Manufacturer mismatch does not affect patient outcomes in primary reverse shoulder arthroplasty

There is a paucity of literature on manufacturer mismatch in reverse shoulder arthroplasty (RSA). It is unclear if the use of different implant manufacturers for the glenoid side and the humeral side influences patient outcomes in primary RSA. We hypothesize that patients undergoing primary RSA with manufacturer mismatch such that humeral and glenoid components are from different manufacturers will not experience adverse outcomes when compared to a cohort of patients with humeral and glenoid components from the same manufacturer.

Between January 2016 and June 2020, all patients who had an RSA implanted by one fellowship-trained shoulder surgeon were considered potentially eligible for inclusion in this retrospective analysis of data prospectively collected during a multicenter study. The inclusion criteria were as follows: primary RSAs implanted through a deltopectoral approach with glenoid and humeral components from different manufacturers, and complete data available at 2 years follow-up. The cohort was divided into a mismatch group and a control group, with the latter comprising patients having undergone RSA with components from the same manufacturer.

From the initial cohort, 191 patients were available for the 2-year clinical and radiological evaluation. Among these individuals were 60 men and 131 women, with a mean age of 74. The mismatch group comprised 39 patients and the control group included 152 patients. Baseline outcome scores of the mismatch and matched cohorts were similar regarding visual analog score (P = .220), Subjective Shoulder Value (P = .518), American Shoulder and Elbow Surgeons (P = .670), and Constant (P = .477) scores. Two-year postoperative outcome scores of the mismatched and matched cohorts were also similar regarding visual analog score (P = .716), Subjective Shoulder Value (P = .125), American Shoulder and Elbow Surgeons (P = .673), and Constant (P = .607) scores. The complication rate and radiological complications were similar.

Mixing of glenoid and humeral components from different manufacturers does not appear to affect patient outcomes in primary RSA at 2 years follow-up. The results may provide valuable information for orthopedic surgeons when selecting the appropriate implant components for RSA and help guide clinical decision-making for better patient outcomes. It appears reasonable to have manufacturer mismatch when appropriate matching of implant material and curvature at a given diameter is used.