Total knee arthroplasty is an artificial joint replacement surgery that removes the joint surface that the body can no longer repair on its own and replaces the damaged joint with an artificial joint component to correct the force lines of the limb, eliminate knee pain, maintain joint stability, and restore knee function. Artificial knee arthroplasty was used later than hip arthroplasty, but it has a history of more than 20 years. Especially in recent years, knee arthroplasty has developed rapidly and solved some technical problems that used to be very difficult. Now, the safety and efficacy of artificial knee arthroplasty is as satisfactory as that of hip arthroplasty. Osteoarthritis of the knee (age-related osteoarthropathy) and rheumatoid arthritis are the most common forms of arthritis of the knee. In the advanced stages of arthritis, severe joint deformity and mobility impairment occur, and total knee surface replacement therapy is required at this time. Total knee surface replacement not only significantly reduces symptoms, but also corrects deformities and improves joint function. In developed countries in Europe and the United States, artificial joint replacement surgery is one of the most common procedures. 1, why artificial joint replacement surgery After the change of joint structure due to various reasons, it is not wise to use medication alone, because medication can only partially relieve pain symptoms, but not change the change of joint structure, while artificial joint replacement can achieve the purpose of relieving pain, correcting deformity, and improving joint function. An artificial joint is an artificial organ designed to save a joint that has lost its function, and among various artificial organs, artificial joints have the best healing effect. Generally speaking, the design life of artificial joints is 50 years, and 80% of the service life can be more than 20 years. 2, artificial total knee joint replacement prosthesis used Knee joint replacement mainly includes: total knee surface replacement, unicondylar joint replacement and hinged knee joint replacement three, of which total knee surface replacement is the most clinically used one. The prosthesis consists of three parts: femoral condyle prosthesis, tibial condyle prosthesis and wear-resistant polymer polyethylene spacer, which are mostly fixed on the femur and tibia respectively using bone cement, and can be divided into types with or without preserving the fork ligaments, using the muscle ligaments and other soft tissues around the knee joint to cover and connect to complete the function. The material of knee prosthesis basically evolved from total hip prosthesis, only the subtle composition and processing of the prosthesis material has been improved. Cobalt and titanium alloys are the two metals commonly used in artificial knee joints today and occupy almost the entire knee prosthesis market. Although they have certain differences in fatigue strength, modulus of elasticity, and wear resistance, their clinical results are basically similar. A very small number of people are allergic to titanium, and should be asked before surgery if they have a history of allergy to titanium eye frames or watch cases, and if so, it is best to use a cobalt alloy prosthesis. 3, which patients are suitable for artificial total knee replacement surgery Artificial total knee replacement plays an important role in the surgical treatment of knee osteoarthritis, mainly for severe joint pain, instability, deformity, serious impairment of daily life activities, after conservative treatment is ineffective or the effect is not significant, mainly including: (1) various inflammatory arthritis of the knee joint, such as rheumatoid arthritis, osteoarthritis (1) various inflammatory arthritis of the knee, such as rheumatoid arthritis, osteoarthritis, hemophilic arthritis, ankylosing spondylitis causing joint destruction, deformity and loss of function, Charcot arthritis, etc.; (2) a few traumatic osteoarthritis; (3) osteoarthritis after failed high tibial osteotomy; (4) patellofemoral arthritis in a few elderly people; (5) resting infectious arthritis (including tuberculosis); (6) a few primary or secondary osteochondral necrosis diseases. (1) Excision of diseased soft tissue, damaged articular cartilage and subchondral bone in the joint, shaping the distal femur, proximal tibia and medial patella to fit the geometry of the artificial joint; (2) Selection of a suitable type of artificial joint, installation of the femoral part, tibial part and patellar part, and fixation with bone cement; (3) Installation of a liner, repositioning, closure of the surgical incision, and the end of the operation; (4) Surgery for total knee arthroplasty. (5) What are the contraindications for total knee arthroplasty? Total knee arthroplasty is contraindicated in the following cases: (1) muscle paralysis around the knee joint, or muscle weakness due to neurological disease; (2) acute or chronic infectious disease, active tuberculosis infection, bleeding disease; (3) the knee joint has been fused in a functional position for a long time, without symptoms such as pain and deformity. (4) Severe osteoporosis, joint instability, severe muscle weakness, fibrous or bony fusion is not an absolute contraindication to surgery. It must be emphasized that total knee arthroplasty is not a perfect surgical procedure, and although the majority of patients have satisfactory results, attention should be paid to the selection of indications, otherwise the outcome will definitely be affected, and cases with other surgical indications should avoid total knee arthroplasty if possible.