Severe pain, impaired movement, serious deformity and (or) instability of the knee due to osteoarthritis or another joint disease are indications for total knee replacement. Contraindications are a high surgical risk and poor function of the M. quadriceps femoris. The main problems immediately after the operation are: wound infection and prosthetic infection, palsy of the peroneal nerve and deep venous thrombosis. These occur in approximately 2% of the patients. After replacement and 3 months' rehabilitation the knee is usually free of pain and stable with a good range of movement. After 10 years, 93-98% of the operated knees are still satisfactory, and after 15 years, 85-95%. Reasons for revision are infection, mechanical loosening of components, wear of polyethylene and progressive instability.