Shoulder:Glenohumeral Arthritis/Reverse Shoulder Arthroplasty
Reverse Shoulder Arthroplasty TABLE OF CONTENT 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 attains, 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 decrease.
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; 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. His father was a teacher and his mother, who chose to raise the children, was trained as a physicist. During his primary and secondary school years, he lived in various cities as his father taught in different schools. After graduation from secondary school, 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, head of the orthopaedic department in Lyon that was particularly well-known for knee and shoulder surgery. He did his military service overseas, in French Guiana where he had the opportunity to operate on many difficult cases. Encouraged by Albert Trillat, he became a Professor of Orthopaedic Surgery and Traumatology in 1974 at the age of 34. He then moved to Dijon in eastern France, where he became the Chairman of the Orthopaedic Department of the University Hospital. While he had few laboratory resources, he was a skilled handyman and began many of his biomechanical experiments on the knee and the shoulder in his own garage before having the opportunity to work in the anatomical and biomechanical labs in the Medical University of Dijon. Grammont was creative: besides developing the reverse shoulder prosthesis,{Grammont, 1987 #1041} he also developed an early patellofemoral prosthesis{Renard, 1989 #4588} and one of the first nails with a self-advancing mechanism designed to lengthen long bones like the tibia and the femur (Albizia nail).{Guichet, 1992 #4589} Paul Grammont died in Lyon the 30 March 2013.
Anecdotes
Demander à Baulot ou trouilloux Frankle une anecdote. 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.{Baulot, 2011 #923} 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.{Inman, 1944 #1060;Pearl, 1930 #919} 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 indicates the more dominant position occupied by the deltoid with strengthening in particular of the middle deltoid abduction component.{Grammont, 1979 #916}
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{Denard, 2012 #926;Denard, 2012 #933;Denard, 2011 #937;Denard, 2011 #943;Denard, 2011 #945;Ladermann, 2011 #938;Ladermann, 2012 #930} with healing of the rotator cuff on the tuberosities{Zumstein, 2008 #961} and even reversal of the associated pseudoparalysis.{Denard, 2015 #3027} 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.{Neer, 1983 #674} Effectively, hemiarthroplasty provides satisfactory pain relief but poor motion,{Pollock, 1992 #984;Sanchez-Sotelo, 2001 #985;Williams, 1996 #986;Zuckerman, 2000 #987} whereas total anatomic shoulder arthroplasty is complicated with early loosening of the glenoid component.{Barrett, 1987 #988;Franklin, 1988 #989;Hawkins, 1989 #990}
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{Grammont, 1993 #917} or more commonly by medializing the center of rotation the glenohumeral joint.{Grammont, 1981 #971} 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 have been implanted in Germany and France.{Gérard, 1973 #972;Kolbel, 1973 #973} 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.{Baulot, 1995 #991;Baulot, 1993 #918} 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 Reverse shoulder arthroplasty, often used in multiply operated patients with distorted anatomy, imparts physiological and biomechanical changes that may increase the potential for complications.{Farshad, 2010 #1697}
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%.{Terrier, 2008 #4424}
Figure: (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.,{Collin, 2017 #3964} 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.{Mélis, 2011 #605} 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,{Lädermann, 2019 #4590} 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.{Gagey, 2000 #993} Under such tension, the reverse glenoid component provides the stable fulcrum essential for shoulder anterior elevation and prosthesis stability.{Boileau, 2005 #121} This tension is determined by arm length.
Reverse Shoulder Arthroplasty Designs Several problems, including scapular notching, lack of improvement in rotation, instability, and loss of shoulder contour, have been attributed to lengthening, Medial Glenoid/Medial Humerus designs or neck shaft angles.{Gerber, 2009 #1558;Zumstein, 2011 #1000} To address problems, changes have been proposed in the design of the prosthesis either on the humeral side or on the glenoid side (neck shaft angle, Medial Glenoid/Lateral Humerus, Lateral Glenoid/Medial Humerus, Lateral Glenoid/Lateral Humerus,).{Boileau, 2011 #1043;Gutierrez, 2008 #1454}
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.{Boileau, 2006 #639;Boileau, 2005 #121;Gagey, 2000 #993;Scarlat, 2013 #1691;Sirveaux, 2001 #757;Valenti, 2001 #758;Boileau, 2006 #639;Boileau, 2005 #121;Gagey, 2000 #993;Sirveaux, 2001 #757;Valenti, 2001 #758} Adequate deltoid tension is thus accepted as a key to prosthetic function and stability.{Boileau, 2005 #121;Lädermann, 2012 #669}
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.{De Biase, 2013 #1855;Lädermann, 2019 #4590;Levigne, 2011 #1538;Mélis, 2011 #649;Mizuno, 2013 #1689;Nyffeler, 2005 #592} 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).{Lädermann, 2014 #2344} 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){Lädermann, 2012 #669} and prosthetic design (Figure).
Figure: Influence of eccentric glenosphere on lengthening
Figure: 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.
Figure: Factors responsible for lengthening
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.
Figure: Relationship between neck-shaft angle and acromiohumeral distance.
Figure: 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.Barth Lädermann Most of these factors nowadays easily be to evaluated thank to navigation software (Figures).Walch Iannotti
Metttre des photos de toutes les mesures de lenghtening arm and humerus, distalization angle, acromio-prosthesis distance
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.{Boileau, 2006 #639} 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.{Boileau, 2005 #121} 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.{Gerber, 2009 #1558} 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.{Boileau, 2011 #1043;Gutierrez, 2008 #2070} Different methods to measure glenoid lateralization have been proposed.{Frankle, 2009 #1451;Jobin, 2012 #1059}
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).
Figure
Figure: 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.
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. LSA Mettre que glenoid lateralization better que humeral Boileau
At the other end of the spectrum, failure to adequately restore bone or prosthetic humeral lateralization may result in loss of humeral contour,{Chacon, 2009 #1792} and deltoid shape curve and thus deltoid retensionning, and could lead to prosthetic instability and poor postoperative function.{Lädermann, 2012 #669;Lädermann, 2009 #654}
Neck-shaft angle More anatomic neck-shaft angles decrease the rate of scapular notching and improve postoperative range of motion.{Lädermann, 2018 #4694} trouver autre réf Lädermann 2019
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.
Preoperative Criteria changer de titre Preoperative planning is mandatory as it allowed to improve ROM…trouver réf. 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.{Jobin, 2012 #1059;Lädermann, 2012 #669;Renaud, 2001 #1395}walch iannotti However, the available software do not take into account soft tissue (stiffness, fatty infiltration,…) Mettre que but est de restaurer deltoid tension, LSA, DSA, laterolisation, que software seems necessarys,…
Indications and Contraindications Indications The reverse shoulder arthroplasty is a powerful tool that has opened new barriers, especially for reconstructive shoulder surgery. Traditionally, the ideal candidate is 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 X years. 16. Black EM, Roberts SM, Siegel E, et al. 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. [PubMed] [Google Scholar] 17. 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. [PubMed] [Google Scholar] 18. Muh SJ, Streit JJ, Wanner JP, et al. 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. [PubMed] [Google Scholar] 19. 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. [PubMed] [Google Scholar] 20. Sershon RA, Van Thiel GS, Lin EC, et al. Clinical outcomes of reverse total shoulder arthroplasty in patients aged younger than 60 years. J Shoulder Elbow Surg 2014;23:395-400. [PubMed] [Google Scholar] 21. 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. [PubMed] [Google Scholar] Reprendre réfs de ma com research meeting Arthrex long term results
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. {Boileau, 2009 #832;Boileau, 2006 #639;Boileau, 2005 #121;Bufquin, 2007 #1002;Cuff, 2008 #833;De Wilde, 2003 #1005;Frankle, 2005 #1006;Gallinet, 2009 #1007;Grassi, 2009 #1008;Guery, 2006 #660;Levy, 2007 #1010;Levy, 2007 #1009;Martin, 2008 #1011;Rittmeister, 2001 #996;Wall, 2007 #658;Wall, 2007 #657;Werner, 2005 #999} Smith CD, Guyver P, Bunker TD. Indications for reverse shoulder replacement: A systematic review. J Bone Joint Surg [Br] 2012;94:577-83. [PubMed] [Google Scholar]
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). Lädermann
Figure : Reverse shoulder athroplasty for fracture
Figure: A) Anteroposterior radiograph of a proximal humerus fracture; B) post-operative radiograph of the fracture treated with reverse shoulder arthroplasty.{Lädermann, 2019 #4454} Pklease refer to fracture chapter
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 (Figure). Amongst the latter, reverse shoulder arthroplasty proved to be the most reliable.
Figure: Reverse shoulder arthroplasty for malunion of proximal humeral fracture.
Figure: A) Anteroposterior radiograph of a malunited proximal humerus fracture; B) post-operative radiograph of the fracture 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.64 Excellent results have been reported in patients with osteoarthritis, an intact rotator cuff and substantial glenoid bone loss treated with reverse shoulder arthroplasty with64 or without66 bone grafting (Figure).
Figure: a) AP radiograph of a shoulder with osteoarthritis, an intact rotator cuff and major glenoid bone loss; b) axial view of a CT scan of the shoulder showing 35° of retroversion; c) AP radiograph of the shoulder treated with RTSA without bone grafting.
Chronic Locked Glenohumeral Joint Dislocation Chronic locked glenohumeral dislocation can also be treated with reverse shoulder arthroplasty (Figure).(Werner et al.)
Open in a separate window
Fig. 7
Figure: A) Anteroposterior radiograph of a locked dislocation; B) axial view of a CT scan of the same patient with glenoid bone loss; C) Anteroposterior radiograph of the shoulder treated with reverse shoulder arthroplasty.
Rheumatoid Arthritis With or Without Associated Rotator Cuff Tears
The use of RTSA for patients with rheumatoid arthritis has been studied by several authors.14,71-74 Two studies have raised concerns about the high incidence of glenoid baseplate radiographic lucency at follow-up in this patient population.14,73 However, excellent to satisfactory results have been reported in up to 95% of patients with rheumatoid arthritis who were treated with RTSA.75
Revision Arthroplasty
The options for revision surgery after primary shoulder arthroplasty (i.e. HA, resurfacing arthroplasty or TSA) are limited by the challenges of rotator cuff deficiency, glenoid bone loss and soft-tissue contractures.76 RTSA has solved many of these challenges and produced high patient satisfaction (Fig. 8).77 However, although some of the clinical results have been excellent, the use of RTSA in these patients is associated with higher complication and failure rates compared with RTSA for patients without previous arthroplasty.78
Fig. 8 a) AP radiograph of a failed TSA; b) AP post-operative radiograph after RTSA. Photo et video pittaccolo
Tumours Several shoulder reconstruction techniques have been reported for patients after wide resection of the proximal humerus and rotator cuff tendons for malignant bone tumours, including allograft, arthrodesis and shoulder arthroplasties.82 However, a prerequisite for the ability to implant a RTSA in these cases requires preservation of the axillary nerve and deltoid muscle to be successful.6,83 Bonnevialle et al82 reported on eight patients treated for malignant tumours of the proximal humerus with transarticular resection of the tumour and shoulder reconstruction with RTSA. They reported improvement in all outcome scores and concluded that RTSA is an acceptable option to preserve function after resection of a malignant tumour of the proximal humerus.
Contraindications Absolute contraindications include an uncontrolled active infection, neuro-arthropathies, and substantial deltoid insufficiency because of the very high probability of recurrent instability and the minimal potential gain in function.{Lädermann, 2012 #1013}
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 for 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.{Boileau, 2005 #31;Mole, 2007 #15} This approach tenotomises the subscapularis or osteotomizes the lesser tuberosity. Failure (observed in 31% of cases, Collin, unpublished data) and dysfunction of the repaired subscapularis remains a concern after both tenotomy{Gerber, 1996 #189;Miller, 2005 #190} and lesser tuberosity osteotomy despite multiple variations in subscapularis takedown and reattachment techniques.{Armstrong, 2006 #191;Gerber, 2005 #192;Qureshi, 2008 #193} Neurologic atrophy and fatty infiltration of the subscapularis muscle belly have been also reported to causes pain and impaired function.{Di Schino, 2012 #198;Scheibel, 2007 #199;Scheibel, 2006 #201}
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 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.
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. Giuseffi SA, Wongtriratanachai P, Omae H, Cil A, Zobitz ME, An KN, et al. Biomechanical comparison of lesser tuberosity osteotomy versus subscapularis tenotomy in total shoulder arthroplasty. J Shoulder Elbow Surg 2012;21:1087-95. http://dx.doi.org/10.1016/j.jse.2011.07.0084, 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. http://dx. doi.org/10.2106/JBJS.E.00441 fleck of lesser tuberosity is taken such that the osteotomy entered the joint medially without violating the humeral head.
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 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. Faire une video
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.
Figure: Passage of the sutures
Figure: 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.
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).
Figure: Passage of the sutures through the subscapularis and needle removal
Figure: 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.
Then, one of the superior limbs and one of the inferior limbs were shuttled through the superior racking hitch knot (Figure).
Figure: Passage of the sutures through the knots
Figure: (A) One suture limb from each pair is selected and (B) passed through the half racking suture.
The suture limbs are passed through a tensioner to remove slack and to tension the repair (Figure).
Figure: Tensioning of the sutures
Figure: 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.{Mole, 2011 #24} This approach is different from the transacromial approach originally described by Grammont and Baulot{Grammont, 1993 #917} and the anterosuperior approach described by Mackenzie.{Mackenzie, 1993 #1035} 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){Ladermann, 2011 #22} and improper postoperative function.{Ladermann, 2013 #52}
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. Movie 1: Movie 1 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).{Walch, 2006 #623} After excision of the bursa, the surgeon explores the cuff through rotator interval. Once an intact subscapularis is confirmed (Figure), deep dissection is carried out either through the supraspinatus tear or after detaching it.
Figure: Confirmation of an intact subscapularis
Figure: Lateral view of a left shoulder. A long broad-tipped Hohmann retractor is placed on the coracoid process superiorly. Brown-Deltoid and Langenbeck retractors, placed posteriorly and medially respectively, retracts the deltoid and the conjoint tendon. This allows confirmation of an intact subscapularis. Reproduced from Lädermann A, Lo EY, Schwitzguebel AJ, Yates E. Subscapularis and deltoid preserving anterior approach for reverse shoulder arthroplasty. Orthop Traumatol Surg Res 2016;102(7): 905-908 with permission.
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 and Illustration).
Figure: 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 (Figure).{Berhouet, 2013 #1777;Gulotta, 2012 #1392;Stephenson, 2011 #1394}
Figure: Preparation of the proximal humerus for osteotomy
Figure: A 20° retroversion guide is placed and the level of the osteotomy is marked on the humeral head with an electrocautery device.
After a retroversion guide placement, the level of the humeral head osteotomy is marked with an electrocautery device, and a free-hand osteotomy is performed. The humeral head osteotomy should be generous to allow optimal exposure of the glenoid. The humeral shaft is then prepared (Figure).
Figure: Preparation of the humeral implant
Figure: 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).
Figure: Glenoid exposure and preparation
Figure: 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 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.{Ladermann, 2015 #2865} 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 via a Morse taper and secured with a locking screw. 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).
Figure: Length of the skin incision
Figure: 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.
Figure: Postoperative X-ray
Figure: Postoperative X-rays after left reverse shoulder arthroplasty with subscapularis-on and deltoid-preserving anterior approach. A) Inferior tilt and B) left glenoid reconstruction with a 15° full wedge baseplate for superior glenoid erosion.
Movie 1: Movie 1 illustrates a right subscapularis-on RSA with superior glenoid erosion.
Complications Tuberosity avulsions that require suture cerclage have been observed. All of them healed without malunion (Figure).
Figure: Intraoperative tuberosity avulsion
Figure: A) Example of tuberosity avulsions (black arrows) requiring 3 suture cerclages. B) Tuberosity healing was observed at two-year follow-up.
Axillary nerve palsy that might be due to insufficient removal of the inferior humeral osteophytes (Figure) have been reported.{Lädermann, 2014 #2091}
Figure: Limit of the subscapularis on technique
Figure: Postoperative X-ray of a patient with right axillary nerve palsy after reverse shoulder arthroplasty. Notable mistakes at the beginning of experience: 1) superior tilt of the glenosphere and 2) neglected inferior humeral osteophyte. Consequent humeral lowering associated with nerve impingement by the osteophyte during its course around the humerus may explain the neuropathy.
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.{Ladermann, 2015 #1} 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 70%.(Collin, unpublished data) 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.{Keating, 1993 #815} If a muscle has to be divided, it seems logical to sacrifice the supraspinatus that accounts for only 14% of the global strength.{Keating, 1993 #815} 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.{Collin, 2014 #16}
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.{Bianchi, 2006 #4425} 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).
Figure: Deltoid impairment
Figure: 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.{Blix, 1891 #1778} 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){Gazielly, 2000 #1207;Glanzmann, 2009 #1014;Tay, 2011 #670} or following tumor resection (Figure).
Figure: Reverse shoulder arthroplasty following deltoid muscular flap transfer
Figure: 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.
Figure: Reverse shoulder arthroplasty following tumor resection
Figure: 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).{Sher, 1997 #1212}
Figure: Disruption of the muscle origin
Figure: 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{Blazar, 1998 #1211;Morisawa, 1997 #1210}, or following trauma (Figure).{Chiba, 2008 #1208;Lin, 2003 #2089}
Figure: Deltoid insertion disruption following trauma
Figure: 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,{Wilbourn, 1998 #874} grade 3 or 4 fatty infiltration,{Goutallier, 1994 #666} previous surgical approach (Figure), trauma (Figure), post radiation syndrome, or myopathy (myositis, Parkinson, Duchenne muscular dystrophy, etc.).{Moser, 2013 #2088}
Figure A-G: Impaired in the setting of previous surgical approach
Figure: Case illustration. A 54 year old man with a previous bilateral below knee amputation due to diabetes mellitus sustained a motor vehicle accident. A) A hemiarthroplasty had been initially implanted for a four-part fracture of the right proximal humerus. B) The patient developed a deep infection that finally required removal of the prosthesis 3 years later. The patient suffered rom consequent pain and was unable to walk with crutches. C) A reverse shoulder arthroplasty was implanted a year later. D) A lack of anterior structures (subscapularis, pectoralis major, conjoint tendon) led to an episode of instability. E) X-ray after revision surgery with placement of a thicker polyethylene spacer D) At one year follow-up, the patient was able to walk with two crutches. F) Active anterior elevation was limited to 40 degrees but the patient was satisfied with the result.
Figure: Impairment in the setting of previous trauma
Figure: 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.
Finally, in the largest series on deltoid impairment with reverse shoulder arthroplasty published to date, the cause of impairment remained obscure/undetermined in 3 on 49 patients (Table).{Lädermann, 2013 #1687}
Table: Etiologies of deltoid impairment in the series of Lädermann et al.{Lädermann, 2013 #1386} Demographics Shoulders (N = 49) Diagnosis*
Trauma sequelae 13 (27%) CTA (Hamada and Fukuda 3 to 5) 9 (18%) RCT (Hamada and Fukuda 1 or 2) 8 (16%) Revision shoulder arthroplasty 13 (27%) Dislocation arthropathy 6 (12%)
Reason(s) for deltoid impairment (multiple reasons possible) †
Post traumatic without surgery 4 Post surgery 25 Axillary nerve lesion 9 Resection or muscular flap transfer 5 Post radiation 2 Deltoid avulsion 3 Unknown 3
Abbreviations: CTA, cuff tear arthropathy; N, number; RCT, rotator cuff tear.
- The values are given as the number, with the percentage in parentheses.
† The values are given as the number.
Once the etiology is determined, the deltoid impairment should be then classified according to its location and extent. Lädermann et al.{Lädermann, 2013 #1687} 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.
Figure: Classification of deltoid impairment
Figure: 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.{Glanzmann, 2009 #1014} 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.{Tay, 2011 #670} 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.{Gulotta, 2012 #3241} 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.{Whatley, 2011 #839} 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.{Essilfie, 2017 #4426} Lattisimus dorsi muscle transfer can also provide an augmentation in patients with deltoid insufficiency.{Dosari, 2017 #4427;Goel, 2012 #4428} 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.{Dosari, 2017 #4427} Deltoid reconstruction at the same time of reverse shoulder arthroplasty is also a viable choice as a salvage procedure for patients with deltoid deficiency.{Marinello, 2016 #4429} 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.{Marinello, 2016 #4429} 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.{Lädermann, 2013 #1687} The indications and etiologies are summarized in Table 1. Postoperative complications occurred in nine (18%) patients, including two postoperative dislocations and two acute postoperative neurological lesions. Five (10%) patients required additional surgery. The functional results are summarized in Table.
Table: Preoperative vs. final follow-up measures Pre-op Post-op Gain P† Range of motion in degree ‡ AFE 50 ± 38 121 ± 40 64 < .0001 AER at side 5 ± 21 12 ± 16 7 .8438 Constant score ‡ 24.8 ± 12.1 (2-51) 58.0 ± 16.7 (16-83) 33.2 < .0001 Satisfaction (%) NA 98% SANE N=29 ‡ NA 70.9 ± 17.0 (10-95) AFE, active forward elevation; AER, active external rotation; †, P values are rom paired t-tests; ‡The values are given as the mean, the standard deviation with the range in parentheses.
Active forward elevation and Constant score improve 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.{Lädermann, 2013 #1687} Schneeberger et al. retrospectively reviewed the outcome of 19 patients treated with reverse shoulder arthroplasty after failed deltoid flap reconstruction.{Schneeberger, 2014 #2087} 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.
Preoperative Planning A meticulous examination should be performed prior to considering reverse shoulder arthroplasty in the setting of deltoid impairment. Inspection is performed to assess for previous scars, deltoid dehiscence, and atrophy to estimate the extent to which the deltoid is impaired. Strength testing examination includes the deltoid and rotator cuff. Notably, candidates for reverse shoulder arthroplasty had to have manual deltoid muscle strength (measured in abduction) at least 3 out of 5{, 1943 #1255}in the sitting position. Patients with grade 2 or less are not considered for reverse shoulder arthroplasty.{Kauffmann, 2005 #1256}
The imaging workup should quantify radiographic evidence of grade 3 or 4 fatty infiltration on a computed tomography (CT) scan{Goutallier, 1994 #666} or magnetic resonance imaging (MRI) study (Figure),{Zanetti, 1998 #667} at the level of the infraglenoid rim according to Greiner et al.{Greiner, 2010 #1253}
Figure: Fatty infiltration quantification
Figure: Axial magnetic resonance imaging (MRI) of a right shoulder demonstrates Grade 4 infiltration of the anterior deltoid and grade 3 of the posterior and middle deltoid at the level of the infraglenoid rim.
Finally, a preoperative electrodiagnostic study is often useful in the setting of deltoid impairment. This can help determine the etiology and severity of deltoid impairment when a neurological lesion is suspected.
Surgical Approach and Implant Design The surgeon faces three specific challenges with reverse shoulder arthroplasty in the setting of preoperative deltoid impairment: respect of the remaining deltoid, protection of the axillary nerve, and avoidance of postoperative instability. The transdeltoid approach result potentially in additional trauma to the deltoid and consequently is not recommend for cases with preoperative deltoid impairment. Another alternative approach has been developed to respect the deltoid by performing a deltopectoral approach, without taking the subscapularis down (subscapularis and deltoid sparing approach).{Lädermann, 2017 #3954;Lädermann, 2016 #3630} This effectively combines the deltopectoral and superior approaches and respects the subscapularis, one of the keys for postoperative stability{Edwards, 2009 #1039} and postoperative function.{Collin, 2014 #2080}
In order to improve the lever arm of the impaired deltoid muscle and allow recruitment of more anterior and posterior deltoid fibers, the use of a medialized glenoid design with a lateralized humeral stem could be recommended (Figure).
Figure: Deltoid recruitment
Figure: The level arm of the deltoid is highly dependent on prosthetic configuration. From Collin et al, with permission.
Furthermore, the principles of restoring humeral length in order to obtain sufficient tension of the remaining deltoid is also employed as it contributes to a lower rate of postoperative dislocation.{Lädermann, 2012 #669;Lädermann, 2009 #654} Nevertheless, arm lengthening compared to the contralateral side should not be attempt as might help prevent a double crush syndrome by decreasing postoperative traction on the plexus.{Upton, 1973 #976} Consequently, implantation of a lower (145 degrees or 135 degrees) neck-shaft angle should be used in case of preoperative axillary nerve injury as it theoretically limits deltoid overlengthening (Figure).
Figure: Role of neck shaft angle to limit arm lengthening
Figure: The neck-shaft angle is one of the biggest variabilities between different prosthesis designs. For every 10 degrees decrease the acromiohumeral distance shortens by approximately 3 mm (more than 1 cm in this example). A low neck-shaft angle limits deltoid lengthening and is an option in case a preoperative deltoid impairment.
Finally, with a deltopectoral approach the authors believe that if the pectoralis major tendon is partially or completely detached during surgery to improve exposure, it may be important to repair this tendon to aid as an anterior constraint. It has also been demonstrated that the muscle, mainly its clavicular part, could at least partially compensate for the anterior deltoid in forward elevation.{Ackland, 2008 #1229;Inman, 1944 #1060}
Discussion Few reports have described the outcome of reverse shoulder arthroplasty in the setting of deltoid impairment.{Glanzmann, 2009 #1014;Goel, 2011 #672;Ladermann, 2013 #1687;Schneeberger, 2014 #2087;Tay, 2011 #670} The available data suggest that reverse shoulder arthroplasty may indeed be a viable treatment option in the setting of mild to moderate, anterior and middle partial deltoid impairment. It is apparent that not all of the deltoid must be intact for the benefits of a reverse shoulder arthroplasty to be realized. Rather, it is important to critically analyze the location of the deltoid impairment and the remaining strength to determine if implantation of a reverse shoulder arthroplasty is possible. It is important to remember that arm elevation is composed of both glenohumeral and scapulothoracic motion. The latter could contribute significantly to postoperative reverse shoulder arthroplasty motion in the context of a preoperative deltoid impairment.{Kim, 2012 #1227;Kwon, 2012 #1440} After reverse shoulder arthroplasty implantation in the case of deltoid impairment, the deltoid contributes to elevation through the glenohumeral joint. However, scapulothoracic motion also probably increases and contributes substantially to elevation.{Kim, 2012 #1227;Kwon, 2012 #1440}
Even if the rate of complications remains high, few complications can be specifically attributed to the preoperative muscle insufficiency as opposed to complications following reverse shoulder arthroplasty in general, particularly revision cases. In fact the complication rate, including the dislocation rate, is comparable to previous series of reverse shoulder arthroplasty performed with normal deltoids.{Gallo, 2011 #1038;Mulieri, 2010 #834} Thus, it does not seem that preoperative deltoid impairment is related to a higher complication rate or prevalence of dislocation, at least when the impairment is not global. In all studies, the improvement is obtained in postoperative active forward elevation and Constant score. However, these functional results are, as expected, lower than that described in cases with a normal deltoid.{Boileau, 2010 #728;Ladermann, 2012 #669;Ladermann, 2009 #654;Sirveaux, 2004 #671;Whatley, 2011 #839} It seems that the reverse design allows restoration of elevation above 90 degrees, even with partial deltoid impairment. Not surprisingly, results are less satisfactory when deltoid impairment involves the entire deltoid (type 4). In other words, it seems that the most important factor for postoperative result is the extent of the lesion, and not its cause.{Ladermann, 2013 #1687} 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 Preoperative Pre- or postoperative acromial pathology, which could theoretically compromise deltoid condition and affect the proper function of the prosthesis, is of legitimate concern. Postoperative fractures occur at least in 3% of cases{Molé, 2007 #1018} 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 5), or osteoporosis-induced insufficiency.{Levy, 2012 #1061}
Figure: Preoperative insufficiency of acromion
Figure: Preoperative insufficiency of a left acromion on an anteroposterior view. Note that a large part of the acromion just seems to have disappeared.
Spine fracture de Bouvier
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.{Crosby, 2011 #1040} Osteoporose et etude George Mettre etude George mettre etude neyton et Lädermann They 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).{Crosby, 2011 #1040}
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).
Figure: Postoperative acromial fracture
Chnager photo Figure: Postoperative anteroposterior X-ray demonstrate an acromial fracture (blue arrow).
The author believes that the use of positron emission tomography-computed tomography is helpful in diagnosis of non-displaced fractures.
Figure: Mettre stress fracture SPECT CT
Good results have surprisingly been reported in patients with preoperative acquired or congenital acromial pathology or postoperative acromial fracture.{Mottier, 2007 #1037} 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.(étude walch) et la notre
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.{Crosby, 2011 #1040;Werner, 2005 #999}
Latissimus Dorsi Transfert in Combination with the Reverse Shoulder Arthroplasty 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.
Reverse Shoulder Arthroplasty in Weight Bearing Patients 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. 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.{Wall, 2007 #658} However, some patients have had unexpectedly poor functional improvements after reverse shoulder arthroplasty.{Wall, 2007 #658} Poor postoperative range of motion following reverse shoulder arthroplasty, has been associated with younger age,{Hartzler, 2015 #3423} gender,{Schwartz, 2014 #2691} surgeon experience,{Walch, 2012 #3141} preoperative diagnosis such as posttraumatic arthritis and revision arthroplasty,{Cuff, 2008 #833;Wall, 2007 #658} pre- and intraoperative range of motion or deltoid impairment,{Lädermann, 2013 #1687;Schwartz, 2014 #2691} postoperative arm lengthening{Lädermann, 2014 #2344;Lädermann, 2012 #669;Lädermann, 2009 #654} or neurological lesion.{Hartzler, 2015 #3423;Lädermann, 2011 #942} Surgery of the non-dominant side, lower preoperative range of motion, and lower functional outcomes scores preoperatively are predictive of a slower recovery of active anterior forward flexion after reverse shoulder arthroplasty.{Collin, 2017 #3923}
Figure: Evolution Constant score after reverse shoulder arthroplasty
Figure: Evolution Constant score during follow-up.
Figure: Evolution of elevation and rotations after reverse shoulder
Figure : Evolution of elevation and active rotations during follow-up. Mettre permissions Mettre excellene tresultats lg terme 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.{Baulot, 1995 #991;Baulot, 1999 #994;Boulahia, 2002 #995;Rittmeister, 2001 #996;Sirveaux, 2004 #671;Valenti, 2008 #998;Werner, 2005 #999} Mettre long term results 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.{Zumstein, 2011 #1000} 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.{Zumstein, 2011 #1000} We thus conducted a retrospective long-term study (Appendix 6). All the current knowledge of this subject is summarized in this work.Mélis Long-term studies reported their prevalence.mettre etude walch
Impingements Scapular Notching Scapular notching is the most frequent radiographic change after a reverse shoulder arthroplasty and has been reported as high as 88%.{Mélis, 2011 #649} 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,{Nyffeler, 2005 #592;Nyffeler, 2004 #1015} radiolucency around the glenoid component,{Werner, 2005 #1579} loosening of the glenoid component,{Cazeneuve, 2009 #760} presence of an inferior bone spur, and ossification in the glenohumeral space.{Boileau, 2006 #639;Levigne, 2008 #1539;Mélis, 2011 #649}
Scapular notching typically occurs within six months after surgery and appears to stabilize in most cases.104,105
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.110 Eccentric glenospheres with an inferior offset and glenoid components with a more lateral offset (bony or metal) can reduce the risk of notching.112,113 Mizuno et al114 analysed the influence of an eccentric glenosphere in 47 consecutive cases compared with an 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. Other authors have reported a negligible rate of notching when using an inferior offset component.115
Mettre figure d’un scapular notching
Two types of impingement interactions are noted (Figure)
Figure: Abutment- and friction-type impingements
Figure: 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. De Wilde L, Walch G (2006) Humeral prosthetic failure of reversed total shoulder arthroplasty: a report of three cases. J Shoulder Elb Surg Am Shoulder Elb Surg Al 15:260–264. doi: 10.1016/j.jse.2005.07.014 As the conformation of the joint changes from spinning to hinging in reverse shoulder arthroplasty, implant version of the humeral stem seems the most predictive factor for the occurrence anterior scapular notching. Grammont already warned that excessive retroversion led to decreased internal rotation.{Grammont, 1993 #917} This was further substantiated and quantified by several imaging and biomechanical studies looking at the impact of implant version on anterior notching and range of motion. Karelse ATJA, Bhatia DN, De Wilde LF (2008) Prosthetic component relationship of the reverse Delta III total shoulder prosthesis in the transverse plane of the body. J Shoulder Elbow Surg 17:602–607. doi: 10.1016/j.jse.2008.02.005 53. Stephenson DR, Oh JH, McGarry MH, et al (2011) Effect of humeral component version on impingement in reverse total shoulder arthroplasty. J Shoulder Elbow Surg 20:652–658. doi: 10.1016/j.jse.2010.08.020 54. Berton A, Gulotta LV, Petrillo S, et al (2015) The effect of humeral version on teres minor muscle moment arm, length, and impingement in reverse shoulder arthroplasty during activities of daily living. J Shoulder Elbow Surg 24:578–586. doi: 10.1016/j.jse.2014.08.019
Karelse et al. first noted that decreasing the so-called anterior divergence angle between the humeral and glenoid axis measured on CT scan decreased anterior notching. Karelse ATJA, Bhatia DN, De Wilde LF (2008) Prosthetic component relationship of the reverse Delta III total shoulder prosthesis in the transverse plane of the body. J Shoulder Elbow Surg 17:602–607. doi: 10.1016/j.jse.2008.02.005 In their biomechanical cadaveric study, Stephenson et al. further stated that anterior notching mostly occurred in adduction and that the best compromise between anterior and posterior notching to favor a functional arc of motion was 20 to 40 degrees of humeral retroversion. Stephenson DR, Oh JH, McGarry MH, et al (2011) Effect of humeral component version on impingement in reverse total shoulder arthroplasty. J Shoulder Elbow Surg 20:652–658. doi: 10.1016/j.jse.2010.08.020 On the other hand, glenoid component version doesn’t seem to influence notching in the axial plane.Favre P, Sussmann PS, Gerber C (2010) The effect of component positioning on intrinsic stability of the reverse shoulder arthroplasty. J Shoulder Elbow Surg 19:550–556. doi: 10.1016/j.jse.2009.11.044
Infection The incidence of infections after primary reverse shoulder arthroplasty is around 5%,{Farshad, 2010 #1016} which is higher than in anatomic shoulder arthroplasty.{Fehringer, 2010 #1019;Seebauer, 2007 #1020} 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.{Coste, 2004 #1021;Molé, 2007 #1018} The commonly identified low-virulence organism are Cutibacterium acnes and Staphylococcus epidermidis.{Boileau, 2006 #639;Molé, 2007 #1018;Wall, 2007 #658;Werner, 2005 #999} 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.{Zimmerli, 2004 #1022;Sperling, 2001 #1023} Late infections should be treated with arthroplasty removal, debridement and reimplantation.{Molé, 2007 #1018;Sperling, 2001 #1023}
Instability Dislocation 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 {Boileau, 2006 #639;Cazeneuve, 2006 #1024;Cuff, 2008 #833;Cuff, 2008 #1026;De Wilde, 2003 #1005;Gohlke, 2007 #1027;Levy, 2007 #1010;Wall, 2007 #658;Werner, 2005 #1579}.
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,{Boileau, 2005 #121} 6) no asymmetric subluxation or tilting of the proximal humeral component on the glenosphere during adduction,{Grammont, 1987 #1041} and 7) free glenohumeral motion without scapula-thoracic motion between 0° to 60° of abduction.{Valenti, 2005 #1042}
Most cases of dislocation occur during the first few months after implantation and are a result of a technical error.{Farshad, 2010 #1697} Risk factors for dislocation include body mass index > 30, male sex, previous surgery, subscapularis deficiency and high neck shaft angle (155 degrees). 96,97 The etiology of dislocation is multifactorial. It can occur due to 1) deltoid insufficiency (Figure),{Ladermann, 2013 #1687;Wall, 2007 #658} 2) lack of anterior restraints including subscapularis insufficiency, conjoint tendon weakness,{Edwards, 2009 #1039} and pectoralis major insufficiency, 3) malpositioning of the components, 4) impingement, and 5) infection. Instability is more frequent in cases of revision arthroplasty.{Zumstein, 2011 #1000} Deltoid insufficiency can be caused by preoperative factors{Ladermann, 2013 #1687;Wall, 2007 #658} or can result from a postoperative lack of deltoid tension, acromion fracture (Figure), polyethylene wear, stem subsidence, or postoperative neurological palsy. Changer et mettre Hovaglian
Figure:
Figure: A) Preoperative anteroposterior x-ray of a right shoulder with an acromial fatigue fracture. B) At two years follow-up, a postoperative tilt of the acromion and a grade 4 scapular notch are noted. C) The prosthetic dislocation could be related to the lack of deltoid tension.
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. Instability at the ball and socket interface is usually detected at its full range, which is anterior or anterolateral dislocation (Figure).
Figure: A) Dislocation of a right reverse shoulder arthroplasty that requires open revision and humeral lengthening with a spacer. B) At 120 months follow-up, the patient had no recurrence.
Subscapularis integrity is important if a 155 degrees is used.{Edwards, 2009 #1039;Gallo, 2011 #1038;Wall, 2007 #658} Low neck shaft angles (145 and 135 degrees) are more stable designs and subscapularis integrity seems less important to prevent instability.
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.{Boardman, 1999 #1029;Bohsali, 2006 #1028;Boileau, 2006 #639;Lynch, 1996 #1030;Plausinis, 2005 #1031} A prospective study determined the electrodiagnostic occurrence of peripheral nerve lesions following 155 degrees neck shaft angle reverse shoulder arthroplasty.{Ladermann, 2011 #942} 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.Trouver réf It seems consequently that distalization is nefaste and lateralization 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).
Figure 7: Glenoid non-assembly. Immediate postoperative imaging revealing a non-assembly (black doted lines) of the glenosphere on the metaglene.
Mettre la mienne
Periprothetic fractures Intraoperative 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. The author prefers to rim the metaphyseal area after glenoid preparation in order not to weaken the humerus. 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.
Figure: 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 anteroposterior and lateral views.
Mettre la pt avec polio
Heterotopic ossification Heterotopic ossification after reverse shoulder arthroplasty (Figure) is a relatively common finding of unknown clinical importance.116
Figure
References
