Indications: Severe joint pain, instability, deformity, ineffective or unsatisfactory after conservative treatment. Including all kinds of severe non-infectious arthritis of the knee, such as: osteoarthritis, rheumatoid arthritis, hemophilic arthritis, severe traumatic arthritis; infectious arthritis has been cured or resting; it is a more ideal treatment for elderly osteoarthritis of the knee. Contraindications: Local or systemic infection is an absolute contraindication to knee replacement; paralysis of the muscles around the knee joint, knee joint that has fused in a functional position, even if there is no pain or deformity.