Pilot Study Evaluating the Safety and Efficacy of a New Hard-on-Hard Total Hip Replacement System

Inclusion Criteria: * At least 21 years old * Skeletally mature * Requires primary, unilateral total hip arthroplasty due to degenerative join disease * Preoperative Harris Hip Score of less than or equal to 70 * Meets an acceptable preoperative medical clearance and is free or treated for conditions that would pose excessive operative risk * Given consent to participate in the study * Able to understand the purpose of the study, his/her role, and is available for follow-up 10 year extension: * Subject has completed the 2 year primary study * Subject has signed an Independent Ethics Committee (IEC) approved Informed Consent Form agreeing to participate in the extension study after the nature, scope and possible consequences of the study have been explained in an understandable form * Subject is able to fully understand the purpose of the study, his/her role as a participant in the study, and plans to be available through ten years post-operative follow-up Exclusion Criteria: * Diagnosis with high risk of Total Hip Arthroplasty (THA) failure * Requires bilateral THA * Requires revision of a prior hip replacement * Active infection or sepsis * History of local hip infection * Known metastatic or neoplastic disease * Conditions that may interfere with THA survival or outcomes * Need for structural bone grafts to support the implant * Contralateral lower extremity condition * Has other joint replacements or plans for other joint replacements within 2 years * Systemic steroid therapy within 3 months prior to surgery * Life expectancy less than 2 years * Intra-articular therapy within 6 months of enrollment * Female of child-bearing age not using contraception * Inadequate bone stock to support the device * Moderate to severe renal insufficiency * Emotional or neurological condition that would pre-empt ability or willingness to participate in the study * BMI \>40 * Above the knee amputation of the contralateral or ipsilateral leg * Known allergies to the components of the devices * Entered into another investigational study * Is a prisoner 10 year extension: • In the opinion of the surgeon, the subject's health, safety or well-being may be compromised or harmed by continuation in the extension phase or participation may not be in the subject's best interests.