What is osteoarthritis? Osteoarthritis is a common chronic joint disease with a high prevalence. The main pathological changes are degenerative changes in the articular cartilage and secondary osteophytes. It can occur in any joint in the body, but is most common in the knee joint. It is often referred to as age-related arthritis, deforming arthritis, degenerative arthritis, intra-articular bone spurs, and old cold leg, and is also called osteoarthrosis. Within the knee joint, the healthy cartilage surfaces of the femur and tibia slide very smoothly between each other and are able to cushion the local pressure generated during physical activity. The cartilage itself is not innervated by nerve endings. In patients with osteoarthritis, the superficial cartilage of the knee joint breaks down and falls off, causing the subchondral bone to contact and rub against each other during knee joint activities, but there are nerve endings assigned inside the subchondral bone, which can cause knee joint pain during the rubbing process, and the synovial membrane inside the knee joint grows and causes joint swelling. The pain and swelling during activity force the patient to reduce the amount of knee activity, and this reduction in activity can lead to stiffness in the knee joint, just like a car bearing “rusting”, resulting in a vicious cycle that eventually leads to a complete loss of knee mobility. Over time, the joint becomes narrowed and deformed, with the appearance of rotundity and X-shaped legs. In addition, “bone spurs” may develop on the edges of the joint as a result of excessive bone growth due to wear and tear. There are also small pieces of bone or cartilage that fall out and float in the joint cavity, called “free bodies”, which are nicknamed “joint rats” because they move around like rats. The free body can get stuck in the joint space during knee movement, which can lead to more severe pain and damage, causing great inconvenience to the patient’s life. Osteoarthritis is characterized by painful joints, swelling of the joints and even dysfunctional joints in the presence of acute or chronic synovitis. Unlike other arthritis, osteoarthritis only affects the joints and does not involve other organs of the body. In developed countries, osteoarthritis has become the most common cause of disability. In the United States alone, the annual economic cost of osteoarthritis (including lost wages and medical expenses) is $55 billion, or almost 1% of the country’s gross national product. Nevertheless, it has been proven that with comprehensive treatment and scientific joint maintenance, the symptoms and course of osteoarthritis can be effectively controlled in most patients. Therefore, patients with osteoarthritis need to receive scientific and standardized treatment. In addition, it is important to understand the pathology, physiology and other medical knowledge of the disease, and to know how to scientifically maintain the joints. In this way, patients can not only actively cooperate with doctors, but also give full play to their subjective initiative, improve joint function, enhance joint cartilage nutrition, and delay further degeneration of the joints. What are the treatment methods for osteoarthritis? Osteoarthritis can be treated in different ways at different times and is a stepwise treatment. If conservative treatment is ineffective, x-rays show no significant joint space narrowing, and the patient is young, minimally invasive arthroscopic cleaning and flushing treatment can be used. In more severe cases of osteoarthritis, the use of artificial joint replacement surgery to obtain satisfactory and pain-free mobility is the ultimate treatment.