Commentary on an Article by B.H. Currier, MChE, et al.: “In Vivo Oxidation in Remelted Highly Cross-Linked Retrievals”

Abstract

Total joint arthroplasty is a highly successful procedure; however, the one major issue that remains is wear of the bearing surfaces and the resultant adverse biological response to wear particles. Many studies of ultra-high molecular weight polyethylene have indicated that residual free radicals combined with oxygen result in increased brittleness and reduction of mechanical properties. The development of highly cross-linked ultra-high molecular weight polyethylene with use of irradiation in inert environments, and subsequent free-radical stabilization by either annealing or remelting, provided a bearing surface with the potential for significant reduction of wear. There have been several clinical studies that have confirmed, with use of radiographic techniques, this reduction in wear. However, in the recent radiographic study by Currier et al., an unexpected increase in wear was seen in this ultra-high molecular weight polyethylene after seven years in vivo. This troubling observation requires further study. Currier …