A radiographic analysis of the effects of glenosphere position on scapular notching following reverse total shoulder arthroplasty.

BACKGROUND: Multiple biomechanical studies have analyzed the potential influence of inferior glenosphere tilt on scapular notching in reverse total shoulder arthroplasty (RTSA). The purpose of this study was to clinically determine the likelihood of scapular notching in a series of shoulders, with the glenospheres placed in neutral versus inferior tilt. METHODS: From a database of all RTSA performed by the senior author, shoulders with a Delta III-type prosthesis and minimum 12-month follow-up (71 shoulders) were included. Notching in shoulders with neutrally placed glenosphere base plates (Group 1) was compared to notching with 10-15° inferiorly tilted base plates (Group 2). The prosthesis-scapular border angle (PSBA) was also defined and used to determine whether the radiographically quantified amount of inferior tilt was predictive of scapular notching independent of group assignment. RESULTS: There were no significant differences in the grade of notching or incidence of notching between groups 1 and 2 after adjusting for length of follow-up and prosthesis selection. The PSBA was also not predictive of scapular notching. CONCLUSION: Despite previous biomechanical studies' predictions that inferiorly tilting the glenosphere might reduce inferior scapular neck impingement and subsequent scapular notching, our data showed no difference at 1-year follow-up.

A complication-based learning curve from 200 reverse shoulder arthroplasties.

BACKGROUND: Reported early complication rates in reverse total shoulder arthroplasty have widely varied from 0% to 75% in part due to a lack of standard inclusion criteria. In addition, it is unclear whether revision arthroplasty is associated with a higher rate of complications than primary arthroplasty. QUESTIONS/PURPOSE: We therefore (1) determined the types and rates of early complications in reverse total shoulder arthroplasty using defined criteria, (2) characterized an early complication-based learning curve for reverse total shoulder arthroplasty, and (3) determined whether revision arthroplasties result in a higher incidence of complications. PATIENTS AND METHODS: From October 2004 to May 2008, an initial series of 200 reverse total shoulder arthroplasties was performed in 191 patients by a single surgeon. Forty of the 200 arthroplasties were revision arthroplasties. Of these, 192 shoulders were available for minimum 6-month followup (mean, 19.4 months; range, 6-49.2 months). We determined local and systemic complications and distinguished major from minor complications. RESULTS: Nineteen shoulders involved local complications (9.9%), including seven major and 12 minor complications. Nine involved perioperative systemic complications (4.7%), including eight major complications and one minor complication. The local complication rate was higher in the first 40 shoulders (23.1%) versus the last 160 shoulders (6.5%). Seven of 40 (17.5%) revision arthroplasties involved local complications, including two major and five minor complications compared to 12 of 152 (7.9%) primary arthroplasties, including five major and seven minor complications. Nerve palsies occurred less frequently in primary arthroplasties (0.6%) compared to revisions (9.8%). CONCLUSIONS: The early complication-based learning curve for reverse total shoulder arthroplasty is approximately 40 cases. There was a trend toward more complications in revision versus primary reverse total shoulder arthroplasty and more neuropathies in revisions. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the guidelines online for a complete description of level of evidence.

A radiographic analysis of the effects of prosthesis design on scapular notching following reverse total shoulder arthroplasty.

BACKGROUND: Scapular notching is a well-recognized complication of reverse total shoulder arthroplasty (RTSA). This paper analyzes the effects of prosthesis design on scapular notching in RTSA. METHODS: From a database of all RTSA performed by the senior author, shoulders with minimum 12-month follow-up were included (65 shoulders). Notching in shoulders with a prosthesis neck-shaft angle of 155° and no center-of-rotation (COR) offset (group 1) was compared to notching in shoulders with a neck-shaft angle of 143° and 2.5-mm COR offset (group 2). P values less than .05 were considered significant. RESULTS: The notching grade was significantly higher in group 1 than in group 2, even after statistically adjusting for differences in length of follow-up (P = .0081). The incidence of notching in group 1 at 60.7% was significantly higher than the 16.2% incidence in group 2 (P = .0107). CONCLUSION: Using prostheses with a smaller neck-shaft angle and increased COR offset can significantly reduce scapular notching in RTSA at 1 year, possibly improving prosthesis survival.

Reverse total shoulder arthroplasty improves function in cuff tear arthropathy.

BACKGROUND: Early failure due to glenoid loosening with anatomic total shoulder arthroplasty in patients with severe rotator cuff deficiency led to the development of the reverse ball-and-socket shoulder prosthesis. The literature reports improved short-term pain and function scores following modern reverse total shoulder arthroplasty (RTSA) in patients with cuff tear arthropathy (CTA). QUESTIONS/PURPOSES: We therefore sought to confirm previously reported short-term improvements in pain, function scores, and range of motion, in patients treated with RTSA for CTA and to identify clinical complications and radiographic notching. METHODS: We retrospectively reviewed 67 patients who underwent 71 primary RTSAs for CTA. The average age was 74 years (range, 54-92 years). All were preoperatively and postoperatively assessed using Constant-Murley and American Shoulder and Elbow Society (ASES) scores. We identified complications and examined radiographs for notching. The minimum followup was 12 months (average, 24 months; range, 12-58 months). RESULTS: Average Constant-Murley scores improved from 28 preoperatively to 62 postoperatively. Average ASES scores improved from 26 to 76. Subjective Shoulder Value (SSV) improved from 23 to 77. Active forward flexion improved from 61° preoperatively (range, 0°-137°) to 121° postoperatively (range, 52°-170°). Active external rotation was not affected. Thirty-five of the 71 shoulders (49%) showed radiographic notching. The overall complication rate was 23%. No patient required reoperation. One patient required closed reduction of a perioperative dislocation. CONCLUSIONS: RTSA for CTA results in functional improvement, with a low complication rate. However, the longevity of the device is currently unknown. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.