Effect of Humeral Component Version on Outcomes in Reverse Shoulder Arthroplasty

Although reverse shoulder arthroplasty provides excellent clinical results in appropriately selected patients, loss of external and internal rotation may occur. Component selection, design, and placement affect postoperative results. Recent studies considered the effect of humeral component version on functional results. The current study investigated whether humeral stem retroversion affects the outcomes of reverse shoulder arthroplasty with a retrospective review of a multisurgeon, industry-sponsored, prospectively gathered database of a single reverse shoulder arthroplasty implant. All patients had at least 2-year follow-up. Clinical outcomes, including American Shoulder and Elbow Surgeons score, visual analog scale pain score, Short Form-12 Mental and Physical Component scores, range of motion, and internal rotation function, were compared between patients with humeral retroversion of 10° or less (group A) and those with humeral retroversion of 20° or greater (group B). Radiographic outcomes were compared. The analysis included 64 patients (group A, 29 patients; group B, 35 patients). No clinical or statistically significant difference was found in American Shoulder and Elbow Surgeons scores. Both groups showed statistical and clinical improvement vs preoperative scores, with group A averaging 77.8 and group B averaging 79.2 at final follow-up. No differences were found between groups in range of motion or ability to perform tasks that require shoulder internal rotation. Patients can expect good clinical improvement after reverse shoulder arthroplasty. No difference was found in clinical or radiologic outcomes based on humeral component retroversion. Despite the theoretical increase in external rotation when the humeral component is placed closer to native retroversion, the results did not show this effect. [Orthopedics. 2017; 40(3):179-186.].