The purpose of this study is to compare the performance of artificial hips with metal heads and metal sockets to artificial hips with ceramic heads articulating with metal socket components. The success of the total hip arthroplasty (THA) will be based upon all of the following clinical and radiographic criteria being met at the two-year evaluation: (1) the patient's clinical results as measured using modified Harris Hip evaluation rating system, and the absence of a complication that requires the surgical removal or replacement of a component; and (2) radiographic findings at study endpoint (i.e., two years follow-up). Clinical and radiographic success at two (2) years postoperative is required for the study hip to be deemed successful.

This study is a prospective, multi-center, randomized, single blind, controlled clinical investigation comparing the safety and efficacy of the cementless Ceramic on Metal total hip prostheses versus the cementless Metal on Metal total hip prostheses.

Inclusion Criteria:

• Able to (or capable of) provide consent to participate in the clinical investigation prior to the day of the surgery.
• Skeletally mature (tibial and femoral epiphyses are closed)
• Undergoing cementless primary hip replacement surgery for Noninflammatory Degenerative Joint Disease
• Affected hip has a Harris Hip Score of 70 or lower and a Pain rating of Moderate or greater
• Radiographic Parameters:
• X-Ray Evaluation confirms the presence of NIDJD
• Femoral and acetabular bone stock is sufficient, regarding strength and shape, and is suitable to receive the implants
• No structural bone grafts required to support to prosthetic component(s)or to shape the bone to receive implant(s)
• Willing to have knowledge of treatment arm (CoM or MoM) withheld for a period of 24 months post-operatively unless disclosure is legally and/or medically necessary
• Previous THA in contralateral hip that is greater than one (1) year postoperative and has a Harris Hip pain rating less than MILD

Exclusion Criteria:

• Bilateral hip disease with the anticipated need for bilateral hip implant during study participation (i.e., within the next 24 months)
• THA required for the revision of a previously failed THA
• Suffering from inflammatory arthritis
• Prior prosthetic hip replacement
• Previous Girdlestone procedure or surgical fusion in the operative hip joint
• Above knee amputation of either the contralateral or ipsilateral leg
• Known allergy to metal (e.g. jewelry)
• The presence of highly communicable disease or diseases that may limit follow-up (e.g., immuno-compromised conditions, hepatitis, active tuberculosis, etc.)
• Significant neurological or musculoskeletal disorders or disease that may adversely affect gait or weight bearing (e.g., muscular dystrophy, multiple sclerosis)
• Conditions that may interfere with the total hip arthroplasty survival or outcome (e.g., Paget's disease, Charcot's disease)
• Unwilling or unable to comply with a rehabilitation program for a cementless THA or difficulty or inability to return for follow-up visits prescribed by the study protocol
• Known to be pregnant, a prisoner, mentally incompetent, and/or alcohol or drug abuser
• Previous treatment for renal disease
• Any systemic steroid therapy, excluding inhalers, within three months prior to surgery