1. Total knee arthroplasty Total knee arthroplasty uses artificial biomaterials to replace the destroyed bone and cartilage in the knee joint. Contemporary artificial knee replacement surgery began in the 1960s and has since become one of the most successful orthopedic surgeries of the 20th century. Since then, surgical results have improved significantly due to the constant updating of implant materials and refinement of surgical techniques. With the use of special surgical instruments, the destroyed surfaces of the femur and tibia (and sometimes the articular surface of the kneecap) can be precisely excised and then fitted with a joint prosthesis made of special artificial biomaterials. The artificial knee prosthesis consists of the following three parts: (1) a metal cast femoral condyle prosthesis (2) a metal cast tibial prosthesis chassis and an ultra-high polymer polyethylene joint surface liner, which can be mechanically connected to each other; (3) an ultra-high polymer polyethylene patellofemoral joint surface prosthesis. The femoral condylar prosthesis matches exactly the morphology of the joint liner surface, resulting in extension motion. More than 600,000 total knee replacements are performed worldwide each year. With the increasing standard of living, changing attitudes and an aging population, more and more patients are willing to undergo total knee replacement surgery in the pursuit of a better quality of life. In many countries, the number of total knee replacements each year has even exceeded that of total hip replacements. 2. Indications and contraindications for total knee replacement surgery Total knee replacement is mainly suitable for patients over 60 years of age who have severe soldier lesions in the knee joint, or with recurrent joint pain, swelling, deformity and joint instability, which seriously affects daily life, and whose conservative treatment is ineffective or ineffective. 3. Post-operative rehabilitation If the success of the surgery is completely pinned on the surgical technique without post-operative rehabilitation, the proper efficacy of the surgery will not be achieved. Extending the foot and ankle immediately after surgery can promote blood circulation in the lower limbs, restore muscle tone, eliminate swelling and prevent deep vein thrombosis in the lower limbs. In the early stage, functional exercises are performed two or three times a day for 10 to 15 minutes each time. The following are the specific methods of postoperative lower limb joint activities and muscle exercises, but should be trained under the guidance of the doctor, step by step, from 10 times per group, gradually increasing: 1, quadriceps exercises: tense your thigh meat, try to straighten the knee joint; 2, straight leg raise: straighten and tense the knee joint in bed, slightly lift the lower limb out of bed; 3, flexion and extension of the ankle joint: rhythmic flexion and extension of your ankle joint; 4, prone flexion and extension of the knee joint 4. Sitting knee flexion: Sit on the side of the bed with the lower leg hanging down and the healthy leg in front of the ankle on the affected side and slowly squeeze the affected leg to help flex the knee as much as possible. For walking on flat ground, walking up and down stairs and other lower limb muscle exercises, please refer to the rehabilitation exercises after total hip replacement. 4. Reminder: Total hip or total knee arthroplasty requires a high level of surgical skills, and some require that the surgeon performing the surgery should have extensive clinical experience, preferably with a full-time surgeon in joint surgery. We recommend that once you have made the decision to treat your hip or knee, you choose a large hospital or a specialized hospital and have an experienced surgeon perform the surgery.