Osteoarthritis is a degenerative disease that seriously affects the quality of life of the elderly. It is primarily a degeneration of the cartilage in the joints, accompanied by degeneration of the synovial membrane, ligaments and meniscus. It occurs in weight-bearing joints, such as the hip and knee. Knee degeneration is more common in Chinese. The symptoms appear without any obvious cause and are gradually aggravated, reduced after rest and aggravated after activity, especially after climbing stairs and hills. Some patients have a stiffness in the morning, which disappears after 10-15 minutes of activity. After sitting for a long time, the joint pain is obvious when standing up, and the fear of cold is aggravated by cold. Long-term failure to treat, mis-treatment, serious joint deformity, lower limb force line change, joint can not be completely straight, limping, straightening loss of walking function. After diagnosis, avoid weight-bearing under the guidance of the doctor, take internal Chinese medicine to strengthen liver and kidney, cartilage protector, local physiotherapy, massage, acupuncture and other conservative treatment. If the treatment is not effective, arthroscopic debridement can be considered. If the patient is 65-70 years old or older, with severe cartilage defects, persistent pain and obvious deformity, artificial joint replacement may be considered. In Germany, a general hospital can perform up to 700-1000 arthroplasties per year. For patients with end-stage osteoarthritis, the procedure is technically mature and effective.