IMPROVED UHMWPE THROUGH THE CONTROL OF STERILIZATION DOSE AND ATMOSPHERE

In this study, the effects of sterilization dose and atmosphere on UHM WPE wear properties and crosslinking were examined. The relationship b etween crosslinking and adhesive / abrasive wear mechanisms of acetabu lar cups was investigated. The use of a vacuum sterilization atmospher e resulted in improvements in the wear resistance of UHMWPE for the ad hesive/abrasive wear mechanisms for the doses examined in this study. The two measures of crosslinking, swelling ratio and gel fraction, val ues can be used to predict hip simulator wear rates over the steriliza tion dose range of 0 to 50 kGy for the vacuum atmosphere samples. Of t he two measures, the swelling ratio is a more sensitive measure of the extent of crosslinking, particularly for highly crosslinked materials and therefore a more sensitive predictor of adhesive/abrasive wear ra tes.