IntroductionThe optimal treatment of elderly patients with an acetabular fracture is unknown. We conducted a prospective clinical trial to compare functional outcomes and reoperation rates in patients older than 60 years with acetabular fracture treated with open reduction and internal fixation (ORIF) alone versus ORIF plus concomitant total hip arthroplasty (ORIF + THA). Our hypothesis was that patients who had ORIF + THA would have better patient reported outcomes and lower reoperation rates postoperatively. MethodsInclusion criteria were patients older than 60 years with acetabular fracture plus at least one of three fracture characteristics: dome impaction, femoral head fracture, or posterior wall component. Eligible patients were operative candidates based on fracture displacement, ambulatory status, and physiological appropriateness. Patients received either ORIF alone or ORIF + THA (accomplished at same surgery through same incision). Outcome measurements included Western Ontario and McMaster Universities Osteoarthritis Index hip score, Short Form 36, Harris Hip Score, and Patient Satisfaction Questionnaire Short Form scores. Additionally, patients were monitored for any unplanned reoperation within 2 years. ResultsForty-seven of 165 eligible patients with an average age of 70.7 years were included. The mean Harris Hip Score difference favored ORIF + THA (mean difference, 12.3, [95% confidence interval (CI), -0.3 to 24.9, p = 0.07]). No clinically important differences were detected in any other validated outcome score or patient satisfaction score 1 year after surgery. ORIF + THA decreased the absolute risk of reoperation by 28% (95% CI, 13% to 44%, p < 0.01). No postoperative hip dislocation occurred in either group. ConclusionsIn patients older than 60 years with an operative displaced acetabular fracture with specific fracture features (dome impaction, femoral head fracture, or posterior wall component), treatment with ORIF + THA resulted in fewer reoperations than treatment with ORIF alone. No differences in patient satisfaction and other validated outcome measures were detected.