Nazeem A. Virani

Reverse Shoulder Arthroplasty for the Treatment of Rotator Cuff Deficiency

BACKGROUND Early designs of reverse shoulder arthroplasty components for the treatment of glenohumeral arthritis associated with severe rotator cuff deficiency in some cases have been associated with mechanical failure. The purpose of this study was to perform a prospective outcomes study of reverse shoulder arthroplasty performed with use of 5.0-mm peripheral locking screws for baseplate fixation and a lateralized center of rotation for the treatment of a rotator cuff deficiency. METHODS From February 2004 to March 2005, 112 patients (114 shoulders) were treated with a reverse shoulder arthroplasty as part of a United States Food and Drug Administration Investigational Device Exemption study. Ninety-four patients (ninety-six shoulders) were available for a minimum follow-up of two years. Of the ninety-six shoulders, thirty-seven had a primary rotator cuff deficiency, thirty-three had a previous rotator cuff operation, twenty-three had a previous arthroplasty, and three had a proximal humeral nonunion. The patients were prospectively followed clinically (the American Shoulder and Elbow Surgeons [ASES] score, the Simple Shoulder Test [SST], and self-reported satisfaction) and radiographically (mechanical failure, loosening, and notching). Patients were videotaped while performing a standard active range-of-motion protocol before and after treatment. These videos were then analyzed in a blinded fashion by three independent observers using a digital goniometer. RESULTS At two years, the average total ASES scores had improved from 30 preoperatively to 77.6; the average ASES pain scores, from 15 to 41.6; and the average SST scores, from 1.8 to 6.8 (p < 0.0001 for all). Blinded analysis of range of motion showed that average abduction improved from 61 degrees preoperatively to 109.5 degrees (p < 0.0001); average flexion, from 63.5 degrees to 118 degrees (p < 0.0001); and average external rotation, from 13.4 degrees to 28.2 degrees (p < 0.0001). The patients rated the outcome as excellent in fifty-three shoulders (55%), good in twenty-six (27%), satisfactory in eleven (12%), and unsatisfactory in six (6%). There was no evidence of mechanical failure of the baseplate or scapular notching in any of the patients. Six of the ninety-four patients in this study had a complication. CONCLUSIONS Recent advances in reverse shoulder arthroplasty have allowed for improvement in patient outcomes while minimizing early mechanical failure and scapular notching and decreasing the overall complication rate at short-term follow-up.

The treatment of deep shoulder infection and glenohumeral instability with debridement, reverse shoulder arthroplasty and postoperative antibiotics

We retrospectively reviewed 21 patients (22 shoulders) who presented with deep infection after surgery to the shoulder, 17 having previously undergone hemiarthroplasty and five open repair of the rotator cuff. Nine shoulders had undergone previous surgical attempts to eradicate their infection. The diagnosis of infection was based on a combination of clinical suspicion (16 shoulders), positive frozen sections (> 5 polymorphonuclear leukocytes per high-power field) at the time of revision (15 shoulders), positive intra-operative cultures (18 shoulders) or the pre-operative radiological appearances. The patients were treated by an extensive debridement, intravenous antibiotics, and conversion to a reverse shoulder prosthesis in either a single- (10 shoulders) or a two-stage (12 shoulders) procedure. At a mean follow-up of 43 months (25 to 66) there was no evidence of recurrent infection. All outcome measures showed statistically significant improvements. Mean abduction improved from 36.1 degrees (sd 27.8) pre-operatively to 75.7 degrees (sd 36.0) (p < 0.0001), the mean forward flexion from 43.1 degrees (sd 33.5) to 79.5 degrees (sd 43.2) (p = 0.0003), and mean external rotation from 10.2 degrees (sd 18.7) to 25.4 degrees (sd 23.5) (p = 0.0037). There was no statistically significant difference in any outcome between the single-stage and the two-stage group.

Revision Arthroplasty with Use of a Reverse Shoulder Prosthesis-allograft Composite

BACKGROUND Patients with disabling pain and loss of shoulder function with associated proximal humeral bone loss following shoulder arthroplasty have limited reliable treatment options. Our objective was to report the results, obtained as part of a prospective outcomes study, of the use of a reverse shoulder prosthesis-allograft composite in these patients. METHODS Between 2002 and 2005, 353 patients treated with a reverse shoulder prosthesis were enrolled in a prospective cohort study. Twenty-five patients received, in addition, a proximal humeral allograft for the management of severe proximal humeral bone loss, and they comprise the study group. The average bone loss measured 53.6 mm (range, 34.5 to 150.3 mm). Patients were followed clinically with use of the American Shoulder and Elbow Surgeons (ASES) score, the Simple Shoulder Test (SST), and a scale with which the patients rated their satisfaction, and they were followed radiographically to detect mechanical failure, loosening, notching, and graft healing. All patients were followed for a minimum of two years (average, 30.2 months). RESULTS The total average ASES score improved from 31.7 points preoperatively to 69.4 points at the time of follow-up (p < 0.0001), and the average SST score improved from 1.4 to 4.5 points (p < 0.0001). Nineteen patients (76%) reported a subjective good or excellent result, five reported a satisfactory result, and one reported that the result was unsatisfactory. The range of motion improved in forward flexion (from 32.7 degrees to 82.4 degrees ; p < 0.0001), abduction (from 40.4 degrees to 81.4 degrees ; p < 0.0001), and internal rotation. Radiographic evaluation at the time of final follow-up showed incorporation of the allograft in the metaphyseal region in 84% (twenty-one) of the twenty-five patients and incorporation of the allograft in the diaphyseal region in 76% (nineteen) of the patients. Four patients had complications. CONCLUSIONS Use of a reverse shoulder prosthesis-proximal humeral allograft composite for the treatment of shoulder dysfunction following arthroplasty associated with substantial proximal humeral bone loss has shown promising early results. The allograft may restore proximal humeral bone stock, thereby helping to maintain the height of the prosthesis bone construct and thus deltoid tension. Additional, long-term studies are needed to evaluate the longevity of this construct.

Young patients with shoulder chondrolysis following arthroscopic shoulder surgery treated with total shoulder arthroplasty.

Chondrolysis following shoulder arthroscopy is a devastating complication, often seen in young patients. After nonoperative measures have been exhausted, there are few treatment options available that reliably improve pain and function. The purpose of this study is to examine the intra-operative findings, radiographic features, and clinical outcomes of a series of patients with chondrolysis following arthroscopic surgery managed with a total shoulder arthroplasty. A retrospective review was performed on 11 patients (average age 39) with shoulder chondrolysis following arthroscopy. Attention was focused on review of the index arthroscopy, radiographs, and functional outcome scores prior to total shoulder arthroplasty, as well as intra-operative cultures, histology, radiographs, and functional outcomes from most recent follow-up. All patients were treated with total shoulder arthroplasty at an average of 26 months after the index arthroscopy. Preoperative and postoperative radiographs were reviewed, and outcomes were compared using validated measurements. Statistically significant improvements in shoulder abduction (89 degrees -123 degrees , P = .027), external rotation (26 degrees -48 degrees , P = .037), total ASES scores (30-77.5, P = .0039), and SST scores (3-8, P = .0078) were noted. Ten patients subjectively rated their outcomes as good or excellent, with 1 as satisfactory. Chondrolysis after shoulder arthroscopy has a rapid clinical progression and is likely multifactorial in etiology. Early results of total shoulder arthroplasty show an opportunity for improvements in pain and function; however, progressive glenoid radiolucencies may develop in these patients.

Large coronal shear fractures of the capitellum and trochlea treated with headless compression screws

BACKGROUND The purpose of this study is to retrospectively evaluate the clinical outcomes of 18 patients with large coronal shear fractures of the capitellum and lateral trochlea that underwent open reduction and internal fixation with headless compression screws. METHODS Eighteen patients were identified (16 women, 2 men) with an average age of 45 years and an average follow-up of 26 months. Fractures were classified according to the Dubberley classification as 11 type-1A injuries and 7 type-2A injuries. RESULTS All patients, with the exception of 1, had good to excellent functional results by the Broberg-Morrey scale (mean score, 93.3). Average arc of motion was 128 degrees in flexion/extension and 176 degrees in pronation/supination. Radiographically, 3 patients had subsequent development of avascular necrosis and 5 developed arthrosis. No significant negative correlation was noted between the development of avascular necrosis and clinical outcome. Minor complications occurred in 2 patients, but there were no re-operations. CONCLUSION Headless compression screw fixation allows for stable fixation in patients with large coronal shear fractures of the distal humerus without posterior comminution. LEVEL OF EVIDENCE 4.

In vitro and finite element analysis of glenoid bone/baseplate interaction in the reverse shoulder design

We developed biomechanical and finite element models, using high-strength polyurethane foam blocks, to represent the glenoid bone/baseplate junction to determine if increasing the distance between the glenoid bone and the center of rotation of the glenosphere increases baseplate motion during static loading in the reverse shoulder design. Although there was a general trend toward increased baseplate motion with increasing distance from the glenoid to the center of rotation, in vitro mechanical testing revealed no significant difference between the 7 glenosphere types tested, with average baseplate motion during 1000 load cycles ranging from 90 mum to 120 mum. Results from the finite element analysis strongly correlated with the in vitro mechanical testing. The magnitude of baseplate motion occurring in a modeled representation of bone under simulated physiologic loading conditions was similar for the 7 reverse shoulder glenoid components tested in this study.

Scapular fractures after reverse shoulder arthroplasty: evaluation of risk factors and the reliability of a proposed classification

BACKGROUND The aims were to determine the sensitivity of plain radiographs to detect scapular fractures after reverse shoulder arthroplasty (RSA), to test the reliability of a proposed classification, and to evaluate risk factors. MATERIALS AND METHODS We matched 53 patients with scapular fractures after RSA to 212 control patients. Clinical risk factors were assessed by correlating comorbidities. Independent observers reviewed radiographs to assess fracture detection accuracy and test the reliability of a proposed classification. Radiographic risks were evaluated by measuring acromial thickness, acromial tilt, glenoid-to-tuberosity distance, and acromion-to-tuberosity (AT) distance. RESULTS Independent reviewers accurately diagnosed 78.8% of fractures and 97.4% of controls with good inter-rater reliability (κ = 0.782) and excellent intrarater reliability (κ = 0.862). Inter-rater reliability of the classification was moderate (κ = 0.422). Osteoporosis significantly increased the risk of fracture (odds ratio, 1.97; 95% confidence interval, 1.00-3.91); however, no difference was found for other comorbidities or between preoperative and postoperative radiographic parameters. A significant difference occurred between groups from the postoperative radiographs to the most recent radiographs for AT distance (0.4 ± 5.5 mm for control group and 8.3 ± 7.6 mm for fracture group, P < .001) and acromial tilt (1.8° ± 6.3° for control group and 14° ± 15° for fracture group, P < .001). Of 16 scapular spine fractures, 14 occurred from a screw tip; however, screw orientation and length were not different between groups. CONCLUSION Osteoporosis is a significant risk factor for scapular fractures after RSA. The current classification has only moderate reliability, suggesting that an alternative classification method is needed. Decreasing AT distance and increasing acromial tilt on consecutive radiographs may improve fracture detection. Advanced imaging may be needed to confirm the diagnosis. Whereas most scapular spine fractures occurred from a screw, the surgical technique did not increase the relative risk.

Correlation of subjective and objective measures before and after shoulder arthroplasty.

The degree to which subjective patient-reported measures reflects objective findings or how well subjective and objective measures reflect patient satisfaction is not well established. The purpose of this study was to determine the correlation between such measures before and after shoulder arthroplasty. A group of 174 patients (93 total shoulder arthroplasty and 81 reverse shoulder arthroplasty) were prospectively evaluated pre- and postoperatively (mean follow-up, 49 months) with the following subjective measures: American Shoulder and Elbow Surgeons score, Simple Shoulder Test, Short Form 36 (SF-36) summary scores, and patient satisfaction. Objective measures included Biodex isometric strength and videotaped range of motion. The objective measures were combined to derive 1 number representative of the overall shoulder function. All measures improved from their preoperative statuses except the SF-36 physical component summary in patients undergoing revision and the SF-36 mental component summary in patients undergoing primary reverse shoulder arthroplasty. A patient satisfaction score of 5 or more was seen in 89% of patients. Preoperatively, a significant (P<.05) correlation existed between the American Shoulder and Elbow Surgeons and the Simple Shoulder Test (ρ=0.546), American Shoulder and Elbow Surgeons score and SF-36 physical component summary (ρ=0.407), and Simple Shoulder Test and SF-36 physical component summary (ρ=0.479). Objective measures had lower correlations (ρ<0.4) with subjective scores. Postoperatively, the correlation improved among all measures. Patient satisfaction correlated more with subjective than objective measures. Subjective measures had relatively low correlations with objective measures. Improvements in the current measures are necessary to provide evidence-based comparisons of the effectiveness of shoulder arthroplasty.

Reverse shoulder arthroplasty components and surgical techniques that restore glenohumeral motion

BACKGROUND Modifications in reverse shoulder arthroplasty (RSA) have been made with the intent of maximizing motion, although there is little objective evidence outlining their benefit. This study investigated the RSA component combinations that impart the greatest effect on impingement-free glenohumeral motion. METHODS A previously validated virtual shoulder model was implanted with RSA components that varied by humeral implant type (inset/onset), glenosphere diameter (30, 36, and 42 mm), glenosphere placement (inferior/neutral), glenosphere center-of-rotation offset (0, 5, and 10 mm), humeral neck-shaft angle (130° and 150°), and humeral offset (zero, five, and ten mm). Motion was simulated in all technique combinations until the point of impingement in abduction, flexion/extension (F/E), and internal/external rotation (IR/ER). Regression analysis was used to rank combinations based on motion. RESULTS Of 216 possible study combinations, 126 constructs (58%) demonstrated no arm-at-side impingement and were included for analysis. Models with the largest motion in abduction, F/E, and IR/ER, respectively, were inset-42-inferior-10-150-zero (107°), inset-36-inferior-10-130-five (146°), and inset-42-inferior-10-130-ten (121°). Humeral neck-shaft angle, glenosphere center-of-rotation offset, glenosphere placement, and glenosphere diameter had a significant effect on motion in all planes tested. Of these variables, humeral neck-shaft angle was most predictive of a change in abduction and F/E motion, whereas glenosphere placement was most predictive of a change in IR/ER motion. CONCLUSION Higher glenosphere center-of-rotation offsets led to an increase in motion in all planes. To maximize motion in abduction, a valgus humeral component should be selected; to maximize F/E, a varus humeral component should be selected; and, to maximize IR/ER, the glenosphere should be placed inferiorly.

Outcomes and Costs of Reverse Shoulder Arthroplasty in the Morbidly Obese: A Case Control Study.

BACKGROUND The rising number of morbidly obese patients has important consequences for the health-care system. We investigated the effect of morbid obesity on outcomes, complications, discharge disposition, and costs in patients undergoing reverse shoulder arthroplasty. METHODS Our joint registry was searched for all patients who had undergone primary reverse shoulder arthroplasty for a reason other than fracture from 2003 to 2010 and had a minimum of twenty-four months of follow-up. Twenty-one patients with a body mass index (BMI) of ≥40 kg/m2 were identified (follow-up, 45 ± 16 months; sex, seventeen female and four male; age, 69 ± 7 years) and were compared with sixty-three matched control patients with a BMI of <30 kg/m2 (follow-up, 48 ± 20 months; sex, fifty female and thirteen male; age, 71 ± 6 years) after an a priori sample size calculation. Outcome instrument data were obtained preoperatively and postoperatively. The Charlson-Deyo comorbidity index (CDI) score, total comorbidities, operative time, blood loss, duration of hospital stay, discharge disposition, costs, and complications were recorded. RESULTS Compared with nonobese patients, morbidly obese patients had similar improvements in functional outcomes (e.g., American Shoulder and Elbow Surgeons score, 32 to 69 compared with 40 to 78) and in shoulder motion (e.g., forward flexion, 61° to 140° compared with 74° to 153°); all improvements were significant (p < 0.05). Morbidly obese patients had a similar rate of scapular notching (odds ratio [OR] = 0.58, p = 0.63), more total comorbidities excluding obesity (six compared with four, p = 0.001), a higher CDI (2 compared with 1, p = 0.025), and a higher rate of obstructive sleep apnea (OR = 27.7, p = 0.0001). Their operative time was thirteen minutes longer (p = 0.014) and their blood loss was 40 mL greater (p = 0.008). Morbidly obese patients had a similar duration of stay (3.1 compared with 2.6 days, p = 0.823) and hospital readmission rate (OR = 16.3, p = 0.08) but a sixfold higher rate of discharge to rehabilitation facilities rather than to home (OR = 8, p < 0.0001). Hospital costs were higher by