Biomedical Tribology : Wear of Polyethylene in Total Joint Replacement

Ultra-high-molecular-weight polyethylene (UHMWPE) is commonly used in biomedical applications mainly as a bearing component for orthopaedic implants. However, wear debris formation from UHMWPE has become a prominent tribological issue in a biomedical application. Other than limiting the life span of UHMWPE, the wear debris could also lead to osteolytic failure, which accounts for 30% of UHMWPE implant failure. Several factors were determined to have influenced the wear phenomenon from the previous studies: design of the joint implant, materials, processing method, surgical technique and patient factor. Processing methods such as cross-linking and sterilization are predominant in increased wear rate as compared to other variables. Oxidized UHMWPE components were more prone to fatigue wear, which affects their clinical performance. Various attempts have been made in the past decades including gamma irradiation to promote cross-linking, vitamin E infusion to reduce oxidation effect, surface texturing to improve the lubrication condition and filler incorporation to enhance the mechanical performance. Therefore, the significant findings that acquire from this chapter would be meant to strengthen the UHMWPE life span to reduce the frequent need for revision procedure.