A Clinical Investigation of the Oxford® Partial Knee System

Inclusion Criteria: * For use in individuals with osteoarthritis or avascular necrosis limited to the medial compartment of the knee. The implant is intended to be implanted with bone cement. Exclusion Criteria: * Infection * Use in the lateral compartment of the knee * Rheumatoid arthritis or other forms of inflammatory joint disease * Revision of a failed prosthesis, failed upper tibial osteotomy or post-traumatic arthritis after tibial plateau fracture * Insufficiency of the collateral, anterior, or posterior cruciate ligaments which would preclude stability of the device * Disease or damage to the lateral compartment of the knee * Uncooperative patient or patient with neurologic disorders who is incapable of following directions * Osteoporosis * Metabolic disorders which may impair bone formation * Osteomalacia * Distant foci of infections which may spread to the implant site * Rapid joint destruction, marked bone loss, or bone resorption apparent on roentgenogram * Vascular insufficiency, muscular atrophy, neuromuscular disease * Incomplete or deficient soft tissue surrounding the knee * Charcot's disease * A fixed varus deformity (not passively correctable) of greater than 15 degrees * A flexion deformity greater than 15 degrees