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1 Chapter 1 : Complications of Shoulder Arthroplasty Musculoskeletal Key Soft Tissue Complications After Shoulder Arthroplasty -- Hersch/Dines D Conversion from Hemiarthroplasty to Total Shoulder Arthroplasty -- Goldberg/Bigliani Reverse Prosthesis for the Rotator Cuff Deficient Shoulder -- Boileau/Hatzidakis Developments in shoulder arthroplasty. Proc Inst Mech Eng H ; 1: Total shoulder arthroplasty TSA is an effective approach for the treatment of a variety of clinical conditions affecting the shoulder, including osteoarthritis, with remarkable results on indolence and shoulder function. For the past decade, there was an exponential increase in the number of total shoulder arthroplasty. The shoulder is the most mobile joint in the body. Constraints are stretching and suspension forces and not, as for the hip, compressive stresses. This is why the most common shoulder disorders are primarily diseases of the muscle-tendon unit of the shoulder and non arthritic pathologies. This is also why a dynamic musculoskeletal vision of shoulder disorders and their solutions is fundamental. Infections, loosening, instability, the list of complications after total shoulder prosthesis is long. Articles published between to and referenced in the online Pubmed database have been reviewed. A focus was made on the intraoperative fractures, infections, primitive and iatrogenic damages to the subscapularis, loosening of the humeral and glenoid implants. Intraoperative Fractures The most immediate intraoperative complication is peri-prosthetic humerus fractures which account for 1. In, Athwa et al. Periprosthetic humeral fractures during shoulder arthroplasty. J Bone Joint Surg Am ; 91 3: They analyzed 45 fractures and depicted three types of fractures: For Athwa et al. Mechanisms of fracture and treatment options. J Shoulder Elbow Surg ; 7 4: Thus, fractures in regions 1 and 2 tuberosity and metaphysis are stable and have to receive a standard stem. The regions 3 and 4 correspond to peri and under protesthetic fractures. They are unstable and all had benefited from a long stem in the series of Campbell, with shaft approach Fig. Periprosthetic humerus fracture areas according to Campbell. Readmissions Two meta-analyses were published in and target early readmissions after 30, 60 and 90 days follow up. Page 1

2 Chapter 2 : Soft tissue balancing in total shoulder replacement Soft tissue complications after shoulder arthroplasty By: Hersch J, Dines D, Thieme Date: September 06, Source: Shoulder Arthroplasty: Complex issues in the primary and revision setting. Unlike in the primary setting, however, the rate of complications for revisions is significantly greater and the management is more complex because of overlapping complications and limited treatment options. Furthermore, there is a paucity of evidence-based literature to direct the management options in these patients. The purposes of this review are to broadly outline the major complications that are seen in revision shoulder arthroplasty and to provide general principles on how to recognize and approach these complex cases. Revision, Complications, Shoulder arthroplasty, Management Introduction With the growing number of shoulder arthroplasties in the USA [ 1 ], complications that lead to the need for revision arthroplasty are reasonably well defined. Complications after revision shoulder arthroplasty are similar to the complications seen after primary shoulder arthroplasty but are more frequently encountered and difficult to manage. Sometimes defining the cause of failure, especially if the main symptom is pain, is complex and multifactorial. Overall, studies have shown that revision arthroplasty has less predictable functional outcomes and increased complication rates compared to primary shoulder arthroplasty [ 2 â 5 ]. Management depends on defining the complication and the etiology and then taking stock of the remaining current anatomy in trying to apply either a surgical or nonsurgical solution. In these complex situations, surgery is not always the best option given the high complication risks associated with a re-revision setting. The situation is further complicated by the fact that revision arthroplasty can either be a reverse or anatomical prosthesis and the approach to each is unique. The focus of this review is to break down some of the most common issues after revision shoulder arthroplasty and assess the management of these issues in a principled approach. Complications of revision arthroplasty Instability With an anatomic prosthesis, instability is due to subscapularis failure until proven otherwise after a revision. In the primary setting, the most common rotator cuff tear is a subscapularis tear. However, this tear rate is likely higher in the revision setting. Subscapularis muscle or tendon disruption can lead to anterior displacement of the prosthesis and poor functional outcomes and pain Fig. Posterior instability is less common than anterior instability after arthroplasty and in most cases is related to preoperative glenoid erosion and posterior subluxation. The classification proposed by Walch et al. In this particular group, the authors noted 19 shoulders had anterior instability and 14 shoulders had posterior instability. The majority of the instability was attributed to abnormal capsular tensioning or rotator cuff dysfunction. The authors concluded that instability after total shoulder arthroplasty TSA is a difficult problem to manage and even with revision surgery, more than half of the patients in this study remained unstable [ 8 ]. Component sizing can also play a role such that an undersized component can lead to laxity of the soft tissues which can compromise the tensioning of the components. Though, unless grossly undersized, this is rarely the cause of instability. Page 2

3 Chapter 3 : Anatomic Shoulder Arthroplasty: Technical Considerations ~ Fulltext Hersch and Dines reported on 13 arthroscopies performed for poor results following shoulder arthroplasty. The arthroscopic diagnoses ranged from rotator cuff tears in five shoulders, fibrosis and scarring of the long head of the biceps in five shoulders, impingement and biceps tendinitis in one shoulder, and capsular contracture in one shoulder. Cofield and colleagues have also provided a compilation of complications seen at the Mayo Clinic over a twodecade span They identified surgical complications in 90 of the patients who had undergone TSA and 49 complications among the 83 patients who had undergone HA for proximal humerus fractures and their sequelae. In contrast to the two reviews mentioned previously, stiffness was rarely, if ever, considered a cause of failure in this series. See also Tables and Although the timing of failure is rarely discussed, the analysis of our revisions revealed interesting trends. The vast majority of causes of failure in this group could be termed avoidable errors. The subset of failed HA for proximal humerus fracture was slowest to revision, at an average of 28 months, and the subset of failed HA for osteoarthritis was fastest, at an average of 12 months Fig. In contrast, the timing of failure of TSA was bimodal. Approximately half failed early, in association with instability, and were revised at an average of 19 months. The other half failed late as a result of aseptic loosening and were revised at an average of 99 months Fig. Because the causes of failure are so disparate, classification is difficult. To improve understanding of the causes of failure, they are often discussed in the context of the index diagnosis. For purposes of simplicity, some complications, such as nerve injury and heterotopic ossification, are grouped with the soft tissues. Additional complications not specific to shoulder arthroplasty e. As much as is possible, the preoperative evaluation should determine the causes of failure and whether a fixable problem exists. Finally, the needs of the patients and their ability to undergo a revision arthroplasty must be considered. Figure Revision of unsuccessful hemiarthroplasty almost inevitably occurred within 24 months of the index surgery. The history is critical in helping to determine the causes of failure of the arthroplasty. The index diagnosis, details of prior surgical procedures, and the timing of failure of the primary arthroplasty all provide critical information. In the patient who fails to improve following an elective arthroplasty, possible problems include instability, often resulting from a ruptured subscapularis repair, an unaddressed lax posterior capsule, or an error of component positioning. Failure of an arthroplasty to relieve pain may also result from failure to resurface an arthritic glenoid or from the development of postoperative stiffness. Patients with unsuccessful arthroplasty for fracture may have problems with tuberosity position or healing or with the position of the humeral component. Infection may occur either early or late and should always be included in the differential for any unsuccessful arthroplasty. Late failure after a period of satisfactory function most typically is the result of glenoid loosening, dissociation after TSA, or the development of glenoid arthrosis following HA. Humeral loosening is less common but may also occur, typically in the setting of TSA, when glenoid wear debris may induce osteolysis around the humeral stem Physical examination begins with inspection of the shoulder for evidence of rotator cuff dysfunction and atrophy or detachment of the deltoid. Active and passive range of motion is recorded, as are the strength of the deltoid, external rotators and subscapularis, and the function of the peripheral nerves. The stability of the shoulder in all directionsâ anterior, posterior, inferior and superiorâ also is evaluated. In addition, a standard shoulder examination should be carried out because more chronic problems such as impingement and acromioclavicular arthritis can also compromise the results of shoulder replacement. Figure Revision of a failed total shoulder arthroplasty was equally likely to occur early, usually as a result of instability, or late, typically as a result of glenoid loosening. For preoperative imaging, standard radiographs usually will suffice. Whenever they are available, serial x-rays should be reviewed for evidence of progressive radiolucent lines, osteolysis, or change in implant position. If fluoroscopy is available, it may occasionally be used to obtain tangential views of the glenoid to enhance the detection of radiolucent lines about the glenoid or the humeral stem to determine humeral version. If questions regarding the status of the osseous or soft-tissue structures Page 3

4 remain Figs. Figure Anteroposterior and axillary views of a painful shoulder arthroplasty are suspicious for infection. Computed tomography CT scans can be helpful in special circumstances, although the quality of the images may be lessened by artifact from the metallic stem. They are particularly useful for determining the position and healing of the tuberosities, for assessing the shape and version of the glenoid, and for evaluating glenoid loosening when the plain films are not conclusive Fig. For the painful arthroplasty that presents a diagnostic dilemma, MRI can also be used to evaluate the rotator cuff and the glenoid cartilage. Sperling and colleagues 17 correlated the MRIs of 22 painful shoulder arthroplasties with operative findings at subsequent revision surgery. At the time of revision surgery, there were full-thickness rotator cuff tears in 11 of 21 shoulders; MRI had correctly predicted 10 of these 11 full-thickness rotator cuff tears, which involved the subscapularis in 8 of 11 shoulders. MRI also correctly predicted glenoid cartilage wear in 8 of 9 shoulders. When the history, physical examination, and radiographic tests do not provide a clear diagnosis, shoulder arthroscopy can provide additional diagnostic information and also presents options for treatment. Bonutti and colleagues 18 reviewed nine patients who underwent arthroscopy followed by open surgery to confirm arthroscopic findings. They found that arthroscopy accurately evaluated glenoid component loosening in all patients with this problem. Hersch and Dines 20 reported on 13 arthroscopies performed for poor results following shoulder arthroplasty. The arthroscopic diagnoses ranged from rotator cuff tears in five shoulders, fibrosis and scarring of the long head of the biceps in five shoulders, impingement and biceps tendinitis in one shoulder, and capsular contracture in one shoulder. They repaired or debrided the lesions at the time of arthroscopy, with few complications and excellent patient satisfaction. Figure Computed tomography scan or magnetic resonance image may be added. Figure Computed tomography scan confirms loosening of the glenoid. Tytherleigh-Strong and colleagues 21 reported on 29 patients who underwent arthroscopy for excessive pain or limitation of motion after a shoulder arthroplasty. Although the procedures were often hindered by limited access and reflection from the prosthesis, preoperative diagnoses were confirmed in 14, including impingement syndrome in 10 patients treated by arthroscopic subacromial decompression. Of the 15 patients without a preoperative diagnosis, 7 had postarthroplasty capsular fibrosis, with 6 undergoing arthroscopic capsular release. A final complication that must be ruled out for any failed, painful arthroplasty is infection. Although infection after shoulder replacement is rare, and there is a paucity of literature regarding the preoperative evaluation of a potentially infected shoulder arthroplasty, there are significant lessons that can be drawn from the literature on infected hip arthroplasty. All patients who had a periprosthetic infection had an elevated erythrocyte sedimentation rate or level of C-reactive protein but not always both. In other words, in this series, if a patient had a combination of a normal erythrocyte sedimentation rate and a normal C-reactive protein level, the probability of infection was zero. Plain radiographs may show bone resorption around the components, endosteal scalloping, or periosteal new bone formation. Indium-labeled white cell scan also may be used occasionally. Aspiration and culture are useful when prior studies do not clearly indicate the status of the shoulder. Gram stain is unreliable. Examination of intraoperative frozen sections is useful in equivocal cases or when hematologic markers could be falsely elevated because of an inflammatory or other condition. In reviews on postoperative instability, Norris and Lipson 24, Hennigan and Iannotti 25, and Warren and colleagues 26 have all noted that the instability may occur in any directionâ anterior, posterior, superior, or inferiorâ based on the position of the components and the condition of the soft tissues. In a separate report on 50 arthroplasties undergoing revision for instability, component problems were a primary cause of the instability in 18 of the 50 shoulders, with the remainder being soft-tissue abnormalities. As with all complications, the best treatment is prevention, with careful attention to soft-tissue technique and component position being the crucial elements in avoiding instability. When instability does occur, it is important to recognize and correct all factors contributing to the problem as early as possible because continued instability may result in component wear or loosening. Although more detailed descriptions of glenoid and humeral revision are presented later in this chapter and in the chapter on revision arthroplasty, this section does address aspects of revision as they particularly apply to instability. In most series, anterior Page 4

5 instability occurs acutely and is typically the result of rupture of the subscapularis tendon or excessive humeral anteversion. Overstuffing the joint with an excessively large humeral head can also cause problems with the subscapularis repair. At the time of revision, a careful search for the subscapularis is an important part of the surgical approach. If it is present and can be mobilized sufficiently, it may be re-repaired, but there may be times when it is irretrievable. In this circumstance, transfer of the pectoralis major may be necessary to restore anterior stability. A number of techniques, including transfer of the sternal head 28 and partial 29 or complete 30 subcoracoid transfer have been described. Our preference is to transfer the upper half of the entire tendon over the conjoined tendon and attach it to the greater tuberosity Figs. Once a dynamic anterior muscle tendon unit has either been mobilized for rerepair or prepared for transfer, attention is directed to the capsule. In cases where anterior instability is severe, it may be necessary to reestablish a capsular restraint as well. Moeckel and colleagues 32 identified seven patients with anterior instability caused by a rupture of the repaired subscapularis tendon after shoulder arthroplasty. Treatment consisted of mobilization and repair of the tendon, but three of the seven patients continued to have instability. A static stabilizer, consisting of an allograft of Achilles tendon, was inserted in these three patients. In Iannotti and colleagues 33 described a method of iliotibial band reconstruction for irreparable capsular deficiency that could also be considered in this situation Fig. In addition to repair of the detached subscapularis or transfer of the pectoralis major, revision consisted of correction of any errors of humeral component position. In many cases, excessive anteversion of the stem is a contributing factor to anterior instability. Although it may occasionally be possible to compensate for errors in stem position by changing the position of an eccentric head, in general, an improperly place humeral component should be revised to the appropriate height, size, and version. Finally, the glenoid must be inspected. In many cases in our series, the unstable humeral head had eroded, loosened, or dissociated a prosthetic glenoid or eroded the anterior rim of the native glenoid. If instability has caused a prosthetic glenoid to fail, it should be removed and a new glenoid should be inserted or cancellous bone graft should be impacted into the empty vault. In some circumstances, we have encountered so much anterior erosion that it has been necessary to either insert a prosthetic glenoid to improve stability or increase the humeral retroversion to match an anterior-facing glenoid. Figure The top half of the pectoralis tendon is identified and released. In contrast to anterior instability, posterior instability may either occur early or develop late and is usually attributable to combined excessive retroversion of the humeral and glenoid components. This is particularly problematic in patients with an index diagnosis of osteoarthritis, with its characteristic combination of posterior glenoid wear, excessive glenoid retroversion, and a lax posterior capsule. Failure to address this pathology at the index surgery can lead to either immediate posterior instability or continued stretching of an already patulous posterior capsule, with the instability developing later Figs. Figure One trough is made lateral to the bicipital groove and tunnels are created for the passage of sutures. Figure Stay sutures in the pectoralis tendon are passed through the tunnels and tied over a bridge of cortical bone. Technique of anterior capsular reconstruction with iliotibial band. Although some have addressed posterior instability from the back of the joint, our preference has been to correct it from the front. After opening the deltopectoral interval, one is usually able to find the subscapularis. Lack of external rotation can also contribute to posterior instability, and if the subscapularis is tight it should be lengthened, either by medializing its insertion or by a zlengthening of the tendon and capsule. Revision is facilitated by modular humeral designs. If the stem is appropriately placed, it is possible to access the glenoid and posterior capsule merely by removing the humeral head. However, if the stem itself is inappropriately located, it should be removed and revised to the appropriate size, height, and version. Page 5

6 Chapter 4 : Shoulder arthroplasty : complex issues in the primary and revision setting - ECU Libraries Cata Recreation of the optimal soft tissue balance is critical for restoration of function after a primary or revision shoulder arthroplasty. Soft tissue balance depends on proper release of the contractures, appropriate lengthening of tendons, and repair or reconstruction of the rotator cuff when possible. American Journal of Sports Medicine. Arthroscopic superior capsular reconstruction with over the top Rotator cuff repair. Accepted to Arthroscopy Technique: Arthroscopic Double Row Subscapularis Repair. A Systematic Reviewa Accepted to Arthroscopy: Long Head of Biceps Tendon Management: Epub Oct Curr Rev Musculoskelet Med. S Biomechanical comparison of acute Hill - Sachs reduction with remplissage to treat complex anterior instability. J Shoulder Elbow Surg. S - 16 Depression and psychiatric disease associated with outcomes after anterior cruciate ligament reconstruction. Internet Resources for Tommy John Injuries: What are patients reading? S Return to sports after shoulder arthroplasty. Accuracy of Suture Passage during Arthroscopic Remplissage: Sports after Shoulder Arthroplasty: Baseline predictors of patient - reported outcomes; An Evidence Based Review. Am J Sports Med. What Are Patients Doing? Effect of bone loss in anterior shoulder instability. World J OrthopJun 18; 6 5: Large Hill - Sachs Lesion: Online Resources for Shoulder Instability: J Bone Joint Surg Am. Dines, and Joshua S. A Review of Current Management. Spine Phila Pa, Dec 1;38 Clinical Orthopedic Related Research. Implications for Scaffold Design and Tissue Engineering. Tissue Engineering Part A. Featured authors for AJSM with recorded podcast on the blog: American Journal of Sports Medicine: Instability and Trauma 1st Edition Link: Thieme Medical Publishers Inc. How Poor Are Online Resources? Return to Sport after Shoulder Arthroplasty: Arthroscopy Association of North America. Remplissage Outcomes and Sports Affected: American Academy of Orthopaedic Surgeons. Are We Getting Our Fill? The Radiological Society of North America. Philadelphia Orthopedic Society for Sports Medicine. Remplissage Arthroscopy Association of North America. Arthroscopic Localization of the Coracohumeral ligament. Philadelphia Orthopedic Research Society. Page 6

7 Chapter 5 : Thieme Medical Publishers - Shoulder Arthroplasty Shoulder arthroplasty: complex issues in the primary and revision setting / Stephen Fealy [and others]. Total shoulder arthroplasty TSA, hemiarthroplasty, and reverse total shoulder arthroplasty RTSA have all been well-described in the context of shoulder osteoarthritis, and the number of these procedures has been steadily rising over the past decade. Total shoulder arthroplasty with the Neer prosthesis. J Bone Joint Surg Am ; 66 6: Functional outcome after shoulder arthroplasty for primary osteoarthritis: For example, between and, the annual number of shoulder arthroplasties increased 2. Increasing incidence of shoulder arthroplasty in the United States. J Bone Joint Surg Am ; 93 The primary goals of shoulder arthroplasty are to provide pain relief, stability, and restore motion [ 4 Bush CA, Hawkins RJ. Prevention of complications in shoulder arthroplasty: Instr Course Lect ; These may be achieved through a thorough understanding of the indications for surgery, indications for each prosthetic type, and proper technique. The purpose of this article is focus on the technical aspects of primary anatomic TSA, and aim to provide a framework to follow to achieve a successful surgical result. Evolving techniques and indications.. Revue du rhumatisme ; 77 6: Glenoid component loosening is the most common complication following TSA, and is often due to technical errors leading to component malposition, which increases stress forces across the glenoid component [ 2 Norris TR, Iannotti JP. Glenoid bone loss in primary total shoulder arthroplasty: J Am Acad Orthop Surg ; 20 9: Complications of total shoulder arthroplasty. J Bone Joint Surg Am ; 88 A careful pre-operative evaluation is necessary in all cases, including standard radiographs, including true AP in neutral, internal, and external rotation, and axillary views of the shoulder. Surgical approach and techniques for total shoulder arthroplasty: Measurement of glenoid version: J shoulder elbow surg Am Shoulder Elbow Surg ; 12 5: Validity of different methods in two-dimensional computed tomography scans. J shoulder elbow surg Am Shoulder Elbow Surg ; 19 8: Glenohumeral osteometry by computed tomography in normal and unstable shoulders. Clin Orthop Relat Res ; A line perpendicular to this drawn from the anterior edge of the glenoid fossa defines neutral version; if the posterior edge of the glenoid fossa lies medial to this line, it is retroverted. Other techniques, such as the scapula body line described elsewhere, have also been used to predict glenoid version [ 12 Randelli M, Gambrioli PL. MRI may be indicated when a rotator cuff tear is suspected, as well as in patients with rheumatoid arthritis of the shoulder, who are known to have a high incidence of atraumatic cuff tears [ 12 Randelli M, Gambrioli PL. Replacement arthroplasty for glenohumeral osteoarthritis. J Bone Joint Surg Am ; 56 1: How to measure it? B The paleoglenoid, which represents the native glenoid version, C Intermediate glenoid, and D The neoglenoid, representing the new version of the glenoid. Page 7

8 Chapter 6 : Jonathan Hersch, MD - Orthopaedic Surgeon in Boca Raton, FL\n Assembles the clinical knowledge of leading orthopaedic surgeons treating patients with arthritic shoulders. The book presents practical approaches to surgically managing each type of arthritis, the challenges of revision surgery, and related complications during and following surgery. Gamradt, MDb, Christopher J. Mattern, MDc, Frank A. Cordasco, MDc, Edward V. Craig, MDc, David M. Dines, MDc, Russell F. Despite advances in technique and implant design, instability after reverse total shoulder arthroplasty remains a challenging postoperative complication. There were 9 cases of instability, all occurring within the first 6 months after surgery. All 9 patients had compromise of the subscapularis tendon at the time of initial reverse total shoulder implantation. With regard to implant positioning, 2 patients had superiorly inclined metaglenes and 3 had metaglenes positioned superior to the inferior glenoid. Each patient with a dislocation had at least 1 revision surgery, and 4 patients had underlying infection. At most recent follow-up, only 3 patients had a concentrically reduced reverse total shoulder arthroplasty in place whereas 3 remained explanted, 2 chronically dislocated, and 1 chronically subluxated. The craniocaudal position of the glenosphere relative to the inferior glenoid rim represents the measurement between the inferior-most point on the glenosphere and the inferior tip of the glenoid. B Reverse total shoulder humeral components inserted with intact tuberosity. C Reverse total shoulder humeral components inserted without intact tuberosity. We present a series of 9 patients who sustained early tions were anterior and confirmed radiographically. The The medical records of these 9 patients who had instability purpose is to review the preoperative, intraoperative, and after reverse shoulder replacement were reviewed for the following information: Initial postoperative radiographs were examined for 1 inclination angle between the glenosphere and scapular neck, 2 craniocaudal position of the glenosphere rela- Materials and methods tive to the inferior glenoid rim, and 3 presence of the greater tuberosity Fig. The proposed mechanism and treatment of This retrospective case series was approved by the Hospital for each dislocation and the eventual outcome were obtained through Special Surgery Institutional Review Board protocol No. Over a 3-year period, a total of 57 consecutive Special notation was made of the implant type and sizes of each reverse total shoulder arthroplasties were performed at our insti- component at revision procedures. The primary indication for surgery was pain associated with limited shoulder range of motion and shoulder pseudopar- alysis due to an absence or inefficiency of the rotator cuff tendons. Results The underlying etiology was rotator cuff tear arthropathy in 36 cases, failure of previous shoulder prosthesis in 18, and proximal The mean age at the time of initial reverse total shoulder humeral fracture and sequelae in 3. The mean age at the time of reverse total shoulder replacement was The mean number of procedures for each on the preference of each of 7 fellowship-trained shoulder patient before reverse total shoulder replacement was 2. Regardless of the implant chosen, a deltopectoral inci- range, None of the 9 patients died or were lost to sion with detachment of the subscapularis tendon, if present, was follow-up. The mean time from reverse total shoulder the surgical approach used for the majority of cases. A total of 24 early complications, including 1 death, 8 dislo- Several perioperative abnormalities were identified cations, 7 infections, 2 fractures, 2 component malfunctions, 2 among this cohort of patients. All 9 had an abnormality of nerve palsies, 1 recurrent subluxation, and 1 component loosening, the subscapularis tendon found at the time of reverse total occurred in 16 patients A total of 24 procedures, including 12 revision surgeries, were required in 11 patients shoulder implantation Fig. Whereas 3 patients had an The revision procedures were performed in 8 patients absent subscapularis tendon, the others had intact or With reverse prosthesis was initially inserted. Whereas recurrent regard to implant positioning, 2 had superiorly angled subluxation was seen in only 1 patient, dislocation occurred in metaglenes and 3 had metaglenes positioned superior to the R. Figure 2 The subscapularis tendon was irregular in all 9 instability cases, including this patient with a significantly atrophied subscapularis tendon on CT scan. Only 5 of 9 had intact, well-reduced greater tuberosities; the remaining 4 had a compromised tuberosity because of either fracture Figure 3 A metaglene positioned superior Page 8

9 to the inferior edge sequelae or previous hemiarthroplasty or both. Table I of the glenoid was among the most common technical errors that provides the background information and original surgical occurred in this series of instability. Instability developed within the first 6 months in all surgical revisions. Therefore, the savvy shoulder surgeon patients in our cohort. Each patient with a dislocation had at must be able to recognize the cause of instability and least 1 revision surgery to treat the reverse total shoulder determine a treatment plan that restores stability while instability. Four cases were complicated by infection. At limiting adverse outcomes. Although we had only 1 case of early loosening recurrent subluxation. Among the 4 cases of instability associated with infection, only 1 involved a patient who had a previous Discussion shoulder replacement; the others had cuff tear arthropathy as the underlying etiology. All 3 non-revision cases were The reverse total shoulder replacement has been an effec- treated surgically to correct the reverse shoulder replacetive option to restore function among those with shoulder ment instability before the discovery of an infection, which pseudoparalysis. Despite its success, this procedure has involved Propionibacterium acnes as the causative agent in been associated with a relatively high complication rate. Most series, particularly those with a large proportion of For those cases with a well-fixed implant and no revision cases, have reported cases of instability after evidence of an infection, the cause of instability should be reverse total shoulder replacement,12,21 yet few discuss sought. Knowledge of the mechanism of dislocation guides methods of prevention and treatment. In our experience, noninfec- Instability of a reverse total shoulder implant remains tious instability can result from either inadequate a difficult problem to solve. In our series, despite each tensioning of the deltoid or impingement of the patient undergoing revision surgery, only 3 prostheses were components. Inadequate tensioning of the deltoid after reverse total Often, revision cases are limited by poor bone stock and shoulder replacement was first described by Grammont. Furthermore, many a condition in which the lack of sufficient tension in the patients undergoing reverse shoulder replacements are deltoid muscle causes the formation of a space between the elderly, medically fragile, and unable to tolerate major ball and the socket. Boileau et al1 suggested that sphere and its baseplate have been made and confirmed proper tensioning of the implant can be roughly gauged by biomechanically to reduce contact between the poly- the tension generated within the conjoined tendon after ethylene cup and the inferior scapular neck. This determination likely contributes to the learning downward tilt of the component. In addition, a recent study using the tension based on humeral length. Edwards respectively, usually do not need to be revised. However, et al5 showed that an irreparable subscapularis at the time caution must be paid to avoid deltoid overtensioning, which of reverse total shoulder replacement is the most significant can result in acromion fracture and brachial plexus risk factor for dislocation after implantation using a delto- neurapraxia. Boileau et al1 suggested that the lack of Impingement of the implant requires a more extensive compromise of the subscapularis tendon in an ante- revision of the components, particularly the baseplate and rosuperior transdeltoid approach contributes to the lower metaglene. In our experience, the implant usually incidence of instability seen with that approach. Indeed, no impinges on the inferior scapular neck as the arm is dislocations have been reported among the 4 published adducted. The mechanism is similar to that responsible for series total of 50 patients that used the subscapularis- inferior scapular notching. Recently, several manufacturer sparing approaches exclusively. A a shoulder aspiration with fluid culture. All cultures should thorough evaluation of the etiology should be sought and be allowed to grow for a minimum of 10 days to adequately used to guide treatment of early instability after detect P acnes. Once infection has been ruled out, radio- a reverse total shoulder replacement. The determination of inclination we used is prone to error and a high degree of interob- server disagreement; however, this method remained the Disclaimer best option to measure inclination. Unfortunately, there were no accurate determinations of version obtained Robert A. Mat- because postoperative axillary radiographic views and CT tern, and Frank A. Cordasco, their immediate families, images were not routinely ordered postoperatively. None- and any research foundations with which they are theless, our measurements, though somewhat imperfect, do affiliated have not received any financial payments or offer additional insight on possible mechanisms of other benefits from any commercial entity related to the Page 9

10 instability. Craig has a royalty Although the surgical learning curve likely contributed agreement with Biomet. Dines has royalty to some of the instability, the exact role that surgeon agreements with Biomet and Biomimetic Therapeutics; experience with the procedure plays in the development of serves as a paid consultant to or is an employee of postoperative complications after reverse total shoulder Biomet, Biomimetic Therapeutics, and Tornier; has arthroplasty remains unproven. A recent study suggested stock considerations with Biomimetic Therapeutics; and that there was no significant difference in intraoperative has received research support from Biomet and Biomi- complication and early complication rate between metic Therapeutics. Reverse total shoulder arthroplasty represents a valuable tool for restoring painless shoulder function in those with References rotator cuff arthropathy and failed shoulder replacements with a deficient rotator cuff. However, there is a significant 1. In all cases of arthritis, fracture sequelae, and revision arthroplasty. J Shoulder Elbow instability, infection and component loosening should be Surg ; Thereafter, the causedeither inadequate deltoid 2. Early results of a reverse tension or component impingement or both dmust be design prosthesis in the treatment of arthritis of the shoulder in elderly determined to successfully treat the instability. For cases of patients with a large rotator cuff tear. Meanwhile, impingement often imal humerus in the elderly: J Bone Joint Surg Br ; J Shoulder Elbow Surg ; Acta Orthop Belg ; The inverse prosthesis as 5. Subscapularis insufficiency and the risk of shoulder Organi Mov ; J Shoulder Elbow Surg Rittmeister M, Kerschbaumer F. Grammont reverse total shoulder ; The reconstructible rotator cuff lesions. Reverse Shoulder Prosthesis for glenohumeral arthritis associated with A minimum two-year follow-up study of Reverse total shoulder arthroplasty for sixty patients. J Bone Joint Surg Am ; Grammont PM, Baulot E. Delta shoulder prosthesis for rotator cuff Reverse total shoulder replacement. Survivorship analysis of eighty replace- doi: Results Range of impingement-free abduction and adduction deficit after of a multicentre study of 80 shoulders. Hierarchy of surgical and implant- Chapter 7 : Orthopaedic Surgery Shoulder Arthroplasty Dr. D.M. Dines is Co-Director, Shoulder Fellowship, and an Attending, Sports and Shoulder Fellowship, Hospital for Special Surgery, New York, New York, and Professor of Orthopedic Surgery, Weill Cornell Medical College, New York, New York. Dr. J.S. Dines is an Attending Orthopedic Surgeon, Shoulder Fellowship and Sports and Shoulder Fellowship. Chapter 8 : Short, Medium and Long Term Complications After Total Anatomical Shoulder Arthroplasty ~ F Complications after revision shoulder arthroplasty are similar to the complications seen after primary shoulder arthroplasty but are more frequently encountered and difficult to manage. Sometimes defining the cause of failure, especially if the main symptom is pain, is complex and multifactorial. Chapter 9 : Revision Shoulder Arthroplasty VuMedi The purpose of this systematic review was to determine indications for shoulder arthroscopy in patients after shoulder arthroplasty and to report patient outcomes after these procedures. Page 10