We sit, stand and walk all depend on the flexion and extension of the knee joint. This hinged movement of the knee relies on the smooth cartilage on the surface of the joint bones and the well-developed muscles surrounding them. In age-related arthritis, this cartilage is broken down, making movement difficult and painful, with inversion or valgus deformity of the knee joint, which appears on X-rays as a narrowing of the joint space, significant osteophytes, and altered force lines in the lower extremities. The incidence of age-related knee osteoarthritis is high in people over 50. In China, the elderly population is about 100 million or more, and about 80 million people will have X-ray manifestations of osteoarthritis, and about 40 million people will have symptoms. In elderly osteoarthritis, if the knee pain significantly affects the patient’s life, there is an indication for surgery as long as the physical condition allows. Surgery is the removal of the bone that has become diseased and the addition of a cap on the surface of each of the thigh and calf bones to form an artificial joint, which is known as artificial knee replacement surgery. This is a very mature surgery in orthopedics and the results are very precise. 【Tips】 Life is movement, movement reflects life. For elderly patients in good health, it is not worthwhile to suffer from pain and quality of life for nothing just because of age-related knee osteoarthritis. Artificial joint replacement surgery should be actively performed so that the elderly can enjoy their old age in peace.