This disease, also known as Sinding-Larsen disease, was reported by Sinding, Larsen and Johansson in 1921 and 1922, respectively, and is thought to be an osteochondrosis caused by excessive tension or pressure on the upper and lower poles of the patella. It is more common in adolescents aged 10 to 14 years who enjoy strenuous sports, more in males than females, and often occurs on one side, more often on the right side, and occasionally on both sides. It involves the inferior pole of the patella and often coexists with osteochondrosis of the tibial tuberosity. The disease is also known as patellar epiphysitis, growth patellitis, and juvenile patellar osteoarthritis. Pathogenesis: When the inferior and inferior patellar epiphyses are overstretched or injured by the quadriceps tendon and patellar ligament attached to them, fatigue fractures or stress fractures may result, causing impaired blood supply to the epiphysis. The pathogenesis and pathological changes are very similar to tibial tuberosity osteochondrosis. The epiphysis is necrotic due to ischemia and is later resorbed, resulting in creeping replacement and finally elongation, enlargement, and deformity of the patella. It is also believed that the disease is caused by endocrine disorders or is thought to be genetically related. Juvenile onset may occur in adulthood with a high patella. Symptoms and signs: The main complaint is anterior knee pain and mild claudication, which is aggravated when running, going upstairs or pedaling on a bicycle and relieved at rest. In acute attacks, pain is present on jumping and landing. There may be mild swelling at the inferior pole of the patella, with thickening of the soft tissue and pressure pain. It is painful on knee extension and kneeling. In a few cases, symptoms may appear at the superior pole of the patella. The duration of the disease is 4 to 6 months. Treatment with medication: early detection and early treatment can minimize the irregular development of the patella. Avoiding strenuous exercise of the affected limb can reduce the activity of the local lesion, and the symptoms will be reduced. Most can heal spontaneously without fixation with a cast, while a few need external fixation such as a cast for at least 6 weeks to promote early healing of the joint fracture and the main body of the patella. Diet and health care: Avoid full knee squatting, slope walking, mountain climbing and up and down ladders to reduce wear and tear. Preventive care: The patella has an important role in the knee joint. If the knee joint flexes and extends and twists excessively in a semi-flexed position, the patellofemoral joint surface is subjected to frequent rubbing, squeezing or punching, and the long-term load exceeds the physiological limit of the cartilage, the cartilage degenerates, leading to the occurrence of chondromalacia patellae, which in severe cases prevents walking. The effect of massage treatment for chondromalacia patella is ideal. The prognosis for this disease is generally good.