Non-destructively Differentiating the Roles of Creep, Wear and Oxidation in Long-Term In Vivo Exposed Polyethylene Cups
Abstract:Wear of polyethylene acetabular cups in patients of total hip arthroplasty is routinely deduced from the penetration of the femoral head into the acetabular liner as observed in the radiographs. However, the linear penetration thus measured represents the cumulative contribution of two components, one due to wear, and the other due to creep or irreversible deformation of the polyethylene structure. The erroneous attribution to wear of the entire penetration displacement of the head in the cup might lead to misinterpretation of the actual performance of acetabular cups. The aim of this study was to quantify the head displacement components due to wear and to creep, as they occur in vivo in acetabular cups, and to relate them to the oxidation state of the material by means of advanced Raman spectroscopy procedures. Throughout the investigation, we compared the behaviors on the molecular scale of acetabular cups subjected to different sterilization methods (i.e., γ-irradiation and ethylene oxide treatment).
Document Type: Research Article
Affiliations: 1: Ceramic Physics Laboratory & Research Institute for Nanoscience, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan; The Center for Advanced Medical Engineering and Informatics, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; Department of Orthopaedics, Orthopaedic Research Center, Loma Linda University, Loma Linda, CA 92354, USA., Email: email@example.com 2: Ceramic Physics Laboratory & Research Institute for Nanoscience, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan 3: Department of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0854, Japan 4: Department of Orthopaedic Surgery, Osaka National Hospital, 2-1-14 Houenzaka, Chuo-ku, Osaka 540-0006, Japan
Publication date: August 1, 2011