The goal of knee arthroplasty is to relieve joint pain, improve joint function, correct joint deformity and obtain long-term stability. The main indications include: 1, degenerative knee osteoarthritis (OA): senile knee OA accounts for the largest proportion of total knee replacements. 2, Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) of the knee joint advanced lesions: RA or AS can often involve bilateral knee, joint. 3, other non-infectious arthritis caused by knee joint lesions with pain and dysfunction. Such as large osteoarthritis, hemophilic arthritis. 4.Traumatic osteoarthritis: osteoarthritis after severe trauma involving joint surfaces, such as cases in which the joint surfaces fail to be repaired after comminuted plateau fracture which seriously affects the function as well as secondary osteoarthritis due to meniscus injury or resection. 5. Cases with large osteochondral necrosis of knee joint or other lesions that cannot be repaired by conventional surgical methods. 6, Joint destruction inherited from infectious arthritis can be a relative indication for TKA when no active infection is confirmed. 7, Cases in which good joint function reconstruction cannot be obtained after resection of a tumor involving the knee joint surface. Such cases may require a specially customized prosthesis. In conclusion, the indications for total knee arthroplasty are broad, but it does not mean that this procedure can be abused. It remains important to be rigorous about the indications for surgery and to consider the age of the patient undergoing TKA. Functional rehabilitation after knee arthroplasty is an important part of the surgical outcome. Rehabilitation should be performed under the principle of painlessness. You can practice walking up and down stairs and squatting only 3-6 weeks after surgery. You can refer to the following methods: 1, knee straightening and flexion exercises: press the leg to practice straightening function: knee flexion contracture deformity of the patient, take a standing or lying position, the heel is placed on a soft cushion of about 30cm, their own or others hands on the distal thigh, even and continuous pressure to the back of the knee joint has a pulling sensation and a painful sensation to maintain for 3min, alternating between the two legs, 5 times a day. Seated knee flexion exercise: the patient sits on the edge of the bed, legs naturally drooping, flexor muscle group contraction to make the knee joint gradually flexed. Prone knee flexion exercise: the patient takes the lying position, the heel moves to the hip to drive the knee flexion. Climbing wall exercise: the patient’s buttocks to the head of the bed, the affected limb up, using the weight of the limb or foot crawling on the wall to help knee flexion. And you can draw a line on the wall to record the progress. 2, quadriceps isometric or isotonic contraction exercises: knee active straightening: patients take a sitting position, hands back or back against the wall, physiotherapist one hand on the knee below, one hand on the distal thigh above the inner, asking the patient to stretch the knee tensing the thigh muscles, the two hands were to feel the pressure of the knee and quadriceps muscle contraction of the medial head in order to assess the strength of the muscle. The contraction is maintained for 20 seconds each time, 10 times as a group, 10 buttons can be taken out of the locket in stages to keep track of the number. Practice 3-5 sets per day. Active straight leg raise: in the knee joint active straightening of the lower limbs raised to the heel from the bed about two fists high, the same each time to maintain 10 seconds. If you can easily complete the daily 5 groups of exercises (after the completion of the muscle without soreness and pain), can be added to the ankle sandbags to strengthen the muscle power, sandbags from half a catty, according to the capacity of each person to gradually increase each time to increase half a catty to three pounds when to stop increasing the weight. Further strengthening of muscle strength can be accomplished by increasing the number of exercise groups per day or weighted squatting and other exercises. Patients sitting on the bedside, active knee flexion and extension exercises, pay attention to the knee extension will be as completely straight as possible. 20 times for a group, 3-5 groups of daily exercises, easy to complete the number of daily exercises, can be tied to the ankle sandbags to strengthen the muscle strength, the method is the same as above. Other muscle isometric or isotonic contraction exercises each contraction maintenance time, the number of times per group, the number of groups per day are the same. 3, squatting exercises: weighted squatting. 50-100 times / day (to the principle of pain-free knee joints).