BackgroundOur objective was to identify acetabular fractures in the elderly population (over 60 years of age), treated with open reduction and internal fixation (ORIF), and to examine their outcomes, primarily the risk for need for further surgery in the form of a total hip arthroplasty (THA), and factors associated with it. Additional outcomes such as infection, avascular necrosis (AVN) of the femoral head, and heterotopic ossification (HO) were also investigated.MethodsFollowing institutional review board (IRB) approval, a retrospective analysis of all consecutive patients presenting to a Level I Trauma Centre over a 13-years period (January 2003–February 2016) was conducted. Patients were excluded if their initial treatment was conservative or simultaneous ORIF with THA.ResultsA total of 62 patients with an age of 71.5 ± 8.04 years were included (14 female; follow-up 54.2 months, range 1–195 months). Sixteen patients required a THA as a secondary procedure due to symptomatic post-traumatic arthritis (25.8%), five (8.1%) of whom having a THA within a year from the original trauma (three patients presenting with loss of reduction and two patients with early AVN). No associations with progression to THA were identified. Surgical approach (ilioinguinal) was the only factor associated with increased risk of development of HO (p= 0.010). The median post-operative survival following an acetabular fracture treated with ORIF was calculated at 90.1 months (95% CI 72.9–107.2).ConclusionAcetabular fractures ORIF in the elderly, is a safe and reliable option. The relatively incidence of development of severe post-operative arthritis was 45.2%. Conversion to THA was 25.8%, with 8.1% having the arthroplasty procedure within a year of the original trauma surgery.Level of evidenceIII.