Outcome Study of Total Knee Arthroplasty in Asian Patients

Inclusion Criteria: * Administrative - the patient is able to understand the evaluation, is able to give consent and will comply with the postoperative follow up regime. * Diagnosis - idiopathic osteoarthritis, rheumatoid arthritis, post traumatic arthritis or any other pathology that in the opinion of the clinical investigator requires a primary total knee arthroplasty. * Implant suitability - patients who in the opinion of the Clinical Investigator are considered suitable for treatment with a mobile bearing knee system (the LCS Classic or Universal). * Bilateral patients - simultaneous bilateral patients are included. Staged bilateral patients are included if the second procedure is performed within the one-year recruitment period. Staged bilateral patients where the second procedure is performed outside of the one-year recruitment period will only be included if the second procedure is performed within 6 months of the end of the one-year recruitment period. * Age - the upper age limit is set at 75 years and expected to live through the 5 years study period.vi. Ethnic Origin - patients must be Asian in ethnic origin * Unicondylar / High Tibial Osteotomy (HTO) conversion - patients that are being converted from a unicondylar / HTO procedure are included providing the reason for conversion is due to progression of the disease process affecting the other condyle. Patients that are converted and have evidence of infection / aseptic loosening / loss of bone stock are excluded. Exclusion Criteria: * Patients with a known history of poor compliance to medical treatment. * Patients that require revision surgery * Patients with gross ligamentous insufficiency. * Patients with a severe valgus deformity (15 degrees or greater) * Patients with a severe varus deformity (20 degrees or greater) * Patients with a fixed flexion contracture (30 degrees or greater) * Patients over the age of 75 years.