Reverse shoulder arthroplasty vs. hemiarthroplasty for proximal humerus fracture: in-hospital outcomes in a national trauma registry.

BACKGROUND: Reverse shoulder arthroplasty (RSA) has rapidly supplanted hemiarthroplasty for acute proximal humerus fracture, driven by superior functional outcomes and lower revision rates. Whether this shift has altered perioperative morbidity at the population level remains poorly characterized. This study compared in-hospital outcomes between RSA and hemiarthroplasty in a national trauma cohort. METHODS: This retrospective cohort study used the National Trauma Data Bank (2017-2022). Adults ( > = 18 years) admitted with proximal humerus fracture who underwent RSA (n = 2657) or hemiarthroplasty (n = 428) during the index hospitalization were included. The primary outcome was non-home discharge; secondary outcomes were any in-hospital complication, extended length of stay exceeding 7 days, and intensive care unit (ICU) admission. Multivariable logistic regression and inverse probability of treatment weighting (IPTW) were used to address confounding by indication. RESULTS: Among 3085 patients (median age, 73 years; 2304 [74.7%] female), RSA patients were older (median, 74 vs. 64 years; P<.001) and more frequently female (77.3% vs. 58.6%; P<.001). After multivariable adjustment, RSA was not significantly associated with non-home discharge (adjusted odds ratio [aOR], 1.20; 95% confidence interval [CI], 0.93-1.55), any complication (aOR, 1.01; 95% CI 0.58-1.77), extended length of stay (aOR, 1.27; 95% CI 0.99-1.62), or ICU admission (aOR, 1.05; 95% CI 0.74-1.50). IPTW analyses were concordant for three of four outcomes; extended length of stay was the only outcome reaching significance under IPTW (OR, 1.38; 95% CI 1.06-1.81), a finding not replicated in the primary model. In a pre-specified subgroup, RSA was associated with higher risk of non-home discharge among patients younger than 65 years (aOR, 1.59; 95% CI 1.06-2.40). CONCLUSION: In this national trauma registry analysis, RSA for proximal humerus fracture was not associated with significantly different in-hospital outcomes compared with hemiarthroplasty after adjustment. LEVEL OF EVIDENCE: Level III Retrospective Cohort Comparison Treatment Study.