Outcomes of Bilateral Shoulder Arthroplasties: A Comparison of Bilateral Total Shoulder Arthroplasties and Bilateral Reverse Shoulder Arthroplasties

BACKGROUND: The purpose of this study was to compare outcomes of patients who underwent bilateral total shoulder arthroplasties (TSAs) for osteoarthritis (OA) versus bilateral reverse shoulder arthroplasties (RSAs) for cuff tear arthropathy (CTA). METHODS: Inclusion criteria were patients who underwent bilateral TSAs for OA or bilateral RSAs for CTA with at least 2 years of follow-up. Twenty-six TSA patients (52 shoulders) were matched 2 to 1 with 13 RSA patients (26 shoulders) by sex, age at first surgery, and time between surgeries. Outcomes measured were shoulder range of motion (ROM), complications, and patient-reported scores. RESULTS: Preoperatively, TSA patients had significantly better forward elevation (FE) of both shoulders than RSA patients (dominant side [Dom]: 103° ± 32° vs. 81° ± 31°, p = 0.047; nondominant side [non-Dom]: 111° ± 28° vs. 70° ± 42°, p = 0.005) without significant differences in external (ER) or internal rotation (IR). Postoperatively, TSA patients had significantly better FE (Dom and non-Dom: 156° ± 12°, 156° ± 14° vs. 134° ± 24°, 137° ± 23°; p = 0.006, p = 0.019) and ER (42° ± 11°, 43° ± 10° vs. 24° ± 12°, 25° ± 10°; p < 0.001, p < 0.001) bilaterally and IR of their dominant arm (L1 vs. L4, p = 0.045). TSA patients had significantly better activities of daily living external and internal rotations (ADLEIR) scores (Dom and non-Dom: 35.3 ± 1.0, 35.5 ± 0.9 vs. 32.1 ± 2.4, 32.5 ± 2.2; p = 0.001, p = 0.001), American Shoulder and Elbow Surgeons scores (94.2 ± 8.4, 94.2 ± 8.2 vs. 84.7 ± 10.0, 84.5 ± 8.0; p = 0.015, p = 0.004), and Single Assessment Numerical Evaluation (SANE) scores (93.5 ± 7.6, 93.8 ± 11.8 vs. 80.5 ± 14.2, 82.3 ± 13.1; p = 0.014, p = 0.025), with no significant difference in visual analog scale pain scores (0.4 ± 1.0, 0.3 ± 1.0 vs. 0.7 ± 1.3, 0.8 ± 1.2) bilaterally. CONCLUSIONS: Overall, patients with bilateral TSAs and RSAs exhibited improved ROM and patient-reported outcomes. Those with bilateral TSAs had better functional outcomes than those with bilateral RSAs.