I. Severity and duration of pain. For advanced lesions of the knee other than infections and severe neuroarthritis. The duration of pain and dysfunction of the patient’s affected knee should be longer than one year. The patient should not be considered for total replacement until all conservative treatments have been ineffective for at least six months and the radiographs show advanced lesions. ii. Third, previous treatment methods are ineffective. Including regular use of non-steroidal anti-inflammatory drugs for more than 3 months, the effect of local rest and physical therapy measures is not obvious. IV. Ability to understand and cooperate with postoperative rehabilitation. Patients who have poor compliance and cannot cooperate with post-operative rehabilitation; or patients who are expected to be unable to walk after surgery despite the severity of the lesion are not suitable for arthroplasty.