The primary objective of this study is to evaluate the performance of the Cormet Hip Resurfacing implant system in the post-approval environment.

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).

Inclusion Criteria:

• Male or female patient who meets eligibility criteria consistent with product labeling
• skeletally mature
• mentally capable of completing follow-up forms
• Will be available for follow-up out to 2 years and annually thereafter until the last patient reaches the two-year evaluation
• Has been deemed a candidate for hip replacement by diagnosis of the investigator
• consented to participate in the clinical study

Exclusion Criteria:

• Patient with active or suspected infection in or around the hip joint;
• Patient with bone stock inadequate to support the device
• Patient with severe osteopenia
• Patient with a family history of severe osteoporosis or severe osteopenia;
• Patient with osteonecrosis or avascular necrosis (AVN) with >50% involvement of the femoral head (regardless of FICAT Grade)
• Patient with multiple cysts of the femoral head (>1cm)
• In cases of questionable bone stock, a DEXA scan may be necessary to assess inadequate bone stock.
• Patient with any vascular insufficiency, muscular atrophy, or neuromuscular disease severe enough to compromise implant stability or postoperative recovery;
• Female of child-bearing age due to unknown effects on the fetus of metal ion release.
• Patient with known moderate or severe renal insufficiency;
• Patient who is immunosuppressed with diseases such as AIDS or person receiving high doses of corticosteroids;
• Patient who is severely overweight;
• Patient with known or suspected metal sensitivity (e.g., jewelry).