Femoral Head Size of 36 mm against Highly Cross-linked Polyethylene in Patients Younger than 60 Years: Minimun Three Years of Follow Up

Abstract

Purpose: The purpose of this study was to evaluate the early results of total hip arthroplasty (THA) performed using large diameter femoral head against with highly cross-linked polyethylene as a bearing surface in patients less than sixty years of age. Materials and Methods: Seventy patients were enrolled and retrospectively reviewed. The mean age of patients at index surgery was 49 years and the mean follow-up period was 61 months. Clinical follow-up involved implementing the Harris hip score (HHS) and a radiographic evaluation that included linear radiolucency, osteolysis, and loosening. An annual wear rate was performed at 6 weeks; at 3, 6, and 12 months; and on a yearly basis thereafter. Results: The average HHS at last follow-up was 94 (range: 82-98). Radiographically, no osteolysis in the pelvis or proximal femur was observed in any patient. No acetabular cup or femoral stem failed due to aseptic loosening. No eccentric wear was observed on any liner, and no liner fracture occurred. However, one patient experienced hip dislocation. The average femoral head penetration rate during the fi postoperative year was 0.077±0.026 mm/year, and the average steady-state wear rate was 0.033±0.023 mm/year. Conclusion: THA with a large diameter femoral head of highly cross-linked polyethylene in patients younger than 60 years of age was found to produce results comparable to previous in vitro laboratory hip simulation studies. In particular, patient satisfaction was high due to no limitation in range of motion or hip posture during the early post-operative period. Longer-term follow-up is required to demonstrate the clinical benefi ts of this new material more comprehensively.