Inclusion Criteria:  ICF obtained End stage bi- or tricompartmental osteoarthritis of the knee meeting the general criteria for TKA  Exclusion Criteria:  Inflammatory arthritis (e.g. rheumatoid arthritis). BMI >30 due to less accurate gait analysis. Extension deficit of >10° and flexion deficit of <110° of the knee. Varus and valgus deviations >10° of the knee Mental retardation, a systemic disease or decline normal health causing post-operative rehabilitation cannot take place properly. Suggestive musculoskeletal deformity of the lower limb or vertebral column, causing postoperative rehabilitation cannot take place properly to prevent confounding. Normal joints are defined as asymptomatic joints with normal physical examination and mild to no changes on radiographs. An exception is made for primary total hip prosthesis.