid tension, increased by the lowered center of rotation, increases muscle fiber recruitment of the anterior and posterior deltoid that compensates for a deficient rotator cuff (Figure). The medialization increased the deltoid moment arm up to 20%, and an inferior move increased the efficacy of the deltoid up to 30%.<ref>Terrier A, Reist A, Merlini F, Farron A. Simulated joint and muscle forces in reversed and anatomic shoulder prostheses. J Bone Joint Surg Br 2008;90:751-6.</ref>

[[File:Muscle recruitment.jpg|thumb|center|(A) Native shoulder. The center of rotation is in the humeral head, and the level of arm of deltoid does not allow deltoid recruitment. (B) Bony increased-offset reverse shoulder arthroplasty with lateral glenoid/medial humerus design. As in native shoulders, the bony lateralization of the center of rotation decreases recruitment of the deltoid for rotation. (C) Grammont reverse shoulder arthroplasty with humeral lateralization with a medial glenoid/lateral humerus design. Medialization of the center of rotation and humeral lateralization allows important deltoid recruitment. Reproduced from Collin et al.,<ref name=":6">Collin P, Liu X, Denard PJ, Gain S, Nowak A, Lädermann A. Standard versus bony increased-offset reverse shoulder arthroplasty: a retrospective comparative cohort study. J Shoulder Elbow Surg. 2018;27(1):59-64</ref> with permission.]]

Second, to provide an inherently stable reverse shoulder arthroplasty, the weight bearing part is convex and the supported part concave (reversal of the ball and socket). The fixed nature of the glenosphere places torsional forces on the humerus that may affect humeral component instability.<ref name=":37">Melis B, DeFranco M, Lädermann A, Molé D, Favard L, Nérot C, Maynou C, Walch G. An evaluation of the radiological changes around the Grammont reverse geometry shoulder arthroplasty after eight to 12 years. J Bone Joint Surg Br. 2011 Sep;93(9):1240-6</ref> The native spinning joint becomes a hinge joint, new configuration that leads to various impingements’ types and locations.

Third, the semi-constrained nature of the prosthesis restores glenohumeral stability which provides the stable fulcrum which is essential for active anterior elevation.

Finally, lengthening of the arm which provides space for range of motion of the proximal humerus,<ref name=":32">Lädermann A, Edwards TB, Walch G. Arm lengthening after reverse shoulder arthroplasty: a review. Int orthop 2014;38:991-1000</ref> enhances stability, and re-tensions the deltoid. The latter factor is critical due to the semi-constrained design of the prosthesis. The increase in compressive force between the humeral and glenoid components has a stabilizing effect.<ref>Gagey O, Hue E. Mechanics of the deltoid muscle. A new approach. Clin Orthop Relat Res 2000:250-7</ref> Under such tension, the reverse glenoid component provides the stable fulcrum essential for shoulder anterior elevation and prosthesis stability.<ref name=":28">Boileau P, Watkinson DJ, Hatzidakis AM, Balg F. Grammont reverse prosthesis: design, rationale, and biomechanics. J Shoulder Elbow Surg 2005;14:147S-61S</ref> This tension is determined by arm length.

===Arm Lengthening===
Failure to adequately tension the deltoid may result in prosthetic instability and poor function which are the most common clinically significant complications following reverse shoulder arthroplasty. On the other hand, other complications following reverse shoulder arthroplasty can be related to excessive deltoid tension such as neurological lesions, fractures of the acromion, or fixed abduction of the arm.<ref name=":28" /><ref>Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. Neer Award 2005: The Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg 2006;15:527-40</ref> Adequate deltoid tension is thus accepted as a key to prosthetic function and stability.<ref name=":28" /><ref name=":32" />

The glenosphere has to be implanted on the lower part of the glenoid to avoid notching and to improve rotation at 90 degrees of abduction.<ref>De Biase CF, Ziveri G, Delcogliano M, de Caro F, Gumina S, Borroni M, Castagna A, Postacchini R.The use of an eccentric glenosphere compared with a concentric glenosphere in reverse total shoulder arthroplasty: two-year minimum follow-up results. Int Orthop. 2013 Oct;37(10):1949-55</ref><ref name=":3">Lädermann A, Tay E, Collin P, Piotton S, Chiu CH, Michelet A, Charbonnier C. Effect of critical shoulder angle, glenoid lateralization, and humeral inclination on range of movement in reverse shoulder arthroplasty. Bone Joint Res. 2019;8(8):378-386</ref><ref>Lévigne C, Garret J, Boileau P, Alami G, Favard L, Walch G. Scapular notching in reverse shoulder arthroplasty: is it important to avoid it and how? Clin Orthop Relat Res. 2011 Sep;469(9):2512-20</ref><ref name=":37" /><ref name=":38">Mizuno N, Denard PJ, Raiss P, Walch G. The clinical and radiographical results of reverse total shoulder arthroplasty with eccentric glenosphere. Int Orthop. 2012 Aug;36(8):1647-53</ref><ref name=":39">Nyffeler RW, Werner CM, Gerber C. Biomechanical relevance of glenoid component positioning in the reverse Delta III total shoulder prosthesis. J Shoulder Elbow Surg 2005;14:524-8.</ref> The type of glenosphere (size, eccentricity) allowed the adjustment of arm length by several millimeters (about 1% of arm length). Consequently, the key factors for arm length are the height of the stem, type of stem, polyethylene thickness and the use of an augment or spacer. Collectively, these factors allow arm lengthening by up to several centimeters (about 10% of arm length).<ref name=":32" /> The tension is thus determined by arm length. The latter is dependent of 1) the position of the glenosphere in the frontal plane (Figure), 2) the size of the glenosphere, 3) the use of an eccentric or inferiorly tilted glenosphere, 4) the use of a spacer, 5) the thickness of the polyethylene, 6) the height of humeral cut and stem implantation (Figure 3)<ref name=":29">Lädermann A, Walch G, Lubbeke A, Drake GN, Melis B, Bacle G, Collin P, Edwards TB, Sirveaux F. Influence of arm lengthening in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2012 Mar;21(3):336-41</ref> and prosthetic design (Figure).

[[File:Image2-19.jpg|thumb|center|Influence of position of glenosphere in vertical plane. (A) A rather high implantation of the baseplate or the use of a non-eccentric glenosphere does not allow proper deltoid re-tensioning. (B) The use of an eccentric glenosphere or a low position of the glenosphere in the vertical plane allows satisfactory deltoid re-tensioning,<ref name=":29" /> with permission]]

[[File:Image3-21.jpg|thumb|center|Influence of the humeral cut on arm length. (A) Preoperative status with a lack of deltoid tension. (B-C) An aggressive humeral cut results in a low implantation of the stem with a lack of deltoid tension. (D-E) A minimal humeral cut leads to a high implantation of the prosthetic stem with adequate deltoid tension. From: Lädermann et al., with permission,<ref name=":29" /> with permission]]

[[File:Image4-23.jpg|thumb|center|The neck-shaft angle is one of the biggest variabilities between different prosthesis designs. A steeper or more anatomic neck-shaft angle (Grammont-type 155 degrees vs. 145 degrees and 135 degrees designs) leads to a decrease in the acromiohumeral distance. For every 10 degrees decrease the acromiohumeral distance shortens by approximately 3 mm. In other words, between a 155 degrees and a 135 degrees configuration, arm lengthening varies by about 10 mm.]]

From a clinical perspective lengthening of the arm and humerus, distalization angle, acromio-prosthesis distance (Figures) have been used as surrogates for deltoid tension since they intuitively correlate with deltoid tension and they have been correlated with functional outcome and risk of postoperative instability.<ref>Boutsiadis A, Lenoir H, Denard PJ, Panisset JC, Brossard P, Delsol P, Guichard F, Barth J. The lateralization and distalization shoulder angles are important determinants of clinical outcomes in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2018 Jul;27(7):1226-1234</ref><ref name=":30">Lädermann A, Williams MD, Melis B, Hoffmeyer P, Walch G. Objective evaluation of lengthening in reverse shoulder arthroplasty.J Shoulder Elbow Surg. 2009 Jul-Aug;18(4):588-95</ref><ref name=":29" /> Most of these factors nowadays can easily be evaluated thank to navigation software.<ref name=":40">Iannotti JP, Walker K, Rodriguez E, Patterson TE, Jun BJ, Ricchetti ET. Accuracy of 3-Dimensional Planning, Implant Templating, and Patient-Specific Instrumentation in Anatomic Total Shoulder Arthroplasty. J Bone Joint Surg Am. 2019 Mar 6;101(5):446-457</ref><ref name=":41">Walch G, Vezeridis PS, Boileau P, Deransart P, Chaoui J. Three-dimensional planning and use of patient-specific guides improve glenoid component position: an in vitro study. J Shoulder Elbow Surg. 2015 Feb;24(2):302-9</ref>

[[File:Figure3.jpg|thumb|center|The epicondylar line (EL) is defined between the most lateral part of the medial and lateral epicondyle. Another line, the diaphyseal axis (DI), is determined by a line drawn in the centre of the proximal medullary canal. Intersection between the epicondylar line and the diaphyseal axis represent the point C. Intersection between the diaphyseal axis and top of the humeral head is named H. The point A is located at the intersection between the diaphyseal axis and a perpendicular line passing through the most lateral and inferior point of the acromion. A, C, and H are represented by small white points, large white points corresponding to centimeter marker stuck on the skin of the arm. A, acromion; C, condyles; H, head; EL, epicondylar line; DI, diaphyseal axis; preop, preoperative; contro, controlateral; EF, enlargement factor, <ref name=":30" /> with permission]]

[[File:DLA 1 blinded.png|thumb|center|The distalization shoulder angle (DSA) angle is formed by a line connecting the most lateral border of the acromion and the superior glenoid tubercle and a line connecting the superior glenoid tubercle and the most superior border of the greater tuberosity. In this case, it is measured at 61 degrees.]]

===Lateralization in Reverse Shoulder Arthroplasty===
The basic biomechanical principles of the Grammont reverse shoulder arthroplasty are a medialization of the glenohumeral center of rotation, the use of a larger ball on the glenoid component, and a lowering of the humerus. These principles increase the deltoid lever arm and provide a space for unrestricted range of motion of the proximal humerus and a stable fulcrum essential for active elevation and stability.<ref name=":28" /> However, many complications, such as limited postoperative range of motion or impingement that could be attributed to the medialized glenoid design, have been reported in the literature.<ref name=":1">Gerber C, Pennington SD, Nyffeler RW. Reverse total shoulder arthroplasty. J Am Acad Orthop Surg 2009;17:284-95</ref> To address these problems, several authors have proposed a change in the design of the Grammont prosthesis, promoting an increased bony or metallic glenoid offset.<ref name=":31">Boileau P, Moineau G, Roussanne Y, O'Shea K. Bony increased-offset reversed shoulder arthroplasty: minimizing scapular impingement while maximizing glenoid fixation. Clin Orthop Relat Res 2011;469:2558-67</ref><ref name=":13">Gutierrez S, Levy JC, Frankle MA, Cuff D, Keller TS, Pupello DR, Lee WE 3rd. Evaluation of abduction range of motion and avoidance of inferior scapular impingement in a reverse shoulder model. J Shoulder Elbow Surg 2008;17:608-15</ref> Different methods to measure glenoid lateralization have been proposed.<ref>Frankle MA, Teramoto A, Luo ZP, Levy JC, Pupello D. Glenoid morphology in reverse shoulder arthroplasty: classification and surgical implications. J Shoulder Elbow Surg 2009;18:874-85</ref><ref name=":8">Jobin CM, Brown GD, Bahu MJ, Gardner TR, Bigliani LU, Levine WN, Ahmad CS. Reverse total shoulder arthroplasty for cuff tear arthropathy: the clinical effect of deltoid lengthening and center of rotation medialization. J Shoulder Elbow Surg 2012;21:1269-77</ref>

====Definitions====
It is important to understand the differences between humeral or glenoid lateralization. These factors can be used to predict range of motion and vary based on prosthesis and technical factors. Humeral lateralization is defined as the distance from the center of the polyethylene cup, and the lateral part of the greater tuberosity (Figure). It can be estimated by the lateralization shoulder angle (Figure).

[[File:Image5-25.jpg|thumb|center|3D distances corresponded to the radius of spheres. Offset of the sphere were centered on the center of the polyethylene cup (pivot point) and of the bony glenoid center (GC) for humeral (A) and global offset (B), respectively, and included the lateral part of the greater tuberosity. ]]

[[File:LSA.png|thumb|center|The lateralization shoulder angle is formed by a line connecting the superior glenoid tubercle and the most lateral border of the acromion and a line connecting the most lateral border of the acromion and the most lateral border of the greater tuberosity. In this case, it is measured at 77 degrees.]]

It depends upon glenoid wearing, reaming and grafting, contact of the baseplate with the glenoid, the offset of the glenosphere and/or baseplate, the glenosphere diameter and tilt, the level of the humeral cut, the humeral neck-shaft angle, the humeral prosthetic design, the use of a spacer, the polyethylene thickness (humeral polyethylene socket offset), and the remaining proximal and lateral humeral bone stock.

At the other end of the spectrum, failure to adequately restore bone or prosthetic humeral lateralization may result in loss of humeral contour,<ref>Chacon A, Virani N, Shannon R, Levy JC, Pupello D, Frankle M. Revision arthroplasty with use of a reverse shoulder prosthesis-allograft composite. J Bone Joint Surg Am. 2009 Jan;91(1):119-27</ref> and deltoid shape curve and thus deltoid retensionning, and could lead to prosthetic instability and poor postoperative function.<ref name=":29" /><ref name=":30" />

===Neck-shaft angle===
More anatomic neck-shaft angles decrease the rate of scapular notching and improve postoperative range of motion.<ref name=":3" /><ref name=":11" />

The launch of this variety of designs on the market has introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

===Range of motion after reverse shoulder arthroplasty: which combinations of humeral stem and glenosphere work the best?===
Reproduced from Lädermann et al., with permission.<ref>Lädermann A, Collin P, Denard PJ. Range of motion after reverse shoulder arthroplasty: Which combinations of humeral stem and glenosphere work the best? Obere Extremität 2020 doi:10.1007/s11678-020-00599-5</ref>
====Introduction====
The initial reverse shoulder arthroplasty design was excellent at restoring forward flexion but had several design-related complications including bony impingement and scapular notching,<ref name=":11">Lädermann A, Denard PJ, Collin P, Zbinden O, Chiu JC, Boileau P, Olivier F, Walch G. Effect of humeral stem and glenosphere designs on range of motion and muscle length in reverse shoulder arthroplasty. Int Orthop. 2020;44(3):519-30</ref><ref name=":37" /> instability,<ref>Chae J, Siljander M, Wiater JM. Instability in Reverse Total Shoulder Arthroplasty. J Am Acad Orthop Surg 2018;26:587-596</ref> acromial fractures,<ref name=":18">Haidamous G, Lädermann A, Frankle M, Gorman A, Denard PJ. The risk of postoperative scapular spine fracture following reverse shoulder arthroplasty is increased with an onlay humeral stem. J Shoulder Elbow Surg. 2020;9:S1058-2746(20)30337-2.</ref> limited range of motion (particularly internal and external rotation),<ref name=":10">Denard PJ, Lädermann A, Haidamous G, Hartzler R, Parsons BO, Lederman ES, Tokish JM. Radiographic Parameters Associated With Excellent Versus Poor Range Of Motion Outcomes Following Reverse Shoulder Arthroplasty. Shoulder & Elbow 2020;9:1758573220936234.</ref><ref>Lädermann A, Denard PJ, Tirefort J, Collin P, Nowak A, Schwitzguebel A J-P. Subscapularis- and deltoid-sparing vs traditional deltopectoral approach in reverse shoulder arthroplasty: a prospective case-control study. J Orthop Surg Res 2017;12:112</ref> and humeral stem loosening.<ref name=":37" /><ref>Lädermann A, Schwitzguebel AJ, Edwards TB, Godeneche A, Favard L, Walch G, Sirveaux F, Boileau P, Gerber C. Glenoid loosening and migration in reverse shoulder arthroplasty. Bone Joint J. 2019;101-B:461-469</ref> Many of these have been attributed to the initial Grammont design which featured a medialized glenosphere and 155 degrees straight stem (Medial Glenoid/Medial Humerus Design).<ref name=":1" />

A variety of changes in prosthetic design have been proposed to address these issues either on the humeral side or on the glenoid side, the goal being to decrease scapular notching, maximize efficiency of the remaining rotator cuff, improve stability and improve range of motion. On the glenoid side authors have promoted increased lateralization either with bone or metal.<ref name=":31" /><ref name=":4">Gutiérrez S, Comiskey CA 4th, Luo ZP, Pupello DR, Frankle MA. Range of impingement-free abduction and adduction deficit after reverse shoulder arthroplasty. Hierarchy of surgical and implant-design-related factors. J Bone Joint Surg Am . 2008;90(12):2606-15</ref> On the humeral side, a more anatomic humeral inclination (i.e. 145 or 135 degrees) and inlay and onlay systems designs have introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

Therefore, the aim of this chapter is to evaluate the advantages and inconvenience of different reverse shoulder arthroplasty’s designs and to provide recommendations accordingly.

====Glenoid Configuration====
Glenoid configuration has an important effect on postoperative range of motion. The three most important variables are glenoid offset, eccentricity, and glenosphere size. None of these latter parameters influence significantly the measured bone strains at the glenoid near the bone-implant interface.<ref>Pauzenberger L, Dwyer C, Obopilwe E, Nowak MD, Cote M, Romeo AA, Mazzocca AD, Dyrna F. Influence of glenosphere and baseplate parameters on glenoid bone strains in reverse shoulder arthroplasty. BMC musculoskeletal disorders 2019;20(1):587</ref>

=====Glenoid Offset (lateralization)=====
The initial Grammont-style reverse shoulder arthroplasty utilized a glenosphere with a medialized center of rotation. While this design reliably improved forward elevation, the high rate of scapular notching and internal and external rotation deficit observed with this design have been attributed to the medialized glenoid design.<ref name=":1" /><ref>Lawrence C, Williams GR, Namdari S. Influence of Glenosphere Design on Outcomes and Complications of Reverse Arthroplasty: A Systematic Review. Clinics in orthopedic surgery 2016;8:288-297</ref> To address these problems, glenoid lateralization have been proposed to decrease scapular notching, improve soft tissue tension, and increase impingement-free range of motion. The glenoid component is considered as lateralized if lateralization equals or exceeds 5 mm compared to Grammont design.<ref>Werthel JD, Walch G, Vegehan E, Deransart P, Sanchez-Sotelo J, Valenti P. Lateralization in reverse shoulder arthroplasty: a descriptive analysis of different implants in current practice. Int Orthop 2019;43:2349-2360</ref> It is important to note that this lateralization of the center of rotation is relative to the implant designed by Grammont, but still medialized compared to the native glenohumeral joint. Lateralization can be achieved by either the placement of bone medial to the baseplate (bone increase offset reverse shoulder arthroplasty (BIO-RSA))<ref name=":31" /> or with metallic lateralization via the baseplate or glenosphere. While both have been associated with clinical improvement,<ref>Ernstbrunner L, Werthel JD, Wagner E, Hatta T, Sperling JW, Cofield RH. Glenoid bone grafting in primary reverse total shoulder arthroplasty. J Shoulder Elbow Surg 2017;26:1441-1447</ref><ref>Klein SM, Dunning P, Mulieri P, Pupello D, Downes K, Frankle MA. Effects of acquired glenoid bone defects on surgical technique and clinical outcomes in reverse shoulder arthroplasty. J Bone Joint Surg Am 2010;92:1144-1154</ref> metallic lateralization appears to be less subject to displacement, particularly with lateralization beyond 5 mm.<ref>Denard PJ, Lederman E, Parsons BO, Romeo AA. Finite element analysis of glenoid-sided lateralization in reverse shoulder arthroplasty. J Orthop Res 2017;35:1548-1555</ref>

Basic science studies show several benefits of lateralization. In both sawbone<ref name=":13" /> and computer models,<ref name=":4" /><ref name=":21">Kim SJ, Jang SW, Jung KH, Kim YS, Lee SJ, Yoo YS. Analysis of impingement-free range of motion of the glenohumeral joint after reverse total shoulder arthroplasty using three different implant models. Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2019;24:87-94</ref><ref name=":3" /> lateralization improves range of motion in all directions.<ref name=":3" /> Lateralization also leads to improvement in stability.<ref>Ferle M, Pastor MF, Hagenah J, Hurschler C, Smith T. Effect of the humeral neck-shaft angle and glenosphere lateralization on stability of reverse shoulder arthroplasty: a cadaveric study. J Shoulder Elbow Surg 2019;28:966-973</ref>

The question remains how much lateralization is ideal. While clinical evidence is currently lacking, computer modeling suggests that 5 to 10 mm of lateralization relative to the native glenoid is ideal.<ref name=":3" /><ref name=":14">Werner BS, Chaoui J, Walch G. The influence of humeral neck shaft angle and glenoid lateralization on range of motion in reverse shoulder arthroplasty. J Shoulder Elbow Surg 2017;26(10):1726-1731</ref><ref>Gutiérrez S, Greiwe RM, Frankle MA, Siegal S, Lee WE 3rd. Biomechanical comparison of component position and hardware failure in the reverse shoulder prosthesis. J Shoulder Elbow Surg 2007;16:S9-S12</ref> Nevertheless, clinical data to date has not necessarily proved that lateralization improves range of motion<ref name=":6" /> or outcome scores<ref>Helmkamp JK, Bullock GS, Amilo NR, Guerrero EM, Ledbetter LS, Sell TC, Garrigues GE. The clinical and radiographic impact of center of rotation lateralization in reverse shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg, 2018, 27:2099-2107</ref> compared to a traditional reverse shoulder arthroplasty. Greiner et al. performed a randomized controlled trial of 17 Grammont reverse shoulder arthroplasties and 17 BIO-RSAs and reported no difference in Constant scores at 1 year postoperative.<ref>Greiner S, Schmidt C, Herrmann S, Pauly S, Perka C. Clinical performance of lateralized versus non-lateralized reverse shoulder arthroplasty: a prospective randomized study. J Shoulder Elbow Surg, 2015, 24:1397-1404</ref> In a retrospective study, Athwal et al. did not observe substantial range of motion, strength, or outcome scores.<ref name=":22">Athwal GS, MacDermid JC, Reddy KM, Marsh JP, Faber KJ, Drosdowech D. Does bony increased-offset reverse shoulder arthroplasty decrease scapular notching? J Shoulder Elbow Surg, 2015, 24:468-473</ref> The frequency of scapular notching, however, was significantly higher (P=.022) in the reverse shoulder arthroplasty cohort than in the BIO-RSA cohort: 75% versus 40%.<ref name=":22" /> This finding has been also reported by Zitkovsky et al.<ref name=":15">Zitkovsky HS, Carducci MP, Mahendraraj KA, Grubhofer F, Jawa A. Lateralization and Decreased Neck-Shaft Angle Reduces Scapular Notching and Heterotopic Ossification. J Am Acad Orthop Surg. 2020 Apr 8. doi: 10.5435/JAAOS-D-19-00808. Online ahead of print.</ref> At 10 years follow-up, Kennon et al. confirmed that scapular notching rates are significantly higher with medialized components compared to lateralized ones (77% in vs. 47%, P= .013).<ref>Kennon JC, Songy C, Bartels D, Statz J, Cofield RH, Sperling JW, Sanchez-Sotelo J. Primary reverse shoulder arthroplasty: how did medialized and glenoid-based lateralized style prostheses compare at 10 years? J Shoulder Elbow Surg. 2020;29(7S):S23-S31</ref> Notably, all of the these studies utilized a 155 degrees humeral prothesis and thus further comparative studies are required with 135 and/or 145 degrees protheses.

=====Glenosphere Eccentricity=====
Inferior eccentric positioning of the glenosphere can also be used to decrease the adduction deficit and thus reduce scapular notching.<ref name=":21" /><ref name=":7">Lädermann A, Denard PJ, Boileau P, Farron A, Deransart P, Walch G. What is the best glenoid configuration in onlay reverse shoulder arthroplasty? Int Orthop. 2018;42(6):1339-1346</ref> Mizuno et al. previously reported that an inferiorly eccentric glenosphere reduced the severity of scapular notching with a 155 degrees prosthesis,<ref name=":38" /> improving thus postoperative rotations elbow at side.<ref name=":2">Lädermann A, Gueorguiev B, Charbonnier C, Stimec BV, Fasel JH, Zderic I, Hagen J, Walch G. Scapular Notching on Kinematic Simulated Range of Motion After Reverse Shoulder Arthroplasty Is Not the Result of Impingement in Adduction. Medicine (Baltimore). 2015;94(38):e1615</ref> While the differences are small, the eccentric glenosphere provided the greatest ability to limit scapular notching while maximizing range of motion by increasing the subacromial space.<ref name=":7" /><ref name=":3" /> Abduction is effectively positively correlated with acromiohumeral distance (r = 0.93; p < 0.001) which is increased with an eccentric glenosphere.<ref name=":11" /> Rotation in abduction is important to activities of daily living. Interestingly, the latter are impossible in most configurations due to inexistent subacromial space (Figure 9). Postero-inferior eccentricity can improve also extension and could favorize as well internal rotation hand in the back (Figure).

[[File:Figure 1.png|thumb|Rotations rotation at 90 degrees of abduction might be impossible due to inexistent subacromial space. Eccentric positioning of the glenosphere creates subacromial space.]]

[[File:Figure 2 Postero-inferior eccentricity.png|thumb|Postero-inferior eccentricity improves extension. A) Inferior eccentricity alone (yellow arrow) allows 52 degrees of extension. B) 40 degrees of postero-inferior eccentricity (yellow arrow) improves extension to 73 degrees.]]

It is important to note, however, that inferior overhang of the glenosphere can be achieved either by an eccentric glenosphere or by baseplate position. Conversely, an eccentric glenosphere with an improperly positioned superior baseplate will not provide clinical benefit. Thus, the surgeon must be cognizant of both the overhang of the given glenosphere relative to the selected baseplate, as well as any eccentricity in the glenosphere. Furthermore, the benefits of overhang or eccentricity must be weighed against the risks of nerve injury and acromial fracture associated with arm lengthening. The ideal amount of overhang relative to the glenoid appears to be about 2.5 mm based on clinical evidence.<ref name=":10" />

=====Glenosphere size=====
The size of the glenosphere influences theoretically and clinically postoperative range of motion. Lädermann et al. found that a small glenosphere (36 mm) improves external rotation in abduction.<ref name=":7" /> However, with the elbow at side, larger diameter glenospheres have been shown to provide a greater impingement-free arc of motion, and decrease scapular notching in biomechanical studies. Werner et al. reported superior values for extension and external rotation with a 39 mm glenosphere compared to a 36 mm glenosphere mm.<ref name=":14" /> Berhouet et al. demonstrated in a cadaveric study that a 42 mm glenosphere was associated with improved rotational range of motion compared to a 36 mm glenosphere (p <0.05).<ref>Berhouet J, Garaud P, Favard L. Evaluation of the role of glenosphere design and humeral component retroversion in avoiding scapular notching during reverse shoulder arthroplasty.J Shoulder Elbow Surg . 2014;23(2):151-8</ref> Another study comparing functional scores and range of motion differences between two groups of patients, one receiving a 36 mm glenosphere and the other receiving a 44 mm glenosphere, found that patients with the larger glenosphere had a 12 degrees increase in external rotation in adduction compared to those with the smaller glenosphere (p <.001).<ref>Muller AM, Born M, Jung C, Flury M, Kolling C, Schwyzer HK, Audigé L. Glenosphere size in reverse shoulder arthroplasty: is larger better for external rotation and abduction strength? J Shoulder Elbow Surg 2018;27(1):44-52</ref> Similarly, Mollon et al. showed that a 42 mm glenosphere size generated a 15 degree improvement in forward flexion and a 6 degree improvement in external rotation compared to the 38 mm size, with an overall improvement in pain scores.<ref>Mollon B, Mahure SA, Roche CP, Zuckerman JD. Impact of glenosphere size on clinical outcomes after reverse total shoulder arthroplasty: an analysis of 297 shoulders. J Shoulder Elbow Surg. 2016;25(5):763-71</ref> Finally, a study by Haidamous et al. demonstrated that larger glenosphere size and inferior positioning as well as posterior humeral offset are associated with improved postoperative range of motion following reverse shoulder arthroplasty with a 135 degrees humeral component.<ref name=":10" /> Nevertheless, larger glenospheres limit abduction and rotations in abduction and are prone to higher volumetric wear rates and experienced greater polyethylene volume loss.<ref>Haggart J, Newton MD, Hartner S, Ho A, Baker KC, Kurdziel MD, Wiater JM. Neer Award 2017: wear rates of 32-mm and 40-mm glenospheres in a reverse total shoulder arthroplasty wear simulation model. J Shoulder Elbow Surg . 2017;26(11):2029-2037</ref> Additionally, one must consider patient size. Overstuffing can occur. Matsuki et al., for instance, demonstrated that small- and large-stature patients achieved lower improvement in range of motion with an RSA system with only 2 glenosphere sizes (38 and 42) likely because the small patients were overstuffed and the large patients did not have large enough glenospheres and/or lateralization.<ref>Matsuki K, King JJ, Wright TW, Schoch BS. Outcomes of reverse shoulder arthroplasty in small- and large-stature patients. J Shoulder Elbow Surg. 2018;27(5):808-815</ref>

====Humeral Stem Designs====
The primary humeral stem variables include stem geometry, neck-shaft angle, inlay versus onlay configuration, and humeral spacers.

=====Stem geometry=====
Short curved stems were initially developed to facilitate implantation, maintain bone stock, and preserve rotator cuff insertion.<ref>Lädermann A, Chiu JC, Cunningham G, Hervé A, Piotton S, Bothorel H, Collin P. Do short stems influence the cervico-diaphyseal angle and the medullary filling after reverse shoulder arthroplasties? Orthop Traumatol Surg Res. 2020;106(2):241-246</ref> These stems also change humeral offset based on their positioning in the humeral canal. In one study an onlay curve stem lead to a 7-mm increase in humeral offset compared to a traditional inlay straight Grammont prosthesis.<ref name=":12">Lädermann A, Denard PJ, Boileau P, Farron A, Deransart P, Terrier A, Ston J, Walch G. Effect of humeral stem design on humeral position and range of motion in reverse shoulder arthroplasty. Int Orthop. 2015;39(11):2205-13</ref> Curve stems decrease the acromiohumeral distance, which may lead to acromial impingement at small abduction angles.<ref name=":12" /> On the other hand, humeral lateralization can be useful to compensate for medialization in case of bone loss (Figure) and has been theorized to improve the mechanics of the remaining rotator cuff and deltoid musculature.<ref>Parry S, Stachler S, Mahylis J. Lateralization in reverse shoulder arthroplasty: A review. Journal of orthopaedics 2020;22:64-67</ref> Stem design appeared to have also a substantial effect on abduction, as combinations with the straight Grammont stem had greater abduction (73–80%), compared to those with the onlay curved stem (54–69%).<ref name=":11" />

[[File:Managing the eroded glenoid in shoulder arthroplasty Noumea 2019.jpg|thumb|Humeral lateralization can help to restore global lateralization in case of glenoid bone loss. A) Massive glenoid bone loss compensated by glenoid allograft and a straight stem (Lateral Glenoid/Medial Humerus concept). Observe that the central peg hardly reaches the native glenoid. Such construct has a potential for failure (B). Another option would have been to use a smaller glenoid graft and a curved stem (Lateral Glenoid/Lateral Humerus)]]

=====Neck-shaft angle (inclination)=====
The Grammont reverse shoulder arthroplasty was designed as a non-anatomic implant with a relative valgus humeral neck inclination of 155 degrees. Based on the work by Gutierrez et al.,<ref name=":13" /> neck-shaft angle has decreased in modern prosthetic designs to a more varus or anatomic inclination of 145 or 135 degrees.

The neck shaft angle is a major factor influencing length of the arm,<ref name=":37" /> but has little effect on humeral lateralization; by changing inclination from 155 degrees to 135 degrees within an onlay design, humeral offset only increased by about 2 mm.<ref name=":12" />

Theoretically, compared to low neck shaft angle stems, higher inclinations (155 degrees) increased abduction by 100% and external rotation in abduction, regardless of glenosphere designs.<ref name=":12" /><ref name=":3" /> This finding is important as such external rotation is a major factor in the ability to perform activities of daily activities such as hair care and facial grooming. However, a 155 degrees is associated with decreased adduction external rotation at the side<ref name=":12" /><ref>Nelson R, Lowe JT, Lawler SM, Fitzgerald M, Mantell MT, Jawa A. Lateralized Center of Rotation and Lower Neck-Shaft Angle Are Associated With Lower Rates of Scapular Notching and Heterotopic Ossification and Improved Pain for Reverse Shoulder Arthroplasty at 1 Year. Orthopedics. 2018;41(4):230-6</ref><ref name=":14" /> and extension due to medial bony impingement (which also leads to scapular notching).<ref name=":3" /><ref name=":11" /><ref name=":4" /><ref name=":14" /><ref>Oh JH, Shin SJ, McGarry MH, Scott JH, Heckmann N, Lee TQ. Biomechanical effects of humeral neck-shaft angle and subscapularis integrity in reverse total shoulder arthroplasty. J Shoulder Elbow Surg.2014;23(8):1091-8</ref><ref>Virani NA, Cabezas A, Gutiérrez S, Santoni BG, Otto R, Frankle M. Reverse shoulder arthroplasty components and surgical techniques that restore glenohumeral motion. J Shoulder Elbow Surg. 2013;22(2):179-87</ref> Lateralization obtained via a lower neck shaft angle increases adduction, by 357% between a 155 degrees prosthesis compared with a 135 degrees prosthesis. Also, an increase in extension, of 381%, and external rotation elbow at side, of 116%, are observed with a 135 degrees prosthesis.<ref name=":12" /> Such finding are important as external rotation with the elbow at the side and extension led to friction between the scapular pillar and the polyethylene insert. Even if this friction phenomenon does not limit range of motion, it likely contributes to progressive polyethylene wear and scapular notching.<ref name=":2" /> Reducing the neck-shaft angle can, however, have some negative effects on reverse shoulder arthroplasty contact mechanics. The contact area is reduced by 29% for 155 degrees to 145 degrees and by 59% for 155 degrees to 135 degrees. Consequently, there is an increased maximum contact stress by 71% for 155 degrees to 145 degrees and by 286% for 155 to 135 degrees.<ref>Langohr GD, Willing R, Medley JB, Athwal GS, Johnson JA. Contact mechanics of reverse total shoulder arthroplasty during abduction: the effect of neck-shaft angle, humeral cup depth, and glenosphere diameter. J Shoulder Elbow Surg. 2016;25(4):589-97</ref>

Gobezie et al. published the results of a randomized controlled trial comparing humeral inclination of 135 degrees to 155 degrees among patients undergoing reverse shoulder arthroplasty with a neutral glenosphere (no lateralization) and found no significant difference in forward flexion, external rotation, or functional outcomes.<ref name=":16">Gobezie R, Shishani Y, Lederman E, Denard PJ. Can a functional difference be detected in reverse arthroplasty with 135° versus 155° prosthesis for the treatment of rotator cuff arthropathy: a prospective randomized study. J Shoulder Elbow Surg. 2019;28(5):813-8</ref> They and other studies have confirmed that scapular notching is decreased with a 135 degrees prothesis.<ref name=":15" /><ref name=":16" /><ref name=":17">Erickson BJ, Frank RM, Harris JD, Mall N, Romeo AA. The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg. 2015;24(6):988-93</ref> A systematic review of 2222 shoulders comparing 135 degrees and 155 degrees prostheses reported higher rates of scapular notching in the 155 degrees group (16.8% vs. 2.8%), improved external rotation in the 135 degrees group, and no difference in instability of forward flexion between groups.<ref name=":17" />

Lastly, in case of fracture, reverse shoulder arthroplasty with a 135 degrees neck shaft angle is associated with higher tuberosity healing rates compared to 145 degrees or 155 degrees.<ref>O'Sullivan J, Lädermann A, Parsons BO, Werner B, Steinbeck J, Tokish JM, Denard PJ. A systematic review of tuberosity healing and outcomes following reverse shoulder arthroplasty for fracture according to humeral inclination of the prosthesis. J Shoulder Elbow Surg. 2020;29(9):1938-49</ref>

=====Onlay vs Inlay=====
Compared to on inlay design, an onlay humeral design with the same 155 degrees inclination increased humeral offset by 6.6 mm.<ref name=":12" /> Acromiohumeral distance varied by 9.8 mm with the smallest occurring with the onlay 135 degrees model and the largest occurring with a Grammont inlay 155 degrees. Compared to the inlay design, an onlay humeral design with the same 155 degrees inclination decreased the acromioclavicular distance by 4.1 mm. Compared to the onlay 155 degrees model, with the inlay 155 degrees model there was a 10 degree decrease (77.8 to 67.9 degrees) in abduction and a 5 degree (range, −15.3 to −20.2 degrees) increase in adduction.<ref name=":12" />

Clinically, Beltrame et al. conducted a prospective clinical study comparing onlay and inlay steams. They found that onlay design 145 degrees may provide better active external rotation, extension, adduction.<ref>Beltrame A, Di Benedetto P, Cicuto C, Cainero V, Chisoni R, Causero A. Onlay versus Inlay humeral steam in Reverse Shoulder Arthroplasty (RSA): clinical and biomechanical study. Acta Biomed. 2019;90(12-S):54-63</ref> However, there are numerous bias in their study (i.e. different neck shaft angle and stem lateralization) that prevent integration of their results in the present analysis.

In a retrospective comparative radiological study, Haidamous et al. showed similarly that an onlay humeral stem design resulted in a 10 mm increase in distalization compared to an inlay humeral stem, and a 2.5 times (11.9% vs 4.7%) increased risk of scapular spine fracture.<ref name=":18" /> It seems thus that the combination of lateralization and distalization in an onlay system dramatically increases the incidence of scapular spine fractures.

Lengthening of the supraspinatus and infraspinatus is systematically observed with an onlay design. It is greatest using onlay stems (7–30%) and lateralized glenospheres (13–31%).<ref name=":11" /> Subscapularis lengthening is observed for onlay stems combined with lateralized glenospheres (5–9%), while excessive subscapularis shortening is observed for the inlay stem combined with all glenospheres except the lateralized design (> 15%).<ref name=":11" />

=====Polyethylene Insert=====
Since inferior impingement between the polyethylene and the scapula is systematic with the arm at the side, another potential way to limit friction and notching in external rotation is to create a notch in the polyethylene inferiorly between 3 and 9 o’clock as it has been done in some prostheses (e.g., Arrow and SMR). Another solution to increase range of motion is to reduce the depth of the polyethylene inlay. De Wilde et al. found that for every 3-mm decrease in depth of polyethylene cup, ROM increased by 12 degrees.<ref>De Wilde LF, Poncet D, Middernacht B, Ekelund A.Prosthetic overhang is the most effective way to prevent scapular conflict in a reverse total shoulder prosthesis. Acta Orthop 2010 81:719-726</ref>

====Discussion====
The literature is controversial with regard to possibilities of regaining range of motion following reverse shoulder arthroplasty. While prosthetic designs are varied and lead to substantial changes in computer models, many of the theoretical advantages have not been confirmed clinically. Table summarizes implant design considerations to improve range of motion. The optimal compromise in range of motion for a primary reverse shoulder arthroplasty without bone loss could be a Lateral Glenoid/Medial (or Intermediate) Humerus design with a low neck shaft angle (145-135 degrees) and an inlay concept. However, all prosthetic designs should be considered on a case-by-case basis to optimize outcome. Glenoid and humeral prosthetic design has to be chosen depending on pre- and intra-operative factors including patient expectations, bone morphology, soft tissue state such as rotator cuff or nerve, approaches, surgical exposure, etc. It may, for example, not be possible to utilize a large glenosphere in all patients as they may not be appropriate for the anatomy of smaller individuals and might be more challenging technically. As a result, the surgeon must continuously weigh the benefits and possibilities of available implant-related variables regarding patient’s specific conditions. The systematic use of patient-specific instrumentation and navigation as well as preoperative determination of components are obviously the next steps in providing more accurate component positioning and size and thus improving range of motion. Despite the advances made by glenoid lateralization and inferiorization, there remains ample opportunity for continued improvement and innovation in prosthetic design.

=Preoperative planning=

Preoperative planning is mandatory as it allows to improve range of motion.<ref>Kolmodin J, Davidson IU, Jun BJ, Sodhi N, Subhas N, Patterson TE, Li ZM, Iannotti JP, Ricchetti ET. Scapular Notching After Reverse Total Shoulder Arthroplasty: Prediction Using Patient-Specific Osseous Anatomy, Implant Location, and Shoulder Motion. J Bone Joint Surg Am. 2018 Jul 5;100(13):1095-1103</ref> To guarantee the best possible functional results, restoration of the appropriate humeral and arm length, a and free range of motion should be the goal.<ref name=":8" /><ref name=":29" /><ref>Renaud P, Wahab H, Bontoux L, Dauty M, Richard I, Bregeon C. [Total inverted shoulder prosthesis and rotator cuff insufficiency: evaluation and determination of anatomical parameters predictive of good functional outcome in 21 shoulders]. Ann Readapt Med Phys 2001 ;44(5):273-80</ref> Even if the available softwares do not take into account soft tissue (stiffness, fatty infiltration,…), they are already able to plan and analyze lateralization and distalization.<ref name=":40" /><ref name=":41" />

=Indications and Contraindications=
==Indications==
Reverse shoulder arthroplasty is a powerful tool that has opened new barriers, especially for reconstructive shoulder surgery. Traditionally, the ideal candidate has been a patient above 70 years old with symptomatic cuff tear arthropathy. Appropriate candidates now include young patients, who have shown excellent clinical improvement with high implant survivorship of up to 10 years.<ref>Black EM, Roberts SM, Siegel E, Yannopoulos P, Higgins LD, Warner JJ. Reverse shoulder arthroplasty as salvage for failed prior arthroplasty in patients 65 years of age or younger. J Shoulder Elbow Surg 2014;23:1036-42</ref><ref>Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: Results after five to fifteen years. J Shoulder Elbow Surg 2013;22:1199-208</ref><ref>Muh SJ, Streit JJ, Wanner JP, Lenarz CJ, Shishani Y, Rowland DY, Riley C, Nowinski RJ, Edwards TB, Gobezie R. Early follow-up of reverse total shoulder arthroplasty in patients sixty years of age or younger. J Bone Joint Surg Am 2013;95:1877-83</ref><ref>Otto RJ, Clark RE, Frankle MA. Reverse shoulder arthroplasty in patients younger than 55 years: 2- to 12-year follow-up. J Shoulder Elbow Surg 2017;26:792-7</ref><ref>Sershon RA, Van Thiel GS, Lin EC, McGill KC, Cole BJ, Verma NN, Romeo AA, Nicholson GP. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg 2014;23:395-400</ref><ref>Walters JD, Barkoh K, Smith RA, Azar FM, Throckmorton TW. Younger patients report similar activity levels to older patients after reverse total shoulder arthroplasty. J Shoulder Elbow Surg2016;25:1418-24</ref>

Many pathologies that could not be treated previously found a solution through this design, and indications are currently expanding. It is now used for various conditions such as failed total shoulder arthroplasty or hemiarthroplasty, complex proximal humeral fractures and defective fracture union or nonunion, chronic locked dislocation, immunological arthritis with or without associated rotator cuff tears, failed or irreparable massive rotator cuff tears, and tumors.<ref>Smith CD, Guyver P, Bunker TD. Indications for reverse shoulder replacement: A systematic review. J Bone Joint Surg [Br] 2012;94:577-83</ref>
===Acute proximal humerus fracture===
Reverse shoulder arthroplasty is a more reliable treatment than hemiarthroplasty for complex proximal humerus fractures at least in elderly patients because its functional outcomes appear to depend less on tuberosity healing and rotator cuff integrity (Figure).<ref>Lädermann A, Chiu J, Collin P, Piotton S, Nover L, Scheibel M. Hemi- vs reverse shoulder arthroplasty for acute proximal humeral fractures: a systematic review of level I and II studies. Obere Extremität 2019;14:127–35</ref>

[[File:Figure 25 Millon.jpg|thumb|center|Reverse shoulder athroplasty for fracture.
Frontal, axial and lateral Lamy radiographs after a reverse total shoulder implant. Note the lower positioning of the glenoid baseplate, the satisfactory reconstruction of the tuberosities, and the absence of cement at the autograft level.]]

===Malunited/nonunited proximal humerus fracture===
Surgical options to address malunited proximal humerus fractures are determined largely by the existing deformity. They can be categorized broadly as humeral head-preserving techniques (e.g. osteotomies, soft-tissue releases and removal of bony protuberances) or humeral head-sacrificing techniques. Amongst the latter, reverse shoulder arthroplasty proved to be the most reliable.

[[File:Malunion Rickenbach.png|thumb|center|Reverse shoulder arthroplasty for malunion of proximal humeral fracture. A) Anteroposterior radiograph of a malunited proximal humerus fracture; B) post-operative radiograph of the fracture sequelae treated with reverse shoulder arthroplasty.]]

===Glenohumeral Osteoarthritis With Severe Glenoid Bone Loss===
The use of reverse shoulder arthroplasty in patients with severe glenoid bone loss and osteoarthritis is the best option. Excellent results have been reported in patients with osteoarthritis, an intact rotator cuff and substantial glenoid bone loss treated with reverse shoulder arthroplasty with or without bone grafting (Video).

[[File:Glenohumeral Osteoarthritis With Severe Glenoid Bone Loss.mp4|thumb|Fifty-one years old patient with right glenoid dysplasia (C glenoid) and an intact rotator cuff. Computed tomography (CT) scan of the shoulder shows 60 degrees of retroversion. The patient has been treated with combined bony and metallic augmentation. At three months follow-up, range of motion improves and imaging reveals satisfactory glenoid reconstruction.]]

===Chronic Locked Glenohumeral Joint Dislocation===
Chronic locked glenohumeral dislocation can also be treated with reverse shoulder arthroplasty (Figure).<ref>Statz JM, Schoch BS, Sanchez-Sotelo J, Sperling JW, Cofield RH.Shoulder arthroplasty for locked anterior shoulder dislocation: a role for the reversed design. Int Orthop. 2017 Jun;41(6):1227-1234</ref>

[[File:Locked dislocation treated by RSA.png|thumb|Locked dislocation of a right shoulder. On the right, postoperative X-ray.]]

===Rheumatoid Arthritis With or Without Associated Rotator Cuff Tears===
Excellent to satisfactory results have been reported for patients with rheumatoid arthritis treated with reverse shoulder arthroplasty. There is no higher complication rates as compared to reverse shoulder arthroplasty in cuff tear arthropathy.<ref>Cho CH, Kim DH, Song KS. Reverse Shoulder Arthroplasty in Patients with Rheumatoid Arthritis: A Systematic Review. Clin Orthop Surg. 2017 Sep;9(3):325-331</ref>

===Revision Arthroplasty===
Revision surgery after primary shoulder arthroplasty (i.e. hemiarthroplasty, resurfacing or total shoulder arthroplasty) produced high patient satisfaction (Figure). It is, however, associated with higher complication and failure rates compared to reverse shoulder arthroplasty for patients without previous arthroplasty.<ref>Gauci MO, Cavalier M, Gonzalez JF, Holzer N, Baring T, Walch G, Boileau P. Revision of failed shoulder arthroplasty: epidemiology, etiology, and surgical options. J Shoulder Elbow Surg. 2019 Oct 6. pii: S1058-2746(19)30531-2</ref>

[[File:Pitacollo TSA-RSA.jpg|thumb|center|A) Anteroposterior radiograph of a failed anatomic total shoulder arthroplasty; B) Anteroposterior post-operative radiograph after reverse shoulder arthroplasty.]]

===Tumours===
Reverse shoulder arthroplasty is an acceptable option for patients after wide resection of the proximal humerus and rotator cuff tendons for malignant bone tumours. However, a prerequisite for the ability to implant a reverse shoulder arthroplasty in these cases requires preservation of the axillary nerve and deltoid muscle to be successful.<ref>Bonnevialle N, Mansat P, Lebon J, Laffosse JM, Bonnevialle P. Reverse shoulder arthroplasty for malignant tumors of proximal humerus. J Shoulder Elbow Surg. 2015 Jan;24(1):36-44.</ref><ref name=":23" />

==Contraindications==
Absolute contraindications include general factors such as non compliance patients (severe psychiatric/neurologic disability, substance abuse), neuro-arthropathies (Charcot) and high patient morbidity (ASA 4+), and local factors like an uncontrolled active infection and substantial deltoid insufficiency because of the very high probability of recurrent instability and the minimal potential gain in function.<ref name=":23" />

=Clinical Practice Guideline=
The goal of this section is to provide clinicians with recommendations based on the best available evidence; to inform clinicians of when there is no evidence; and finally, to help clinicians deliver the best health care possible.

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=Approaches=
==Introduction==
Reverse shoulder arthroplasty can be performed through several approaches, the deltopectoral and anterosuperior being the most common, each with their advantages and disadvantages. The preparation is standardized for all approaches. The patient lies in the beach chair position with a 60° tilt of the chest, at the lateral extremity of the table, leaving the anterior and posterior sides of the shoulder free from obstruction. The elbow must be free from any support to enable the operating assistant to apply a proximally directed force at the elbow allowing proximal subluxation of the humeral head. The front arm rests on an armrest and is draped free.

==Deltopectoral Approach==
The deltopectoral approach allows increased visibility and accessibility of the humerus, better positioning of the glenoid component, reduced implant loosening and scapular notching, and does not compromise the deltoid, which is the important motor of the shoulder. This approach tenotomises the subscapularis or osteotomizes the lesser tuberosity. Failure (observed in 45% of cases, Collin, unpublished data) and dysfunction of the repaired subscapularis remains a concern after both tenotomy and lesser tuberosity osteotomy despite multiple variations in subscapularis takedown and reattachment techniques. Neurologic atrophy and fatty infiltration of the subscapularis muscle belly have been also reported to causes pain and impaired function.

===Surgical technique===
The deltopectoral approach consisted of a 10 to 15 cm skin incision being made from the coracoid process toward the deltoid insertion. The infraclavicular fossa (Mohrenheim fossa) is found, the cephalic vein identified and the consistent medial branches, which give the appearance of the Mercedes Benz symbol, are ligated. A self-retaining retractor is used to maintain exposure between the deltoid and pectoralis major. The subacromial bursa was resected to allow placement of a Hohmann retractor under the deltoid over the top of the coracoid process. The arm was abducted and internally rotated. The subacromial bursa is resected to allow placement of a Brown-Deltoid retractor.

====Subscapularis Tenotomy====
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====Osteotomy of the Lesser Tuberosity====
The osteotomy is initiated at the bicipital groove with a 2-mm saw blade and then completed with a curved osteotome. An approximately 2.5 cm2 in the coronal plane and 5 mm thick fleck of lesser tuberosity is taken such that the osteotomy entered the joint medially without violating the humeral head.<ref>Giuseffi SA, Wongtriratanachai P, Omae H, Cil A, Zobitz ME, An KN, Sperling JW, Steinmann SP. Biomechanical comparison of lesser tuberosity osteotomy versus subscapularis tenotomy in total shoulder arthroplasty. J Shoulder Elbow Surg 2012;21:1087-95.</ref><ref>Ponce BA, Ahluwalia RS, Mazzocca AD, Gobezie RG, Warner JJ, Millett PJ. Biomechanical and clinical evaluation of a novel lesser tuberosity repair technique in total shoulder arthroplasty. J Bone Joint Surg Am 2005;87(Suppl 2):1-8</ref>

A complete release of the subscapularis tendon is then performed and the tendon is pushed in the subscapularis fossa. A glenoid retractor is placed anteriorly. The humeral head is resected with a guide or a free-handed anatomic cut respecting native humeral head version and inclination.

====Subscapularis Repair====
The healing rate of the subscapularis following reverse shoulder arthroplasty is only 52.6%.<ref>Collin P, Rol M, Muniandy M, Gain S, Lädermann A, Ode G. Relationship between postoperative integrity of subscapularis tendon and functional outcome in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2021;30;S1058-2746(21)00523-1</ref> Internal rotation function in patients with an intact subscapularis at two years after reverse shoulder arthroplasty is significantly better than in patients with failed or absent tendon repairs. Primary repair of reparable subscapularis tendons during reverse shoulder arthroplasty should be thus strongly considered.

====Lesser Osteotomy Repair====
Before placement of the humeral stem, two holes are created with a 2-mm drill bit in the bicipital groove at the superior and inferior aspects of the lesser tuberosity osteotomy. One hole was created in the metaphysis just medial to the lesser tuberosity osteotomy. The sutures are then passed from lateral to medial by entering the bicipital groove, passing around the humeral stem, and exiting medially (Figure). A racking hitch is positioned to rest in the bicipital groove. The two sutures are passed through the subscapularis just medial to the lesser tuberosity osteotomy. The needle is removed from each construct to leave two superior and two inferior limbs (Figure). Then, one of the superior limbs and one of the inferior limbs were shuttled through the superior racking hitch knot (Figure). The suture limbs are passed through a tensioner to remove slack and to tension the repair (Figure).

{| class="wikitable"
|-
|[[File:Capture d’écran 2020-03-28 à 08.56.41.png|thumb|Passage of the sutures. A suture with a half racking suture on the end is passed from lateral to medial through the inferior two holes, and (B) a separate suture is passed through the superior hole.]]
|[[File:Capture d’écran 2020-03-28 à 08.57.27.png|thumb|Passage of the sutures through the subscapularis and needle removal. The stem is placed so that the sutures pass around the prosthesis. (A) The sutures are passed through the subscapularis tendon, and (B) the wedged ends are cut to provide access to four free limbs.]]
|-
|[[File:Capture d’écran 2020-03-28 à 08.58.02.png|thumb|Passage of the sutures through the knots. (A) One suture limb from each pair is selected and (B) passed through the half racking suture.]]
|[[File:Capture d’écran 2020-03-28 à 08.58.27.png|thumb|Tensioning of the sutures. The suture limbs passed through the half racking suture are tensioned. Tensioning is done under visual inspection.]]
|}

==Anterosuperior (Transdeltoid) Approach==
Molé et al. reported superolateral approach that has the main advantage of better post-operative stability, because the anterior structures, including ligament complexes, are preserved.<ref>Molé D, Wein F, Dézaly C, Valenti P, Sirveaux F. Surgical technique: the anterosuperior approach for reverse shoulder arthroplasty. Clin Orthop Relat Res. 2011 Sep;469(9):2461-8</ref> This approach is different from the transacromial approach originally described by Grammont and Baulot<ref name=":35">Grammont PM, Baulot E. Delta shoulder prosthesis for rotator cuff rupture. Orthopedics 1993;16:65-8</ref> and the anterosuperior approach described by Mackenzie.<ref>Mackenzie D. The antero-superior exposure for total shoulder replacement. Orthop Traumatol 1993;2:71-7</ref> While this technique has shown good results, it involves splitting of the deltoid muscle with the risk of weakening of the anterior deltoid (mechanical or neurologic by damage to the distal branches of axillary nerve) and improper postoperative function.

===Surgical technique===
The skin incision extends from the posterior part of the acromioclavicular joint. It is 9 cm long and runs along the axis of the arm. The surgeon dissociates the anterior deltoid fibers and positions a stop suture on the distal portion of the dissociation to prevent any injury of the axillary nerve. The deltoid muscle fibers are divided to open and excise the subacromial bursa and the anterior deltoid from the anterior edge of the acromion and takes away the proximal attachment of the coracoacromial ligament as one piece. The humeral head osteotomy should be generous to allow optimal exposure of the glenoid. Glenoid exposure is completed, labrum is resected, and peripheral capsular release performed. The inferior labrum is carefully released with a knife while maintaining contact with the bony rim and avoiding electric cautery, considering the proximity of the axillary nerve, which is not visualized. This allows the positioning of a hooked retractor that presses the humeral epiphysis, which is protected by a trial humeral prosthesis. Once the glenoid implant is in place, the surgeon subluxates the humerus superiorly and anteriorly and cuffs the trial humeral stem with a trial insert; the reduction enables the surgeon to test the stability and tension. At the end of surgery, the deltoid is closed using laterolateral sutures.

==Deltoid and Subscapularis Sparing Approach (Subscapularis On)==
Indications for subscapularis-on approach were all types of primary reverse shoulder with an intact subscapularis.

[[File:SSc sparing reduit.mp4|thumb|center|Illustrates a right subscapularis-on RSA with superior glenoid erosion.]]

===Surgical technique===
The skin incision extends from the tip of the coracoid process and runs along the axis of the arm. A deltopectoral approach is performed (please refer to deltopectoral approach). After excision of the bursa, the surgeon explores the cuff through rotator interval. Once an intact subscapularis is confirmed, deep dissection is carried out either through the supraspinatus tear or after detaching it. With the arm held in extension and adduction, two long blunt-tipped Hohmann retractors are placed around the humeral head, allowing clear exposure of the proximal humerus (Figure).

[[File:Fig 2.jpg|thumb|center|Illustration: With the arm held in extension and adduction, two long broad-tipped Hohmann retractors are placed around the humeral head, retracting the subscapularis and the remnant posterior rotator cuff, allowing clear exposure of the humeral head.]]

The humerus is prepared to accommodate a stem. After a retroversion guide placement, the level of the humeral head osteotomy is marked with an electrocautery device (Figure), and a free-hand osteotomy is performed. The humeral head osteotomy should be generous to allow optimal exposure of the glenoid.

[[File:Fig 3.jpg|thumb|center|A 20 degrees retroversion guide is placed and the level of the osteotomy is marked on the humeral head with an electrocautery device.]]

The humeral shaft is then prepared (Figure).

[[File:Fig 4.jpg|thumb|center|Following humeral head removal, preparation of the humeral shaft is completed using only compactors.]]

If the initial osteotomy is too shallow or the inclination is suboptimal, it is then revised to maximize the anatomic fit between the prosthesis and the bone. After preparing the humerus, a trial humeral prosthesis is inserted in humeral canal to protect the humeral epiphysis during glenoid preparation. Cartilage removal, labrum resection, and peripheral capsular release are then completed sequentially. Tight inferior glenohumeral ligaments, which may prevent adequate exposure of the glenoid or post-operative shoulder mobility, are released using an electrocautery device with close contact with the inferior glenoid rim. A forked retractor is then inserted inferiorly to maintain visualization and accessibility to the glenoid (Figure).

[[File:Fig 5.jpg|thumb|center|A forked retractor is placed inferior to the glenoid to maintain visualization and accessibility. The glenoid is prepared according to the recommended surgical technique to obtain neutral inclination and version.]]

This maneuver pushes the humeral epiphysis inferiorly or antero-inferiorly (compared to standard deltopectoral approach in which the humeral head is dislocated posteriorly) for better visualization of the glenoid. The glenoid is prepared according to the recommended surgical technique to obtain neutral inclination and version. Preoperative planning software is used to determine the amount of inferior tilt and whether an augmented baseplate is required. The baseplate is secured onto the glenoid with non-locking and locking peripheral screws. An eccentric 36 or 39 mm glenosphere is used to limit impingement in adduction, extension and external rotation. It is not recommended implanting a larger glenosphere as the excessive lateralization may hinder access to the humerus. The glenosphere is impacted into the baseplate. Once the glenoid implant is in place, the surgeon subluxs the humerus superiorly and anteriorly. A stem is inserted. The shoulder is reduced via gentle traction on the arm and range of motion tested in all planes to ensure stability and confirm the prosthesis moves easily without impingement. The prothesis is then dislocated for final implantation of a definitive polyethylene. Osteophytes are removed and lateral tuberoplasty can be performed to maximize flexibility and avoid bony impingement. The surgical incision measures about 7 to 10 cm (Figure).

[[File:Fig 6 améliorée.jpg|thumb|center|Length of the surgical incision.]]

===Postoperative Rehabilitation===
By using this subscapularis-on approach, patients do not require any immobilization with a sling following the operation. Immediate active motion in all planes is allowed post-operatively.

===Complications===
Tuberosity avulsions that require suture cerclage can bee observed (Figure).

[[File:Figure 8.jpg|thumb|center|A) Example of tuberosity avulsions (black arrows) requiring 3 suture cerclages. B) Tuberosity healing was observed at two-year follow-up. ]]

===Advantages of Subscapularis-on Approach===
There are several reasons why the integrity of the subscapularis tendon should be maintained when performing a reverse shoulder arthroplasty. First, acute muscle lengthening related to the non-anatomic design of the prosthesis plays a role. The muscle lengthening occurs mainly in the supraspinatus (19 mm with a bony increased offset reverse shoulder arthroplasty (BIO-RSA) implant), followed by the upper part of the subscapularis, which accounts for 70% or more of the strength and function of the subscapular muscle-tendon unit. Muscle lengthening could theoretically make reinsertion of the subscapularis more challenging, particularly with lateral offset designs.
Secondly, the inferior part of the subscapularis has no tendon macroscopically; the muscle attaches directly to the bone, making reinsertion difficult. Healing rate is consequently low, at around 55%. Thirdly, the subscapularis is described as being the largest muscle in the rotator cuff and stronger (53% of global strength of the rotator cuff) than the supraspinatus, infraspinatus and teres minor combined.<ref name=":33">Keating JF, Waterworth P, Shaw-Dunn J, Crossan J. The relative strengths of the rotator cuff muscles. A cadaver study. J Bone Joint Surg Br 1993;75:137-40</ref> If a muscle has to be divided, it seems logical to sacrifice the supraspinatus that accounts for only 14% of the global strength.<ref name=":33" /> Fourth, the subscapularis plays a crucial role in anterior elevation. Collin et al. previously demonstrated that the subscapularis is the most important rotator cuff muscle for elevation in native shoulders.<ref>Collin P, Matsumura N, Lädermann A, Denard PJ, Walch G. Relationship between massive chronic rotator cuff tear pattern and loss of active shoulder range of motion. J Shoulder Elbow Surg 2014;23:1195-202</ref>

===Disadvantages of Subscapularis-on Approach===
The main disadvantage of the subscapularis-on technique is limited surgical exposure. Even though specialized jigs were not required for the above-mentioned technique, the development of specifically-designed instrumentation for this procedure seems necessary. Moreover, limited exposure prevents the use of patient-specific surgical guides. Development of less invasive guides or navigation systems may become inevitable in the future. Even if good exposure of the humeral head is achieved, the free-hand humeral osteotomy can be problematic. Subscapularis-on approach is technically challenging in certain cases (e.g. stiff shoulders, small patients) and may not be practical or possible in all circumstances. Intra-operatively, important lateralization (> 5 mm) of the glenoid is impossible, as subsequent exposure of the humerus is insufficient to implant the stem.

=Specific Conditions=
==Reverse Shoulder Arthroplasty in Patients with Preoperative Deltoid Impairment==
===Definition, Causes, and Classification of Deltoid Impairment===
The deltoid is critical for shoulder motion and any pathology involving this muscle is highly detrimental to normal glenohumeral function. It generates over 50% of the force necessary to elevate the arm in scapula plane in a normal shoulder and is the only muscle remaining to provide an abduction moment in patients with massive rotator cuff tears.<ref>Bianchi S, Martinoli C, Abdelwahab IF. Imaging findings of spontaneous detachment of the deltoid muscle as a complication of massive rotator cuff tear. Skeletal radiology 2006;35:410-5</ref> Deltoid impairment is defined as any condition which compromise its physiological function. Such impairment may be permanent or transient and can occur from a variety of conditions.

The deltoid muscle may be shortened upon itself and lose function by disruption of normal length-tension relationships (Figure).

[[File:Image21-57.jpg|thumb|center|Proximal migration of the humeral head leads to a lack of deltoid tension.]]

Effectively, as the Blix curve describes, maintenance of length is required for a muscle to generate adequate tension.<ref>Blix M. Die lange und dle spannung des muskels. Skand Arch Physiol 1891:295-318</ref> Therefore shortening either by proximal migration of the deltoid insertion (rotator cuff arthropathy) or distal migration of the origin (scapular spine fracture) will compromise deltoid function. Proximal migration in particular can be considered a transient cause of deltoid impairment since it can be treated with reverse shoulder arthroplasty. Distal migration, on the other hand, may be permanent or transient depending on the situation.

In the most severe conditions, part or all of the deltoid muscle may be completely absent. Such permanent impairment is rare but may be observed following deltoid muscular flap transfer (for irreparable rotator cuff tears, Figure)<ref>Gazielly D. The deltoid flap procedure. Tech Shoulder Elbow Surg 2000:117–27</ref><ref name=":42">Glanzmann MC, Flury M, Simmen BR. Reverse shoulder arthroplasty as salvage procedure after deltoid muscle flap transfer for irreparable rotator cuff tear: a case report. J Shoulder Elbow Surg 2009;18:e1-2</ref><ref name=":20">Tay AK, Collin P. Irreparable spontaneous deltoid rupture in rotator cuff arthropathy: the use of a reverse total shoulder replacement. J Shoulder Elbow Surg 2011;20:e5-8</ref> or following tumor resection (Figure).

[[File:Image22-59.jpg|thumb|center| Status after a left deltoid muscular flap transfer for irreparable rotator cuff tears. A: Schematic drawing of the surgical technique (with permission of Gazielly D.). B: Frontal magnetic resonance imaging demonstrates absence of the deltoid muscle laterally. C. Clinical photo demonstrating atrophy of the anterior and middle deltoid.]]

[[File:Image23-61.jpg|thumb|center|A: Intraoperative view of a left anterior deltoid resection in the context of proximal humerus neoplasm. Isolation of the anterior deltoid through which an open biopsy had previously been performed. B: Resection of the entire anterior deltoid and proximal humerus. C: Intraoperative view following implantation of a reverse shoulder arthroplasty. D: Postoperative anterior-posterior radiograph.]]

One of the most common forms of deltoid impairment seen clinically is disruption of the muscle origin (without removal of the entire muscle belly). This most commonly occurs in the postsurgical setting after an open rotator cuff repair in which a deltoid split approach is used and part of the deltoid origin is take-down to gain exposure (Figure).<ref>Sher JS, Iannotti JP, Warner JJ, Groff Y, Williams GR. Surgical treatment of postoperative deltoid origin disruption. Clin Orthop Relat Res 1997:93-8</ref>

[[File:Image24-63.jpg|thumb|center|Sequelae of a right open rotator cuff repair involving violation of the deltoid insertion. A: clinical appearance with an anterior deltoid with severe atrophy. B: Anterior-posterior radiograph demonstrating rotator cuff arthropathy. C: Postoperative anterior-posterior view of the reverse shoulder arthroplasty. D and E: Coronal and sagittal views of postoperative anterior forward elevation.]]

Failure of the deltoid to heal back to the acromion can easily be appreciated clinically by a defect to palpation. Additionally, deltoid insertion disruption can occur through chronic attritional rupture as in chronic rotator cuff arthropathy with anterosuperior escape,<ref>Blazar PE, Williams GR, Iannotti JP. Spontaneous detachment of the deltoid muscle origin. J Shoulder Elbow Surg 1998;7:389-92</ref><ref>Morisawa K, Yamashita K, Asami A, Nishikawa H, Watanabe H. Spontaneous rupture of the deltoid muscle associated with massive tearing of the rotator cuff. J Shoulder Elbow Surg 1997;6:556-8</ref> or following trauma (Figure).<ref>Chiba D, Sano H, Nakajo S, Fujii F. Traumatic deltoid rupture caused by seatbelt during a traffic accident: a case report. Journal of orthopaedic surgery 2008;16:127-9</ref><ref>Lin JT, Nagler W. Partial tear of the posterior deltoid muscle in an elderly woman. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine 2003;13:120-1</ref>

[[File:Image25-65.jpg|thumb|center|Evaluation in an acute phase of left posterior deltoid insertion disruption on T2 weighted fat saturated magnetic resonance imaging (MRI) arthrogram sagittal sequences revealed an edema (red arrows) propagating into the muscle.]]

The deltoid muscle may be globally impaired in the setting of persistent denervation,<ref>Wilbourn AJ, Aminoff MJ. AAEM minimonograph 32: the electrodiagnostic examination in patients with radiculopathies. American Association of Electrodiagnostic Medicine. Muscle Nerve 1998:1612-31</ref> grade 3 or 4 fatty infiltration,<ref>Goutallier D, Postel JM, Bernageau J, Lavau L, Voisin MC. Fatty muscle degeneration in cuff ruptures. Pre- and postoperative evaluation by CT scan. Clin Orthop Relat Res 1994:78-83</ref> previous surgical approach, trauma (Figure), post radiation syndrome, or myopathy (myositis, Parkinson, Duchenne muscular dystrophy, etc.).<ref>Moser T, Lecours J, Michaud J, Bureau NJ, Guillin R, Cardinal E. The deltoid, a forgotten muscle of the shoulder. Skeletal radiology 2013;42:1361-75</ref>

[[File:Image29-73.jpg|thumb|Preoperative (A, anterior-posterior and B, lateral scapular views) and post reverse shoulder arthroplasty (C anterior-posterior view) of a right shoulder after a gunshot in a patient that presented post-traumatically with global neurological impairment including the axillary nerve.]]

Once the etiology is determined, the deltoid impairment should be then classified according to its location and extent. Lädermann et al.<ref name=":23">Lädermann A, Walch G, Denard PJ, Collin P, Sirveaux F, Favard L, Edwards TB, Kherad O, Boileau P. Reverse shoulder arthroplasty in patients with pre-operative impairment of the deltoid muscle. The bone & joint journal 2013;95-B:1106-13</ref> proposed a classification for deltoid impairment based on location: type 1 corresponds to an impairment localized anteriorly, type 2 an anterior and middle one, type 3 involves only the middle deltoid, and type 4 is a global impairment (Figure). As discussed subsequently, this classification related to prognosis with type 4 in particular having a poorer function following reverse shoulder arthroplasty.

[[File:Classification atteinte deltoid.jpg|thumb|center|Deltoid impairment based on location: type 1 corresponds to an impairment localized anteriorly, type 2 an anterior and middle one, type 3 involves only the middle deltoid, and type 4 is a global impairment. ]]

====Results====
Glanzmann et al. first published a case report of the results of a reverse shoulder arthroplasty after deltoid muscle flap transfer.<ref name=":42" /> At two years follow-up, the patient was satisfied and had a Constant score of 62 points, suggesting that the entire deltoid may not be necessary for a successful outcome. Tay and Collin also described successful results of a reverse shoulder arthroplasty implanted in the setting of an irreparable rupture of the middle portion of the deltoid muscle.<ref name=":20" /> No intra- or postoperative complication was noticed. At two years follow-up, the patient was pain free, had active anterior elevation of 150 degrees, and the Constant score was 65 points. Gulotta et al. reported in their biomechanical study that scapular plane elevation may still be possible following a reverse shoulder arthroplasty in the setting of anterior deltoid deficiency. When the anterior deltoid is deficient, there is a compensatory increase in the force required by the subscapularis and middle deltoid.<ref>Gulotta LV, Choi D, Marinello P, Wright T, Cordasco FA, Craig EV, Warren RF. Anterior deltoid deficiency in reverse total shoulder replacement: a biomechanical study with cadavers. J Bone Joint Surg Br 2012;94:1666-9</ref> In this condition, surgeons should focus on preserving the subscapularis as much as possible during approach of reverse shoulder arthroplasty. Whatley et al. reported three cases who had postoperative rupture of the anterolateral deltoid following failed mini-open or open rotator cuff repairs. Successful repair of the deltoid was achieved using a transosseous suture repair in all three patients.<ref>Whatley AN, Fowler RL, Warner JJ, Higgins LD. Postoperative rupture of the anterolateral deltoid muscle following reverse total shoulder arthroplasty in patients who have undergone open rotator cuff repair. J Shoulder Elbow Surg 2011;20:114-22</ref> Essilfie et al. presented a case with deltoid failure after anatomical total shoulder arthroplasty revised with reverse shoulder arthroplasty. His ASES score after reverse shoulder arthroplasty was better than historical outcomes for resection arthroplasty and glenohumeral arthrodesis.<ref>Essilfie A, McKnight B, Heckmann N, Rick Hatch GF, 3rd, Omid R. Revision reverse total shoulder arthroplasty in a patient with preoperative deltoid insufficiency: a case report. J Shoulder Elbow Surg 2017;26:e232-e5</ref> Lattisimus dorsi muscle transfer can also provide an augmentation in patients with deltoid insufficiency.<ref name=":43">Dosari M, Hameed S, Mukhtar K, Elmhiregh A. Reverse shoulder arthroplasty for deltoid-deficient shoulder following latissimus dorsi flap transfer. Case report. Int J Surg Case Rep 2017;39:256-9</ref><ref>Goel DP, Ross DC, Drosdowech DS. Rotator cuff tear arthropathy and deltoid avulsion treated with reverse total shoulder arthroplasty and latissimus dorsi transfer: case report and review of the literature. J Shoulder Elbow Surg 2012;21:e1-7</ref> Dosari et al. presented a patient with a history of gunshot injury and loss of most of his shoulder bony and muscular structures. Due to deltoid muscle deficiency, the patient underwent lattisimus dorsi muscle flap followed by reverse shoulder arthroplasty with successful result.<ref name=":43" /> Deltoid reconstruction at the same time of reverse shoulder arthroplasty is also a viable choice as a salvage procedure for patients with deltoid deficiency.<ref name=":25">Marinello PG, Amini MH, Peers S, O'Donnell J, Iannotti JP. Reverse total shoulder arthroplasty with combined deltoid reconstruction in patients with anterior and/or middle deltoid tears. J Shoulder Elbow Surg 2016;25:936-41</ref> Marinello suggested if less than 50% of any part of the anterior or middle deltoid was involved (≤3 cm), reattachment or reconstruction was not needed. If all of the anterior and/or middle deltoid were involved, then reattachment or reconstruction was indicated.<ref name=":25" /> In a multicentered study, Lädermann et al. reviewed 49 patients (49 shoulders) at a mean of 38 ± 30 months postoperative following reverse shoulder arthroplasty in the setting of deltoid impairment.<ref name=":23" /> Postoperative complications occurred in nine (18%) patients, including two postoperative dislocations and two acute postoperative neurological lesions. Five (10%) patients required additional surgery. Active forward elevation and Constant score improved significantly. However, these values are significantly lower for patients suffering from global deltoid impairment (type 4) compared to types 1 through 3. The mean postoperative forward elevation was lower in the setting of global deltoid impairment (70 degrees) compared to partial impairment (127 degrees, 136 degrees and 125 degrees, groups 1-3 respectively) (P=.002). The postoperative Constant score was lower in the setting of global impairment (41) compared to partial impairment (57, 63 and 68, groups 1-3 respectively) (P=.006). Overall, the rate of patient satisfaction was 98% at final follow-up.<ref name=":23" /> Schneeberger et al. retrospectively reviewed the outcome of 19 patients treated with reverse shoulder arthroplasty after failed deltoid flap reconstruction.<ref>Schneeberger AG, Muller TM, Steens W, Thur C. Reverse total shoulder arthroplasty after failed deltoid flap reconstruction. Arch Orthop Trauma Surg 2014;134:317-23</ref> They noticed a high rate of complication (37%), including one instability. Nonetheless, at a mean follow-up of 4.5 years, only two patients had moderate to severe pain, all patients regained anterior active elevation above 90 degrees, and 15 of 19 patients were very satisfied.

It seems that the most important factor for postoperative result is the extent of the lesion, and not its cause. Interestingly, patient satisfaction is high in all publications on reverse shoulder arthroplasty in the setting of deltoid impairment. However, this is likely related to very poor preoperative function and moderate preoperative expectations of this population.

==Acromial Insufficiency==
Pre- or postoperative acromial pathology, which could theoretically compromise deltoid condition and affect the proper function of the prosthesis, is of legitimate concern.

===Preoperative===
Postoperative fractures occur at least in 3% of cases and their causes are numerous. Preoperatively, the acromion may be subject to a congenital or acquired abnormality such as an os acromiale. It can also already be eroded, fragmented or even fractured from the underlying head in case of cuff tear arthropathy (Figure), or osteoporosis-induced insufficiency.

[[File:Image37-89.jpg|thumb|center|Preoperative insufficiency of a left acromion on an anteroposterior view. Note that a large part of the acromion just seems to have disappeared.]]

[[File:Bouvier.jpg|thumb|center|Preoperative spine fracture in a patient suffering from rotator cuff arthropathy with severe Glenoid bone loss.]]

===Postoperative===
It has been suggested that these fractures may be the result of a stress coming from the tip of the superior metaglene fixation screw.<ref name=":34">Crosby LA, Hamilton A, Twiss T. Scapula fractures after reverse total shoulder arthroplasty: classification and treatment. Clin Orthop Relat Res 2011;469:2544-9</ref> Another risk factor is osteoporosis<ref>Otto RJ, Virani NA, Levy JC, Nigro PT, Cuff DJ, Frankle MA. Scapular fractures after reverse shoulder arthroplasty: evaluation of risk factors and the reliability of a proposed classification. J Shoulder Elbow Surg. 2013 Nov;22(11):1514-21</ref><ref name=":24">Schenk P, Aichmair A, Beeler S, Ernstbrunner L, Meyer DC, Gerber C. Acromial Fractures Following Reverse Total Shoulder Arthroplasty: A Cohort Controlled Analysis. Orthopedics. 2020 Jan 1;43(1):15-22</ref> The role of prosthetic design, distalization, global lateralization and Glenoid medicalization is still debated.<ref name=":24" /><ref>Wong MT, Langohr GDG, Athwal GS, Johnson JA. Implant positioning in reverse shoulder arthroplasty has an impact on acromial stresses. J Shoulder Elbow Surg. 2016 Nov;25(11):1889-1895</ref>

Acromial fractures can be classified as avulsion fractures of the anterior acromion (Type I), fractures of the acromion posterior to the acromioclavicular joint (Type II) and fractures of the scapular spine (Type III).<ref name=":34" />

The symptomatology usually appears within the first year with sudden pain and decrease of function. The localization of the former is typically posterior. The fracture is best seen on an axillary lateral view to differentiate acromial fracture from scapular spine fracture (Figure).

[[File:Acromial fracture.png|thumb|center|Postoperative anteroposterior X-ray demonstrate an acromial fracture.]]

The use of positron emission tomography-computed tomography is helpful in diagnosis of non-displaced fractures.

[[File:SPECT CT acromial fracture.png|thumb|center|SPECT CT of a left shoulder after a reverse shoulder arthroplasty. The patient developed pain 6 months after surgery. X-ray did not revealed fracture. SCPECT CT clearly demonstrated a hypersignal on the acromion.]]

Good results have surprisingly been reported in patients with preoperative acquired or congenital acromial pathology or postoperative acromial fracture.<ref>Mottier F, Wall B, Nove-Josserand L, Galoisy Guibal L, Walch G. [Reverse prosthesis and os acromiale or acromion stress fracture]. Rev Chir Orthop Reparatrice Appar Mot 2007;93:133-41</ref> This can be explained by the persistent attachment of the deltoid to the spine of the scapula and clavicle and the more predominant postoperative scapulothoracic motion compared to the glenohumeral one. In case of postoperative acromial or scapular fractures, results are usually disappointing.<ref>Neyton L, Erickson J, Ascione F, Bugelli G, Lunini E, Walch G. Grammont Award 2018: Scapular fractures in reverse shoulder arthroplasty (Grammont style): prevalence, functional, and radiographic results with minimum 5-year follow-up. J Shoulder Elbow Surg. 2019 Feb;28(2):260-267</ref>

The best treatment option for acromial fractures is thus conservative, as it does not lead to major shoulder dysfunction. Outcome of scapular spine fractures are more unpredictable with displacement of the bony support for the entire deltoid, pain and dysfunction. Consequently, some authors recommend open reduction, internal fixation and allograft associated with postoperative immobilization on a 60° abduction splint in order to avoid nonunion and acromiohumeral contact secondary to inferior acromial tilt.<ref name=":34" />

==Latissimus Dorsi Transfert in Combination with the Reverse Shoulder Arthroplasty==
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==Reverse Shoulder Arthroplasty in Weight Bearing Patients==
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=Results=
With a mean anterior forward flexion of 137 degrees and a mean external rotation elbow at the side of 6 degrees, reverse shoulder arthroplasty typically provides satisfactory clinical outcomes for a variety of complex shoulder diagnoses associated with severe pain and limitation of range of motion.<ref name=":26">Wall B, Nove-Josserand L, O'Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am 2007;89:1476-85</ref> However, some patients have had unexpectedly poor functional improvements after reverse shoulder arthroplasty.<ref name=":26" /> Poor postoperative range of motion following reverse shoulder arthroplasty, has been associated with younger age,<ref name=":44">Hartzler RU, Steen BM, Hussey MM, Cusick MC, Cottrell BJ, Clark RE, Frankle MA. Reverse shoulder arthroplasty for massive rotator cuff tear: risk factors for poor functional improvement. J Shoulder Elbow Surg 2015;24:1698-706</ref> gender,<ref name=":45">Schwartz DG, Cottrell BJ, Teusink MJ, Clark RE, Downes KL, Tannenbaum RS, Frankle MA. Factors that predict postoperative motion in patients treated with reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2014 Sep;23(9):1289-95</ref> surgeon experience,<ref>Walch G, Bacle G, Lädermann A, Nové-Josserand L, Smithers CJ. Do the indications, results, and complications of reverse shoulder arthroplasty change with surgeon's experience? J Shoulder Elbow Surg. 2012 Nov;21(11):1470-7</ref> preoperative diagnosis such as posttraumatic arthritis and revision arthroplasty,<ref>Cuff D, Pupello D, Virani N, Levy J, Frankle M. Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency. J Bone Joint Surg Am 2008;90:1244-51.</ref><ref name=":26" /> pre- and intraoperative range of motion or deltoid impairment,<ref name=":23" /><ref name=":45" /> postoperative arm lengthening<ref name=":32" /><ref>Lädermann A, Lubbeke A, Collin P, Edwards TB, Sirveaux F, Walch G. Influence of surgical approach on functional outcome in reverse shoulder arthroplasty. Orthopaedics & traumatology, surgery & research : OTSR 2011;97:579-82</ref><ref name=":30" /> or neurological lesion.<ref name=":44" /><ref name=":46">Lädermann A, Lübbeke A, Mélis B, Stern R, Christofilopoulos P, Bacle G, Walch G. Prevalence of neurologic lesions after total shoulder arthroplasty. J Bone Joint Surg Am 2011;93:1288-93</ref> Surgery of the non-dominant side, lower preoperative range of motion, and lower functional outcome scores preoperatively are predictive of a slower recovery of active anterior forward flexion after reverse shoulder arthroplasty.<ref>Collin P, Matsukawa T, Denard PJ, Gain S, Lädermann A.Pre-operative factors influence the recovery of range of motion following reverse shoulder arthroplasty. Int Orthop. 2017 Oct;41(10):2135-2142</ref>

=Complications=
The first series of reverse shoulder arthroplasty with an at least two years follow-up, confirmed the preliminary results with excellent functional outcome and stable glenoid fixation.<ref name=":36" /> Beck S, Patsalis T, Busch A, Dittrich F, Dudda M, Jäger M, Wegner A. A substantial and durable improvement in the long term has been reported.<ref>Beck S, Patsalis T, Busch A, Dittrich F, Dudda M, Jäger M, Wegner A. Long-term results of the reverse Total Evolutive Shoulder System (TESS). Arch Orthop Trauma Surg. 2019 Aug;139(8):1039-1044</ref><ref>Ernstbrunner L, Rahm S, Suter A, Imam MA, Catanzaro S, Grubhofer F, Gerber C. Salvage reverse total shoulder arthroplasty for failed operative treatment of proximal humeral fractures in patients younger than 60 years: long-term results. J Shoulder Elbow Surg. 2019 Oct 6. pii: S1058-2746(19)30537-3.</ref><ref>van Ochten JHM, van der Pluijm M, Pouw M, Felsch QTM, Heesterbeek P, de Vos MJ. Long - Term survivorship and clinical and radiological follow - up of the primary uncemented Delta III reverse shoulder prosthesis. J Orthop. 2019 Mar 24;16(4):342-346</ref> However, the complexity of this procedure with regards to its singular anatomy and special patient population, is reflected by the large number of reported problems and complications. As defined by Zumstein et al., problems can be defined as intra- or postoperative events that are not likely to affect the patient’s final outcome.<ref name=":19">Zumstein MA1, Pinedo M, Old J, Boileau P. Problems, complications, reoperations, and revisions in reverse total shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg. 2011 Jan;20(1):146-57</ref> This will include hematomas, phlebitis, heterotopic ossification, algodystrophy and will not be part of the treated subjects of this thesis. Complications are defined as any intra- or postoperative events that are likely to have a negative influence on the patient’s final outcome, such as intraoperative cement extravasation, intra- or postoperative fractures, dislocations, infections, neurological lesions, radiographic changes such as glenoid or humeral lucent lines, scapular notching, stress shielding, aseptic loosening, reinterventions (without replacement of the component) or revisions (with replacement of the component).

==Radiological Changes==
This is the most frequently reported complication after reverse shoulder arthroplasty.<ref name=":19" /> Long-term studies reported their prevalence.<ref name=":37" />

===Impingements===
====Scapular Notching====
Scapular notching is the most frequent radiographic change after a reverse shoulder arthroplasty and has been reported as high as 88%.<ref name=":37" /> It was initially described as the result of abutment of the prosthetic metaphysis against the scapular neck with the arm in adduction consequent to humerus medialization. Repetitive contact between polyethylene and bone may result in polyethylene wear debris, chronic inflammation and osteolysis,<ref name=":39" /> radiolucency around the glenoid component,<ref>Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-86</ref> loosening of the glenoid component,<ref>Cazeneuve JF, Cristofari DJ. Delta III reverse shoulder arthroplasty: radiological outcome for acute complex fractures of the proximal humerus in elderly patients. OOrthop Traumatol Surg Res 2009;95:325-9</ref> presence of an inferior bone spur, and ossification in the glenohumeral space.<ref name=":37" />

Scapular notching (Figure) typically occurs within six months after surgery and appears to stabilize in most cases. The use of an anterosuperior approach, a high position of the baseplate on the glenoid and superior tilting have all been associated with higher rates of notching caused by mechanical impingement with the arm in adduction. Eccentric glenospheres with an inferior offset and glenoid components with a more lateral offset (bony or metal) can reduce the risk of notching.<ref name=":11" /><ref name=":3" /> Mizuno et al. analyzed the influence of an eccentric glenosphere in 47 consecutive cases compared with a historical group treated by the same surgeon. The rates of notching were not different but the severity of notching was less when using an eccentric glenosphere.<ref name=":38" /> Other authors have reported a negligible rate of notching when using an inferior offset component.

[[File:Scapular notching.png|thumb|center|Scapular notching. The severe superior glenoid bone loss (left) has not been corrected intraoperatively (middle), resulting in a severe scapular notching of grade 4 according to Sirveaux.]]

Two types of impingement interactions are noted (Figure).

[[File:Image41-97.jpg|thumb|Two types of impingement interactions coexist; it could correspond to a friction of the polyethylene against the bone (Figure A and B). These repetitive frictions might lead with time to progressive bony abrasion. These phenomena are probably the cause of a rapid apparition of scapular notching. They are the results of multiple motions (adduction, rotations, extension) and not the consequence of a simple contact with the pillar in adduction arm at the side as previously believed. Contrarily, some impingements are related to an abutment with no possibilities to either component to continue the movement (Figure C and D). ]]

====Anterior Impingement====
Anterior impingement can also occur in the setting of reverse shoulder arthroplasty. Anterior impingement may specifically jeopardize the clinical outcome and implant survivorship, ranging from limitation in internal rotation to dislocation by decoaptation, or failure.<ref>De Wilde L1, Walch G. Humeral prosthetic failure of reversed total shoulder arthroplasty: a report of three cases. J Shoulder Elbow Surg. 2006 Mar-Apr;15(2):260-4</ref> As the conformation of the joint changes from spinning to hinging in reverse shoulder arthroplasty, implant version of the humeral stem seems to be the most predictive factor for the occurrence anterior scapular notching. Grammont already warned that excessive retroversion led to decreased internal rotation.<ref name=":35" /> The anterior notching mostly occurred in adduction. The best compromise between anterior and posterior notching to favor a functional arc of motion seems to be 20 to 40 degrees of humeral retroversion.<ref>Stephenson DR, Oh JH, McGarry MH, Rick Hatch GF 3rd, Lee TQ. Effect of humeral component version on impingement in reverse total shoulder arthroplasty. J Shoulder Elbow Surg. 2011 Jun;20(4):652-8</ref> On the other hand, glenoid component version doesn’t seem to influence notching in the axial plane.<ref>Favre P, Sussmann PS, Gerber C. The effect of component positioning on intrinsic stability of the reverse shoulder arthroplasty. J Shoulder Elbow Surg 2010;19:550–556</ref>

==Infection==
The incidence of infections after primary reverse shoulder arthroplasty is around 5%,<ref name=":5" /> which is higher than in anatomic shoulder arthroplasty.<ref>Fehringer EV, Mikuls TR, Michaud KD, Henderson WG, O'Dell JR. Shoulder arthroplasties have fewer complications than hip or knee arthroplasties in US veterans. Clin Orthop Relat Res 2010;468:717-22</ref><ref>Seebauer L. Total reverse shoulder arthroplasty: European lessons and future trends. Am J Orthop (Belle Mead NJ). 2007 Dec;36(12 Suppl 1):22-8</ref> Reasons are the large dead space caused by the ball-and-socket configuration, the frequent postoperative hematoma, the extensive surgical dissection, and in some patients the compromised general health and the numerous previous surgeries. The commonly identified low-virulence organisms are Cutibacterium acnes and Staphylococcus epidermidis. Proven and suspected infections should be revised operatively. Acute infection of less than three weeks in a stable arthroplasty should be treated with debridement and antibiotics. Late infections should be treated with arthroplasty removal, debridement and reimplantation.

==Instability==

Dislocation is one of the most common complications after reverse shoulder arthroplasty, with rates as high as 14% which account for almost half of the complications in some series. Intraoperative criteria have been proposed by other authors to assess prosthetic stability. The recommendations are numerous and include 1) a prosthesis implantation in such a way that it is difficult to reduce, 2) the absence of pistoning of the prosthesis when applying axial traction on the arm, 3) stability throughout a full range of motion, 4) passive adduction of the arm with elbow at side, 5) palpation of the tension in the conjoint tendon after reduction with the arm at the side and the elbow extended, 6) no asymmetric subluxation or tilting of the proximal humeral component on the glenosphere during adduction, and 7) free glenohumeral motion without scapula-thoracic motion between 0° to 60° of abduction. Most cases of dislocation occur during the first few months after implantation and are a result of a technical error. Risk factors for dislocation include body mass index > 30, male sex, previous surgery, subscapularis deficiency and high neck shaft angle (155 degrees). The etiology of dislocation is multifactorial. It can occur due to 1) deltoid insufficiency, 2) lack of anterior restraints including subscapularis insufficiency, conjoint tendon weakness, and pectoralis major insufficiency, 3) malpositioning of the components, 4) impingement, and 5) infection. Instability is more frequent in cases of revision arthroplasty. Deltoid insufficiency can be caused by preoperative factors or can result from a postoperative lack of deltoid tension, acromion fracture, polyethylene wear, stem subsidence, or postoperative neurological palsy. Lädermann et al. noted a strong correlation (p < 0.0001) between preoperative humeral length and dislocation. Postoperative shortening of the humerus, as compared to preoperative or contralateral humeral length, was observed in all cases of dislocation.<ref name=":30" /> Subscapularis integrity is important if a 155 degrees is used.<ref>Edwards TB, Williams MD, Labriola JE, Elkousy HA, Gartsman GM, O'Connor DP. Subscapularis insufficiency and the risk of shoulder dislocation after reverse shoulder arthroplasty. J Shoulder Elbow Surg 2009;18:892-6</ref><ref>Cheung EV, Sarkissian EJ, Sox-Harris A, Comer GC, Saleh JR, Diaz R, Costouros JG. Instability after reverse total shoulder replacement. J Shoulder Elbow Surg 2011;20:584-90</ref> Low neck shaft angles (145 and 135 degrees) are more stable designs and subscapularis integrity seems less important to prevent instability.

[[File:Instability.jpg|thumb|center|One month after implantation of a reverse shoulder arthroplasty for a proximal humeral fracture. The X-ray revealed a prosthetic dislocation. Electroneuromyography (ENMG) confirmed a severe axonotmesis of the axillary nerve.]]

==Neurological Lesions==
Lengthening of the arm during reverse shoulder arthroplasty, because of its nonanatomic design and/or maneuver of glenohumeral reduction, may be a major factor responsible for the increased prevalence of neurologic injury. Clinically relevant neurological complications involving the brachial plexus or the axillary nerve, however, are rare following reverse shoulder arthroplasty. A prospective study determined the electrodiagnostic occurrence of peripheral nerve lesions following 155 degrees neck shaft angle reverse shoulder arthroplasty.<ref name=":46" /> If one also takes into account subclinical deterioration of preoperative lesions, 63% of patients in this study had postoperative neurologic lesions. However, only 5% of patients had a lesion that was present beyond 6 months postoperative. The rate of postoperative lesions seems lower using low neck shaft angles.<ref>Lowe JT, Lawler SM, Testa EJ, Jawa A. Lateralization of the glenosphere in reverse shoulder arthroplasty decreases arm lengthening and demonstrates comparable risk of nerve injury compared with anatomic arthroplasty: a prospective cohort study. J Shoulder Elbow Surg. 2018 Oct;27(10):1845-1851</ref> It seems consequently that distalization put the nerve at risk and that lateralization is rather protective for the plexus.

==Glenoid or humeral non- or disassembly==
Glenoid or humeral non- or disassembly, and polyethylene disassociation are minor problems and are mainly due to prosthetic design (Figure).

[[File:Glenoid dissociation.png|thumb|center|Glenoid disassembly. Six weeks postoperative anteroposterior, Neer and axial imaging revealing a disassembly of the glenosphere on the metaglene.]]

==Periprothetic fractures==
===Humerus===
Humeral fractures occurred intra- or postoperatively.

====Intraoperative====
Intraoperatively, they can appear in the metaphyseal area (“controlled fracture” according to Walch) and are related to retractor positioning. Humeral diaphyseal fractures occur intraoperatively in case of an incorrect sizing of the component or excessive external rotation during preparation of the glenoid and release. They usually require the use of a longer implant to bypass the fracture line or an open reduction internal fixation (ORIF).

====Postoperative====
Postoperatively, fractures usually result from trauma (Figure). They can be treated either conservatively if the component is stable or they require revision in cases of unstable components.

[[File:Image47-109.jpg|thumb|center|Postoperative fracture under the stem of the prosthesis that has been treated conservatively.]]

[[File:Image49-113.png|thumb|Patient known for a right reverse shoulder arthroplasty that sustained a fall on the ipsilateral elbow. A transverse supracondylar fracture of the distal humerus is noted on lateral view.]]

==Heterotopic ossification==
Heterotopic ossification after reverse shoulder arthroplasty (Figure) is a relatively common finding of unknown clinical importance.

[[File:Heterotopic ossifications.png|thumb|center|Heterotopic ossification after reverse shoulder arthroplasty ]]

=References=
<references />

Shoulder:Glenohumeral Arthritis/Reverse Shoulder Arthroplasty

2021-09-10T10:30:31Z

Alexandre.laedermann: /* Subscapularis Repair */

==Bullet Points==

*Indications for reverse shoulder arthroplasty expended. Weight-bearing patients, preoperative deltoid or acromial impairment, in certain circumstances, are not an absolute contraindication to reverse shoulder arthroplasty.

*Deltopectoral, anterosuperior (transdeltoid), and deltoid and subscapularis sparing approaches are currently used. Transacromial approach has been abandoned.

*Adequate deltoid tension obtained through restoration of humeral and arm length is one of the keys for postoperative function and prevention of instability following reverse shoulder arthroplasty. With a classic Grammont prosthesis postoperative humeral lengthening is approximately 2 mm and arm lengthening is approximately 24 mm.

*Subclinical neurologic lesions after Medial Glenoid/Medial Humerus Design are a frequent with consequence of lengthening with a drastically increasing prevalence above 40 mm of arm lengthening. Lateralized designs seem to be protective. Arm lengthening should be controlled with 0 to 2 cm being a reasonable goal to avoid postoperative neurological impairment.

*Medial Glenoid/Medial Humerus 155 degrees neck-shaft angle designs are progressively replaced by lateralized and lower neck-shaft angle (145-135 degrees) designs that theoretically attain, compared to traditional Grammont-type prosthesis, an optimal compromise in range of motion and soft tissue tension.

*Anterior forward flexion and Constant scores after reverse shoulder arthroplasty plateau at 6 months postoperative whereas internal and external rotation continue to improve up to 2 years postoperative. Several preoperative factors are correlated with postoperative range of motion.

*Previously, complications have been reported to affect 19% to 68% of patients and include acromial fracture, haematoma, infection, instability, mechanical baseplate failure, neurological injury, periprosthetic fracture and scapular notching. The rate of postoperative complications has dramatically decreased.

*The launch of a variety of reverse shoulder arthroplasty designs on the market has introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

==Key words==
Reverse total shoulder arthroplasty; prosthesis; postoperative function; humerus and arm length; deltoid impairment; muscle insufficiency; complications; indications, contraindications; impingement; humeral lateralization; glenoid; neck-shaft angle; function; range of motion; active forward flexion; predicting factors; results; clinical outcomes; weight-bearing joint; wheelchair; crutches.

==History==
Paul Grammont was born on April 1940 in Salins-les-Bains, in the northeastern part of France. He began medical studies in Lyon. Very quickly he became interested in surgery, and more specifically in orthopaedic surgery. He first became the fellow and then assistant of Professor Albert Trillat. He became a Professor of Orthopaedic Surgery and Traumatology in 1974 at the age of 34. He then moved to Dijon (France) where he became the Chairman of the Orthopaedic Department of the University Hospital. While he had few laboratory resources, he began many of his biomechanical shoulder experiments in his own garage. Grammont was creative: besides developing the reverse shoulder prosthesis,<ref>Grammont PM, Latfay, J, Deries X. [In French] Etude et réalisation d’une nouvelle prothèse d’épaule. Rhumatologie 1987;39: 407-418</ref> he also developed an early patellofemoral prosthesis<ref>Renard JF, Grammont P. [In French] La prothe`se autocentrique de rotule: technique et re´sultats apre`s 7 ans de recul. Rhumatologie.
1989;41:241–245.</ref> and one of the first nails with a self-advancing mechanism designed to lengthen long bones like the tibia and the femur (Albizia nail).<ref>Guichet JM, Grammont PM, Trouilloud P. [A nail for progressive lengthening. An animal experiment with a 2-year follow-up]. Chirurgie. 1992;118(6-7):405-410</ref> Paul Grammont died in Lyon the 30 March 2013.

==Anecdotes==
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==Human Development==
During evolution the permanently orthograde posture has freed the human shoulder girdle of its quadruped functions. The anterior limbs became the upper limbs with the characteristics of a non-weight-bearing joint. Major bony and muscular adaptations occurred.<ref>Baulot, E. Sirveaux, F. Boileau, P. Grammont's idea: The story of Paul Grammont's functional surgery concept and the development of the reverse principle. Clin Orthop Relat Res. 2011 Sep;469(9):2425-31</ref> The scapulohumeral complex underwent drastic changes to facilitate prehension, leading to major bony and muscular modifications. A relative atrophy of the supraspinatus muscle occurred, as illustrated by a decrease in the scapular index.<ref>Inman, VT. Saunders, M. Abbott, MC. Observations on the function of the shoulder joint. J Bone Joint Surg Br 1944;26(1):1-30</ref><ref>Pearl, R., and Schultz, F.: Human Biology: A Record of Research. Edited, Baltimore, Warwick and York Inc Publishers, 1930</ref> The decrease in the effectiveness of the latter muscle was at the same time compensated for by the increase in size, mass, and lateral extension of the acromion process. The progressive distal migration of the point of insertion of the deltoid muscle and lateralization of the acromion indicate the more dominant position occupied by the deltoid with strengthening in particular of the middle deltoid abduction component.<ref name=":27">Grammont, P. M.: Place de l’ostéotomie de l’épine de l’omoplate avec translation, rotation, élévation de l’acromion dans les ruptures chroniques de la coiffe des rotateurs. Lyon Chir 1979;55:327–329</ref>

The glenohumeral joint is highly mobile and relatively unconstrained. Stability of the joint relies upon concavity-compression whereby the rotator cuff exerts a compressive force of the humeral head upon the glenoid. In the absence of concavity-compression, the unopposed contraction of the deltoid creates a force vector that displaces the head superiorly rather than in abduction. Depending on the type of rotator cuff lesion, a patient may present with pseudoparalysis.

To compensate the loss of function of the rotator cuff, several options have been proposed; the most reasonable, whenever possible, is to repair the rotator cuff. Good results are obtained in the vast majority of the cases with healing of the rotator cuff on the tuberosities. In some circumstances, rotator cuff repair is however contraindicated or technically impossible.

For instance, a rotator cuff insufficiency associated with pain and pseudoparalysis remains a challenging condition. It is extremely difficult, if not impossible, to obtain a functionally good result with a conventional prosthetic arthroplasty in this situation, where only a “limited goals surgery” is appropriate, a concept introduced by Neer.<ref>Neer, C. S., 2nd; Craig, E. V.; and Fukuda, H.: Cuff-tear arthropathy. J Bone Joint Surg Am 1983;65(9):1232-44</ref> Effectively, hemiarthroplasty provides satisfactory pain relief but poor motion,<ref>Sanchez-Sotelo, J.; Cofield, R. H.; and Rowland, C. M.: Shoulder hemiarthroplasty for glenohumeral arthritis associated with severe rotator cuff deficiency. J Bone Joint Surg Am 2001;83(12):1814-22</ref> whereas total anatomic shoulder arthroplasty is complicated with early loosening of the glenoid component.<ref>Barrett, W. P.; Franklin, J. L.; Jackins, S. E.; Wyss, C. R.; and Matsen, F. A., 3rd: Total shoulder arthroplasty. J Bone Joint Surg Am 1987;69(6):865-72</ref>

In order to provide active forward elevation above 90 degrees, the abduction role of the deltoid has to be increased. This can be obtained by several mechanisms, such as an osteotomy of the scapular spine<ref name=":27" /> or more commonly by medializing the center of rotation the glenohumeral joint.<ref>Grammont, P. M.; Bourgon, J.; and Pelzer, P.: Study of a Mechanical Model for a Shoulder Total Prosthesis: Realization of a Prototype. In ECAM de Lyon. Edited, Dijon, Université Dijon, 1981</ref> The concept of functional surgery is born from the latter option: whereas no effective anatomic solution exists, restoration of function has to be proposed through a novel morphology.

The first-generation of reverse shoulder arthroplasty has been implanted in Germany and France.<ref>Gérard, Y.; Leblanc, J. P.; and Rousseau, B.: A complete shoulder prosthesis. Chirurgie 1973;99:655–663</ref><ref>Kolbel, R., and Friedebold, G.: [Shoulder joint replacement]. Arch Orthop Unfallchir 1973;76(1):31-9</ref> However, early loosening and mechanical complications forced to abandon their use. Nevertheless, successive improvements imagined by Grammont followed and, in 1991, a reverse shoulder arthroplasty called the “Delta III” has been developed.<ref name=":36">Baulot, E.; Chabernaud, D.; and Grammont, P. M.: [Results of Grammont's inverted prosthesis in omarthritis associated with major cuff destruction. Apropos of 16 cases]. Acta Orthop Belg 1995;61(Suppl 1):112-9</ref> The two major innovations were a large metal hemisphere with no neck on the glenoid side, and a small humeral polyethylene cup (covering less than half of the hemisphere), oriented with a nonanatomic inclination of 155 degree.

==Biomechanics==

#REDIRECT [[https://wiki.beemed.com/view/Shoulder:Biomechanics]<nowiki>]</nowiki>

Reverse shoulder arthroplasty, often used in multiply operated patients with distorted anatomy, imparts physiological and biomechanical changes that may increase the potential for complications.<ref name=":5">Farshad M, Gerber C. Reverse total shoulder arthroplasty-from the most to the least common complication. Int Orthop. 2010 Dec;34(8):1075-82</ref>

First, the arthroplasty position medializes and lowers the glenohumeral center of rotation, thereby increasing the lever of the deltoid muscle (Medial Glenoid/Medial Humerus Design). Deltoid tension, increased by the lowered center of rotation, increases muscle fiber recruitment of the anterior and posterior deltoid that compensates for a deficient rotator cuff (Figure). The medialization increased the deltoid moment arm up to 20%, and an inferior move increased the efficacy of the deltoid up to 30%.<ref>Terrier A, Reist A, Merlini F, Farron A. Simulated joint and muscle forces in reversed and anatomic shoulder prostheses. J Bone Joint Surg Br 2008;90:751-6.</ref>

[[File:Muscle recruitment.jpg|thumb|center|(A) Native shoulder. The center of rotation is in the humeral head, and the level of arm of deltoid does not allow deltoid recruitment. (B) Bony increased-offset reverse shoulder arthroplasty with lateral glenoid/medial humerus design. As in native shoulders, the bony lateralization of the center of rotation decreases recruitment of the deltoid for rotation. (C) Grammont reverse shoulder arthroplasty with humeral lateralization with a medial glenoid/lateral humerus design. Medialization of the center of rotation and humeral lateralization allows important deltoid recruitment. Reproduced from Collin et al.,<ref name=":6">Collin P, Liu X, Denard PJ, Gain S, Nowak A, Lädermann A. Standard versus bony increased-offset reverse shoulder arthroplasty: a retrospective comparative cohort study. J Shoulder Elbow Surg. 2018;27(1):59-64</ref> with permission.]]

Second, to provide an inherently stable reverse shoulder arthroplasty, the weight bearing part is convex and the supported part concave (reversal of the ball and socket). The fixed nature of the glenosphere places torsional forces on the humerus that may affect humeral component instability.<ref name=":37">Melis B, DeFranco M, Lädermann A, Molé D, Favard L, Nérot C, Maynou C, Walch G. An evaluation of the radiological changes around the Grammont reverse geometry shoulder arthroplasty after eight to 12 years. J Bone Joint Surg Br. 2011 Sep;93(9):1240-6</ref> The native spinning joint becomes a hinge joint, new configuration that leads to various impingements’ types and locations.

Third, the semi-constrained nature of the prosthesis restores glenohumeral stability which provides the stable fulcrum which is essential for active anterior elevation.

Finally, lengthening of the arm which provides space for range of motion of the proximal humerus,<ref name=":32">Lädermann A, Edwards TB, Walch G. Arm lengthening after reverse shoulder arthroplasty: a review. Int orthop 2014;38:991-1000</ref> enhances stability, and re-tensions the deltoid. The latter factor is critical due to the semi-constrained design of the prosthesis. The increase in compressive force between the humeral and glenoid components has a stabilizing effect.<ref>Gagey O, Hue E. Mechanics of the deltoid muscle. A new approach. Clin Orthop Relat Res 2000:250-7</ref> Under such tension, the reverse glenoid component provides the stable fulcrum essential for shoulder anterior elevation and prosthesis stability.<ref name=":28">Boileau P, Watkinson DJ, Hatzidakis AM, Balg F. Grammont reverse prosthesis: design, rationale, and biomechanics. J Shoulder Elbow Surg 2005;14:147S-61S</ref> This tension is determined by arm length.

===Arm Lengthening===
Failure to adequately tension the deltoid may result in prosthetic instability and poor function which are the most common clinically significant complications following reverse shoulder arthroplasty. On the other hand, other complications following reverse shoulder arthroplasty can be related to excessive deltoid tension such as neurological lesions, fractures of the acromion, or fixed abduction of the arm.<ref name=":28" /><ref>Boileau P, Watkinson D, Hatzidakis AM, Hovorka I. Neer Award 2005: The Grammont reverse shoulder prosthesis: results in cuff tear arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow Surg 2006;15:527-40</ref> Adequate deltoid tension is thus accepted as a key to prosthetic function and stability.<ref name=":28" /><ref name=":32" />

The glenosphere has to be implanted on the lower part of the glenoid to avoid notching and to improve rotation at 90 degrees of abduction.<ref>De Biase CF, Ziveri G, Delcogliano M, de Caro F, Gumina S, Borroni M, Castagna A, Postacchini R.The use of an eccentric glenosphere compared with a concentric glenosphere in reverse total shoulder arthroplasty: two-year minimum follow-up results. Int Orthop. 2013 Oct;37(10):1949-55</ref><ref name=":3">Lädermann A, Tay E, Collin P, Piotton S, Chiu CH, Michelet A, Charbonnier C. Effect of critical shoulder angle, glenoid lateralization, and humeral inclination on range of movement in reverse shoulder arthroplasty. Bone Joint Res. 2019;8(8):378-386</ref><ref>Lévigne C, Garret J, Boileau P, Alami G, Favard L, Walch G. Scapular notching in reverse shoulder arthroplasty: is it important to avoid it and how? Clin Orthop Relat Res. 2011 Sep;469(9):2512-20</ref><ref name=":37" /><ref name=":38">Mizuno N, Denard PJ, Raiss P, Walch G. The clinical and radiographical results of reverse total shoulder arthroplasty with eccentric glenosphere. Int Orthop. 2012 Aug;36(8):1647-53</ref><ref name=":39">Nyffeler RW, Werner CM, Gerber C. Biomechanical relevance of glenoid component positioning in the reverse Delta III total shoulder prosthesis. J Shoulder Elbow Surg 2005;14:524-8.</ref> The type of glenosphere (size, eccentricity) allowed the adjustment of arm length by several millimeters (about 1% of arm length). Consequently, the key factors for arm length are the height of the stem, type of stem, polyethylene thickness and the use of an augment or spacer. Collectively, these factors allow arm lengthening by up to several centimeters (about 10% of arm length).<ref name=":32" /> The tension is thus determined by arm length. The latter is dependent of 1) the position of the glenosphere in the frontal plane (Figure), 2) the size of the glenosphere, 3) the use of an eccentric or inferiorly tilted glenosphere, 4) the use of a spacer, 5) the thickness of the polyethylene, 6) the height of humeral cut and stem implantation (Figure 3)<ref name=":29">Lädermann A, Walch G, Lubbeke A, Drake GN, Melis B, Bacle G, Collin P, Edwards TB, Sirveaux F. Influence of arm lengthening in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2012 Mar;21(3):336-41</ref> and prosthetic design (Figure).

[[File:Image2-19.jpg|thumb|center|Influence of position of glenosphere in vertical plane. (A) A rather high implantation of the baseplate or the use of a non-eccentric glenosphere does not allow proper deltoid re-tensioning. (B) The use of an eccentric glenosphere or a low position of the glenosphere in the vertical plane allows satisfactory deltoid re-tensioning,<ref name=":29" /> with permission]]

[[File:Image3-21.jpg|thumb|center|Influence of the humeral cut on arm length. (A) Preoperative status with a lack of deltoid tension. (B-C) An aggressive humeral cut results in a low implantation of the stem with a lack of deltoid tension. (D-E) A minimal humeral cut leads to a high implantation of the prosthetic stem with adequate deltoid tension. From: Lädermann et al., with permission,<ref name=":29" /> with permission]]

[[File:Image4-23.jpg|thumb|center|The neck-shaft angle is one of the biggest variabilities between different prosthesis designs. A steeper or more anatomic neck-shaft angle (Grammont-type 155 degrees vs. 145 degrees and 135 degrees designs) leads to a decrease in the acromiohumeral distance. For every 10 degrees decrease the acromiohumeral distance shortens by approximately 3 mm. In other words, between a 155 degrees and a 135 degrees configuration, arm lengthening varies by about 10 mm.]]

From a clinical perspective lengthening of the arm and humerus, distalization angle, acromio-prosthesis distance (Figures) have been used as surrogates for deltoid tension since they intuitively correlate with deltoid tension and they have been correlated with functional outcome and risk of postoperative instability.<ref>Boutsiadis A, Lenoir H, Denard PJ, Panisset JC, Brossard P, Delsol P, Guichard F, Barth J. The lateralization and distalization shoulder angles are important determinants of clinical outcomes in reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2018 Jul;27(7):1226-1234</ref><ref name=":30">Lädermann A, Williams MD, Melis B, Hoffmeyer P, Walch G. Objective evaluation of lengthening in reverse shoulder arthroplasty.J Shoulder Elbow Surg. 2009 Jul-Aug;18(4):588-95</ref><ref name=":29" /> Most of these factors nowadays can easily be evaluated thank to navigation software.<ref name=":40">Iannotti JP, Walker K, Rodriguez E, Patterson TE, Jun BJ, Ricchetti ET. Accuracy of 3-Dimensional Planning, Implant Templating, and Patient-Specific Instrumentation in Anatomic Total Shoulder Arthroplasty. J Bone Joint Surg Am. 2019 Mar 6;101(5):446-457</ref><ref name=":41">Walch G, Vezeridis PS, Boileau P, Deransart P, Chaoui J. Three-dimensional planning and use of patient-specific guides improve glenoid component position: an in vitro study. J Shoulder Elbow Surg. 2015 Feb;24(2):302-9</ref>

[[File:Figure3.jpg|thumb|center|The epicondylar line (EL) is defined between the most lateral part of the medial and lateral epicondyle. Another line, the diaphyseal axis (DI), is determined by a line drawn in the centre of the proximal medullary canal. Intersection between the epicondylar line and the diaphyseal axis represent the point C. Intersection between the diaphyseal axis and top of the humeral head is named H. The point A is located at the intersection between the diaphyseal axis and a perpendicular line passing through the most lateral and inferior point of the acromion. A, C, and H are represented by small white points, large white points corresponding to centimeter marker stuck on the skin of the arm. A, acromion; C, condyles; H, head; EL, epicondylar line; DI, diaphyseal axis; preop, preoperative; contro, controlateral; EF, enlargement factor, <ref name=":30" /> with permission]]

[[File:DLA 1 blinded.png|thumb|center|The distalization shoulder angle (DSA) angle is formed by a line connecting the most lateral border of the acromion and the superior glenoid tubercle and a line connecting the superior glenoid tubercle and the most superior border of the greater tuberosity. In this case, it is measured at 61 degrees.]]

===Lateralization in Reverse Shoulder Arthroplasty===
The basic biomechanical principles of the Grammont reverse shoulder arthroplasty are a medialization of the glenohumeral center of rotation, the use of a larger ball on the glenoid component, and a lowering of the humerus. These principles increase the deltoid lever arm and provide a space for unrestricted range of motion of the proximal humerus and a stable fulcrum essential for active elevation and stability.<ref name=":28" /> However, many complications, such as limited postoperative range of motion or impingement that could be attributed to the medialized glenoid design, have been reported in the literature.<ref name=":1">Gerber C, Pennington SD, Nyffeler RW. Reverse total shoulder arthroplasty. J Am Acad Orthop Surg 2009;17:284-95</ref> To address these problems, several authors have proposed a change in the design of the Grammont prosthesis, promoting an increased bony or metallic glenoid offset.<ref name=":31">Boileau P, Moineau G, Roussanne Y, O'Shea K. Bony increased-offset reversed shoulder arthroplasty: minimizing scapular impingement while maximizing glenoid fixation. Clin Orthop Relat Res 2011;469:2558-67</ref><ref name=":13">Gutierrez S, Levy JC, Frankle MA, Cuff D, Keller TS, Pupello DR, Lee WE 3rd. Evaluation of abduction range of motion and avoidance of inferior scapular impingement in a reverse shoulder model. J Shoulder Elbow Surg 2008;17:608-15</ref> Different methods to measure glenoid lateralization have been proposed.<ref>Frankle MA, Teramoto A, Luo ZP, Levy JC, Pupello D. Glenoid morphology in reverse shoulder arthroplasty: classification and surgical implications. J Shoulder Elbow Surg 2009;18:874-85</ref><ref name=":8">Jobin CM, Brown GD, Bahu MJ, Gardner TR, Bigliani LU, Levine WN, Ahmad CS. Reverse total shoulder arthroplasty for cuff tear arthropathy: the clinical effect of deltoid lengthening and center of rotation medialization. J Shoulder Elbow Surg 2012;21:1269-77</ref>

====Definitions====
It is important to understand the differences between humeral or glenoid lateralization. These factors can be used to predict range of motion and vary based on prosthesis and technical factors. Humeral lateralization is defined as the distance from the center of the polyethylene cup, and the lateral part of the greater tuberosity (Figure). It can be estimated by the lateralization shoulder angle (Figure).

[[File:Image5-25.jpg|thumb|center|3D distances corresponded to the radius of spheres. Offset of the sphere were centered on the center of the polyethylene cup (pivot point) and of the bony glenoid center (GC) for humeral (A) and global offset (B), respectively, and included the lateral part of the greater tuberosity. ]]

[[File:LSA.png|thumb|center|The lateralization shoulder angle is formed by a line connecting the superior glenoid tubercle and the most lateral border of the acromion and a line connecting the most lateral border of the acromion and the most lateral border of the greater tuberosity. In this case, it is measured at 77 degrees.]]

It depends upon glenoid wearing, reaming and grafting, contact of the baseplate with the glenoid, the offset of the glenosphere and/or baseplate, the glenosphere diameter and tilt, the level of the humeral cut, the humeral neck-shaft angle, the humeral prosthetic design, the use of a spacer, the polyethylene thickness (humeral polyethylene socket offset), and the remaining proximal and lateral humeral bone stock.

At the other end of the spectrum, failure to adequately restore bone or prosthetic humeral lateralization may result in loss of humeral contour,<ref>Chacon A, Virani N, Shannon R, Levy JC, Pupello D, Frankle M. Revision arthroplasty with use of a reverse shoulder prosthesis-allograft composite. J Bone Joint Surg Am. 2009 Jan;91(1):119-27</ref> and deltoid shape curve and thus deltoid retensionning, and could lead to prosthetic instability and poor postoperative function.<ref name=":29" /><ref name=":30" />

===Neck-shaft angle===
More anatomic neck-shaft angles decrease the rate of scapular notching and improve postoperative range of motion.<ref name=":3" /><ref name=":11" />

The launch of this variety of designs on the market has introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

===Range of motion after reverse shoulder arthroplasty: which combinations of humeral stem and glenosphere work the best?===
Reproduced from Lädermann et al., with permission.<ref>Lädermann A, Collin P, Denard PJ. Range of motion after reverse shoulder arthroplasty: Which combinations of humeral stem and glenosphere work the best? Obere Extremität 2020 doi:10.1007/s11678-020-00599-5</ref>
====Introduction====
The initial reverse shoulder arthroplasty design was excellent at restoring forward flexion but had several design-related complications including bony impingement and scapular notching,<ref name=":11">Lädermann A, Denard PJ, Collin P, Zbinden O, Chiu JC, Boileau P, Olivier F, Walch G. Effect of humeral stem and glenosphere designs on range of motion and muscle length in reverse shoulder arthroplasty. Int Orthop. 2020;44(3):519-30</ref><ref name=":37" /> instability,<ref>Chae J, Siljander M, Wiater JM. Instability in Reverse Total Shoulder Arthroplasty. J Am Acad Orthop Surg 2018;26:587-596</ref> acromial fractures,<ref name=":18">Haidamous G, Lädermann A, Frankle M, Gorman A, Denard PJ. The risk of postoperative scapular spine fracture following reverse shoulder arthroplasty is increased with an onlay humeral stem. J Shoulder Elbow Surg. 2020;9:S1058-2746(20)30337-2.</ref> limited range of motion (particularly internal and external rotation),<ref name=":10">Denard PJ, Lädermann A, Haidamous G, Hartzler R, Parsons BO, Lederman ES, Tokish JM. Radiographic Parameters Associated With Excellent Versus Poor Range Of Motion Outcomes Following Reverse Shoulder Arthroplasty. Shoulder & Elbow 2020;9:1758573220936234.</ref><ref>Lädermann A, Denard PJ, Tirefort J, Collin P, Nowak A, Schwitzguebel A J-P. Subscapularis- and deltoid-sparing vs traditional deltopectoral approach in reverse shoulder arthroplasty: a prospective case-control study. J Orthop Surg Res 2017;12:112</ref> and humeral stem loosening.<ref name=":37" /><ref>Lädermann A, Schwitzguebel AJ, Edwards TB, Godeneche A, Favard L, Walch G, Sirveaux F, Boileau P, Gerber C. Glenoid loosening and migration in reverse shoulder arthroplasty. Bone Joint J. 2019;101-B:461-469</ref> Many of these have been attributed to the initial Grammont design which featured a medialized glenosphere and 155 degrees straight stem (Medial Glenoid/Medial Humerus Design).<ref name=":1" />

A variety of changes in prosthetic design have been proposed to address these issues either on the humeral side or on the glenoid side, the goal being to decrease scapular notching, maximize efficiency of the remaining rotator cuff, improve stability and improve range of motion. On the glenoid side authors have promoted increased lateralization either with bone or metal.<ref name=":31" /><ref name=":4">Gutiérrez S, Comiskey CA 4th, Luo ZP, Pupello DR, Frankle MA. Range of impingement-free abduction and adduction deficit after reverse shoulder arthroplasty. Hierarchy of surgical and implant-design-related factors. J Bone Joint Surg Am . 2008;90(12):2606-15</ref> On the humeral side, a more anatomic humeral inclination (i.e. 145 or 135 degrees) and inlay and onlay systems designs have introduced a myriad of prosthetic configurations that has rendered analysis and delivery of universal guidelines difficult.

Therefore, the aim of this chapter is to evaluate the advantages and inconvenience of different reverse shoulder arthroplasty’s designs and to provide recommendations accordingly.

====Glenoid Configuration====
Glenoid configuration has an important effect on postoperative range of motion. The three most important variables are glenoid offset, eccentricity, and glenosphere size. None of these latter parameters influence significantly the measured bone strains at the glenoid near the bone-implant interface.<ref>Pauzenberger L, Dwyer C, Obopilwe E, Nowak MD, Cote M, Romeo AA, Mazzocca AD, Dyrna F. Influence of glenosphere and baseplate parameters on glenoid bone strains in reverse shoulder arthroplasty. BMC musculoskeletal disorders 2019;20(1):587</ref>

=====Glenoid Offset (lateralization)=====
The initial Grammont-style reverse shoulder arthroplasty utilized a glenosphere with a medialized center of rotation. While this design reliably improved forward elevation, the high rate of scapular notching and internal and external rotation deficit observed with this design have been attributed to the medialized glenoid design.<ref name=":1" /><ref>Lawrence C, Williams GR, Namdari S. Influence of Glenosphere Design on Outcomes and Complications of Reverse Arthroplasty: A Systematic Review. Clinics in orthopedic surgery 2016;8:288-297</ref> To address these problems, glenoid lateralization have been proposed to decrease scapular notching, improve soft tissue tension, and increase impingement-free range of motion. The glenoid component is considered as lateralized if lateralization equals or exceeds 5 mm compared to Grammont design.<ref>Werthel JD, Walch G, Vegehan E, Deransart P, Sanchez-Sotelo J, Valenti P. Lateralization in reverse shoulder arthroplasty: a descriptive analysis of different implants in current practice. Int Orthop 2019;43:2349-2360</ref> It is important to note that this lateralization of the center of rotation is relative to the implant designed by Grammont, but still medialized compared to the native glenohumeral joint. Lateralization can be achieved by either the placement of bone medial to the baseplate (bone increase offset reverse shoulder arthroplasty (BIO-RSA))<ref name=":31" /> or with metallic lateralization via the baseplate or glenosphere. While both have been associated with clinical improvement,<ref>Ernstbrunner L, Werthel JD, Wagner E, Hatta T, Sperling JW, Cofield RH. Glenoid bone grafting in primary reverse total shoulder arthroplasty. J Shoulder Elbow Surg 2017;26:1441-1447</ref><ref>Klein SM, Dunning P, Mulieri P, Pupello D, Downes K, Frankle MA. Effects of acquired glenoid bone defects on surgical technique and clinical outcomes in reverse shoulder arthroplasty. J Bone Joint Surg Am 2010;92:1144-1154</ref> metallic lateralization appears to be less subject to displacement, particularly with lateralization beyond 5 mm.<ref>Denard PJ, Lederman E, Parsons BO, Romeo AA. Finite element analysis of glenoid-sided lateralization in reverse shoulder arthroplasty. J Orthop Res 2017;35:1548-1555</ref>

Basic science studies show several benefits of lateralization. In both sawbone<ref name=":13" /> and computer models,<ref name=":4" /><ref name=":21">Kim SJ, Jang SW, Jung KH, Kim YS, Lee SJ, Yoo YS. Analysis of impingement-free range of motion of the glenohumeral joint after reverse total shoulder arthroplasty using three different implant models. Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2019;24:87-94</ref><ref name=":3" /> lateralization improves range of motion in all directions.<ref name=":3" /> Lateralization also leads to improvement in stability.<ref>Ferle M, Pastor MF, Hagenah J, Hurschler C, Smith T. Effect of the humeral neck-shaft angle and glenosphere lateralization on stability of reverse shoulder arthroplasty: a cadaveric study. J Shoulder Elbow Surg 2019;28:966-973</ref>

The question remains how much lateralization is ideal. While clinical evidence is currently lacking, computer modeling suggests that 5 to 10 mm of lateralization relative to the native glenoid is ideal.<ref name=":3" /><ref name=":14">Werner BS, Chaoui J, Walch G. The influence of humeral neck shaft angle and glenoid lateralization on range of motion in reverse shoulder arthroplasty. J Shoulder Elbow Surg 2017;26(10):1726-1731</ref><ref>Gutiérrez S, Greiwe RM, Frankle MA, Siegal S, Lee WE 3rd. Biomechanical comparison of component position and hardware failure in the reverse shoulder prosthesis. J Shoulder Elbow Surg 2007;16:S9-S12</ref> Nevertheless, clinical data to date has not necessarily proved that lateralization improves range of motion<ref name=":6" /> or outcome scores<ref>Helmkamp JK, Bullock GS, Amilo NR, Guerrero EM, Ledbetter LS, Sell TC, Garrigues GE. The clinical and radiographic impact of center of rotation lateralization in reverse shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg, 2018, 27:2099-2107</ref> compared to a traditional reverse shoulder arthroplasty. Greiner et al. performed a randomized controlled trial of 17 Grammont reverse shoulder arthroplasties and 17 BIO-RSAs and reported no difference in Constant scores at 1 year postoperative.<ref>Greiner S, Schmidt C, Herrmann S, Pauly S, Perka C. Clinical performance of lateralized versus non-lateralized reverse shoulder arthroplasty: a prospective randomized study. J Shoulder Elbow Surg, 2015, 24:1397-1404</ref> In a retrospective study, Athwal et al. did not observe substantial range of motion, strength, or outcome scores.<ref name=":22">Athwal GS, MacDermid JC, Reddy KM, Marsh JP, Faber KJ, Drosdowech D. Does bony increased-offset reverse shoulder arthroplasty decrease scapular notching? J Shoulder Elbow Surg, 2015, 24:468-473</ref> The frequency of scapular notching, however, was significantly higher (P=.022) in the reverse shoulder arthroplasty cohort than in the BIO-RSA cohort: 75% versus 40%.<ref name=":22" /> This finding has been also reported by Zitkovsky et al.<ref name=":15">Zitkovsky HS, Carducci MP, Mahendraraj KA, Grubhofer F, Jawa A. Lateralization and Decreased Neck-Shaft Angle Reduces Scapular Notching and Heterotopic Ossification. J Am Acad Orthop Surg. 2020 Apr 8. doi: 10.5435/JAAOS-D-19-00808. Online ahead of print.</ref> At 10 years follow-up, Kennon et al. confirmed that scapular notching rates are significantly higher with medialized components compared to lateralized ones (77% in vs. 47%, P= .013).<ref>Kennon JC, Songy C, Bartels D, Statz J, Cofield RH, Sperling JW, Sanchez-Sotelo J. Primary reverse shoulder arthroplasty: how did medialized and glenoid-based lateralized style prostheses compare at 10 years? J Shoulder Elbow Surg. 2020;29(7S):S23-S31</ref> Notably, all of the these studies utilized a 155 degrees humeral prothesis and thus further comparative studies are required with 135 and/or 145 degrees protheses.

=====Glenosphere Eccentricity=====
Inferior eccentric positioning of the glenosphere can also be used to decrease the adduction deficit and thus reduce scapular notching.<ref name=":21" /><ref name=":7">Lädermann A, Denard PJ, Boileau P, Farron A, Deransart P, Walch G. What is the best glenoid configuration in onlay reverse shoulder arthroplasty? Int Orthop. 2018;42(6):1339-1346</ref> Mizuno et al. previously reported that an inferiorly eccentric glenosphere reduced the severity of scapular notching with a 155 degrees prosthesis,<ref name=":38" /> improving thus postoperative rotations elbow at side.<ref name=":2">Lädermann A, Gueorguiev B, Charbonnier C, Stimec BV, Fasel JH, Zderic I, Hagen J, Walch G. Scapular Notching on Kinematic Simulated Range of Motion After Reverse Shoulder Arthroplasty Is Not the Result of Impingement in Adduction. Medicine (Baltimore). 2015;94(38):e1615</ref> While the differences are small, the eccentric glenosphere provided the greatest ability to limit scapular notching while maximizing range of motion by increasing the subacromial space.<ref name=":7" /><ref name=":3" /> Abduction is effectively positively correlated with acromiohumeral distance (r = 0.93; p < 0.001) which is increased with an eccentric glenosphere.<ref name=":11" /> Rotation in abduction is important to activities of daily living. Interestingly, the latter are impossible in most configurations due to inexistent subacromial space (Figure 9). Postero-inferior eccentricity can improve also extension and could favorize as well internal rotation hand in the back (Figure).

[[File:Figure 1.png|thumb|Rotations rotation at 90 degrees of abduction might be impossible due to inexistent subacromial space. Eccentric positioning of the glenosphere creates subacromial space.]]

[[File:Figure 2 Postero-inferior eccentricity.png|thumb|Postero-inferior eccentricity improves extension. A) Inferior eccentricity alone (yellow arrow) allows 52 degrees of extension. B) 40 degrees of postero-inferior eccentricity (yellow arrow) improves extension to 73 degrees.]]

It is important to note, however, that inferior overhang of the glenosphere can be achieved either by an eccentric glenosphere or by baseplate position. Conversely, an eccentric glenosphere with an improperly positioned superior baseplate will not provide clinical benefit. Thus, the surgeon must be cognizant of both the overhang of the given glenosphere relative to the selected baseplate, as well as any eccentricity in the glenosphere. Furthermore, the benefits of overhang or eccentricity must be weighed against the risks of nerve injury and acromial fracture associated with arm lengthening. The ideal amount of overhang relative to the glenoid appears to be about 2.5 mm based on clinical evidence.<ref name=":10" />

=====Glenosphere size=====
The size of the glenosphere influences theoretically and clinically postoperative range of motion. Lädermann et al. found that a small glenosphere (36 mm) improves external rotation in abduction.<ref name=":7" /> However, with the elbow at side, larger diameter glenospheres have been shown to provide a greater impingement-free arc of motion, and decrease scapular notching in biomechanical studies. Werner et al. reported superior values for extension and external rotation with a 39 mm glenosphere compared to a 36 mm glenosphere mm.<ref name=":14" /> Berhouet et al. demonstrated in a cadaveric study that a 42 mm glenosphere was associated with improved rotational range of motion compared to a 36 mm glenosphere (p <0.05).<ref>Berhouet J, Garaud P, Favard L. Evaluation of the role of glenosphere design and humeral component retroversion in avoiding scapular notching during reverse shoulder arthroplasty.J Shoulder Elbow Surg . 2014;23(2):151-8</ref> Another study comparing functional scores and range of motion differences between two groups of patients, one receiving a 36 mm glenosphere and the other receiving a 44 mm glenosphere, found that patients with the larger glenosphere had a 12 degrees increase in external rotation in adduction compared to those with the smaller glenosphere (p <.001).<ref>Muller AM, Born M, Jung C, Flury M, Kolling C, Schwyzer HK, Audigé L. Glenosphere size in reverse shoulder arthroplasty: is larger better for external rotation and abduction strength? J Shoulder Elbow Surg 2018;27(1):44-52</ref> Similarly, Mollon et al. showed that a 42 mm glenosphere size generated a 15 degree improvement in forward flexion and a 6 degree improvement in external rotation compared to the 38 mm size, with an overall improvement in pain scores.<ref>Mollon B, Mahure SA, Roche CP, Zuckerman JD. Impact of glenosphere size on clinical outcomes after reverse total shoulder arthroplasty: an analysis of 297 shoulders. J Shoulder Elbow Surg. 2016;25(5):763-71</ref> Finally, a study by Haidamous et al. demonstrated that larger glenosphere size and inferior positioning as well as posterior humeral offset are associated with improved postoperative range of motion following reverse shoulder arthroplasty with a 135 degrees humeral component.<ref name=":10" /> Nevertheless, larger glenospheres limit abduction and rotations in abduction and are prone to higher volumetric wear rates and experienced greater polyethylene volume loss.<ref>Haggart J, Newton MD, Hartner S, Ho A, Baker KC, Kurdziel MD, Wiater JM. Neer Award 2017: wear rates of 32-mm and 40-mm glenospheres in a reverse total shoulder arthroplasty wear simulation model. J Shoulder Elbow Surg . 2017;26(11):2029-2037</ref> Additionally, one must consider patient size. Overstuffing can occur. Matsuki et al., for instance, demonstrated that small- and large-stature patients achieved lower improvement in range of motion with an RSA system with only 2 glenosphere sizes (38 and 42) likely because the small patients were overstuffed and the large patients did not have large enough glenospheres and/or lateralization.<ref>Matsuki K, King JJ, Wright TW, Schoch BS. Outcomes of reverse shoulder arthroplasty in small- and large-stature patients. J Shoulder Elbow Surg. 2018;27(5):808-815</ref>

====Humeral Stem Designs====
The primary humeral stem variables include stem geometry, neck-shaft angle, inlay versus onlay configuration, and humeral spacers.

=====Stem geometry=====
Short curved stems were initially developed to facilitate implantation, maintain bone stock, and preserve rotator cuff insertion.<ref>Lädermann A, Chiu JC, Cunningham G, Hervé A, Piotton S, Bothorel H, Collin P. Do short stems influence the cervico-diaphyseal angle and the medullary filling after reverse shoulder arthroplasties? Orthop Traumatol Surg Res. 2020;106(2):241-246</ref> These stems also change humeral offset based on their positioning in the humeral canal. In one study an onlay curve stem lead to a 7-mm increase in humeral offset compared to a traditional inlay straight Grammont prosthesis.<ref name=":12">Lädermann A, Denard PJ, Boileau P, Farron A, Deransart P, Terrier A, Ston J, Walch G. Effect of humeral stem design on humeral position and range of motion in reverse shoulder arthroplasty. Int Orthop. 2015;39(11):2205-13</ref> Curve stems decrease the acromiohumeral distance, which may lead to acromial impingement at small abduction angles.<ref name=":12" /> On the other hand, humeral lateralization can be useful to compensate for medialization in case of bone loss (Figure) and has been theorized to improve the mechanics of the remaining rotator cuff and deltoid musculature.<ref>Parry S, Stachler S, Mahylis J. Lateralization in reverse shoulder arthroplasty: A review. Journal of orthopaedics 2020;22:64-67</ref> Stem design appeared to have also a substantial effect on abduction, as combinations with the straight Grammont stem had greater abduction (73–80%), compared to those with the onlay curved stem (54–69%).<ref name=":11" />

[[File:Managing the eroded glenoid in shoulder arthroplasty Noumea 2019.jpg|thumb|Humeral lateralization can help to restore global lateralization in case of glenoid bone loss. A) Massive glenoid bone loss compensated by glenoid allograft and a straight stem (Lateral Glenoid/Medial Humerus concept). Observe that the central peg hardly reaches the native glenoid. Such construct has a potential for failure (B). Another option would have been to use a smaller glenoid graft and a curved stem (Lateral Glenoid/Lateral Humerus)]]

=====Neck-shaft angle (inclination)=====
The Grammont reverse shoulder arthroplasty was designed as a non-anatomic implant with a relative valgus humeral neck inclination of 155 degrees. Based on the work by Gutierrez et al.,<ref name=":13" /> neck-shaft angle has decreased in modern prosthetic designs to a more varus or anatomic inclination of 145 or 135 degrees.

The neck shaft angle is a major factor influencing length of the arm,<ref name=":37" /> but has little effect on humeral lateralization; by changing inclination from 155 degrees to 135 degrees within an onlay design, humeral offset only increased by about 2 mm.<ref name=":12" />

Theoretically, compared to low neck shaft angle stems, higher inclinations (155 degrees) increased abduction by 100% and external rotation in abduction, regardless of glenosphere designs.<ref name=":12" /><ref name=":3" /> This finding is important as such external rotation is a major factor in the ability to perform activities of daily activities such as hair care and facial grooming. However, a 155 degrees is associated with decreased adduction external rotation at the side<ref name=":12" /><ref>Nelson R, Lowe JT, Lawler SM, Fitzgerald M, Mantell MT, Jawa A. Lateralized Center of Rotation and Lower Neck-Shaft Angle Are Associated With Lower Rates of Scapular Notching and Heterotopic Ossification and Improved Pain for Reverse Shoulder Arthroplasty at 1 Year. Orthopedics. 2018;41(4):230-6</ref><ref name=":14" /> and extension due to medial bony impingement (which also leads to scapular notching).<ref name=":3" /><ref name=":11" /><ref name=":4" /><ref name=":14" /><ref>Oh JH, Shin SJ, McGarry MH, Scott JH, Heckmann N, Lee TQ. Biomechanical effects of humeral neck-shaft angle and subscapularis integrity in reverse total shoulder arthroplasty. J Shoulder Elbow Surg.2014;23(8):1091-8</ref><ref>Virani NA, Cabezas A, Gutiérrez S, Santoni BG, Otto R, Frankle M. Reverse shoulder arthroplasty components and surgical techniques that restore glenohumeral motion. J Shoulder Elbow Surg. 2013;22(2):179-87</ref> Lateralization obtained via a lower neck shaft angle increases adduction, by 357% between a 155 degrees prosthesis compared with a 135 degrees prosthesis. Also, an increase in extension, of 381%, and external rotation elbow at side, of 116%, are observed with a 135 degrees prosthesis.<ref name=":12" /> Such finding are important as external rotation with the elbow at the side and extension led to friction between the scapular pillar and the polyethylene insert. Even if this friction phenomenon does not limit range of motion, it likely contributes to progressive polyethylene wear and scapular notching.<ref name=":2" /> Reducing the neck-shaft angle can, however, have some negative effects on reverse shoulder arthroplasty contact mechanics. The contact area is reduced by 29% for 155 degrees to 145 degrees and by 59% for 155 degrees to 135 degrees. Consequently, there is an increased maximum contact stress by 71% for 155 degrees to 145 degrees and by 286% for 155 to 135 degrees.<ref>Langohr GD, Willing R, Medley JB, Athwal GS, Johnson JA. Contact mechanics of reverse total shoulder arthroplasty during abduction: the effect of neck-shaft angle, humeral cup depth, and glenosphere diameter. J Shoulder Elbow Surg. 2016;25(4):589-97</ref>

Gobezie et al. published the results of a randomized controlled trial comparing humeral inclination of 135 degrees to 155 degrees among patients undergoing reverse shoulder arthroplasty with a neutral glenosphere (no lateralization) and found no significant difference in forward flexion, external rotation, or functional outcomes.<ref name=":16">Gobezie R, Shishani Y, Lederman E, Denard PJ. Can a functional difference be detected in reverse arthroplasty with 135° versus 155° prosthesis for the treatment of rotator cuff arthropathy: a prospective randomized study. J Shoulder Elbow Surg. 2019;28(5):813-8</ref> They and other studies have confirmed that scapular notching is decreased with a 135 degrees prothesis.<ref name=":15" /><ref name=":16" /><ref name=":17">Erickson BJ, Frank RM, Harris JD, Mall N, Romeo AA. The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg. 2015;24(6):988-93</ref> A systematic review of 2222 shoulders comparing 135 degrees and 155 degrees prostheses reported higher rates of scapular notching in the 155 degrees group (16.8% vs. 2.8%), improved external rotation in the 135 degrees group, and no difference in instability of forward flexion between groups.<ref name=":17" />

Lastly, in case of fracture, reverse shoulder arthroplasty with a 135 degrees neck shaft angle is associated with higher tuberosity healing rates compared to 145 degrees or 155 degrees.<ref>O'Sullivan J, Lädermann A, Parsons BO, Werner B, Steinbeck J, Tokish JM, Denard PJ. A systematic review of tuberosity healing and outcomes following reverse shoulder arthroplasty for fracture according to humeral inclination of the prosthesis. J Shoulder Elbow Surg. 2020;29(9):1938-49</ref>

=====Onlay vs Inlay=====
Compared to on inlay design, an onlay humeral design with the same 155 degrees inclination increased humeral offset by 6.6 mm.<ref name=":12" /> Acromiohumeral distance varied by 9.8 mm with the smallest occurring with the onlay 135 degrees model and the largest occurring with a Grammont inlay 155 degrees. Compared to the inlay design, an onlay humeral design with the same 155 degrees inclination decreased the acromioclavicular distance by 4.1 mm. Compared to the onlay 155 degrees model, with the inlay 155 degrees model there was a 10 degree decrease (77.8 to 67.9 degrees) in abduction and a 5 degree (range, −15.3 to −20.2 degrees) increase in adduction.<ref name=":12" />

Clinically, Beltrame et al. conducted a prospective clinical study comparing onlay and inlay steams. They found that onlay design 145 degrees may provide better active external rotation, extension, adduction.<ref>Beltrame A, Di Benedetto P, Cicuto C, Cainero V, Chisoni R, Causero A. Onlay versus Inlay humeral steam in Reverse Shoulder Arthroplasty (RSA): clinical and biomechanical study. Acta Biomed. 2019;90(12-S):54-63</ref> However, there are numerous bias in their study (i.e. different neck shaft angle and stem lateralization) that prevent integration of their results in the present analysis.

In a retrospective comparative radiological study, Haidamous et al. showed similarly that an onlay humeral stem design resulted in a 10 mm increase in distalization compared to an inlay humeral stem, and a 2.5 times (11.9% vs 4.7%) increased risk of scapular spine fracture.<ref name=":18" /> It seems thus that the combination of lateralization and distalization in an onlay system dramatically increases the incidence of scapular spine fractures.

Lengthening of the supraspinatus and infraspinatus is systematically observed with an onlay design. It is greatest using onlay stems (7–30%) and lateralized glenospheres (13–31%).<ref name=":11" /> Subscapularis lengthening is observed for onlay stems combined with lateralized glenospheres (5–9%), while excessive subscapularis shortening is observed for the inlay stem combined with all glenospheres except the lateralized design (> 15%).<ref name=":11" />

=====Polyethylene Insert=====
Since inferior impingement between the polyethylene and the scapula is systematic with the arm at the side, another potential way to limit friction and notching in external rotation is to create a notch in the polyethylene inferiorly between 3 and 9 o’clock as it has been done in some prostheses (e.g., Arrow and SMR). Another solution to increase range of motion is to reduce the depth of the polyethylene inlay. De Wilde et al. found that for every 3-mm decrease in depth of polyethylene cup, ROM increased by 12 degrees.<ref>De Wilde LF, Poncet D, Middernacht B, Ekelund A.Prosthetic overhang is the most effective way to prevent scapular conflict in a reverse total shoulder prosthesis. Acta Orthop 2010 81:719-726</ref>

====Discussion====
The literature is controversial with regard to possibilities of regaining range of motion following reverse shoulder arthroplasty. While prosthetic designs are varied and lead to substantial changes in computer models, many of the theoretical advantages have not been confirmed clinically. Table summarizes implant design considerations to improve range of motion. The optimal compromise in range of motion for a primary reverse shoulder arthroplasty without bone loss could be a Lateral Glenoid/Medial (or Intermediate) Humerus design with a low neck shaft angle (145-135 degrees) and an inlay concept. However, all prosthetic designs should be considered on a case-by-case basis to optimize outcome. Glenoid and humeral prosthetic design has to be chosen depending on pre- and intra-operative factors including patient expectations, bone morphology, soft tissue state such as rotator cuff or nerve, approaches, surgical exposure, etc. It may, for example, not be possible to utilize a large glenosphere in all patients as they may not be appropriate for the anatomy of smaller individuals and might be more challenging technically. As a result, the surgeon must continuously weigh the benefits and possibilities of available implant-related variables regarding patient’s specific conditions. The systematic use of patient-specific instrumentation and navigation as well as preoperative determination of components are obviously the next steps in providing more accurate component positioning and size and thus improving range of motion. Despite the advances made by glenoid lateralization and inferiorization, there remains ample opportunity for continued improvement and innovation in prosthetic design.

=Preoperative planning=

Preoperative planning is mandatory as it allows to improve range of motion.<ref>Kolmodin J, Davidson IU, Jun BJ, Sodhi N, Subhas N, Patterson TE, Li ZM, Iannotti JP, Ricchetti ET. Scapular Notching After Reverse Total Shoulder Arthroplasty: Prediction Using Patient-Specific Osseous Anatomy, Implant Location, and Shoulder Motion. J Bone Joint Surg Am. 2018 Jul 5;100(13):1095-1103</ref> To guarantee the best possible functional results, restoration of the appropriate humeral and arm length, a and free range of motion should be the goal.<ref name=":8" /><ref name=":29" /><ref>Renaud P, Wahab H, Bontoux L, Dauty M, Richard I, Bregeon C. [Total inverted shoulder prosthesis and rotator cuff insufficiency: evaluation and determination of anatomical parameters predictive of good functional outcome in 21 shoulders]. Ann Readapt Med Phys 2001 ;44(5):273-80</ref> Even if the available softwares do not take into account soft tissue (stiffness, fatty infiltration,…), they are already able to plan and analyze lateralization and distalization.<ref name=":40" /><ref name=":41" />

=Indications and Contraindications=
==Indications==
Reverse shoulder arthroplasty is a powerful tool that has opened new barriers, especially for reconstructive shoulder surgery. Traditionally, the ideal candidate has been a patient above 70 years old with symptomatic cuff tear arthropathy. Appropriate candidates now include young patients, who have shown excellent clinical improvement with high implant survivorship of up to 10 years.<ref>Black EM, Roberts SM, Siegel E, Yannopoulos P, Higgins LD, Warner JJ. Reverse shoulder arthroplasty as salvage for failed prior arthroplasty in patients 65 years of age or younger. J Shoulder Elbow Surg 2014;23:1036-42</ref><ref>Ek ET, Neukom L, Catanzaro S, Gerber C. Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: Results after five to fifteen years. J Shoulder Elbow Surg 2013;22:1199-208</ref><ref>Muh SJ, Streit JJ, Wanner JP, Lenarz CJ, Shishani Y, Rowland DY, Riley C, Nowinski RJ, Edwards TB, Gobezie R. Early follow-up of reverse total shoulder arthroplasty in patients sixty years of age or younger. J Bone Joint Surg Am 2013;95:1877-83</ref><ref>Otto RJ, Clark RE, Frankle MA. Reverse shoulder arthroplasty in patients younger than 55 years: 2- to 12-year follow-up. J Shoulder Elbow Surg 2017;26:792-7</ref><ref>Sershon RA, Van Thiel GS, Lin EC, McGill KC, Cole BJ, Verma NN, Romeo AA, Nicholson GP. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg 2014;23:395-400</ref><ref>Walters JD, Barkoh K, Smith RA, Azar FM, Throckmorton TW. Younger patients report similar activity levels to older patients after reverse total shoulder arthroplasty. J Shoulder Elbow Surg2016;25:1418-24</ref>

Many pathologies that could not be treated previously found a solution through this design, and indications are currently expanding. It is now used for various conditions such as failed total shoulder arthroplasty or hemiarthroplasty, complex proximal humeral fractures and defective fracture union or nonunion, chronic locked dislocation, immunological arthritis with or without associated rotator cuff tears, failed or irreparable massive rotator cuff tears, and tumors.<ref>Smith CD, Guyver P, Bunker TD. Indications for reverse shoulder replacement: A systematic review. J Bone Joint Surg [Br] 2012;94:577-83</ref>
===Acute proximal humerus fracture===
Reverse shoulder arthroplasty is a more reliable treatment than hemiarthroplasty for complex proximal humerus fractures at least in elderly patients because its functional outcomes appear to depend less on tuberosity healing and rotator cuff integrity (Figure).<ref>Lädermann A, Chiu J, Collin P, Piotton S, Nover L, Scheibel M. Hemi- vs reverse shoulder arthroplasty for acute proximal humeral fractures: a systematic review of level I and II studies. Obere Extremität 2019;14:127–35</ref>

[[File:Figure 25 Millon.jpg|thumb|center|Reverse shoulder athroplasty for fracture.
Frontal, axial and lateral Lamy radiographs after a reverse total shoulder implant. Note the lower positioning of the glenoid baseplate, the satisfactory reconstruction of the tuberosities, and the absence of cement at the autograft level.]]

===Malunited/nonunited proximal humerus fracture===
Surgical options to address malunited proximal humerus fractures are determined largely by the existing deformity. They can be categorized broadly as humeral head-preserving techniques (e.g. osteotomies, soft-tissue releases and removal of bony protuberances) or humeral head-sacrificing techniques. Amongst the latter, reverse shoulder arthroplasty proved to be the most reliable.

[[File:Malunion Rickenbach.png|thumb|center|Reverse shoulder arthroplasty for malunion of proximal humeral fracture. A) Anteroposterior radiograph of a malunited proximal humerus fracture; B) post-operative radiograph of the fracture sequelae treated with reverse shoulder arthroplasty.]]

===Glenohumeral Osteoarthritis With Severe Glenoid Bone Loss===
The use of reverse shoulder arthroplasty in patients with severe glenoid bone loss and osteoarthritis is the best option. Excellent results have been reported in patients with osteoarthritis, an intact rotator cuff and substantial glenoid bone loss treated with reverse shoulder arthroplasty with or without bone grafting (Video).

[[File:Glenohumeral Osteoarthritis With Severe Glenoid Bone Loss.mp4|thumb|Fifty-one years old patient with right glenoid dysplasia (C glenoid) and an intact rotator cuff. Computed tomography (CT) scan of the shoulder shows 60 degrees of retroversion. The patient has been treated with combined bony and metallic augmentation. At three months follow-up, range of motion improves and imaging reveals satisfactory glenoid reconstruction.]]

===Chronic Locked Glenohumeral Joint Dislocation===
Chronic locked glenohumeral dislocation can also be treated with reverse shoulder arthroplasty (Figure).<ref>Statz JM, Schoch BS, Sanchez-Sotelo J, Sperling JW, Cofield RH.Shoulder arthroplasty for locked anterior shoulder dislocation: a role for the reversed design. Int Orthop. 2017 Jun;41(6):1227-1234</ref>

[[File:Locked dislocation treated by RSA.png|thumb|Locked dislocation of a right shoulder. On the right, postoperative X-ray.]]

===Rheumatoid Arthritis With or Without Associated Rotator Cuff Tears===
Excellent to satisfactory results have been reported for patients with rheumatoid arthritis treated with reverse shoulder arthroplasty. There is no higher complication rates as compared to reverse shoulder arthroplasty in cuff tear arthropathy.<ref>Cho CH, Kim DH, Song KS. Reverse Shoulder Arthroplasty in Patients with Rheumatoid Arthritis: A Systematic Review. Clin Orthop Surg. 2017 Sep;9(3):325-331</ref>

===Revision Arthroplasty===
Revision surgery after primary shoulder arthroplasty (i.e. hemiarthroplasty, resurfacing or total shoulder arthroplasty) produced high patient satisfaction (Figure). It is, however, associated with higher complication and failure rates compared to reverse shoulder arthroplasty for patients without previous arthroplasty.<ref>Gauci MO, Cavalier M, Gonzalez JF, Holzer N, Baring T, Walch G, Boileau P. Revision of failed shoulder arthroplasty: epidemiology, etiology, and surgical options. J Shoulder Elbow Surg. 2019 Oct 6. pii: S1058-2746(19)30531-2</ref>

[[File:Pitacollo TSA-RSA.jpg|thumb|center|A) Anteroposterior radiograph of a failed anatomic total shoulder arthroplasty; B) Anteroposterior post-operative radiograph after reverse shoulder arthroplasty.]]

===Tumours===
Reverse shoulder arthroplasty is an acceptable option for patients after wide resection of the proximal humerus and rotator cuff tendons for malignant bone tumours. However, a prerequisite for the ability to implant a reverse shoulder arthroplasty in these cases requires preservation of the axillary nerve and deltoid muscle to be successful.<ref>Bonnevialle N, Mansat P, Lebon J, Laffosse JM, Bonnevialle P. Reverse shoulder arthroplasty for malignant tumors of proximal humerus. J Shoulder Elbow Surg. 2015 Jan;24(1):36-44.</ref><ref name=":23" />

==Contraindications==
Absolute contraindications include general factors such as non compliance patients (severe psychiatric/neurologic disability, substance abuse), neuro-arthropathies (Charcot) and high patient morbidity (ASA 4+), and local factors like an uncontrolled active infection and substantial deltoid insufficiency because of the very high probability of recurrent instability and the minimal potential gain in function.<ref name=":23" />

=Clinical Practice Guideline=
The goal of this section is to provide clinicians with recommendations based on the best available evidence; to inform clinicians of when there is no evidence; and finally, to help clinicians deliver the best health care possible.

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=Approaches=
==Introduction==
Reverse shoulder arthroplasty can be performed through several approaches, the deltopectoral and anterosuperior being the most common, each with their advantages and disadvantages. The preparation is standardized for all approaches. The patient lies in the beach chair position with a 60° tilt of the chest, at the lateral extremity of the table, leaving the anterior and posterior sides of the shoulder free from obstruction. The elbow must be free from any support to enable the operating assistant to apply a proximally directed force at the elbow allowing proximal subluxation of the humeral head. The front arm rests on an armrest and is draped free.

==Deltopectoral Approach==
The deltopectoral approach allows increased visibility and accessibility of the humerus, better positioning of the glenoid component, reduced implant loosening and scapular notching, and does not compromise the deltoid, which is the important motor of the shoulder. This approach tenotomises the subscapularis or osteotomizes the lesser tuberosity. Failure (observed in 45% of cases, Collin, unpublished data) and dysfunction of the repaired subscapularis remains a concern after both tenotomy and lesser tuberosity osteotomy despite multiple variations in subscapularis takedown and reattachment techniques. Neurologic atrophy and fatty infiltration of the subscapularis muscle belly have been also reported to causes pain and impaired function.

===Surgical technique===
The deltopectoral approach consisted of a 10 to 15 cm skin incision being made from the coracoid process toward the deltoid insertion. The infraclavicular fossa (Mohrenheim fossa) is found, the cephalic vein identified and the consistent medial branches, which give the appearance of the Mercedes Benz symbol, are ligated. A self-retaining retractor is used to maintain exposure between the deltoid and pectoralis major. The subacromial bursa was resected to allow placement of a Hohmann retractor under the deltoid over the top of the coracoid process. The arm was abducted and internally rotated. The subacromial bursa is resected to allow placement of a Brown-Deltoid retractor.

====Subscapularis Tenotomy====
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====Osteotomy of the Lesser Tuberosity====
The osteotomy is initiated at the bicipital groove with a 2-mm saw blade and then completed with a curved osteotome. An approximately 2.5 cm2 in the coronal plane and 5 mm thick fleck of lesser tuberosity is taken such that the osteotomy entered the joint medially without violating the humeral head.<ref>Giuseffi SA, Wongtriratanachai P, Omae H, Cil A, Zobitz ME, An KN, Sperling JW, Steinmann SP. Biomechanical comparison of lesser tuberosity osteotomy versus subscapularis tenotomy in total shoulder arthroplasty. J Shoulder Elbow Surg 2012;21:1087-95.</ref><ref>Ponce BA, Ahluwalia RS, Mazzocca AD, Gobezie RG, Warner JJ, Millett PJ. Biomechanical and clinical evaluation of a novel lesser tuberosity repair technique in total shoulder arthroplasty. J Bone Joint Surg Am 2005;87(Suppl 2):1-8</ref>

A complete release of the subscapularis tendon is then performed and the tendon is pushed in the subscapularis fossa. A glenoid retractor is placed anteriorly. The humeral head is resected with a guide or a free-handed anatomic cut respecting native humeral head version and inclination.

====Subscapularis Repair====
The healing rate of the subscapularis following reverse shoulder arthroplasty is only 52.6%. Internal rotation function in patients with an intact subscapularis at two years after reverse shoulder arthroplasty is significantly better than in patients with failed or absent tendon repairs. Primary repair of reparable subscapularis tendons during reverse shoulder arthroplasty should be thus strongly considered.

====Lesser Osteotomy Repair====
Before placement of the humeral stem, two holes are created with a 2-mm drill bit in the bicipital groove at the superior and inferior aspects of the lesser tuberosity osteotomy. One hole was created in the metaphysis just medial to the lesser tuberosity osteotomy. The sutures are then passed from lateral to medial by entering the bicipital groove, passing around the humeral stem, and exiting medially (Figure). A racking hitch is positioned to rest in the bicipital groove. The two sutures are passed through the subscapularis just medial to the lesser tuberosity osteotomy. The needle is removed from each construct to leave two superior and two inferior limbs (Figure). Then, one of the superior limbs and one of the inferior limbs were shuttled through the superior racking hitch knot (Figure). The suture limbs are passed through a tensioner to remove slack and to tension the repair (Figure).

{| class="wikitable"
|-
|[[File:Capture d’écran 2020-03-28 à 08.56.41.png|thumb|Passage of the sutures. A suture with a half racking suture on the end is passed from lateral to medial through the inferior two holes, and (B) a separate suture is passed through the superior hole.]]
|[[File:Capture d’écran 2020-03-28 à 08.57.27.png|thumb|Passage of the sutures through the subscapularis and needle removal. The stem is placed so that the sutures pass around the prosthesis. (A) The sutures are passed through the subscapularis tendon, and (B) the wedged ends are cut to provide access to four free limbs.]]
|-
|[[File:Capture d’écran 2020-03-28 à 08.58.02.png|thumb|Passage of the sutures through the knots. (A) One suture limb from each pair is selected and (B) passed through the half racking suture.]]
|[[File:Capture d’écran 2020-03-28 à 08.58.27.png|thumb|Tensioning of the sutures. The suture limbs passed through the half racking suture are tensioned. Tensioning is done under visual inspection.]]
|}

==Anterosuperior (Transdeltoid) Approach==
Molé et al. reported superolateral approach that has the main advantage of better post-operative stability, because the anterior structures, including ligament complexes, are preserved.<ref>Molé D, Wein F, Dézaly C, Valenti P, Sirveaux F. Surgical technique: the anterosuperior approach for reverse shoulder arthroplasty. Clin Orthop Relat Res. 2011 Sep;469(9):2461-8</ref> This approach is different from the transacromial approach originally described by Grammont and Baulot<ref name=":35">Grammont PM, Baulot E. Delta shoulder prosthesis for rotator cuff rupture. Orthopedics 1993;16:65-8</ref> and the anterosuperior approach described by Mackenzie.<ref>Mackenzie D. The antero-superior exposure for total shoulder replacement. Orthop Traumatol 1993;2:71-7</ref> While this technique has shown good results, it involves splitting of the deltoid muscle with the risk of weakening of the anterior deltoid (mechanical or neurologic by damage to the distal branches of axillary nerve) and improper postoperative function.

===Surgical technique===
The skin incision extends from the posterior part of the acromioclavicular joint. It is 9 cm long and runs along the axis of the arm. The surgeon dissociates the anterior deltoid fibers and positions a stop suture on the distal portion of the dissociation to prevent any injury of the axillary nerve. The deltoid muscle fibers are divided to open and excise the subacromial bursa and the anterior deltoid from the anterior edge of the acromion and takes away the proximal attachment of the coracoacromial ligament as one piece. The humeral head osteotomy should be generous to allow optimal exposure of the glenoid. Glenoid exposure is completed, labrum is resected, and peripheral capsular release performed. The inferior labrum is carefully released with a knife while maintaining contact with the bony rim and avoiding electric cautery, considering the proximity of the axillary nerve, which is not visualized. This allows the positioning of a hooked retractor that presses the humeral epiphysis, which is protected by a trial humeral prosthesis. Once the glenoid implant is in place, the surgeon subluxates the humerus superiorly and anteriorly and cuffs the trial humeral stem with a trial insert; the reduction enables the surgeon to test the stability and tension. At the end of surgery, the deltoid is closed using laterolateral sutures.

==Deltoid and Subscapularis Sparing Approach (Subscapularis On)==
Indications for subscapularis-on approach were all types of primary reverse shoulder with an intact subscapularis.

[[File:SSc sparing reduit.mp4|thumb|center|Illustrates a right subscapularis-on RSA with superior glenoid erosion.]]

===Surgical technique===
The skin incision extends from the tip of the coracoid process and runs along the axis of the arm. A deltopectoral approach is performed (please refer to deltopectoral approach). After excision of the bursa, the surgeon explores the cuff through rotator interval. Once an intact subscapularis is confirmed, deep dissection is carried out either through the supraspinatus tear or after detaching it. With the arm held in extension and adduction, two long blunt-tipped Hohmann retractors are placed around the humeral head, allowing clear exposure of the proximal humerus (Figure).

[[File:Fig 2.jpg|thumb|center|Illustration: With the arm held in extension and adduction, two long broad-tipped Hohmann retractors are placed around the humeral head, retracting the subscapularis and the remnant posterior rotator cuff, allowing clear exposure of the humeral head.]]

The humerus is prepared to accommodate a stem. After a retroversion guide placement, the level of the humeral head osteotomy is marked with an electrocautery device (Figure), and a free-hand osteotomy is performed. The humeral head osteotomy should be generous to allow optimal exposure of the glenoid.

[[File:Fig 3.jpg|thumb|center|A 20 degrees retroversion guide is placed and the level of the osteotomy is marked on the humeral head with an electrocautery device.]]

The humeral shaft is then prepared (Figure).

[[File:Fig 4.jpg|thumb|center|Following humeral head removal, preparation of the humeral shaft is completed using only compactors.]]

If the initial osteotomy is too shallow or the inclination is suboptimal, it is then revised to maximize the anatomic fit between the prosthesis and the bone. After preparing the humerus, a trial humeral prosthesis is inserted in humeral canal to protect the humeral epiphysis during glenoid preparation. Cartilage removal, labrum resection, and peripheral capsular release are then completed sequentially. Tight inferior glenohumeral ligaments, which may prevent adequate exposure of the glenoid or post-operative shoulder mobility, are released using an electrocautery device with close contact with the inferior glenoid rim. A forked retractor is then inserted inferiorly to maintain visualization and accessibility to the glenoid (Figure).

[[File:Fig 5.jpg|thumb|center|A forked retractor is placed inferior to the glenoid to maintain visualization and accessibility. The glenoid is prepared according to the recommended surgical technique to obtain neutral inclination and version.]]

This maneuver pushes the humeral epiphysis inferiorly or antero-inferiorly (compared to standard deltopectoral approach in which the humeral head is dislocated posteriorly) for better visualization of the glenoid. The glenoid is prepared according to the recommended surgical technique to obtain neutral inclination and version. Preoperative planning software is used to determine the amount of inferior tilt and whether an augmented baseplate is required. The baseplate is secured onto the glenoid with non-locking and locking peripheral screws. An eccentric 36 or 39 mm glenosphere is used to limit impingement in adduction, extension and external rotation. It is not recommended implanting a larger glenosphere as the excessive lateralization may hinder access to the humerus. The glenosphere is impacted into the baseplate. Once the glenoid implant is in place, the surgeon subluxs the humerus superiorly and anteriorly. A stem is inserted. The shoulder is reduced via gentle traction on the arm and range of motion tested in all planes to ensure stability and confirm the prosthesis moves easily without impingement. The prothesis is then dislocated for final implantation of a definitive polyethylene. Osteophytes are removed and lateral tuberoplasty can be performed to maximize flexibility and avoid bony impingement. The surgical incision measures about 7 to 10 cm (Figure).

[[File:Fig 6 améliorée.jpg|thumb|center|Length of the surgical incision.]]

===Postoperative Rehabilitation===
By using this subscapularis-on approach, patients do not require any immobilization with a sling following the operation. Immediate active motion in all planes is allowed post-operatively.

===Complications===
Tuberosity avulsions that require suture cerclage can bee observed (Figure).

[[File:Figure 8.jpg|thumb|center|A) Example of tuberosity avulsions (black arrows) requiring 3 suture cerclages. B) Tuberosity healing was observed at two-year follow-up. ]]

===Advantages of Subscapularis-on Approach===
There are several reasons why the integrity of the subscapularis tendon should be maintained when performing a reverse shoulder arthroplasty. First, acute muscle lengthening related to the non-anatomic design of the prosthesis plays a role. The muscle lengthening occurs mainly in the supraspinatus (19 mm with a bony increased offset reverse shoulder arthroplasty (BIO-RSA) implant), followed by the upper part of the subscapularis, which accounts for 70% or more of the strength and function of the subscapular muscle-tendon unit. Muscle lengthening could theoretically make reinsertion of the subscapularis more challenging, particularly with lateral offset designs.
Secondly, the inferior part of the subscapularis has no tendon macroscopically; the muscle attaches directly to the bone, making reinsertion difficult. Healing rate is consequently low, at around 55%. Thirdly, the subscapularis is described as being the largest muscle in the rotator cuff and stronger (53% of global strength of the rotator cuff) than the supraspinatus, infraspinatus and teres minor combined.<ref name=":33">Keating JF, Waterworth P, Shaw-Dunn J, Crossan J. The relative strengths of the rotator cuff muscles. A cadaver study. J Bone Joint Surg Br 1993;75:137-40</ref> If a muscle has to be divided, it seems logical to sacrifice the supraspinatus that accounts for only 14% of the global strength.<ref name=":33" /> Fourth, the subscapularis plays a crucial role in anterior elevation. Collin et al. previously demonstrated that the subscapularis is the most important rotator cuff muscle for elevation in native shoulders.<ref>Collin P, Matsumura N, Lädermann A, Denard PJ, Walch G. Relationship between massive chronic rotator cuff tear pattern and loss of active shoulder range of motion. J Shoulder Elbow Surg 2014;23:1195-202</ref>

===Disadvantages of Subscapularis-on Approach===
The main disadvantage of the subscapularis-on technique is limited surgical exposure. Even though specialized jigs were not required for the above-mentioned technique, the development of specifically-designed instrumentation for this procedure seems necessary. Moreover, limited exposure prevents the use of patient-specific surgical guides. Development of less invasive guides or navigation systems may become inevitable in the future. Even if good exposure of the humeral head is achieved, the free-hand humeral osteotomy can be problematic. Subscapularis-on approach is technically challenging in certain cases (e.g. stiff shoulders, small patients) and may not be practical or possible in all circumstances. Intra-operatively, important lateralization (> 5 mm) of the glenoid is impossible, as subsequent exposure of the humerus is insufficient to implant the stem.

=Specific Conditions=
==Reverse Shoulder Arthroplasty in Patients with Preoperative Deltoid Impairment==
===Definition, Causes, and Classification of Deltoid Impairment===
The deltoid is critical for shoulder motion and any pathology involving this muscle is highly detrimental to normal glenohumeral function. It generates over 50% of the force necessary to elevate the arm in scapula plane in a normal shoulder and is the only muscle remaining to provide an abduction moment in patients with massive rotator cuff tears.<ref>Bianchi S, Martinoli C, Abdelwahab IF. Imaging findings of spontaneous detachment of the deltoid muscle as a complication of massive rotator cuff tear. Skeletal radiology 2006;35:410-5</ref> Deltoid impairment is defined as any condition which compromise its physiological function. Such impairment may be permanent or transient and can occur from a variety of conditions.

The deltoid muscle may be shortened upon itself and lose function by disruption of normal length-tension relationships (Figure).

[[File:Image21-57.jpg|thumb|center|Proximal migration of the humeral head leads to a lack of deltoid tension.]]

Effectively, as the Blix curve describes, maintenance of length is required for a muscle to generate adequate tension.<ref>Blix M. Die lange und dle spannung des muskels. Skand Arch Physiol 1891:295-318</ref> Therefore shortening either by proximal migration of the deltoid insertion (rotator cuff arthropathy) or distal migration of the origin (scapular spine fracture) will compromise deltoid function. Proximal migration in particular can be considered a transient cause of deltoid impairment since it can be treated with reverse shoulder arthroplasty. Distal migration, on the other hand, may be permanent or transient depending on the situation.

In the most severe conditions, part or all of the deltoid muscle may be completely absent. Such permanent impairment is rare but may be observed following deltoid muscular flap transfer (for irreparable rotator cuff tears, Figure)<ref>Gazielly D. The deltoid flap procedure. Tech Shoulder Elbow Surg 2000:117–27</ref><ref name=":42">Glanzmann MC, Flury M, Simmen BR. Reverse shoulder arthroplasty as salvage procedure after deltoid muscle flap transfer for irreparable rotator cuff tear: a case report. J Shoulder Elbow Surg 2009;18:e1-2</ref><ref name=":20">Tay AK, Collin P. Irreparable spontaneous deltoid rupture in rotator cuff arthropathy: the use of a reverse total shoulder replacement. J Shoulder Elbow Surg 2011;20:e5-8</ref> or following tumor resection (Figure).

[[File:Image22-59.jpg|thumb|center| Status after a left deltoid muscular flap transfer for irreparable rotator cuff tears. A: Schematic drawing of the surgical technique (with permission of Gazielly D.). B: Frontal magnetic resonance imaging demonstrates absence of the deltoid muscle laterally. C. Clinical photo demonstrating atrophy of the anterior and middle deltoid.]]

[[File:Image23-61.jpg|thumb|center|A: Intraoperative view of a left anterior deltoid resection in the context of proximal humerus neoplasm. Isolation of the anterior deltoid through which an open biopsy had previously been performed. B: Resection of the entire anterior deltoid and proximal humerus. C: Intraoperative view following implantation of a reverse shoulder arthroplasty. D: Postoperative anterior-posterior radiograph.]]

One of the most common forms of deltoid impairment seen clinically is disruption of the muscle origin (without removal of the entire muscle belly). This most commonly occurs in the postsurgical setting after an open rotator cuff repair in which a deltoid split approach is used and part of the deltoid origin is take-down to gain exposure (Figure).<ref>Sher JS, Iannotti JP, Warner JJ, Groff Y, Williams GR. Surgical treatment of postoperative deltoid origin disruption. Clin Orthop Relat Res 1997:93-8</ref>

[[File:Image24-63.jpg|thumb|center|Sequelae of a right open rotator cuff repair involving violation of the deltoid insertion. A: clinical appearance with an anterior deltoid with severe atrophy. B: Anterior-posterior radiograph demonstrating rotator cuff arthropathy. C: Postoperative anterior-posterior view of the reverse shoulder arthroplasty. D and E: Coronal and sagittal views of postoperative anterior forward elevation.]]

Failure of the deltoid to heal back to the acromion can easily be appreciated clinically by a defect to palpation. Additionally, deltoid insertion disruption can occur through chronic attritional rupture as in chronic rotator cuff arthropathy with anterosuperior escape,<ref>Blazar PE, Williams GR, Iannotti JP. Spontaneous detachment of the deltoid muscle origin. J Shoulder Elbow Surg 1998;7:389-92</ref><ref>Morisawa K, Yamashita K, Asami A, Nishikawa H, Watanabe H. Spontaneous rupture of the deltoid muscle associated with massive tearing of the rotator cuff. J Shoulder Elbow Surg 1997;6:556-8</ref> or following trauma (Figure).<ref>Chiba D, Sano H, Nakajo S, Fujii F. Traumatic deltoid rupture caused by seatbelt during a traffic accident: a case report. Journal of orthopaedic surgery 2008;16:127-9</ref><ref>Lin JT, Nagler W. Partial tear of the posterior deltoid muscle in an elderly woman. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine 2003;13:120-1</ref>

[[File:Image25-65.jpg|thumb|center|Evaluation in an acute phase of left posterior deltoid insertion disruption on T2 weighted fat saturated magnetic resonance imaging (MRI) arthrogram sagittal sequences revealed an edema (red arrows) propagating into the muscle.]]

The deltoid muscle may be globally impaired in the setting of persistent denervation,<ref>Wilbourn AJ, Aminoff MJ. AAEM minimonograph 32: the electrodiagnostic examination in patients with radiculopathies. American Association of Electrodiagnostic Medicine. Muscle Nerve 1998:1612-31</ref> grade 3 or 4 fatty infiltration,<ref>Goutallier D, Postel JM, Bernageau J, Lavau L, Voisin MC. Fatty muscle degeneration in cuff ruptures. Pre- and postoperative evaluation by CT scan. Clin Orthop Relat Res 1994:78-83</ref> previous surgical approach, trauma (Figure), post radiation syndrome, or myopathy (myositis, Parkinson, Duchenne muscular dystrophy, etc.).<ref>Moser T, Lecours J, Michaud J, Bureau NJ, Guillin R, Cardinal E. The deltoid, a forgotten muscle of the shoulder. Skeletal radiology 2013;42:1361-75</ref>

[[File:Image29-73.jpg|thumb|Preoperative (A, anterior-posterior and B, lateral scapular views) and post reverse shoulder arthroplasty (C anterior-posterior view) of a right shoulder after a gunshot in a patient that presented post-traumatically with global neurological impairment including the axillary nerve.]]

Once the etiology is determined, the deltoid impairment should be then classified according to its location and extent. Lädermann et al.<ref name=":23">Lädermann A, Walch G, Denard PJ, Collin P, Sirveaux F, Favard L, Edwards TB, Kherad O, Boileau P. Reverse shoulder arthroplasty in patients with pre-operative impairment of the deltoid muscle. The bone & joint journal 2013;95-B:1106-13</ref> proposed a classification for deltoid impairment based on location: type 1 corresponds to an impairment localized anteriorly, type 2 an anterior and middle one, type 3 involves only the middle deltoid, and type 4 is a global impairment (Figure). As discussed subsequently, this classification related to prognosis with type 4 in particular having a poorer function following reverse shoulder arthroplasty.

[[File:Classification atteinte deltoid.jpg|thumb|center|Deltoid impairment based on location: type 1 corresponds to an impairment localized anteriorly, type 2 an anterior and middle one, type 3 involves only the middle deltoid, and type 4 is a global impairment. ]]

====Results====
Glanzmann et al. first published a case report of the results of a reverse shoulder arthroplasty after deltoid muscle flap transfer.<ref name=":42" /> At two years follow-up, the patient was satisfied and had a Constant score of 62 points, suggesting that the entire deltoid may not be necessary for a successful outcome. Tay and Collin also described successful results of a reverse shoulder arthroplasty implanted in the setting of an irreparable rupture of the middle portion of the deltoid muscle.<ref name=":20" /> No intra- or postoperative complication was noticed. At two years follow-up, the patient was pain free, had active anterior elevation of 150 degrees, and the Constant score was 65 points. Gulotta et al. reported in their biomechanical study that scapular plane elevation may still be possible following a reverse shoulder arthroplasty in the setting of anterior deltoid deficiency. When the anterior deltoid is deficient, there is a compensatory increase in the force required by the subscapularis and middle deltoid.<ref>Gulotta LV, Choi D, Marinello P, Wright T, Cordasco FA, Craig EV, Warren RF. Anterior deltoid deficiency in reverse total shoulder replacement: a biomechanical study with cadavers. J Bone Joint Surg Br 2012;94:1666-9</ref> In this condition, surgeons should focus on preserving the subscapularis as much as possible during approach of reverse shoulder arthroplasty. Whatley et al. reported three cases who had postoperative rupture of the anterolateral deltoid following failed mini-open or open rotator cuff repairs. Successful repair of the deltoid was achieved using a transosseous suture repair in all three patients.<ref>Whatley AN, Fowler RL, Warner JJ, Higgins LD. Postoperative rupture of the anterolateral deltoid muscle following reverse total shoulder arthroplasty in patients who have undergone open rotator cuff repair. J Shoulder Elbow Surg 2011;20:114-22</ref> Essilfie et al. presented a case with deltoid failure after anatomical total shoulder arthroplasty revised with reverse shoulder arthroplasty. His ASES score after reverse shoulder arthroplasty was better than historical outcomes for resection arthroplasty and glenohumeral arthrodesis.<ref>Essilfie A, McKnight B, Heckmann N, Rick Hatch GF, 3rd, Omid R. Revision reverse total shoulder arthroplasty in a patient with preoperative deltoid insufficiency: a case report. J Shoulder Elbow Surg 2017;26:e232-e5</ref> Lattisimus dorsi muscle transfer can also provide an augmentation in patients with deltoid insufficiency.<ref name=":43">Dosari M, Hameed S, Mukhtar K, Elmhiregh A. Reverse shoulder arthroplasty for deltoid-deficient shoulder following latissimus dorsi flap transfer. Case report. Int J Surg Case Rep 2017;39:256-9</ref><ref>Goel DP, Ross DC, Drosdowech DS. Rotator cuff tear arthropathy and deltoid avulsion treated with reverse total shoulder arthroplasty and latissimus dorsi transfer: case report and review of the literature. J Shoulder Elbow Surg 2012;21:e1-7</ref> Dosari et al. presented a patient with a history of gunshot injury and loss of most of his shoulder bony and muscular structures. Due to deltoid muscle deficiency, the patient underwent lattisimus dorsi muscle flap followed by reverse shoulder arthroplasty with successful result.<ref name=":43" /> Deltoid reconstruction at the same time of reverse shoulder arthroplasty is also a viable choice as a salvage procedure for patients with deltoid deficiency.<ref name=":25">Marinello PG, Amini MH, Peers S, O'Donnell J, Iannotti JP. Reverse total shoulder arthroplasty with combined deltoid reconstruction in patients with anterior and/or middle deltoid tears. J Shoulder Elbow Surg 2016;25:936-41</ref> Marinello suggested if less than 50% of any part of the anterior or middle deltoid was involved (≤3 cm), reattachment or reconstruction was not needed. If all of the anterior and/or middle deltoid were involved, then reattachment or reconstruction was indicated.<ref name=":25" /> In a multicentered study, Lädermann et al. reviewed 49 patients (49 shoulders) at a mean of 38 ± 30 months postoperative following reverse shoulder arthroplasty in the setting of deltoid impairment.<ref name=":23" /> Postoperative complications occurred in nine (18%) patients, including two postoperative dislocations and two acute postoperative neurological lesions. Five (10%) patients required additional surgery. Active forward elevation and Constant score improved significantly. However, these values are significantly lower for patients suffering from global deltoid impairment (type 4) compared to types 1 through 3. The mean postoperative forward elevation was lower in the setting of global deltoid impairment (70 degrees) compared to partial impairment (127 degrees, 136 degrees and 125 degrees, groups 1-3 respectively) (P=.002). The postoperative Constant score was lower in the setting of global impairment (41) compared to partial impairment (57, 63 and 68, groups 1-3 respectively) (P=.006). Overall, the rate of patient satisfaction was 98% at final follow-up.<ref name=":23" /> Schneeberger et al. retrospectively reviewed the outcome of 19 patients treated with reverse shoulder arthroplasty after failed deltoid flap reconstruction.<ref>Schneeberger AG, Muller TM, Steens W, Thur C. Reverse total shoulder arthroplasty after failed deltoid flap reconstruction. Arch Orthop Trauma Surg 2014;134:317-23</ref> They noticed a high rate of complication (37%), including one instability. Nonetheless, at a mean follow-up of 4.5 years, only two patients had moderate to severe pain, all patients regained anterior active elevation above 90 degrees, and 15 of 19 patients were very satisfied.

It seems that the most important factor for postoperative result is the extent of the lesion, and not its cause. Interestingly, patient satisfaction is high in all publications on reverse shoulder arthroplasty in the setting of deltoid impairment. However, this is likely related to very poor preoperative function and moderate preoperative expectations of this population.

==Acromial Insufficiency==
Pre- or postoperative acromial pathology, which could theoretically compromise deltoid condition and affect the proper function of the prosthesis, is of legitimate concern.

===Preoperative===
Postoperative fractures occur at least in 3% of cases and their causes are numerous. Preoperatively, the acromion may be subject to a congenital or acquired abnormality such as an os acromiale. It can also already be eroded, fragmented or even fractured from the underlying head in case of cuff tear arthropathy (Figure), or osteoporosis-induced insufficiency.

[[File:Image37-89.jpg|thumb|center|Preoperative insufficiency of a left acromion on an anteroposterior view. Note that a large part of the acromion just seems to have disappeared.]]

[[File:Bouvier.jpg|thumb|center|Preoperative spine fracture in a patient suffering from rotator cuff arthropathy with severe Glenoid bone loss.]]

===Postoperative===
It has been suggested that these fractures may be the result of a stress coming from the tip of the superior metaglene fixation screw.<ref name=":34">Crosby LA, Hamilton A, Twiss T. Scapula fractures after reverse total shoulder arthroplasty: classification and treatment. Clin Orthop Relat Res 2011;469:2544-9</ref> Another risk factor is osteoporosis<ref>Otto RJ, Virani NA, Levy JC, Nigro PT, Cuff DJ, Frankle MA. Scapular fractures after reverse shoulder arthroplasty: evaluation of risk factors and the reliability of a proposed classification. J Shoulder Elbow Surg. 2013 Nov;22(11):1514-21</ref><ref name=":24">Schenk P, Aichmair A, Beeler S, Ernstbrunner L, Meyer DC, Gerber C. Acromial Fractures Following Reverse Total Shoulder Arthroplasty: A Cohort Controlled Analysis. Orthopedics. 2020 Jan 1;43(1):15-22</ref> The role of prosthetic design, distalization, global lateralization and Glenoid medicalization is still debated.<ref name=":24" /><ref>Wong MT, Langohr GDG, Athwal GS, Johnson JA. Implant positioning in reverse shoulder arthroplasty has an impact on acromial stresses. J Shoulder Elbow Surg. 2016 Nov;25(11):1889-1895</ref>

Acromial fractures can be classified as avulsion fractures of the anterior acromion (Type I), fractures of the acromion posterior to the acromioclavicular joint (Type II) and fractures of the scapular spine (Type III).<ref name=":34" />

The symptomatology usually appears within the first year with sudden pain and decrease of function. The localization of the former is typically posterior. The fracture is best seen on an axillary lateral view to differentiate acromial fracture from scapular spine fracture (Figure).

[[File:Acromial fracture.png|thumb|center|Postoperative anteroposterior X-ray demonstrate an acromial fracture.]]

The use of positron emission tomography-computed tomography is helpful in diagnosis of non-displaced fractures.

[[File:SPECT CT acromial fracture.png|thumb|center|SPECT CT of a left shoulder after a reverse shoulder arthroplasty. The patient developed pain 6 months after surgery. X-ray did not revealed fracture. SCPECT CT clearly demonstrated a hypersignal on the acromion.]]

Good results have surprisingly been reported in patients with preoperative acquired or congenital acromial pathology or postoperative acromial fracture.<ref>Mottier F, Wall B, Nove-Josserand L, Galoisy Guibal L, Walch G. [Reverse prosthesis and os acromiale or acromion stress fracture]. Rev Chir Orthop Reparatrice Appar Mot 2007;93:133-41</ref> This can be explained by the persistent attachment of the deltoid to the spine of the scapula and clavicle and the more predominant postoperative scapulothoracic motion compared to the glenohumeral one. In case of postoperative acromial or scapular fractures, results are usually disappointing.<ref>Neyton L, Erickson J, Ascione F, Bugelli G, Lunini E, Walch G. Grammont Award 2018: Scapular fractures in reverse shoulder arthroplasty (Grammont style): prevalence, functional, and radiographic results with minimum 5-year follow-up. J Shoulder Elbow Surg. 2019 Feb;28(2):260-267</ref>

The best treatment option for acromial fractures is thus conservative, as it does not lead to major shoulder dysfunction. Outcome of scapular spine fractures are more unpredictable with displacement of the bony support for the entire deltoid, pain and dysfunction. Consequently, some authors recommend open reduction, internal fixation and allograft associated with postoperative immobilization on a 60° abduction splint in order to avoid nonunion and acromiohumeral contact secondary to inferior acromial tilt.<ref name=":34" />

==Latissimus Dorsi Transfert in Combination with the Reverse Shoulder Arthroplasty==
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==Reverse Shoulder Arthroplasty in Weight Bearing Patients==
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=Results=
With a mean anterior forward flexion of 137 degrees and a mean external rotation elbow at the side of 6 degrees, reverse shoulder arthroplasty typically provides satisfactory clinical outcomes for a variety of complex shoulder diagnoses associated with severe pain and limitation of range of motion.<ref name=":26">Wall B, Nove-Josserand L, O'Connor DP, Edwards TB, Walch G. Reverse total shoulder arthroplasty: a review of results according to etiology. J Bone Joint Surg Am 2007;89:1476-85</ref> However, some patients have had unexpectedly poor functional improvements after reverse shoulder arthroplasty.<ref name=":26" /> Poor postoperative range of motion following reverse shoulder arthroplasty, has been associated with younger age,<ref name=":44">Hartzler RU, Steen BM, Hussey MM, Cusick MC, Cottrell BJ, Clark RE, Frankle MA. Reverse shoulder arthroplasty for massive rotator cuff tear: risk factors for poor functional improvement. J Shoulder Elbow Surg 2015;24:1698-706</ref> gender,<ref name=":45">Schwartz DG, Cottrell BJ, Teusink MJ, Clark RE, Downes KL, Tannenbaum RS, Frankle MA. Factors that predict postoperative motion in patients treated with reverse shoulder arthroplasty. J Shoulder Elbow Surg. 2014 Sep;23(9):1289-95</ref> surgeon experience,<ref>Walch G, Bacle G, Lädermann A, Nové-Josserand L, Smithers CJ. Do the indications, results, and complications of reverse shoulder arthroplasty change with surgeon's experience? J Shoulder Elbow Surg. 2012 Nov;21(11):1470-7</ref> preoperative diagnosis such as posttraumatic arthritis and revision arthroplasty,<ref>Cuff D, Pupello D, Virani N, Levy J, Frankle M. Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency. J Bone Joint Surg Am 2008;90:1244-51.</ref><ref name=":26" /> pre- and intraoperative range of motion or deltoid impairment,<ref name=":23" /><ref name=":45" /> postoperative arm lengthening<ref name=":32" /><ref>Lädermann A, Lubbeke A, Collin P, Edwards TB, Sirveaux F, Walch G. Influence of surgical approach on functional outcome in reverse shoulder arthroplasty. Orthopaedics & traumatology, surgery & research : OTSR 2011;97:579-82</ref><ref name=":30" /> or neurological lesion.<ref name=":44" /><ref name=":46">Lädermann A, Lübbeke A, Mélis B, Stern R, Christofilopoulos P, Bacle G, Walch G. Prevalence of neurologic lesions after total shoulder arthroplasty. J Bone Joint Surg Am 2011;93:1288-93</ref> Surgery of the non-dominant side, lower preoperative range of motion, and lower functional outcome scores preoperatively are predictive of a slower recovery of active anterior forward flexion after reverse shoulder arthroplasty.<ref>Collin P, Matsukawa T, Denard PJ, Gain S, Lädermann A.Pre-operative factors influence the recovery of range of motion following reverse shoulder arthroplasty. Int Orthop. 2017 Oct;41(10):2135-2142</ref>

=Complications=
The first series of reverse shoulder arthroplasty with an at least two years follow-up, confirmed the preliminary results with excellent functional outcome and stable glenoid fixation.<ref name=":36" /> Beck S, Patsalis T, Busch A, Dittrich F, Dudda M, Jäger M, Wegner A. A substantial and durable improvement in the long term has been reported.<ref>Beck S, Patsalis T, Busch A, Dittrich F, Dudda M, Jäger M, Wegner A. Long-term results of the reverse Total Evolutive Shoulder System (TESS). Arch Orthop Trauma Surg. 2019 Aug;139(8):1039-1044</ref><ref>Ernstbrunner L, Rahm S, Suter A, Imam MA, Catanzaro S, Grubhofer F, Gerber C. Salvage reverse total shoulder arthroplasty for failed operative treatment of proximal humeral fractures in patients younger than 60 years: long-term results. J Shoulder Elbow Surg. 2019 Oct 6. pii: S1058-2746(19)30537-3.</ref><ref>van Ochten JHM, van der Pluijm M, Pouw M, Felsch QTM, Heesterbeek P, de Vos MJ. Long - Term survivorship and clinical and radiological follow - up of the primary uncemented Delta III reverse shoulder prosthesis. J Orthop. 2019 Mar 24;16(4):342-346</ref> However, the complexity of this procedure with regards to its singular anatomy and special patient population, is reflected by the large number of reported problems and complications. As defined by Zumstein et al., problems can be defined as intra- or postoperative events that are not likely to affect the patient’s final outcome.<ref name=":19">Zumstein MA1, Pinedo M, Old J, Boileau P. Problems, complications, reoperations, and revisions in reverse total shoulder arthroplasty: a systematic review. J Shoulder Elbow Surg. 2011 Jan;20(1):146-57</ref> This will include hematomas, phlebitis, heterotopic ossification, algodystrophy and will not be part of the treated subjects of this thesis. Complications are defined as any intra- or postoperative events that are likely to have a negative influence on the patient’s final outcome, such as intraoperative cement extravasation, intra- or postoperative fractures, dislocations, infections, neurological lesions, radiographic changes such as glenoid or humeral lucent lines, scapular notching, stress shielding, aseptic loosening, reinterventions (without replacement of the component) or revisions (with replacement of the component).

==Radiological Changes==
This is the most frequently reported complication after reverse shoulder arthroplasty.<ref name=":19" /> Long-term studies reported their prevalence.<ref name=":37" />

===Impingements===
====Scapular Notching====
Scapular notching is the most frequent radiographic change after a reverse shoulder arthroplasty and has been reported as high as 88%.<ref name=":37" /> It was initially described as the result of abutment of the prosthetic metaphysis against the scapular neck with the arm in adduction consequent to humerus medialization. Repetitive contact between polyethylene and bone may result in polyethylene wear debris, chronic inflammation and osteolysis,<ref name=":39" /> radiolucency around the glenoid component,<ref>Werner CM, Steinmann PA, Gilbart M, Gerber C. Treatment of painful pseudoparesis due to irreparable rotator cuff dysfunction with the Delta III reverse-ball-and-socket total shoulder prosthesis. J Bone Joint Surg Am 2005;87:1476-86</ref> loosening of the glenoid component,<ref>Cazeneuve JF, Cristofari DJ. Delta III reverse shoulder arthroplasty: radiological outcome for acute complex fractures of the proximal humerus in elderly patients. OOrthop Traumatol Surg Res 2009;95:325-9</ref> presence of an inferior bone spur, and ossification in the glenohumeral space.<ref name=":37" />

Scapular notching (Figure) typically occurs within six months after surgery and appears to stabilize in most cases. The use of an anterosuperior approach, a high position of the baseplate on the glenoid and superior tilting have all been associated with higher rates of notching caused by mechanical impingement with the arm in adduction. Eccentric glenospheres with an inferior offset and glenoid components with a more lateral offset (bony or metal) can reduce the risk of notching.<ref name=":11" /><ref name=":3" /> Mizuno et al. analyzed the influence of an eccentric glenosphere in 47 consecutive cases compared with a historical group treated by the same surgeon. The rates of notching were not different but the severity of notching was less when using an eccentric glenosphere.<ref name=":38" /> Other authors have reported a negligible rate of notching when using an inferior offset component.

[[File:Scapular notching.png|thumb|center|Scapular notching. The severe superior glenoid bone loss (left) has not been corrected intraoperatively (middle), resulting in a severe scapular notching of grade 4 according to Sirveaux.]]

Two types of impingement interactions are noted (Figure).

[[File:Image41-97.jpg|thumb|Two types of impingement interactions coexist; it could correspond to a friction of the polyethylene against the bone (Figure A and B). These repetitive frictions might lead with time to progressive bony abrasion. These phenomena are probably the cause of a rapid apparition of scapular notching. They are the results of multiple motions (adduction, rotations, extension) and not the consequence of a simple contact with the pillar in adduction arm at the side as previously believed. Contrarily, some impingements are related to an abutment with no possibilities to either component to continue the movement (Figure C and D). ]]

====Anterior Impingement====
Anterior impingement can also occur in the setting of reverse shoulder arthroplasty. Anterior impingement may specifically jeopardize the clinical outcome and implant survivorship, ranging from limitation in internal rotation to dislocation by decoaptation, or failure.<ref>De Wilde L1, Walch G. Humeral prosthetic failure of reversed total shoulder arthroplasty: a report of three cases. J Shoulder Elbow Surg. 2006 Mar-Apr;15(2):260-4</ref> As the conformation of the joint changes from spinning to hinging in reverse shoulder arthroplasty, implant version of the humeral stem seems to be the most predictive factor for the occurrence anterior scapular notching. Grammont already warned that excessive retroversion led to decreased internal rotation.<ref name=":35" /> The anterior notching mostly occurred in adduction. The best compromise between anterior and posterior notching to favor a functional arc of motion seems to be 20 to 40 degrees of humeral retroversion.<ref>Stephenson DR, Oh JH, McGarry MH, Rick Hatch GF 3rd, Lee TQ. Effect of humeral component version on impingement in reverse total shoulder arthroplasty. J Shoulder Elbow Surg. 2011 Jun;20(4):652-8</ref> On the other hand, glenoid component version doesn’t seem to influence notching in the axial plane.<ref>Favre P, Sussmann PS, Gerber C. The effect of component positioning on intrinsic stability of the reverse shoulder arthroplasty. J Shoulder Elbow Surg 2010;19:550–556</ref>

==Infection==
The incidence of infections after primary reverse shoulder arthroplasty is around 5%,<ref name=":5" /> which is higher than in anatomic shoulder arthroplasty.<ref>Fehringer EV, Mikuls TR, Michaud KD, Henderson WG, O'Dell JR. Shoulder arthroplasties have fewer complications than hip or knee arthroplasties in US veterans. Clin Orthop Relat Res 2010;468:717-22</ref><ref>Seebauer L. Total reverse shoulder arthroplasty: European lessons and future trends. Am J Orthop (Belle Mead NJ). 2007 Dec;36(12 Suppl 1):22-8</ref> Reasons are the large dead space caused by the ball-and-socket configuration, the frequent postoperative hematoma, the extensive surgical dissection, and in some patients the compromised general health and the numerous previous surgeries. The commonly identified low-virulence organisms are Cutibacterium acnes and Staphylococcus epidermidis. Proven and suspected infections should be revised operatively. Acute infection of less than three weeks in a stable arthroplasty should be treated with debridement and antibiotics. Late infections should be treated with arthroplasty removal, debridement and reimplantation.

==Instability==

Dislocation is one of the most common complications after reverse shoulder arthroplasty, with rates as high as 14% which account for almost half of the complications in some series. Intraoperative criteria have been proposed by other authors to assess prosthetic stability. The recommendations are numerous and include 1) a prosthesis implantation in such a way that it is difficult to reduce, 2) the absence of pistoning of the prosthesis when applying axial traction on the arm, 3) stability throughout a full range of motion, 4) passive adduction of the arm with elbow at side, 5) palpation of the tension in the conjoint tendon after reduction with the arm at the side and the elbow extended, 6) no asymmetric subluxation or tilting of the proximal humeral component on the glenosphere during adduction, and 7) free glenohumeral motion without scapula-thoracic motion between 0° to 60° of abduction. Most cases of dislocation occur during the first few months after implantation and are a result of a technical error. Risk factors for dislocation include body mass index > 30, male sex, previous surgery, subscapularis deficiency and high neck shaft angle (155 degrees). The etiology of dislocation is multifactorial. It can occur due to 1) deltoid insufficiency, 2) lack of anterior restraints including subscapularis insufficiency, conjoint tendon weakness, and pectoralis major insufficiency, 3) malpositioning of the components, 4) impingement, and 5) infection. Instability is more frequent in cases of revision arthroplasty. Deltoid insufficiency can be caused by preoperative factors or can result from a postoperative lack of deltoid tension, acromion fracture, polyethylene wear, stem subsidence, or postoperative neurological palsy. Lädermann et al. noted a strong correlation (p < 0.0001) between preoperative humeral length and dislocation. Postoperative shortening of the humerus, as compared to preoperative or contralateral humeral length, was observed in all cases of dislocation.<ref name=":30" /> Subscapularis integrity is important if a 155 degrees is used.<ref>Edwards TB, Williams MD, Labriola JE, Elkousy HA, Gartsman GM, O'Connor DP. Subscapularis insufficiency and the risk of shoulder dislocation after reverse shoulder arthroplasty. J Shoulder Elbow Surg 2009;18:892-6</ref><ref>Cheung EV, Sarkissian EJ, Sox-Harris A, Comer GC, Saleh JR, Diaz R, Costouros JG. Instability after reverse total shoulder replacement. J Shoulder Elbow Surg 2011;20:584-90</ref> Low neck shaft angles (145 and 135 degrees) are more stable designs and subscapularis integrity seems less important to prevent instability.

[[File:Instability.jpg|thumb|center|One month after implantation of a reverse shoulder arthroplasty for a proximal humeral fracture. The X-ray revealed a prosthetic dislocation. Electroneuromyography (ENMG) confirmed a severe axonotmesis of the axillary nerve.]]

==Neurological Lesions==
Lengthening of the arm during reverse shoulder arthroplasty, because of its nonanatomic design and/or maneuver of glenohumeral reduction, may be a major factor responsible for the increased prevalence of neurologic injury. Clinically relevant neurological complications involving the brachial plexus or the axillary nerve, however, are rare following reverse shoulder arthroplasty. A prospective study determined the electrodiagnostic occurrence of peripheral nerve lesions following 155 degrees neck shaft angle reverse shoulder arthroplasty.<ref name=":46" /> If one also takes into account subclinical deterioration of preoperative lesions, 63% of patients in this study had postoperative neurologic lesions. However, only 5% of patients had a lesion that was present beyond 6 months postoperative. The rate of postoperative lesions seems lower using low neck shaft angles.<ref>Lowe JT, Lawler SM, Testa EJ, Jawa A. Lateralization of the glenosphere in reverse shoulder arthroplasty decreases arm lengthening and demonstrates comparable risk of nerve injury compared with anatomic arthroplasty: a prospective cohort study. J Shoulder Elbow Surg. 2018 Oct;27(10):1845-1851</ref> It seems consequently that distalization put the nerve at risk and that lateralization is rather protective for the plexus.

==Glenoid or humeral non- or disassembly==
Glenoid or humeral non- or disassembly, and polyethylene disassociation are minor problems and are mainly due to prosthetic design (Figure).

[[File:Glenoid dissociation.png|thumb|center|Glenoid disassembly. Six weeks postoperative anteroposterior, Neer and axial imaging revealing a disassembly of the glenosphere on the metaglene.]]

==Periprothetic fractures==
===Humerus===
Humeral fractures occurred intra- or postoperatively.

====Intraoperative====
Intraoperatively, they can appear in the metaphyseal area (“controlled fracture” according to Walch) and are related to retractor positioning. Humeral diaphyseal fractures occur intraoperatively in case of an incorrect sizing of the component or excessive external rotation during preparation of the glenoid and release. They usually require the use of a longer implant to bypass the fracture line or an open reduction internal fixation (ORIF).

====Postoperative====
Postoperatively, fractures usually result from trauma (Figure). They can be treated either conservatively if the component is stable or they require revision in cases of unstable components.

[[File:Image47-109.jpg|thumb|center|Postoperative fracture under the stem of the prosthesis that has been treated conservatively.]]

[[File:Image49-113.png|thumb|Patient known for a right reverse shoulder arthroplasty that sustained a fall on the ipsilateral elbow. A transverse supracondylar fracture of the distal humerus is noted on lateral view.]]

==Heterotopic ossification==
Heterotopic ossification after reverse shoulder arthroplasty (Figure) is a relatively common finding of unknown clinical importance.

[[File:Heterotopic ossifications.png|thumb|center|Heterotopic ossification after reverse shoulder arthroplasty ]]

=References=
<references />