Clinical Research Directory

Inclusion Criteria: 1. Patient is aged 18 to 85 years old, inclusive; 2. Patients who diagnosed with AMOA of the knee, and have undergone Open Wedge HTO, or primary unilateral partial knee arthroplasty with Oxford Partial Knee with Microplasty® instrumentation in accordance to indications of UKA and the following radiographic assessments in the knee joint: * exposed bone on both the femur and tibia in the medial compartment. * functionally intact ACL * full thickness lateral cartilage (ignore osteophytes) * functionally normal MCL: correctable deformity (normal medial opening) * acceptable patellofemoral joint: normal, medial facet OA with or without bone loss, lateral facet OA without bone loss. 3. UKA or HTO procedure completed one year prior to study participation; 4. Patient provides written informed consent by signing and dating the Institutional Review Board/Ethics Committee (IRB/EC) approved informed consent form. Exclusion Criteria: 1. Has undergone UKA but met any of the contraindications included in the product labeling of Oxford Partial Knee system; 2. Has rheumatoid arthritis or other forms of inflammatory joint disease; 3. Uncooperative or with neurologic disorders who are incapable of following directions; 4. Has a diagnosed systemic disease that could affect his/her safety or the study outcome; 5. Anterior cruciate ligament and posterior cruciate ligament injury, collateral ligament instability; 6. Known to be pregnant; 7. Prisoner or known alcohol / drug abuser.