Improved UHMWPE through the control of sterilization dose and atmosphere

In this study, the effects of sterilization dose and atmosphere on UHMWPE wear properties and crosslinking were examined. The relationship between crosslinking and adhesive / abrasive wear mechanisms of acetabular cups was investigated.

The use of a vacuum sterilization atmosphere resulted in improvements in the wear resistance of UHMWPE for the adhesive/abrasive wear mechanisms for the doses examined in this study. The two measures of crosslinking, swelling ratio and gel fraction, values can be used to predict hip simulator wear rates over the sterilization dose range of 0 to 50 kGy for the vacuum atmosphere samples. Of the 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 rates.