The knee joint is the most complex and weight-bearing joint in the human body, just like the most wearable spindle in a car. Therefore, of all the joints in the human body, the knee joint is the most prone to degeneration, and the medical term for the disease that develops when the knee joint degenerates is osteoarthritis of the knee joint. According to statistics, 60% of people over the age of 50 suffer from osteoarthritis, and 90% of women and 80% of men over the age of 65 suffer from this disease. These diseases seriously affect the quality of life of the elderly, and elderly patients not only suffer from pain, but also bring many burdens to their families and society. Causes ① Trauma to the knee joint. ②Ageing. ③Endocrine disorders. ④Neurotrophic disorders. (5) Local wear and tear of the joint. ⑥Congenital or developmental bone and joint disorders, etc. Clinical manifestations 1, joint pain: the most common symptom of the disease, early pain is light, mostly occurs during activity, and relieved after rest, later it is also pain at rest, and often night pain occurs. Overexertion can make the pain suddenly aggravate. 2. Morning stiffness: it is limited and relieved after activity. The duration will not exceed 30 minutes. 3. Difficulty in movement: It is slowly progressive. In the early stage, it is mild, only in the morning or after sitting for a long time, and can recover after activity. As the disease progresses, the symptoms gradually worsen to the extent that the range of motion of the joint is significantly reduced. Treatment 1.Conservative treatment: including medication, intra-articular injection, functional exercise, physiotherapy, etc. 2.Minimally invasive treatment: arthroscopic surgery Arthroscopic surgery is suitable for osteoarthritis with obvious meniscal damage, free body and other diseases. For such diseases, the use of arthroscopic knee joint cleanup can effectively relieve the symptoms. 3.Artificial knee surface replacement The ultimate solution for severe knee osteoarthritis is to replace the joint surface with an artificial knee surface. For severely degenerated knee joints, artificial joint replacement has the combined advantages of relieving joint pain, maintaining joint mobility, maintaining joint stability and not affecting limb length.