Pipkin type IV femoral head fractures: a case series and review of literature

Introduction: Femoral head fractures with associated acetabular fractures are uncommon injuries usually resulting from high-energy mechanisms such as motor vehicle collisions. Outcomes of Pipkin type IV fractures have been historically poor, with high rates of osteonecrosis, post-traumatic arthritis, and heterotopic ossification. The objective of this study was to define the outcomes of operatively treated Pipkin type IV fractures In addition, we reviewed the available literature of this uncommon injury pattern. Methods: A retrospective chart review at a single level 1 trauma center from 2007 to 2016 identified 10 patients with Pipkin IV femoral head fractures. Demographic information, fracture type, associated injuries, operative details, and complications were evaluated. Clinical and radiological outcomes were assessed at latest follow-up including conversion to total hip arthroplasty. Results: Six of the seven patients were treated with open reduction and internal fixation of the femoral head fracture and acetabular fracture through a Kocher–Langenbeck approach aided by a trochanteric flip and one had fragment excision. Six patients (87.5%) developed post-traumatic arthritis. Four (57.1%) later underwent conversion to total hip arthroplasty (THA) a mean of 20.5 months after index procedure. Conclusion: Our study shows a rate of osteonecrosis and osteoarthritis that is even higher than the previously reported studies. The former may relate to longer-term follow-up and the latter possibly due to associated comminuted posterior wall fracture.