Outcomes of revision versus re-revision reverse total shoulder arthroplasty: A case-control-matched cohort study

Background: The increasing incidence of reverse total shoulder arthroplasties (RTSA) has led to an increase in revision surgery. We aimed to compare patients undergoing re-revision RTSA to a matched cohort undergoing first-revision RTSA. Methods: A retrospective review of all revision RTSAs was performed at a single institution. Sixteen shoulders that underwent re-revision RTSA were matched 1:3 to shoulders that underwent revision RTSA with a minimum two-year follow-up. Outcome scores including the American Shoulder and Elbow Surgeons Shoulder Score (ASES), Short-Form 12 (SF-12), Shoulder Pain and Disability Index (SPADI), and Simple Shoulder Test (SST) scores, range of motion (ROM), and improvement from preoperative to postoperative outcomes after re-revision RTSA were assessed. Additionally, postoperative outcomes after re-revision RTSA were compared to patients that underwent first revision RTSA and subsequently compared to the minimal clinically important difference (MCID) values for the outcome scores and ROM measurements assessed. Results: Sixteen shoulders that underwent re-revision RTSA and 78 revision RTSAs met the final inclusion criteria to be included in this study. Significant improvement from preoperative to postoperative re-revision RTSA was seen in the ASES score (p = 0.046), SPADI score (p = 0.044), SST (p = 0.008), abduction (p = 0.016), and elevation (p = 0.025), but not the SF-12 score (p = 0.396), external rotation (p = 0.449), or internal rotation (p = 0.451). Outcomes after revision RTSA were found to be superior to outcomes after re-revision RTSA for all outcome scores (ASES p = 0.029, SF-12 p = 0.018, SPADI p = 0.003) except the SST score (p = 0.080) and all ROM measures (p > 0.05 for all). Internal rotation was equivalent postoperatively between both groups. From preoperative to postoperative re-revision RTSA, the mean improvement exceeded the MCID for the SST score, abduction, forward elevation, and external rotation. When comparing postoperative revision RTSA to postoperative re-revision RTSA, the mean difference between revision and re-revision RTSA exceeded the MCID for the SPADI score and external rotation. The complication rate was 19% in shoulders undergoing first revision and 41% in shoulders undergoing re-revision RTSA. Conclusion: Patients undergoing re-revision RTSA receive improvement in clinical outcomes, but do not achieve outcomes comparable to those achieved after first revision RTSA.