I. What conditions are suitable for knee replacement surgery? Various inflammatory arthritis of knee joint, including rheumatoid arthritis, osteoarthritis, hemophilic arthritis, Charcot arthritis, etc.; a few traumatic arthritis; osteoarthritis after failure of tibial osteotomy; patellofemoral arthritis of a few elderly people; resting infectious arthritis (including tuberculosis); and a few primary or secondary osteochondral necrosis diseases. II. In what cases is knee replacement surgery contraindicated? Artificial total knee replacement is contraindicated in the following cases: paralysis of the muscles around the knee joint; the knee joint has been fused in the functional position for a long time without symptoms such as pain and deformity. According to experience, severe flexion contracture deformity (greater than 60 degrees), severe osteoporosis, joint instability, severe muscle weakness, fibrous or bony fusion are not absolute contraindications to surgery. How to choose a good artificial knee joint? When a patient decides to adopt the treatment of artificial joint replacement, a question often mentioned is: what kind of artificial joint is the best artificial joint? It should be said that different patients should choose different artificial joints. Artificial joint prosthesis has very strict requirements on the design of its shape, surface treatment, material selection, manufacturing process and packaging; at the same time, it also needs sufficient clinical practice to confirm the effect of a certain artificial joint. As for the current situation, the artificial knee joint has become a very mature artificial joint both in terms of the prosthesis itself and in terms of surgical operation techniques. In developed countries, artificial knee joints have been widely used in clinical practice and have achieved good clinical results. Choosing an artificial knee joint prosthesis is very different from choosing other commodities, because once the artificial knee joint prosthesis is put into the human body, it is not easy to be “replaced” at will, and even if it is “replaced”, the cost is quite large, which can’t be measured by money only. So how to choose a good artificial joint should be under the guidance of experts to make a careful choice. Four, postoperative examination three months after discharge from the hospital to the hospital review, X-ray film, to understand the position of the joint prosthesis and stability is good. After six months after the operation, you will be rechecked again, and every six months thereafter, you will be required to take X-rays. If there is any discomfort, such as redness, swelling, pain or difficulty in movement of the joint and injury of the hip joint due to accidental circumstances, you should go to the hospital for examination in time. Fifth, the use of artificial knee joint duration and efficacy of the human knee is an important joint, it has to walk, run, jump, squat and other functions, and it is also the burden of your body weight. Once the knee joint is diseased, the cartilage of the joint will be destroyed, and the original smooth surface like a mirror will become a rough or even defective surface, and furthermore, the femoral condyle will be deformed. As a result, you will experience pain, difficulty walking, limited mobility, limping, and sometimes difficulty in making even easy movements. When the above diseases have progressed to a certain point and the joint has been destroyed, surgery is required. An artificial knee joint is used to replace the damaged joint (the surgeon decides when to operate) to restore function such as walking. The greatest benefit of artificial joint surgery is that it eliminates joint pain after surgery, greatly improves the function of the joint, and improves the patient’s quality of life so that he or she can work and live well during his or her lifetime. Currently, more and more patients are happy to accept the suggestion of artificial joint surgical treatment. The problem of the longevity of the artificial knee joint is determined by two main points: the wear and tear of the joint and the loosening of the prosthesis caused by wear particles. Artificial knee joint material strength and wear resistance is after hundreds of wear and tear experiments, high-quality imported artificial joints, such as Germany snake (AESCULAP) artificial joints, the United States Stryker (STRYKER) artificial joints, etc., generally can meet the patient more than 20 years. The artificial joints currently used in the clinic have improved a lot compared to that of twenty years ago, and it is believed that more than 95% of the artificial joints that have been placed in the clinic for twenty years can continue to be used. Successful artificial joint replacement surgery can enable you to live pain-free and meet the daily activities, for the knee joint has been destroyed, other treatment methods can not achieve the same effect. Of course, the longevity of the artificial joint is also related to many factors, such as the amount of exercise the patient does, the choice of prosthesis, the surgeon’s surgical technique, and his or her own condition. The orthopedic community is currently working with engineers and material scientists, among others, to continually improve artificial joint materials, processes and surgical techniques. The future is bright for patients who choose joint replacement to improve their quality of life and want to move around healthily and painlessly. Sixth, the artificial knee joint loosening after the treatment of artificial knee joint once the infection or aseptic loosening, the need for joint revision surgery. There are hip prostheses and surgical instruments specially made for revision surgery. Revision surgery is more complex than the initial surgery and may require bone grafting, changing the type of joint prosthesis, or the use of specialized prostheses. After revision surgery, the vast majority of patients can achieve the desired results. Seventh, the protection of artificial knee replacement surgery after artificial knee replacement surgery, you need to develop good habits of life and activities, to maintain the stability of the joints, and at the same time to learn some simple knowledge of rehabilitation, joint rehabilitation exercises. You should pay attention to the prevention and treatment of infections, and actively treat infections such as tonsillitis, skin infections, ringworm and so on. After surgery, you can do cycling, walking, dancing, swimming and other sports, but do not encourage running, jumping and other strenuous exercise, as well as long-distance walking, mountain climbing and so on. In addition, some hospitals provide postoperative rehabilitation manuals for patients’ reference. Eight, rehabilitation after knee replacement surgery rehabilitation exercise is vital to the success of total knee replacement surgery. After the operation, isometric contraction exercise of the affected limb muscles can be carried out. If the joint position and fixation are good, the patient can start the rehabilitation exercise under the guidance of doctor and rehabilitator, including the straight leg raising exercise for quadriceps muscle and walking training, etc. Even after the patient has fully recovered and discharged from the hospital, the rehabilitation exercise is very important for the success of total knee replacement. Even after complete recovery and discharge from the hospital, it is generally required to adhere to regular rehabilitation exercises. Nine, artificial knee surgery advantages and disadvantages of artificial knee surgery began in 1960, this surgical method has been identified as an effective surgery. However, the time for total knee replacement in China is relatively short, and the procedure requires a very experienced surgeon to perform. Artificial knee surgery is able to turn an immobile joint into a movable one. However, once the surgery fails, there are few ways to compensate for it. The advantage of the surgery is that it can be performed on patients with worsening osteoarthritis of the knee and severe deformity. The surgical treatment period is short, about one month. The pain in the joint can be removed completely. The disadvantages are as follows: it has an impact on sports such as running and mountain biking. After surgery, the knee is usually bent at a slightly greater than right angle, around 120o. After 10-15 years after the surgery, there is loosening between the bone and the artificial joint, and the percentage of replacement is about 5-10%. Infection of the artificial joint is very difficult to treat; it often causes osteomyelitis of the femur and tibia. 3%-5% of the people who have an infection after the surgery need to prolong the treatment time, and the treatment is so difficult that the artificial joint has to be removed, and the joint will be replaced after the infection has been under control for 1-2 years. The infection rate of the replacement joint is much higher than that of the first surgery. Wear and loosening of the artificial joint is also a cause of pain after surgery and failure of the surgery. It is expensive and not affordable for the general public. However, once most of the articular cartilage of the knee is destroyed, high tibial osteotomy cannot be performed and only artificial joint replacement or joint fixation can be done. Along with the arrival of aging in China, the general improvement of people’s living standard, the increase of economic income, and the implementation of social labor and medical insurance, especially the rapid popularization of artificial joint technology, it is certain that the number of cases and success rate of artificial joint surgery in China will increase rapidly, and the complications will be less and less.