Artificial joint replacement is the ultimate procedure for the treatment of advanced knee disease, and it is a proven and productive treatment modality. Joint replacement has become popular and widely accepted in developed countries in Europe and the United States, with the number of joint replacements in the United States currently approaching one million per year. In large hospitals in China’s major cities, this technology is also being mastered by specialists and is being used for the benefit of knee patients. Modern artificial joint prosthesis is developing very rapidly, but the majority of patients know little about joint prosthesis, how to choose a suitable joint prosthesis, is the majority of patients are concerned about the issue. Modern artificial joint prosthesis materials and design processes are changing rapidly, and the current artificial knee joint is made of cobalt-chromium-molybdenum alloy and highly cross-linked ultra-high polymer polyethylene, which is durable. There are dozens of manufacturers of knee prostheses, and there are imported and domestic joint prostheses, so it is important to choose the right type and model of prosthesis for the individual patient. Artificial total knee prosthesis consists of three parts: 1, femoral prosthesis: placed in the distal femur femoral condyle prosthesis, composed of metal alloy; 2, tibial prosthesis: can have a single prosthesis design, composed of high cross-linked polyethylene. It can also have a combined design with two components, consisting of a metal tray and a high cross-linked polyethylene spacer. The spacer is fixed or sliding on the metal tray. The femoral prosthesis slides on the tibial component; 3. Patellar prosthesis: placed on the residual bone bed of the patella, forming the patello-femoral articular surface between the condyles of the femoral prosthesis, and consisting of high cross-linked polyethylene with a metal backing plate. Artificial total knee arthroplasty in the usual sense means that these three components are matched to replace the diseased surface bone of the corresponding knee joint. Knee prosthesis classification, according to the use of different parts, can be divided into unicondylar prosthesis, bicondylar prosthesis and tricompartmental (total knee) prosthesis. According to the fixation method, they can be divided into cemented and non-cemented (biological) fixed prostheses. According to the degree of restriction of the prosthesis design, it can be divided into non-restrictive prosthesis, partially restrictive prosthesis, highly restrictive prosthesis and fully restrictive prosthesis. How to choose a suitable knee prosthesis? These are the main aspects involved: 1. Choice of fixation method: The most clinically used prosthesis is the bone cement fixation method, which has obtained long-term reliable follow-up results in the clinic. The role of bone cement is not only to fix the prosthesis, so that the prosthesis to obtain an initial stability, but also to strengthen the bearing strength of the bone bed, and sometimes the bone cement can be mixed with specific antibiotics for fixation. 2, the choice of unicondylar prosthesis: unicondylar prosthesis is non-restrictive prosthesis. The purpose of choosing a unicondylar prosthesis is to maximize the preservation of the joint’s tissue structure, bone volume, and motor function for subsequent total knee replacement. It is mainly used for lesions of the medial or lateral compartment alone. The proportion of unicondylar replacements in clinical practice is small, accounting for about 7% to 10% of cases. 3, the choice of total knee prosthesis: the mechanical restrictions of the knee prosthesis ensure the stability of the prosthesis, but at the same time contradict the joint mobility. In general, less restrictive prosthesis can obtain better joint motion function, more restrictive prosthesis is designed to provide additional stability of the joint prosthesis, but it may truncate too much bone, and high restriction may also lead to loosening between the prosthesis and the bone interface. For initial knee replacement, the majority of non-restrictive and partially restrictive prostheses are chosen, with posterior stable (PS) prostheses, which are more widely indicated because they do not require preservation of posterior cruciate ligament function. For patients with posterior cruciate ligament insufficiency or flexion contracture that prevents preservation of the posterior cruciate ligament, such as those with rheumatoid arthritis, it is more appropriate to choose a posterior stable prosthesis. For revision of the knee joint, highly restrictive prostheses, such as LCCK and TC3, are mostly chosen for patients with lateral collateral ligament insufficiency, the presence of large bone defects or severe valgus deformity, and for patients with knee revision. Fully restrictive prostheses, such as hinged knees, can be used for arthroplasty in patients with proximal knee tumors or for total knee revision with loss of knee stability. Partially restrictive prostheses with the addition of extension bars are also an option. In addition, for patients with osteoporosis or severe obesity, or for patients with knee revision, the prosthesis should be selected with additional extension bars to increase joint stability and weight-bearing capacity and to prevent premature mechanical loosening of the prosthesis. There are many types of clinical prostheses and many manufacturers, but the design concepts are similar, so there are rules to follow in the selection of joint prostheses. Knee replacement is a millimeter surgery, and the efficacy of knee replacement depends not only on the prosthesis, but also on the operator’s operating technique and proper postoperative rehabilitation, as well as the operator’s knowledge and familiarity with the prosthesis. Therefore, when choosing a prosthesis in clinical practice, if the patient’s financial situation allows, it is important to follow the basic principles of prosthesis selection, based on the type of knee deformity and the degree of soft tissue integrity, and to choose a prosthesis with which the operator is familiar.