Bearing Surfaces in Patients Undergoing Total Hip Arthroplasty with Osteonecrosis of the Femoral Head

The treatment of patients with osteonecrosis (ON) of the femoral head has changed over the last 30 years from the concept of saving the femoral head at all costs to the more recent concept of treating symptomatic femoral head collapse, in the setting of ON, with total hip arthroplasty (THA). The reported prevalence of ON of the femoral head has increased over the past 10 years, which may be due in part to diagnostic advancement [1–5]. Approximately 20,000 patients are diagnosed in the United States with ON of the femoral head every year [6] with the average age at presentation being 38 years. Although femoral head core decompression, with or without adjunctive measures for the early stages of ON is still performed with reasonable success, it plays no role in the patient with collapse [7]. Adjunctive measures, in the setting of core decompression, have been directed towards enhancing results and include bone graft, synthetic bone substitutes, bone morphogenetic proteins, tantalum rods, or adjunctive cells [8]. The results of cell enhanced core decompression have provided early positive results and come with the advantage of less invasive procedures as compared to bone grafting, particularly vascularized bone grafting [9]. Proximal femoral redirectional osteotomies are described in the treatment of ON where collapse may be present with the aim of shifting the affected areas of the femoral head away from weight-bearing regions [10]. These osteotomies have been described as a treatment option in cases of younger patients with modest-sized lesions [11]. However, they are technically demanding surgeries with significant associated complications and can make any subsequent THA more difficult [12].