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, if so it is best to use a cobalt alloy prosthesis.