Michael van der Merwe, Matthew J. Boyle, Christopher M.A. Frampton, Craig M. Ball

Complex proximal humeral fractures may require prosthetic replacement of the humeral head. Surgical options include reverse shoulder arthroplasty (RSA) and shoulder hemiarthroplasty; however, the optimal technique remains controversial. The goal of this study was to compare functional outcomes and revision rates of RSA with hemiarthroplasty in patients with acute proximal humeral fractures. Between January 1, 1999, and December 31, 2014, there were 218 patients who underwent RSA and 427 who underwent hemiarthroplasty for acute proximal humeral fractures identified through New Zealand Joint Registry records. Study groups were compared with regard to baseline characteristics, operative characteristics, and postoperative outcomes (Oxford Shoulder Score [OSS], revision rate, mortality rate) at 6 months and 5 years after surgery. RSA patients were significantly older (mean age, 78.2 vs. 71.6 years; P < .001), with a higher proportion of female patients (90% vs. 77%; P < .001) than in the hemiarthroplasty group. No statistically significant difference existed in revision rate per 100 component-years (0.58 [RSA] vs. 1.16 [hemiarthroplasty]; P = .137) or 1-year mortality (3.8% vs. 3.4%; P = .805) between both groups. There was no significant difference in 6-month OSS (29.6 vs. 28.4; P = .305). The RSA group demonstrated a superior mean 5-year OSS (37.6 vs. 32.7; P = .078); however, the difference did not achieve statistical significance. Although our results suggest that RSA patients may experience superior 5-year functional scores, we have identified no significant difference in functional outcomes and revision rates between RSA and hemiarthroplasty in the treatment of acute proximal humeral fractures.