Derek J. Cuff

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.

Evaluation of abduction range of motion and avoidance of inferior scapular impingement in a reverse shoulder model.

The purpose of this study was to determine the effects of prosthetic design and surgical technique of reverse shoulder implants on total abduction range of motion and impingement on the inferior scapular neck. Custom implants in three glenosphere diameters (30, 36, and 42 mm), with 3 different centers of rotation offsets (0, +5, and +10 mm), were placed into a Sawbones scapula (Pacific Research Laboratories, Vashon, WA) in 3 different positions: superior, center, and inferior glenoid. Humeral sockets were manufactured with a 130 degrees , 150 degrees , and 170 degrees neck-shaft angle. Four independent factors (glenosphere diameter, center of rotation offset, glenosphere position on the glenoid, and humeral neck-shaft angle) were compared with the 2 dependent factors of range of motion and inferior scapular impingement. Center of rotation offset had the largest effect on range of motion, followed by glenosphere position. Neck-shaft angle had the largest effect on inferior scapular impingement, followed by glenosphere position. This information may be useful to the surgeon when deciding on the appropriate reverse implant.

Comparison of Hemiarthroplasty and Reverse Shoulder Arthroplasty for the Treatment of Proximal Humeral Fractures in Elderly Patients

BACKGROUND Treatment of complex three and four-part proximal humeral fractures with hemiarthroplasty in elderly patients has yielded mixed clinical results. Reverse shoulder arthroplasty has emerged as a treatment option for comminuted proximal humeral fractures for these patients. The purpose of the study was to perform a prospective evaluation of patient outcomes comparing hemiarthroplasty and reverse shoulder arthroplasty for the treatment of comminuted proximal humeral fractures in elderly patients. METHODS Fifty-three consecutive elderly patients (average age, 74.4 years) underwent an arthroplasty for a complex proximal humeral fracture. Indications for arthroplasty were four-part fractures, three-part fractures with severe comminution of the greater tuberosity, and fractures that involved an articular split of the humeral head. Twenty-six patients underwent hemiarthroplasty (the HA group), followed by twenty-seven patients who underwent reverse shoulder arthroplasty (the RSA group). A total of forty-seven patients (twenty-three in the HA group and twenty-four in the RSA group) were available for follow-up at a minimum of two years. RESULTS Final average outcome scores were lower in the HA group than in the RSA group (American Shoulder and Elbow Surgeons [ASES] score of 62 versus 77 [p = 0.0001] and Simple Shoulder Test [SST] of 5.8 versus 7.4 [p = 0.0062]), and patient-reported satisfaction was lower in the HA group than in the RSA group (61% versus 91%; p = 0.038). Radiographic healing of the tuberosities occurred in 61% of the patients in the HA group compared with 83% of the patients in the RSA group (p = 0.17). Forward elevation of the arm was higher in the RSA group (139°) than in the HA group (100°) (p = 0.0002), but no significant differences were observed for shoulder external rotation or internal rotation. Complication rates in both groups were similar. Three patients (13%) in the HA group elected revision to reverse shoulder arthroplasty because of failed tuberosity healing and resultant shoulder pseudoparesis. CONCLUSIONS In this series, reverse shoulder arthroplasty resulted in better clinical outcomes and a similar complication rate compared with hemiarthroplasty for the treatment of comminuted proximal humeral fractures in the elderly.

Prospective randomized study of arthroscopic rotator cuff repair using an early versus delayed postoperative physical therapy protocol.

BACKGROUND This study evaluated patient outcomes and rotator cuff healing after arthroscopic rotator cuff repair using a postoperative physical therapy protocol with early passive motion compared with a delayed protocol that limited early passive motion. MATERIALS AND METHODS The study enrolled 68 patients (average age, 63.2 years) who met inclusion criteria. All patients had a full-thickness crescent-shaped tear of the supraspinatus that was repaired using a transosseous equivalent suture-bridge technique along with subacromial decompression. In the early group, 33 patients were randomized to passive elevation and rotation that began at postoperative day 2. In the delayed group, 35 patients began the same protocol at 6 weeks. Patients were monitored clinically for a minimum of 12 months, and rotator cuff healing was assessed using ultrasound imaging. RESULTS Both groups had similar improvements in preoperative to postoperative American Shoulder and Elbow Surgeons scores (early group: 43.9 to 91.9, P < .0001; delayed group: 41.0 to 92.8, P < .0001) and Simple Shoulder Test scores (early group: 5.5 to 11.1, P < .0001; delayed group: 5.1 to 11.1, P < .0001). There were no significant differences in patient satisfaction, rotator cuff healing, or range of motion between the early and delayed groups. CONCLUSIONS Patients in the early group and delayed group both demonstrated very similar outcomes and range of motion at 1 year. There was a slightly higher rotator cuff healing rate in the delayed passive range of motion group compared with the early passive range of motion group (91% vs 85%).

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.

Revision reverse shoulder arthroplasty for glenoid baseplate failure after primary reverse shoulder arthroplasty

BACKGROUND The aim of this study is to document a single surgeons experience performing revision reverse shoulder arthroplasty after baseplate failure. METHODS Revision reverse shoulder arthroplasty (RSA) for mechanical failure of the glenoid baseplate after RSA was performed in 14 patients. Clinical and radiographic data were collected preoperatively, prior to baseplate failure, after baseplate failure, and at latest follow-up after revision (average, 33 months). RESULTS When comparing the pre-operative values to post-revision, ASES, forward elevation, and abduction were significantly improved. There was no significant difference in any of the outcome measures when comparing the prefailure data to the post-revision data. The post-revision prosthesis-scapular neck angle (PSNA) showed a significant increase in inferior tilt of the baseplate when compared to pre-failure PSNA (P < .001). Two patients (14%) required a second revision RSA for glenoid baseplate failure (1) and dislocation (1); 1 additional patient developed a postoperative hematoma which resolved without surgery. CONCLUSION Revision RSA for the treatment of glenoid baseplate mechanical failure can restore pain relief and function to the levels gained after the index RSA.

Reverse shoulder arthroplasty for the treatment of rotator cuff deficiency: a concise follow-up, at a minimum of five years, of a previous report.

UNLABELLED We previously evaluated ninety-four patients (ninety-six shoulders) who underwent reverse shoulder arthroplasty with use of a central compressive screw along with 5.0-mm peripheral locking screws for baseplate fixation and a center of rotation lateral to the glenoid. The purpose of this study was to report updated results at a minimum follow-up of five years. Since the last report, an additional two patients underwent revision surgery: one for recurrent instability and one for resorption of a proximal humeral allograft. The patients continue to have improved outcome scores and range of motion. Survivorship with the end point being revision for any reason was 73.5 months, with 94% survival at sixty months. Radiographic follow-up showed that two (3%) of seventy-six patients included in the survivorship analysis had asymptomatic humeral loosening, seven (9%) had scapular notching, and no patient had glenoid baseplate loosening or baseplate failure. The patients have maintained their improved function with durable clinical and radiographic results at a minimum of five years. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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.

Partial rotator cuff repair and biceps tenotomy for the treatment of patients with massive cuff tears and retained overhead elevation: midterm outcomes with a minimum 5 years of follow-up

BACKGROUND A subset of patients with massive irreparable rotator cuff tears present with retained overhead elevation and pain as their primary complaint. Our aim was to evaluate the outcomes of partial arthroscopic rotator cuff repair with biceps tenotomy and to report the failure rate of this procedure for patients with >5 years of follow-up. METHODS Thirty-four patients underwent partial rotator cuff repair and biceps tenotomy for treatment of a massive rotator cuff tear. Patients had preoperative active forward elevation >120° and no radiographic evidence of glenohumeral arthritis. Patients were followed up clinically and radiographically, and 28 patients had a minimum of 5 years of follow-up. Failure was defined as an American Shoulder and Elbow Surgeons score of <70, loss of active elevation >90°, or revision to reverse shoulder arthroplasty during the study period. RESULTS Patients demonstrated improvements in average preoperative to postoperative American Shoulder and Elbow Surgeons scores (46.6 to 79.3 [P < .001]) and Simple Shoulder Test scores (5.7 to 9.1 [P < .001]) along with decrease in visual analog scale for pain scores (6.9 to 1.9 [P < .001]). No significant change in forward elevation (168° to 154° [P = .07]), external rotation (38° to 39° [P = 1.0]), or internal rotation (84% to 80% [P = 1.0]) was identified; 36% of patients had progression of the Hamada stage. The failure rate was 29%; 75% of patients were satisfied with their index procedure. CONCLUSION Partial rotator cuff repair and biceps tenotomy for patients with massive irreparable rotator cuff tears with retained overhead elevation and pain as the primary complaint produced reasonable outcomes at midterm follow-up of at least 5 years.

Glenosphere dissociation after reverse shoulder arthroplasty

BACKGROUND Reverse shoulder arthroplasty (RSA) is gaining popularity for the treatment of debilitating shoulder disorders. Despite marked improvements in patient satisfaction and function, the RSA complication rate is high. Glenosphere dissociation has been reported and may result from multiple mechanisms. However, few RSA retrieval studies exist. METHODS We reviewed our RSA database and identified patients with glenosphere dissociation between 1999 and 2013. Prosthesis type, glenosphere size, and contributing factors to dissociation were noted. Five retrieved implants were available for analysis, and evidence of wear or corrosion on the Morse taper was documented. Further, we biomechanically investigated improper Morse taper engagement that may occur intraoperatively as a potential cause of acute dissociation. RESULTS Thirteen patients with glenosphere dissociation were identified (0.5 months to 7 years postoperatively). Glenosphere size distribution was as follows: 32 mm (n = 1), 36 mm (n = 4), 40 mm (n = 6), and 44 mm (n = 2). Incidence of dissociation was correlated to glenosphere size (P < .001). Taper damage was limited to fretting wear, and there was minimal evidence of taper corrosion. Biomechanically, improper taper engagement reduced the torsional capacity of the glenosphere-baseplate interface by 60% from 19.2 ± 1.0 N-m to 7.5 ± 1.5 N-m. CONCLUSION We identified several mechanisms contributing to glenosphere dissociation after RSA, including trauma and improper taper engagement. Limited evidence of corrosive wear on the taper interface was identified. Although it is rare, the incidence of glenosphere dissociation was higher when 40- and 44-mm glenospheres were implanted compared with smaller glenospheres (32 and 36 mm), probably because of the larger exposed surface area for potential impingement.