Osteoarthritis of the knee is the most common form of osteoarthritis in clinical practice, and is most common in middle-aged and elderly people. If the patellofemoral joint is also involved, the pain is more pronounced when walking up and down stairs, especially when going downstairs. When squatting, the pain may be relieved by holding the hand on the ground or propping up the body when standing up. When moving the knee joint, patients may feel a “babbling” sound in the joint or a feeling of friction behind the patella. Some patients even have “locking” of the knee joint, which requires rest and light activity before they can continue walking. Patients suffer a lot, the preventive measures are: 1, strict weight control: the knee is the main weight-bearing joint, overweight will increase the load on the joint, increase the incidence of osteoarthritis and aggravate the symptoms of osteoarthritis. Change and properly adjust their dietary structure, coarse and fine grains with a reasonable mix, eat more vegetables, fruits and vegetables, reduce weight is very beneficial to reduce the burden on the joints, improve joint function, reduce pain, etc. 2, reduce trauma to the knee joint: repeated multiple minor injuries to the joint or single trauma may lead to different degrees of damage to the joint cartilage, changing the normal structure of the joint, thus increasing the risk of developing osteoarthritis. To try to avoid and reduce trauma and repeated stress stimulation of the knee joint, especially in the middle and elderly, in daily life and physical exercise, some strenuous activities should be avoided, such as long-distance running, repeated squatting, kneeling, frequent lifting of heavy objects, etc. 3, master the scientific method of exercise: regular, scientific exercise should be seen as a healthy and important way of life. To maintain good health it is necessary to participate in sports, long-term non-exercise will lead to stiff joints and atrophy of the surrounding soft tissues, the body’s flexibility and responsiveness is significantly reduced. Physical activity is especially important for middle-aged and elderly people or patients with osteoarthritis. However, because of the great individual differences, but not blind exercise, inappropriate exercise will accelerate the development of osteoarthritis or further deterioration of the condition, some patients may also have cardiovascular accidents, for patients with combined osteoporosis and may lead to fractures. For middle-aged and elderly patients should not participate in such strenuous sports as long-distance running, mountain climbing, stair climbing, playing tennis or badminton. For middle-aged and elderly patients it is more suitable to increase off? mobility, muscle strength, aerobic or endurance training exercise methods, such as walking, swimming, massage, massage, cycling, etc., and at the same time to ensure that a certain period of time every day to adhere to the functional exercise of various parts of the joint. Exercise should be gradual and persistent, so that the flexibility of the joints gradually increases. 4, prevention of osteoporosis mainly includes: maintain a healthy state of mind, reasonable diet, appropriate exercise, do not smoke and drink, often participate in outdoor activities, more sunshine, etc.. For patients with more serious osteoporosis, some calcium supplements, active vitamin D, bisphosphonates, salmon calcitonin, etc. can be taken as appropriate.