Humeral Component Version Has No Effect on Outcomes Following Reverse Total Shoulder Arthroplasty: A Prospective, Double-Blinded, Randomized Controlled Trial

Background: Controversy exists regarding the ideal humeral component version to optimize humeral rotation and patient outcomes in reverse total shoulder arthroplasty (rTSA).

Methods: Patients undergoing primary rTSA for rotator cuff tear arthropathy, a massive rotator cuff tear, or primary osteoarthritis with a rotator cuff tear were randomized to placement of the humeral component in neutral version or 30° of retroversion. Shoulder active range of motion and strength and visual analog scale (VAS) pain, American Shoulder and Elbow Surgeons (ASES), and Patient-Reported Outcomes Measurement Information System Global 10 (PROMIS-10) scores were collected up to 2 years postoperatively. The goal of the study was to determine whether humeral external rotation and internal rotation are affected by humeral component version following rTSA at 2 years postoperatively.

Results: Sixty-six patients were included in the analysis. The median follow-up was 26 months for the neutral and 27 months for the 30° retroversion group. No differences between the groups were observed with respect to the primary diagnosis, sex, age, body mass index, or American Society of Anesthesiologists (ASA) class. The 2 groups did not differ significantly in terms of improvement at 2 years in active shoulder abduction (p = 0.969), forward elevation (p = 1.000), internal rotation measured as the highest spinal level reached (p = 1.000), internal rotation with the arm abducted 90° (p = 0.451), external rotation (p = 0.362), or muscle strength in forward elevation (p = 1.000), abduction (p = 1.000), external rotation (p = 0.617), or internal rotation (p = 1.000). The 2 groups did not differ significantly in terms of improvement in postoperative ASES (p = 1.000), PROMIS-10 physical (p = 1.000), or VAS pain scores (p = 0.718) at the time of final follow-up. In the neutral version group, 1 patient underwent revision for instability and 1 for stiffness. One acromial stress fracture occurred in the 30° humeral retroversion group. Scapular notching was observed in 7 (21.2%) of the patients in neutral version group and 5 (15.2%) of the patients in the 30° retroversion group (p = 0.750).

Conclusions: Securing the humeral component at neutral version or 30° of retroversion in rTSA resulted in similar active shoulder external rotation, internal rotation, forward elevation, abduction, and strength measurements, complication rates, and VAS pain, PROMIS-10 physical, and ASES scores at 2 years postoperatively.

Level of evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.