Comparison of clinical outcomes of revision reverse total shoulder arthroplasty for failed primary anatomic vs. reverse shoulder arthroplasty.

BACKGROUND

Both anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (RTSA) are being increasingly performed. In the event of a complication necessitating revision, RTSA is more commonly performed in both scenarios. The purpose of this study was to compare clinical outcomes between patients undergoing revision RTSA for failed primary anatomic versus reverse total shoulder arthroplasty.

METHODS

We performed a retrospective review of a prospective single-institution shoulder arthroplasty database. All revision RTSAs performed between 2007 and 2019 with a minimum 2-year clinical follow-up were initially included. After excluding patients with a preoperative diagnosis of infection, an oncologic indication, or incomplete outcomes assessment, we included 45 revision RTSAs performed for failed primary aTSA and 15 for failed primary RTSA. Demographics, surgical characteristics, active range of motion (external rotation [ER], internal rotation, forward elevation [FE], abduction), outcome scores (American Shoulder and Elbow Surgeons score, Constant Score, Shoulder Pain and Disability Index, Simple Shoulder Test, and University of California, Los Angeles score), and the incidence of postoperative complications was compared between groups.

RESULTS

Primary aTSA was most often indicated for degenerative joint disease (82%), whereas primary RTSA was more often indicated for rotator cuff arthropathy (60%). On bivariate analysis, no statistically significant differences in any range of motion or clinical outcome measure were found between revision RTSA performed for failed aTSA vs. RTSA. On multivariate linear regression analysis, revision RTSA performed for failed aTSA vs. RTSA was not found to significantly influence any outcome measure. Humeral loosening as an indication for revision surgery was associated with more favorable outcomes for all four range of motion measures and all five outcome scores assessed. In contrast, an indication for revision of peri-prosthetic fracture was associated with poorer outcomes for three of four range of motion measures (ER, FE, abduction) and four of five outcome scores (Constant, Shoulder Pain and Disability Index, Simple Shoulder Test, University of California, Los Angeles). A preoperative diagnosis of fracture was associated with a poorer postoperative range of motion in ER, FE, and abduction, but was not found to significantly influence any outcome score. However, only two patients in our cohort had this indication. Complication and re-revision rates after revision RTSA for failed primary aTSA and RTSA were 27% and 9% vs. 20% and 14% ( = .487 and  = .515), respectively.

CONCLUSION

Clinical outcomes of patients undergoing revision RTSA for failed primary shoulder arthroplasty did not significantly differ based on whether aTSA or RTSA was initially performed. However, larger studies are needed to definitively ascertain the influence of the primary construct on the outcomes of revision RTSA.