Outcomes of Total Hip Arthroplasty Versus Open Reduction Internal Fixation for Acetabular Fractures in Older Adults

OBJECTIVES: To compare outcomes of total hip arthroplasty (THA) versus open reduction internal fixation (ORIF) for acetabular fractures in older adults using a large national database. METHODS: Design: Retrospective cohort study using the Medicare Limited Data Set. Setting: Seven hundred ninety-eight acute short-stay hospitals. Patient Selection Criteria: Fee-for-service Medicare beneficiaries aged 65+ years who underwent inpatient ORIF or THA for acetabular fractures (OTA/AO 62) (without associated femoral fractures) from January 2013 to December 2020 were included. Outcome Measures and Comparisons: To minimize confounding, 1 patient with THA was matched with up to 2 patients with ORIF based on sociodemographic factors, comorbidities, and surgery year using a propensity score approach. Multivariable generalized linear models identified adjusted associations between surgery type and outcomes; adjusted odds ratios (ORs) or mean differences with 95% confidence intervals were reported. RESULTS: Among 5656 eligible procedures, the matched cohort included 2879 patients (1027 THA, mean age 78.6 years, 42.3% men; 1852 ORIF, mean age 78.6 years, 42.4% men). Patients with THA (vs. ORIF) had an increased odds of 30-day and 90-day hospital returns (30-day: OR = 1.54, P < 0.001; 90-day: OR = 1.25, P = 0.01) and 90-day and 1-year infection (90-day: OR = 1.92, P < 0.001; 1-year: OR = 1.74, P < 0.001). THA was also associated with higher odds of 90-day reoperation (OR = 2.47, P < 0.001) but not 1-year reoperation (OR = 0.84, P = 0.16). No significant associations were observed for hospital length of stay (P = 0.42), discharge disposition (P = 0.93), use of 90-day home health services (P = 0.13), 90-day venous thromboembolism (P = 0.75), or 1-year mortality (P = 0.65). CONCLUSIONS: Patients who underwent THA for acetabular fractures were more likely to return to the hospital within 30 and 90 days postsurgery, have an infection in the year after surgery, and undergo a reoperation in the 90-day postoperative period than those who underwent ORIF. Further investigation of the mechanisms of the observed associations is necessary to understand which surgical approach provides optimal outcomes.