This clinical study will verify the clinical and radiographic performance of the prosthesis when used in human subjects over a period of 10 years. All complications will be documented.

The clinical evaluations will be based on standard, functional and pain parameters Harris Hip Score pre-operatively, and at 6 months, 3, 5, 7.5 and 10 years post-operatively. Postal Oxford questionnaire preoperatively, and yearly thereafter. The objective of this study is to analyse the clinical and radiographic responses and the complication rates for patients undergoing primary total hip arthroplasty using the Anthology Hip Replacement System (Anthology Hip System).

Inclusion criteria:

1. Those presenting with primary or secondary osteoarthritis or avascular necrosis of the femoral head or patients suitable for a primary total hip replacement. This is the patient group that will benefit from operative surgery to treat osteoarthritis.
2. Those deemed capable of giving informed consent, understanding the aims of the study and expressing willingness to comply with the post-operative review programme. Patients capable of giving informed consent are eligible for inclusion into the study.
3. Participants who signed the Ethics Committee approved specific Informed Consent Form prior to surgery. Patients who have not given informed consent will not be eligible for inclusion into the study.

Exclusion criteria:

1. Patients whose prospects for a recovery to independent mobility would be compromised by known coexistent, medical problems.
2. Patients not suitable for primary hip replacement.
3. Patients with active or suspected infection.

Those presenting with primary or secondary osteoarthritis or avascular necrosis of the femoral head or patients suitable for a primary total hip replacement (THR).