%0 Journal Article
%T Comparison of Conventional Polyethylene Wear and Signs of Cup Failure in Two Similar Total Hip Designs
%A Thomas B. Pace
%A Kevin C. Keith
%A Estefania Alvarez
%A Rebecca G. Snider
%A Stephanie L. Tanner
%A John D. DesJardins
%J Advances in Orthopedics
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/710621
%X Multiple factors have been identified as contributing to polyethylene wear and debris generation of the acetabular lining. Polyethylene wear is the primary limiting factor in the functional behavior and consequent longevity of a total hip arthroplasty (THA). This retrospective study reviewed the clinical and radiographic data of 77 consecutive THAs comparing in vivo polyethylene wear of two similar acetabular cup liners. Minimum follow-up was 7 years (range 7¨C15). The incidence of measurable wear in a group of machined liners sterilized with ethylene oxide and composed of GUR 1050 stock resin was significantly higher (61%) than the compression-molded, GUR 1020, O2-free gamma irradiation sterilized group (24%) . Clinically, at a 9-year average followup, both groups had comparable HHS scores and incidence of thigh or groin pain, though the machined group had an increased incidence of osteolysis and annual linear wear rate. 1. Introduction Ultra high molecular weight polyethylene (UHMWPE) is currently the most widely used polymer for joint replacement prosthesis. Polyethylene mm head were used in all cases. The ceramicwear is the primary limiting factor in the functional behavior and consequent longevity of a total hip arthroplasty (THA). Polyethylene debris has been often linked to the development of osteolysis with subsequent loss of bone stock and implant fixation [1]. Linear wear rate of polyethylene is closely associated with osteolysis following THA, more so than patient weight, femoral head material, or implant design and offset. Acetabular cup loosening due to polyethylene wear is the most frequent reason for long-term revision in THAs, especially in young and active patients [2, 3]. Multiple factors have been identified as contributing to polyethylene wear and debris generation of acetabular lining. These variables include conformity of the articulating surface, polyethylene thickness, femoral head diameter, polyethylene locking mechanism, polyethylene additives [4], sterilization technique [5, 6], manufacturing method [4, 7], and surgical implantation technique [8]. Linear penetration of the femoral head into the polyethylene occurs through creep and wear. Creep occurs at a rate of approximately 0.18¨C0.2£¿mm/year and subsides after approximately the first 24 months. The remaining penetration is considered wear from multifactorial sources and typically occurs at reported rates of 0.05¨C0.18£¿mm/year for conventional polyethylene in THA, with compression molding having comparatively less wear [9¨C11]. This study compares linear wear rate of two similar
%U http://www.hindawi.com/journals/aorth/2013/710621/