Total Hip Arthroplasty Is Associated With Lower 90-Day Inpatient Readmission Than Hemiarthroplasty for Femoral Neck Fracture in Patients Aged 65-75 Years: A Propensity Score-Matched Nationwide Readmissions Database Study.

Background: Comparative early hospital-based outcomes of hemiarthroplasty and total hip arthroplasty (THA) for femoral neck fracture remain uncertain in patients aged 65-75 years. Methods: Using the 2022 Nationwide Readmissions Database, we identified patients aged 65-75 years admitted with an acute femoral neck fracture who underwent hemiarthroplasty or THA. Patients were matched 1:1 using exact matching on age, Hospital Frailty Risk Score category, and mental-disorder status, plus propensity-score matching with a 0.20-standard-deviation caliper. The primary outcome was all-cause inpatient readmission within 90 days. Results: Among 8,012 eligible admissions, 5,108 patients underwent hemiarthroplasty and 2,904 underwent THA. Matching yielded 2,702 patients per group, with all postmatch absolute standardized mean differences <0.10. THA was associated with a lower observed 90-day inpatient readmission rate than hemiarthroplasty (10.1% vs 15.7%; odds ratio, 0.60; 95% confidence interval, 0.51-0.71; Conclusions: In this observational claims-based study, THA was associated with a lower observed 90-day inpatient readmission rate than hemiarthroplasty. Residual selection bias may partly explain this association, and these findings do not establish a causal benefit of THA. Level of Evidence: Level III, Retrospective comparative study.