The incidence of chondromalacia patella is higher in women than in men. Chondromalacia patella is the most common early manifestation of osteoarthritis of the knee joint and is one of the common causes of knee pain. Softening of the patellar cartilage is actually a degenerative lesion of the patellar cartilage. There is a layer of cartilage behind the patella, which is often referred to as the “brittle bone” and plays a cushioning role between the patella and the femoral condyle. The cartilage surface of the patella becomes swollen, eroded, cracked, broken and detached as a result of long-term chronic injury, gradually forming reactive hyperplasia of the patella and other bones of the joint, which can develop into osteoarthritis of the knee. According to statistics, the incidence of chondromalacia patella is as high as 36.2%, mostly in young adults and the elderly, especially in the age group of 30-40 years old, with the highest incidence in women significantly higher than in men. Second, long-term wear and tear degeneration is a common cause of chondromalacia patella Why is there such a high incidence of chondromalacia patellae? It is related to the anatomy and function of the patella. The patella is located at the front of the knee joint and plays a role in transmitting power and acting as a fulcrum during knee movements such as squatting, standing and jumping, just like the pulley needed to carry water from the well. At the same time, the patella is one of the main devices that maintain the stability of the knee joint. In life, the knee often needs to flex and extend, and the patellofemoral articular surface will be squeezed and rubbed against the femoral articular surface for a long time. As we age, this can cause damage to the patellofemoral cartilage, such as cartilage degeneration, softening, fragmentation, and unsmooth joint surfaces, causing knee pain. Especially in the process of knee flexion and extension, the pain will increase due to the increased pressure on the patellofemoral joint. If the repeated extrusion and wear of the patella is accompanied by other problems, such as a history of knee trauma, especially if there has been a patellar fracture or abnormal patellar development, the rate of patellar cartilage wear and degeneration will be greatly accelerated and the symptoms will appear early and severe. Patients with chondromalacia patella initially have subpatellar pain, which is apparent at the beginning of activity and gradually disappears after rest. Patients’ symptoms first appear in a semi-squatting position, and due to the unevenness of the patellar surface, friction sounds and rubbing sensations can occur under the patella. With the prolongation of the disease, reactive inflammatory thickening of the subpatellar fat pad and synovitis occur, resulting in recurrent joint effusion and gradually increasing pain, resulting in inability to squat, difficulty in going up and down stairs, especially the most difficult to go downstairs, and possible sudden fall due to pain or weakness during activities. The knee joint may not be able to flex and extend suddenly, but after a little activity, it may be able to move again after making a crisp sound under the patella. Most chondromalacia patellae can be treated non-surgically. The patella itself has no blood or lymphatic fluid supply, so recovery after injury is slow, which can make treatment difficult. The treatment of chondromalacia patella is mainly non-surgical, and most patients with simple chondromalacia patella can be relieved by conservative treatment. The treatment of chondromalacia patellae should be standardized according to the degree and stage of the lesion. For patients with initial onset or mild pain, rehabilitation exercises combined with physical therapy can be used. The rehabilitation method is mainly to improve the stability of the patella by strengthening the quadriceps (the muscle in front of the thigh). The main focus is on straight leg raising exercises, and a sandbag of about 5 pounds can be tied to the calf during exercise. It is important to try to avoid increasing the burden on the patella and to reduce movements such as going up and down stairs, squatting, climbing, kneeling and jumping. If there is reactive inflammatory thickening or swelling of the fat pad or soft tissues around the patella and the pain increases, physical therapy, Chinese herbal hot compresses or massage are feasible to improve the blood circulation of the patella to reduce the symptoms. For patients with more severe symptoms, rehabilitation exercises and physiotherapy can be supplemented with non-steroidal anti-inflammatory and analgesic drugs, such as fentanyl and fotarine. In recent years, based on the research on cartilage degeneration, many new drugs have emerged that directly target cartilage degeneration and damage repair, such as intra-articular injection of sodium hyaluronate and oral administration of glucosamine chondroitin, both of which have achieved very good results. A small number of patients with severe symptoms that do not improve with non-surgical treatment require surgical treatment. The traditional surgical treatment method mostly uses tibial tuberosity elevation, which is effective, but the surgery is traumatic and recovery is slow, so many people are reluctant to undergo surgery. With the maturity of arthroscopic minimally invasive surgery technology, most patients can now undergo arthroscopic joint surface cleaning, drilling and decompression, and lateral release. Arthroscopic surgery is less traumatic and quicker to recover. You can walk on the ground on the second day after surgery and be discharged on the fourth day, and the long-term efficiency rate is about 70%. Fourth, to protect the joint, appropriate exercise, prevention of patellar cartilage chondromalacia and joint injury have their internal and external causes. With age and long-term wear and tear of the joint, the joint itself will undergo natural degeneration, which is related to age and other factors. External causes include trauma, improper use of the joints, and other damage to the joints. Therefore, it is important to develop good habits, pay attention to reducing the continuous pressure on the patellofemoral joint in your daily work, improve the nutrition of the cartilage, and do not let your patellofemoral cartilage become soft prematurely. 1, active full movement of the joint, to be carried out under non-weight-bearing conditions. Such as lying flat on the bed to actively extend and flex the knee joint. Fully moving the joint can make all parts of the patellofemoral joint surface stimulated, synovial fluid nutrients can evenly penetrate into the cartilage tissue, and can enhance the lubrication of the joint. 2, to prevent continuous pressure on the patellofemoral articular surface. The patella is under greater pressure in the bent knee position, which can easily damage the joint surface. The elderly or people who usually have knee discomfort should not climb steep hills or go up and down long, large steps. Avoid prolonged squatting and repeated squatting up and down movements. 3, appropriate activities and exercise. Some people suffering from joint disease, fear of pain, afraid to move, or even bedridden, which is not conducive to the protection of joints, will lead to muscle atrophy, weakness, further aggravating the injury and instability of the joints. Proper and appropriate exercise can strengthen the muscles and ligaments and slow down the process of arthrosis. The general principle is “rest your joints, exercise your muscles”. Swimming and walking are good ways to exercise without increasing the weight-bearing capacity of the knee joint, but also to exercise the muscles and ligaments around the knee joint. 4, the knee joint discomfort or knee pain, to consider the possibility of early chondromalacia patella, to timely treatment, to prevent the degeneration of joint cartilage aggravation.