Multi-centre Study to Assess Long-term Safety and Efficacy of the Silent™ Hip Prosthesis in Primary THR

Inclusion Criteria: * Male or female subjects, aged 18 years or above at the point of screening for participation. * Subjects who are able to give voluntary, written informed consent to participate in this clinical investigation and from whom consent has been obtained. * Subjects who, in the opinion of the Clinical Investigator, are able to understand this clinical investigation, co-operate with the investigational procedures and are willing to return to the hospital for all the required post-treatment follow-ups. * Subjects with non-inflammatory osteoarthritis of the hip who require a primary total hip replacement and are considered suitable for a cementless femoral and acetabular component. Exclusion Criteria: * Subjects who, in the opinion of the Investigator, have an existing condition that would compromise their participation and follow-up in this study. * Women who are pregnant. * Subjects who are known drug or alcohol abusers or with psychological disorders that could affect follow-up care or treatment outcomes. * Subjects who have participated in a clinical study with an investigational product in the last 6 months. This exclusion does not apply to those subjects who are participating in the pilot investigation of the DePuy Silent Hip (CT01/27) * Subjects who are currently involved in any injury litigation claims. * Subjects who have osteonecrosis of the femoral neck * Subjects with significant bone loss or gross deformity in the region of the neck of the femur as identified on the pre-operative radiographs, where in the Investigator's opinion, there could be considerable migration of the DePuy Silent Hip or a significant chance of fracture of the femoral shaft and/or the lack of adequate bone to support the DePuy Silent Hip. * Subjects with a Charnley C classification. * Subjects with an active local or systemic infection. * Subjects with loss of musculature, neuromuscular compromise or vascular deficiency in the affected limb rendering the arthroplasty procedure unjustified. * Subjects with Paget's disease