The effect of glenoid bone loss and rotator cuff status in failed anatomic shoulder arthroplasty after revision to reverse shoulder arthroplasty.

ABSTRACT

HYPOTHESIS: We evaluated outcomes and the risk of re-revision in patients with a failed anatomic total shoulder arthroplasty (TSA) revised to a reverse shoulder arthroplasty (RSA) based on rotator cuff deficiency and glenoid bone loss. METHODS: From 2004 to 2017, 123 patients with failed TSAs underwent revision to RSAs with minimum 2-year follow-up. Preoperative radiographs were evaluated to determine whether the glenoid component was fixed or loose. The rotator cuff was assessed intraoperatively and as intact or deficient. Patient outcomes including shoulder motion and American Shoulder and Elbow Surgeons (ASES) scores were obtained preoperatively and postoperatively. Patient outcomes were compared based on glenoid fixation and rotator cuff status. There were 18 TSAs revised to RSAs that underwent subsequent revision. RESULTS: The mean preoperative ASES score was 31 (95% confidence interval [CI], 29-33) with no difference in preoperative ASES scores based on glenoid status (P = .412) or rotator cuff status (P = .89). No difference in postoperative ASES score was found based on glenoid component status or rotator cuff status. However, improvement in the ASES score was greater with an intact rotator cuff (mean postoperative score, 67 [95% CI, 57-76] vs. 55 [95% CI, 50-60]; P = .025). The overall re-revision rate was 11.4%, with a mean time to re-revision of 22 months (range, 0-89 months). The odds ratio was 1.786 for subsequent revision in patients with glenoid loosening compared with those without loose glenoids on preoperative radiographs. CONCLUSION: There was an overall improvement in patient outcomes for failed TSAs revised to RSAs; however, patients with an intact cuff had a greater improvement in ASES scores.