Advances in the processing, sterilization, and crosslinking of ultra-high molecular weight polyethylene for total joint arthroplasty

Despite the recognized success and worldwide acceptance of total joint arth roplasty, wear is a major obstacle limiting the longevity of implanted UHMW PE components. Efforts to solve the wear problem in UHMWPE have spurred num erous detailed studies into the structure, morphology, and mechanical prope rties of the polymer at every stage of its production from original resin i nto stock material and final fabricated form. Scientific developments in th is field are occurring at an accelerating rate, and periodic review of UHMW PE technology is therefore increasingly necessary. The present article prov ides a four-part comprehensive review of technological advancements in the processing, manufacture, sterilization, and crosslinking of UHMWPE for tota l joint replacements. The first part of this article describes the recently updated nomenclature of UHMWPE, including the process of resin production and conversion to stock material. The second part outlines the methods of m anufacturing UHMWPE into joint replacement components and provides overview s of alternate forms of UHMWPE, namely carbon-fiber reinforced UHMWPE (Poly II(TM)) and UHMWPE recrystallized under high temperature and pressure (Hyl amer(TM)). The third part summarizes the sterilization and degradation of U HMWPE. Newly developed methods for accelerating the oxidation of UHMWPE aft er sterilization (for preconditioning of test specimens), as well as method s for quantifying the oxidation of UHMWPE, are also discussed. Finally, the fourth part reviews the development and properties of crosslinked UHMWPE, a promising alternate biomaterial for total joint replacements. (C) 1999 El sevier Science Ltd. All rights reserved.