Shoulder:Rotator Cuff Pathology/Thickness Rotator Cuff Tears/Anterior Rotator Cuff Tears (Subscapularis)

From WikiBeemed
Jump to navigation Jump to search

Bullet Points

  • Pseudoparalysis is defined as an inability to actively elevate the arm beyond 90 degrees with full passive forward flexion.
  • Prevalence of subscapularis lesion is high (around 50% of arthroscopic rotator cuff procedures, 10% are isolated).
  • The superior two-thirds of the subscapularis ends as a tendon that inserts on the lesser tuberosity of the humerus. The inferior part has no tendon; the muscle attaches directly to the bone.
  • The subscapularis should be considered as two different muscles. It is the largest and most powerful of the rotator cuff muscles. The subscapularis is an internal rotator and is crucial for shoulder elevation.
  • Several special tests have been described to aid in diagnosis, including the lift-off, belly-press, and bear-hug tests.
  • Mulitple magnetic resonance imaging (MRI) views should be analyzed to increas the chance of subscapularis lesion detection.
  • FUSSI and SAM are similar conditions causing abrasion of the upper and medial part of the subscapularis tendon.
  • 90% of patients with a subscapularis tear have associated long head of the biceps lesions or instability. Preservation of the intra-articular biceps will frequently jeopardize the repair.
  • Results are good or excellent in around 80% of cases. Around 90% of patients returned to normal activities, and 90% are satisfied.

Key words

Subscapularis tendon; Rotator cuff lesion; Biomechanics; Classification; FUSSI; SAM; Lafosse; Toussain; Results; Complications; Irreparable; Anatomy; Pectoralis major transfer; Imaging; Pseudoparalysis.

Definition of Pseudoparalytic Shoulder

Pseudoparalysis is defined as an inability to actively elevate the arm beyond 90 degrees with full passive forward flexion. It is also important to note that this is functional limitation and not pain inhibition; this can be distinguished by the inability to hold the arm at 90 degrees and/or an evaluation of motion after a subacromial injection. Anatomically, pseudoparalysis requires the disruption of at least one rotator cable attachment. Recently it has been demonstrated that dysfunction of the entire subscapularis and supraspinatus or three rotator cuff muscles are risk factors for pseudoparalysis.[1]

Primary arthroscopic repair can lead to reversal of pre-operative pseudoparalysis in 90% of patients, but in only 43% of revision surgeries.[2]

Anecdote

Like teres minor, the subscapularis has been a “forgotten tendon” of the rotator cuff.[3]

In the 1980s, at a meeting of the American Academy of Orthopaedic Surgeons in Orlando, Christian Gerber presented a new, unknown clinical entity, the “Isolated tear of the subscapularis tendon“. The presentation was based on 16 cases with computed tomography (CT)-arthrography or magnetic resonance imaging (MRI), intraoperative photographs of all cases and included a detailed description of the clinical features including lift- off test, belly-press test and increased passive external rotation. The discusser of the paper felt that this was a nice presentation which unfortunately lacked a bit of relevance as this entity was not observed in the US and was probably a "Swiss disease“. Certainly, he and his experienced expert colleagues had never seen it. Dr Richard Hawkins, who had visited Christian Gerber a few weeks earlier and participated in two isolated subscapularis tendon repairs got up in the audience and told the discusser: "I don’t doubt that you, as I, have never seen an isolated subscapularis tear, but after my visit I can tell you that many have seen us".

Christian Gerber submitted the paper to the American Journal of Bone and Joint Surgery which rejected it, because the reviewers could not see the relevance for the English speaking readership. It was published in the British Journal of Bone and Joint Surgery in 1991.

Isolated subscapularis tears are currently known to represent about 8-10% of all the rotator cuff tendon tears as well in Europe as in America.

Prevalence

Because articular sided tears are not commonly visualized during open approaches, subscapularis tears were previously believed to be rare. They are now recognized to have a prevalence of nearly 30% in all arthroscopic shoulder surgery, and up to 59% in arthroscopic rotator cuff procedures. Isolated subscapularis tears are currently known to represent about 8-10% of all the rotator cuff tendon tears.[4][5][6][7]

Anatomy of the Subscapularis

The subscapularis muscle arises from the anterior surface of the scapula, courses laterally beneath the coracoid, and becomes tendinous near the level of the glenoid rim. The tendinous footprint is roughly trapezoidal in shape, with its widest portion superior, and has a mean superior to inferior length of 2.5 cm.[8]

Macroscopically, the superior two-thirds of the subscapularis ends as a tendon that inserts on the lesser tuberosity of the humerus. The inferior part has no tendon; the muscle attaches directly to the bone, as with the teres minor on the posterior aspect of the humerus. Due to anatomical, biomechanical but also electrophysiological considerations, the subscapularis muscle, usually perceived as a single muscle, should be considered as two different muscles (inferior and superior).[9]

The superior and inferior subscapularis are innervated by two different nerves.11,12 The superior part is innervated by the upper subscapularis nerve that comes directly from the posterior cord. The inferior part is innervated by the lower subscapularis nerve arising from either the axillary nerve or the thoracodorsal nerve.[10][11]

Electrophysiology studies confirm this division and have shown different activity in the superior and inferior parts of the subscapularis.[10]

Different activation patterns in the two parts of the subscapularis are also found during a positron emission tomography (PET) study.[12]

The superior margin of the subscapularis marks the inferior border of the rotator interval, which contains the superior glenohumeral ligament and the coracohumeral ligament. The medial sling, composed of a robust deep layer (medial head of the coracohumeral ligament) and a thin superficial layer (superior glenohumeral ligament), has an insertional footprint at the top of the lesser tuberosity that is directly adjacent to the footprint of the superolateral subscapularis on the lesser tuberosity. As such, when the upper subscapularis tears away from its bone attachment, the medial sling (which is directly adjacent to it), also tears away from the bone. As this sling is part of the bicipital pulley, biceps pathology is frequently associated with subscapularis tears.

Biomechanics

The subscapularis is the largest and most powerful of the rotator cuff muscles, providing more than 50% of the rotator cuff force alone.[13]

Functionally, the subscapularis internally rotates the humerus, contributes to anterior stability of the shoulder, and plays an important role in balancing force couples of the glenohumeral joint. In the coronal plane, the superior deltoid moment is balanced by the inferomedial moment of the inferior rotator cuff (Figure 1).

Balanced force couples are required to maintain the normal glenohumeral relationship. In the coronal plane the combined inferior rotator cuff force (C) is balanced against the deltoid (D).

In the transverse plane, the subscapularis anteriorly is balanced with the infraspinatus and teres minor posteriorly (Figure).[14][15][16]

In the transverse plane the subscapularis (S) is balanced against the infraspinatus and teres minor (I). O, center of rotation; A, moment arm of the deltoid; a, moment arm of the inferior rotator cuff; r, moment arm of the subscapularis; R, moment arm of the infraspinatus and teres minor.

Muscle activation of the subscapularis tendon has been shown to be higher in patients with asymptomatic rotator cuff tears, demonstrating that the subscapularis tendon plays an important role in compensating for posterosuperior rotator cuff tears.[17]

Additionally, the anterior attachment of the rotator cable extends to the upper subscapularis insertion.[18]

Maintenance of the subscapularis footprint is thus integral to normal biomechanical function of the shoulder. Finally, repair of the upper subscapularis decreases the stress on the adjacent repair of the supraspinatus, thereby protecting repair of the latter.[19] It is thus important to be adept at recognizing and treating these tears.

The subscapularis is crucial for shoulder elevation. Effectively, pseudoparalysis is almost always correlated to subscapularis tears (Figure). This is particularly the case when tears involve the lower half of the subscapularis tendon. Therefore, treatment of large cuff tears should include subscapularis repair to avoid the anterior extension of the tear and development of pseudoparalysis.[1]

A) Percentage of pseudoparalysis, which is defined as the inability to elevate the arm actively beyond 90 degrees with full passive range of motion. Observe the high rate of pseudoparalysis in case of massive rotator cuff tears involving the subscapularis (B and C massive rotator cuff tears). Reproduce from Collin et al., with permission.
B) Pseudoparalysis. No or limited active forward flexion but full passive range of motion.

History and Physical Examination

The etiology of subscapularis tears can be traumatic or non-traumatic. Traumatic tears are infrequent and typically occur in younger patients resulting from forced hyperextension or forced external rotation with the arm either at the side or in a position of abduction.[20]

Non-traumatic tears are probably related to intrinsic degeneration, long head of the biceps instability, as well as anterosuperior impingement that occurs against the anterosuperior glenoid rim during flexion and internal rotation.[21]

The pain is typically located more anteriorly compared to posterosuperior rotator cuff tears and can radiate down the arm. Difficulty with activities of daily living are common, particularly with reaching behind and reaching across the body.

On physical examination palpation is not specific. Pain may be provoked with anterior elevation and internal rotation. The classic finding of increased passive external rotation compare to the other side, does not typically occur without a complete tear. Strength testing may reveal pain or decreased power with resisted internal rotation. Several special tests have been described to aid in diagnosis, including the lift-off, belly-press, and bear-hug tests.

Lift-off

The lift-off test is performed by placing the hand behind the back and asking the patient to internally rotate the arm to lift the hand posteriorly off the back. Placing the arm behind the back isolates the subscapularis as an internal rotator. The test is considered positive if the patient is unable to lift the arm off the back.[20]

Belly-press

The belly-press is performed by placing the palm on the navel with the wrist in a neutral position (Figure). In a positive test the wrist flexes and the elbow moves posteriorly as the patient actively extends the shoulder by means of the posterior deltoid to maintain the palm position. One advantage of the belly-press compared to the lift-off test is that the latter requires to put the hand of the patient in the back, manoeuver that is often painful.[22]

Figure 4. Belly press.

Bear-hug

The bear-hug test is performed by placing the palm on the contralateral shoulder with the fingers extended and the arm in approximately 45 degrees of forward flexion (Figure). The position is maintained while the examiner attempts to pull the forearm away from the shoulder in a perpendicular manner. A positive test is indicated by weakness with this maneuver, in which the examiner is able to pull the patient’s hand away from the shoulder.[5]

The bear-hug test. The hand on the affected side is placed on the opposite shoulder with the fingers extended and the elbow flexed forward. The patient resists as the examiner tries to pull the hand off the shoulder in a direction that is perpendicular to the plane of the forearm (arrow). If the examiner is able to lift the hand off the shoulder, the patient likely has a torn (either partial or complete) upper subscapularis tendon.


Imaging

X-ray

Three views of the shoulder (anteroposterior views in neutral rotation, axillary view, outlet view) should be obtained. Most patients will have normal radiographs. Although uncommon, lesser tuberosity cysts on plain radiographs have been reported to have an 87% specificity for subscapularis tears.[23]

In massive tears, patients may demonstrate proximal migration of the humerus.

Ultrasound

Ultrasound (US) can be used as a non-invasive test to screen for subscapularis tears. However, the sensitivity of this methodology is also low.[24]

Using ultrasound imaging, the subscapularis tendon is best visualised with the shoulder in external rotation, elbow kept firmly by the thorax (Figure), drawing the tendon out from beneath the coracoid process. While looking at the tendon’s long axis, its integrity can be analyzed, as well as its relationship with surrounding structures by dynamically performing internal and external rotation of the shoulder. Examination of the short axis of the tendon (by rotating the probe by 90 degrees) reveals its multifascicular pattern, and allows complete analysis from its upper border (with the biceps tendon lying supero-laterally), where injuries often begin, to its lower border.[25]

Ultrasound is also very helpful to detect a dynamic instability of the long head of the biceps. Reproduced from Plomb-Holmes et al., with permission.


Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging (MRI) is used to characterize the subscapularis tear, retraction, fatty infiltration according to Goutallier, and provides information about concomitant pathology. However, it is important to note that the sensitivity for detection is often low; in some studies it is below 50%. Therefore a high index of suspicion should be maintained and multiple views should be analyzed to increase the chance of detection.[26]

Axial View

Classically, the subscapularis is best evaluated on T2 the axial views. Complete tears demonstrate a bare lesser tuberosity with a retracted tendon margin (Figure).

T-2 weighted axial magnetic resonance images demonstrating subscapularis tears. Complete retracted tear (yellow arrow, retracted tendon edge) with narrowed coracohumeral interval (yellow line).

Increased signal in the tendon on T2 images without retraction can indicate a partial tear (Figure 8).

Partial tear with increased signal at the subscapularis insertion at the lesser tuberosity. Observe the medial biceps subluxation that is pathonomoic for a subscapularis tear.

Saggital view

T1 saggital view is also important to review, particularly to analyse the bicipital pulley and subtle anterior dislocation of the long head of the biceps in type-I to type-II subscapular tears. Furthermore, fatty degeneration of the upper half of the subscapularis tendon on this view is a tell-tale sign of a tear of the subscapularis (Figure).

T1 saggital view. A) Long head of the biceps (asterix) and coracohumeral ligament (white arrow). B) Long head of the biceps (asterix) interposed between the subscapularis tendon (white arrows) and the smaller tuberosity, indicating a subscapularis lesion. C) Grade 4 fatty infiltration of the upper subscapularis (black arrow).

Coronal view

On coronal oblique images, normal appearance usually shows four (rarely up to six) digitations and their insertion on the lesser tuberosity over the bicipital groove.[27][28]

Figure


Types of Lesions and Tear Classifications

Lateral Disruption and Associated Lesions

Identifying the subscapularis tendon stump is the key to determine the type of lesion and how to treat them. The upper border of a normal subscapularis tendon is smooth and regular. Any delamination is a sign of failure (Video).

Video


A particular type of superior abrasion is part of anterosuperior impingement (FUSSI or SAM lesion). Please also refer below and to anterior impingement chapter.[29]

The subscapularis tendon has several lesion patterns:

A) The tear of the subscapularis can be vertical, caused by a portion of the superior glenohumeral ligament/coracohumeral ligament complex that has torn off the humerus, forming the comma sign of Lo and Burkhart. The tendon is then retracted medially (medial retraction) and the structure observed in front of the shoulder consist of ligaments (Figure).[30]

Tear of the subscapularis. The upper border is not smooth and regular due to a medial retraction of the tendon. The coma sign (*)(superior glenohumeral ligament/coracohumeral ligament complex) is seen on the right.

2) The tear of the subscapularis can be horizontal with verticalization of the subscapularis superior creating a Dilisio and Neyton coma sign. In such cases, the subscapularis is retracted superiorly and the structure observed in front of the shoulder is a tendon (Figure).[31]

Tear of the subscapularis with a coma sign from Diliso and Neyton. The subscapularis is split with a verticalization of the upper border (blue arrow). G, glenoid; H, humeral head; SSc, subscapularis tendon.

3) Finally, the tendon can fail in continuity, leading to lengthening as described by Meyer et al. The retraction is, in these cases, medial as well as lateral and the structure observed in front of the shoulder is predominantly fibrosis (scar tissue).[32]

Tear of the subscapularis with a failure in continuity. The subscapularis is elongated (blue arrow) as seen on the intra-articular view (superior figure) and axial plane of imaging resonance magnetic (inferior image). H, humeral head, SSc, subscapularis.

Different types of tear patterns

Type of tear Displacement of the tendon Sign Tissue
Vertical Medial Lo and Burkhart comma sign Ligament
Horizontal Superior Dilisio and Neyton somma sign Tendon
Rupture in continuity Elongation (medial and lateral) Tendon Length > 60 mm Fibrous (scar tissue)


Lafosse Classification

Lafosse et al. described a classification in order to characterize subscapularis tears arthroscopically and to guide operative approach (as subsequently described). Subscapularis tears are divided into five types. Type-I tears are localized to the superior third of the subscapularis tendon. They are partial tears of the deep fibers at the insertion onto the lesser tuberosity that never display tendon retraction because the superficial fibers of the subscapularis remain intact. Type-II tears are complete ruptures that are limited to the superior third of the tendon (including both the superficial and deep fibers). Type-III tears are complete tears of the superior two thirds of the subscapularis tendon. Type-IV tears are complete tears of the entire subscapularis tendon from its insertion, combined with retraction of the tendon edge to the level of the glenoid rim without anterior eccentricity of the humeral head on the glenoid. Type-V tears are complete tears of the subscapularis with retraction and an eccentric humeral head that is displaced anteriorly on the glenoid because of disruption of the force-couple of the rotator cuff.[7]

Toussain Classification

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.

Middle Glenohumeral Ligament Abrasion Causing Upper Subscapularis Tear (FUSSI, SAM tears)

From Brady et al., with permission.

Introduction

In some cases, the middle glenohumeral ligament or even the anterior glenoid abrades against the upper edge of the subscapularis medial to its insertion at the lesser tuberosity. The middle glenohumeral ligament compresses into the upper edge of the subscapularis causing pain and intraarticular pathology. The acronym of the SAM lesion (for Subscapularis Abrasion from the Middle glenohumeral ligament) or the FUSSI lesion described by Snyder (for Frayed Upper SubScapularis with Impingement)(https://www.vumedi.com/video/fussi-lesions) have been used.[29][33]

The SAM and FUSSI lesion may differ in some ways. First the FUSSI lesion is described as a capsular reflection causing abrasion whereas the SAM lesion describes the middle glenohumeral ligament as being the offending structure. Second the lesion caused by the capsular reflection is typically quite medial and often not visible from the posterior portal with a standard arthroscope whereas the condition the SAM lesion is always visible from the posterior portal as the pathology lies at the level (or lateral to) the middle glenohumeral ligament.

Third the abrasion of the subscapularis caused by the capsular reflection is noted to be worse with external rotation. However, with the SAM lesion the middle glenohumeral ligament compresses the upper subscapularis with internal rotation.

Clinical Examination

Preoperatively these patients have presented somewhat of a diagnostic conundrum. They frequently have vague and nondescript anterior shoulder pain. Symptoms are primarily reproduced with resisted internal rotation of the shoulder, however, the patients have good strength with subscapularis testing including negative bear hug, belly press, lift off, and Napoleon exams.

Biceps exam is typically equivocal and often biceps pathology is suspected in these patients secondary to their symptoms of primarily anterior shoulder pain with activities. Patients have failed exhaustive conservative treatments and even failed previous operative intervention.31

Imaging Studies

Imaging studies including MRI and radiographs are typically non-diagnostic.

Musculotendinous Junction Lesion of the Subscapularis

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 subscapularis in 25% of cases (more than one muscle is occasionally involved).[34]

Rotator Cuff Incarceration

Rotator cuff incarceration after a first episode of anterior dislocation.

Management

In the absence of a medical contraindication, most acute traumatic subscapularis tendon tears should be treated operatively. This is an urgency that as to be performed within a few weeks following trauma, as further delay results in severe retraction and poorer results.[35]

Small non-traumatic tears resulting in minimal disability, particularly in patients over the age of seventy, can be managed with a trial of nonoperative modalities including physical therapy and limited corticosteroid injections. However, due to the integral role of the subscapularis discussed above, many patients are significantly disabled and require surgical intervention. Most subscapularis tendon tears observed during arthroscopy should be repaired.

Surgical Technique

Subscapularis tears have several unique aspects that make it difficult to repair. First of all, the different compositions of the comma signs (ligaments, tendon, fibrous) and its relation to the intact anatomic structures must be understood in order to achieve an anatomic repair. Secondly, complete tears of the subscapularis tend to retract more than other cuff tears (particularly in traumatic cases), necessitating significant dissections and releases in order to mobilize the tendon and get it back out to length. Third, the retracted subscapularis tends to scar against the coracoid in close proximity to important neurovascular structures, so mobilization can be daunting. Finally, the dissection and repair must be performed in the tightly packed subcoracoid space, requiring specific techniques, positioning maneuvers, and instrumentation. Because this space can become compromised rapidly by soft tissue swelling from extravasation of arthroscopic irrigant fluid, it is essential to address the subscapularis prior to repairing the rest of the cuff.

Order of Steps

In general, when the subscapularis is torn, the order of steps is as follows: 1. Arthroscopic evaluation 2. Biceps tenotomy in the case of medial dislocation 3. Make a window in rotator interval 4. If subscapularis tendon is adhesed, then skeletonize posterolateral coracoid, mobilize tendon, and do a 3-sided release 5. Prepare bone bed on lesser tuberosity 6. Repair the subscapularis 7. Do a biceps tenodesis if tenotomy was not previously done 8. Repair the rest of the rotator cuff

Following induction of anesthesia, the patient is placed in a beach chair position or in a lateral decubitus position. Three to four kilos of balanced suspension is used. A standard diagnostic arthroscopy is performed with a 30 degrees arthroscope viewing through a posterior portal with a pump maintaining pressure of 40 to 50 mmHg. In order to “open up” the subcoracoid space, an assistant can provide a “posterior lever push” in which he pushes posteriorly on the proximal humerus while pulling the distal humerus anteriorly (Figure).

Sensitive-content.png
A) Visualization is improved with internal rotation
Sensitive-content.png
B) Visualization can also be improved with a “posterior lever-push”.

Improving subscapularis visualization. Posterior view of subscapularis tendon insertion in a right shoulder with the arm in the standard neutral rotation.


Forward flexion and internal rotation of the shoulder can also provide a more complete view. Viewing with a 70 degree arthroscope will give a more complete view of the inferior footprint of the subscapularis (Figure) and allows subcoracoid dissection with the scope remaining through a posterior portal.

The subscapularis is inspected. Since most tears begin at the upper articular surface, a bare lesser tuberosity footprint is indicative of a tear. The extent of the tear can be estimated by comparing to known dimensions of the subscapularis footprint which averages 2.5 cm superior to inferior. In the case of a retracted tear, the upper border of the subscapularis can be located by the “comma sign”. Following identification of a tear, an anterosuperolateral portal is established off the anterolateral border of the acromion, guided by an 18-gauge spinal needle in an outside-in technique. Placement should be parallel to the subscapularis tendon. An action on the biceps is always indicated. Given that more than 90% of patients with a subscapularis tear have associated long head of the biceps lesions or instability, preservation of the intra-articular biceps will frequently jeopardize the repair.[36]

At this stage, it is important to make sure that the bicipial tendon does not come to intervene between the lesser tuberosity and the tendon during the subscapularis repair.

Assessment of the subcoracoid space is an essential component of subscapularis repair. The first step is to identify the tip of the coracoid, which is usually located just anterior to the upper border of the subscapularis tendon. Most work can be performed through the anterosuperolateral working portal while continuing to view from the posterior portal with 30 and 70 degree arthroscopes. However, to have better view medial to the coracoid or if a 70 degree arthroscope is not available, the anterosuperolateral working portal can also be used as a viewing portal. At the level of the coracoid tip, an electrocautery is used to make a window in the rotator interval just superior to the subscapularis tendon. While viewing through the window, instruments in the anterosuperolateral portal can work anterior to the subscapularis. The medial sling of the biceps and the superior glenohumeral ligament should be preserved laterally. Once the coracoid tip is identified, the posterolateral aspect of the coracoid is skeletonized while viewing with a 70 degree arthroscope. The conjoined tendon insertion is easily identified and preserved; an anterior release of the subscapularis is done. An anterior working portal is then performed using an 18-gauge spinal needle with an outside-in technique to determine the proper “deadman angle” of approach for anchor positioning.

Retracted tears require mobilization in addition to the steps above. In these cases, a traction suture is placed medial to the junction of the “comma sign” with the upper subscapularis (Figure 16).

Posterior viewing portal, right shoulder. A traction suture (black asterix) is placed medial to the junction of the “comma sign” with the upper subscapularis. G, glenoid; H, humeral head; SS, subscapularis; ST, supraspinatus tendon.


The sutures can be pulled either from the anterosuperolateral or the anterior portal. A superior release of the subscapularis is performed by clearing the neck and base of the coracoid of soft tissue and then using a 30 degree elevator to break adhesions between the coracoid neck and the superior tendon border; it is important to keep the instruments on bone during this step (Figure 16). It is not necessary to release any further medially than coracoid neck. A posterior release of the subscapularis tendon is performed with an electrocautery between the posterior subscapularis and anterior glenoid neck.

Restoration of the Footprint

The lesser tuberosity bone bed should be prepped by removing soft tissue in order to facilitate tendon to bone healing. A variety of techniques then exist for repair. Much like the approach to posterosuperior rotator cuff tears, the repair should follow the tear pattern with a goal of restoring anatomy. In type-I and type-II, one anchor is inserted through the anterior portal if needed. For a knotted technique, sutures are passed either antegrade or in a mattress configuration with a retrograde penetrating instrument, the final superior suture according to a “lasso-loop” technique.[37]

The knots are then tied successively from bottom to top. In case of associated biceps tenodesis, the upper sutures can be incorporated into the biceps tenodesis. This technique allows one to realize a double-row fixation of the upper subscapularis footprint without an additional anchor.[38]

Surgical Technique for Middle Glenohumeral Ligament Abrasion Causing Upper Subscapularis Tear (FUSSI, SAM tears)

Posterior portal is utilized and diagnostic arthroscopy performed. During this portion of the procedure the anterior structures of the shoulder are particularly visualized and dynamically examined with internal rotation and flexion of the humerus (Video).

Video

On initial inspection of the upper border of the subscapularis an abrasion lesion or a tendon indentation / partial tearing is noted approximately 1-2 cm medial to the articular insertion of the upper subscapularis on the lesser tuberosity bone bed. The lesion is in close approximation to the lateral edge of the middle glenohumeral ligament. Typically, with internal rotation of the humerus the middle glenohumeral ligament is seen “cutting” into the upper boarder of the subscapularis (Figure).

(A) Posterior portal view of the right shoulder with a 30_ arthroscope. The humeral head (H) is on the lower right. The MGHL (labeled) sits approximately 1 cm medial to a significant abrasion lesion of the upper border of the subscapularis (*). (B) Posterior portal view of the right shoulder with a 30_ arthroscope. The glenoid (G) is visible on the left side of the field of view. With internal rotation of the humerus, the MGHL (labeled) can clearly be seen to be the offending lesion cutting into the upper subscapuaris causing the pathology in the subscapularis. (MGHL, middle glenohumeral ligament.) Reproduce from Brady et al., with permission.

Frequently the middle glenohumeral ligament will have a relatively sharpened edge which can clearly be seen as the pathologic lesion creating the upper subscapularis pathology. After completion of the intraarticular diagnostic arthroscopy, an anterosuperolateral and / or anterior portal are created. Through this anterior portal the edge (and usually the entirety) of the middle glenohumeral ligament is divided with arthroscopic scissors, shaver, electrocautery, or combination of the above. The anterior aspect of the shoulder is then re-examined and rotation of the humerus performed to confirm that the previous lesion is now adequately addressed (Figure 18).

(A) Posterior portal view of the right shoulder with a 30_ arthroscope. An anterior portal is created and curved arthroscopic scissors (Arthrex) are used to divide the MGHL just over top of the upper subscapularis (SSc) tendon. The humeral head (H) is visible on the lower right. (B) Posterior portal view of the right shoulder with a 30_ arthroscope. An arthroscopic shaver is also used to assure complete excision of the MGHL (*) over the top and front of the subscapularis (SSc). The humeral head (H) is visible in the lower right. (MGHL, middle glenohumeral ligament.) Reproduce from Brady et al., with permission.

Particular care is also taken to thoroughly examine the remainder of the intraarticular structures in the anterior aspect of the shoulder (Figure 19). Eventually anterior glenoplasty or coracoplasty, in order to allow proper gliding of the superior border of the tendon, is performed.[39] File:Sensitive-content.pnged and the upper subscapularis contour returns to near normal. Reproduce from Brady et al., with permission.

Postoperative Management

The inferior subscapularis, depending of the movements or exercises proposed after the surgery, is elongated up to 122%.[40]

If repaired, this muscle must consequently be protected during rehabilitation. Postoperatively the patient is placed in a sling for four to six weeks, depending of the type of lesion. In the case of type-I to type-II, external rotation is allowed to 30 degrees during this period. If the tear was a type-III or a type-IV, external rotation past neutral and internal rotation hand in the back are forbidden for six weeks.

Results

Since the first description in 2002, several authors have reported the results of arthroscopic repair of subscapularis tendon tears.[7][41][42][43]

These studies have all demonstrated good results at short- to intermediate-term follow-up. Lafosse and colleagues reported the functional outcome and integrity of repair of 17 arthroscopically repaired isolated subscapularis tears.8 At an average 29 month follow-up UCLA scores had improved from 16 to 32 and relative Constant scores improved from 58 to 96. Healing was assessed with computed tomography arthrography and showed complete healing in 15 patients and partial re-rupture in two patients. Denard et al. published a long-term follow-up after arthroscopic subscapularis repair. Seventy-nine patients with an average age of 60.8 years at the time of surgery were available for follow-up at a mean of 104.7 months. Compared to preoperative values, UCLA mean scores improved from 16.5 to 30.1 and mean ASES scores improved from 40.8 to 88.5 (p < .001). Results were rated as good or excellent in 83.3% of cases, 92.4% of patients returned to normal activities, and 92.4% of patients were satisfied. Improvement in functional outcome following arthroscopic repair of a subscapularis tendon tear is maintained long-term.[44]

Complications

The complication rate after shoulder arthroscopy is very low. Theoretically there is risk of damage to neurovascular structures when performing work around the coracoid. These structures are all greater than 2.5 cm from the coracoid tip. Therefore, maintaining visualization of the coracoid ensures safety of the procedure.[45]

Subscapularis Dysfunction After Shoulder Arthroplasty

Please refer to Glenohumeral Arthritis/Anatomic Shoulder Arthroplasty

Irreparable Subscapularis Tear

Pectoralis major transfer

Currently, the most commonly used transfer for irreparable A, B and C type massive rotator cuff tears is the pectoralis major transfer. The direction of pull of the pectoralis major tendon can help restore internal rotation and the transverse force couple in the setting of subscapularis deficiency without static anterosuperior migration of the humeral head. Pain can be improved, but functional restoration is often disappointing.[46]

Video


Pectoralis minor transfer

Pectoralis minor tendon transfer has also been described, but does not improve strength and cannot be recommended.

Anterior latissimus dorsi transfer

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.

References

  1. ↑ 1.0 1.1 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.
  2. ↑ 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.
  3. ↑ Walch G, Nové-Josserand L, Liotard JP, Noel E, Tavernier TH, Barthélémy R. Le petit rond (teres minor): l'oublié de la coiffe. In: Blum A TT, Brasseur J-L, Noël E, Walch G, Cotten A, Bard HG, ed. L'Epaule: une approche pluridisciplinaire. Montpellier: Sauramps Medical; 2005:237–44.
  4. ↑ Arai R, Sugaya H, Mochizuki T, Nimura A, Moriishi J, Akita K. Subscapularis tendon tear: an anatomic and clinical investigation. Arthroscopy 2008;24:997-1004.
  5. ↑ 5.0 5.1 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.
  6. ↑ Bennett WF. Subscapularis, medial, and lateral head coracohumeral ligament insertion anatomy. Arthroscopic appearance and incidence of "hidden" rotator interval lesions. Arthroscopy 2001;17:173-80.
  7. ↑ 7.0 7.1 7.2 Lafosse L, Jost B, Reiland Y, Audebert S, Toussaint B, Gobezie R. Structural integrity and clinical outcomes after arthroscopic repair of isolated subscapularis tears. J Bone Joint Surg Am 2007;89:1184-93.
  8. ↑ Richards DP, Burkhart SS, Tehrany AM, Wirth MA. The subscapularis footprint: an anatomic description of its insertion site. Arthroscopy 2007;23:251-4.
  9. ↑ Collin P, Lädermann A, Le Bourg M, Walch G. Subscapularis minor--an analogue of the Teres minor? Orthopaedics & traumatology, surgery & research : OTSR 2013;99:S255-8.
  10. ↑ 10.0 10.1 Kadaba MP, Cole A, Wootten ME, McCann P, Reid M, Mulford G, April E, Bigliani L. Intramuscular wire electromyography of the subscapularis. J Orthop Res 1992;10:394-7.
  11. ↑ Kasper JC, Itamura JM, Tibone JE, Levin SL, Stevanovic MV. Human cadaveric study of subscapularis muscle innervation and guidelines to prevent denervation. J Shoulder Elbow Surg 2008;17:659-62.
  12. ↑ Omi R, Sano H, Ohnuma M, Kishimoto KN, Watanuki S, Tashiro M, Itoi E. Function of the shoulder muscles during arm elevation: an assessment using positron emission tomography. Journal of anatomy 2010;216:643-9.
  13. ↑ 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.
  14. ↑ Burkhart SS. Fluoroscopic comparison of kinematic patterns in massive rotator cuff tears. A suspension bridge model. Clin Orthop Relat Res 1992:144-52.
  15. ↑ Burkhart SS. Reconciling the paradox of rotator cuff repair versus debridement: a unified biomechanical rationale for the treatment of rotator cuff tears. Arthroscopy 1994;10:4-19.
  16. ↑ Hansen ML, Otis JC, Johnson JS, Cordasco FA, Craig EV, Warren RF. Biomechanics of massive rotator cuff tears: implications for treatment. J Bone Joint Surg Am 2008;90:316-25.
  17. ↑ Kelly BT, Williams RJ, Cordasco FA, Backus SI, Otis JC, Weiland DE, Altchek DW, Craig EV, Wickiewicz TL, Warren RF. Differential patterns of muscle activation in patients with symptomatic and asymptomatic rotator cuff tears. J Shoulder Elbow Surg 2005;14:165-71.
  18. ↑ Burkhart SS, Esch JC, Jolson RS. The rotator crescent and rotator cable: an anatomic description of the shoulder's "suspension bridge". Arthroscopy 1993;9:611-6.
  19. ↑ Ticker JB, Burkhart SS. Why repair the subscapularis? A logical rationale. Arthroscopy 2011;27:1123-8.
  20. ↑ 20.0 20.1 Gerber C, Krushell RJ. Isolated rupture of the tendon of the subscapularis muscle. Clinical features in 16 cases. J Bone Joint Surg Br 1991;73:389-94.
  21. ↑ Gerber C, Sebesta A. Impingement of the deep surface of the subscapularis tendon and the reflection pulley on the anterosuperior glenoid rim: a preliminary report. J Shoulder Elbow Surg 2000;9:483-90.
  22. ↑ Gerber C, Hersche O, Farron A. Isolated rupture of the subscapularis tendon. J Bone Joint Surg Am 1996;78:1015-23.
  23. ↑ Studler U, Pfirrmann CW, Jost B, Rousson V, Hodler J, Zanetti M. Abnormalities of the lesser tuberosity on radiography and MRI: association with subscapularis tendon lesions. AJR American journal of roentgenology 2008;191:100-6.
  24. ↑ Singisetti K, Hinsche A. Shoulder ultrasonography versus arthroscopy for the detection of rotator cuff tears: analysis of errors. Journal of orthopaedic surgery 2011;19:76-9.
  25. ↑ Plomb-Holmes C, Clavert P, Kolo F, Tay E, Ladermann A, French Society of A. An orthopaedic surgeon's guide to ultrasound imaging of the healthy, pathological and postoperative shoulder. Orthop Traumatol Surg Res. 2018 Dec;104(8S):S219-S232.27.
  26. ↑ Adams CR, Brady PC, Koo SS, Narbona P, Arrigoni P, Karnes GJ, Burkhart SS. A systematic approach for diagnosing subscapularis tendon tears with preoperative magnetic resonance imaging scans. Arthroscopy. 2012;28:1592-600.
  27. ↑ Cash CJ, MacDonald KJ, Dixon AK, Bearcroft PW, Constant CR. Variations in the MRI appearance of the insertion of the tendon of subscapularis. Clin Anat 2009;22:489-94.
  28. ↑ In the case of Lafosse III-V subscapularis tears, one or more of the pennate muscular components may present a structural distortion, up to a total absence of the tendon structure with the presence of only fluid-type signal. This radiological sign is called the digitation sign (Figure) (unpublished data from Lionel Neyton).
  29. ↑ 29.0 29.1 Brady PC, Grubbs H, Lädermann A, Adams CR. Middle Glenohumeral Ligament Abrasion Causing Upper Subscapularis Tear. Arthrosc Tech 2017;6:e2151-e4.
  30. ↑ Lo IK, Burkhart SS. The comma sign: An arthroscopic guide to the torn subscapularis tendon. Arthroscopy 2003;19:334-7.
  31. ↑ Dilisio M, Neyton L. Comma Sign - Directed Repair of Anterosuperior Rotator Cuff Tears. Arthroscopy Techniques 2014;3:e695-e8.
  32. ↑ Meyer DC, Zimmermann SM, Wieser K, Bensler S, Gerber C, Germann M. Lengthening of the subscapularis tendon as a sign of partial tearing in continuity. J Shoulder Elbow Surg 2016;25:31-7.
  33. ↑ FUSSI Lesions. at https://www.vumedi.com/video/fussi-lesions/.)
  34. ↑ 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.
  35. ↑ Bartl C, Imhoff AB. [Management of isolated subscapularis tendon tears]. Der Orthopade 2007;36:848-54.
  36. ↑ Godenèche A, Nové-Josserand L, Audebert S, Toussaint B, Denard PJ; French Society for Arthroscopy (SFA), Lädermann A. Relationship between subscapularis tears and injuries to the biceps pulley. Knee Surg Sports Traumatol Arthrosc. 2017;25:2114-2120.
  37. ↑ Lafosse L, Van Raebroeckx A, Brzoska R. A new technique to improve tissue grip: "the lasso-loop stitch". Arthroscopy 2006;22:1246 e1-3.
  38. ↑ Denard PJ, Lädermann A, Burkhart SS. Double-row fixation of upper subscapularis tears with a single suture anchor. Arthroscopy 2011;27:1142-9.
  39. ↑ Cunningham G, Lädermann A. Redefining anterior shoulder impingement: a literature review. Int Orthop. 2018 Feb;42(2):359-366. doi:
  40. ↑ Charbonnier C, Lädermann A, Kevelham B, Chague S, Hoffmeyer P, Holzer N. Shoulder strengthening exercises adapted to specific shoulder pathologies can be selected using new simulation techniques: a pilot study. Int J Comput Assist Radiol Surg. 2018 Feb;13(2):321-330.
  41. ↑ Bennett WF. Arthroscopic repair of isolated subscapularis tears: A prospective cohort with 2- to 4-year follow-up. Arthroscopy 2003;19:131-43.
  42. ↑ Ide J, Tokiyoshi A, Hirose J, Mizuta H. Arthroscopic repair of traumatic combined rotator cuff tears involving the subscapularis tendon. J Bone Joint Surg Am 2007;89:2378-88.
  43. ↑ Kim SH, Oh I, Park JS, Shin SK, Jeong WK. Intra-articular repair of an isolated partial articular-surface tear of the subscapularis tendon. Am J Sports Med 2005;33:1825-30.
  44. ↑ Denard PJ, Jiwani AZ, Ladermann A, Burkhart SS. Long-term outcome of a consecutive series of subscapularis tendon tears repaired arthroscopically. Arthroscopy 2012;28:1587-91.
  45. ↑ Lo IK, Burkhart SS, Parten PM. Surgery about the coracoid: neurovascular structures at risk. Arthroscopy 2004;20:591-5.
  46. ↑ Gavriilidis I, Kircher J, Magosch P, Lichtenberg S, Habermeyer P. Pectoralis major transfer for the treatment of irreparable anterosuperior rotator cuff tears. Int orthop 2010;34:689-94.
Retrieved from "https://wiki.beemed.com/index.php?title=Shoulder:Rotator_Cuff_Pathology/Thickness_Rotator_Cuff_Tears/Anterior_Rotator_Cuff_Tears_(Subscapularis)&oldid=2606"