Linear penetration of highly cross-linked polyethylene in Total Hip Arthroplasty for Chinese Patients aged 40 years or below

Abstract

Introduction: The study aimed to examine the clinical outcomes and linear penetration rate of highly cross-linked polyethylene (PE) liner in young patients aged ≤ 40 years with total hip arthroplasty (THA). Methods: A retrospective review of primary THAs using marathon highly cross-linked PE liner and Duraloc cementless acetabular socket (DePuy, US) was performed. Two-dimensional wear was measured using PolyWare software on annual radiographs. Results: There were 18 THAs in 14 (7 female and 7 male) patients; 9 were on right and 9 were left THAs. Their mean (± standard deviation) age at operation was 33.7 ± 2.7 (range, 29-38) years. All patients had at least 8 years of follow-up. All articulations were of the metal-on-PE type. Hip balls were 28 mm in diameter. The mean body mass index was 21.3 ± 2.8 kg/m2 . The mean abduction angle of the socket was 44.1 ± 6.2 (range, 29.1-53.8) degrees. The respective mean amount of annual PE wear from first to eighth year was as follows: 0.263 ± 0.152 (range, 0.08 to 0.553); 0.023 ± 0.166 (-0.317 to 0.433); 0.029 ± 0.143 (-0.195 to 0.25); 0.011 ± 0.156 (-0.258 to 0.354); 0.007 ± 0.111 (-0.256 to 0.203); 0.044 ± 0.095 (-0.158 to 0.25); -0.0166 ± 0.142 (-0.318 to 0.199); and 0.070 ± 0.126 (-0.086 to 0.376). The mean annual penetration was 0.022 mm. Conclusion: Highly cross-linked PE has a low linear penetration rate in young Chinese patients. There was no osteolysis or radiological loosening. Intermediate–to–long-term results are promising.