Factors limiting postoperative range of motion after reverse shoulder arthroplasty

Background Reverse shoulder arthroplasty (rTSA) provides reliable outcomes, but postoperative range of motion (ROM) varies. This study examined factors influencing the ROM after rTSA. Methods Seventy-three shoulders (70 patients) undergoing primary rTSA between 2014 and 2023 with ≥1-year follow-up were reviewed. Demographic, clinical, perioperative, and radiographic data were analyzed. Forward flexion (FF), external rotation (ER), and internal rotation (IR) were evaluated using multivariable linear regression to identify predictors. Results FF improved from 70° to 119° ( p < 0.001), and ER from 12° to 22° ( p = 0.002), whereas IR decreased from L3 to L4 ( p = 0.009). Older age ( β = −1.26, p = 0.003) and greater postoperative global lateralization, measured as lateral offset ( β = −1.88, p = 0.001), predicted poorer FF, while taller height ( β = 0.88, p = 0.015) and higher preoperative abduction ( β = 0.26, p = 0.002) were favorable. For ER, older age was detrimental, whereas prior arthroscopic repair ( β = 11.06, p = 0.031) and greater preoperative ER ( β = 0.19, p = 0.041) were beneficial. No predictors were identified for IR. Discussion Older age and increased global lateralization limit elevation, whereas taller stature, preoperative abduction, and prior arthroscopic repair predict better motion.