This study tracks the performance of the Cormet Hip Resurfacing system in the post-approval environment to see if there are significant changes in device performance from the pre-market IDE setting as compared to the post-approval setting. Specifically this study will compare the proportion of subjects achieving a Month 24 composite clinical success (CCS) criterion and 24 month cumulative revision rate among the newly enrolled post-approval study subjects to the IDE subjects' performance on CCS as reported in the Pre-Market Application (PMA).