Ischemic necrosis of the femoral head in children is also known as osteochondrosis of the femoral head, aseptic necrosis of the femoral head, Perthes disease, and juvenile deformational osteochondritis of the femoral head. In terms of its etiology, pathology, symptoms, treatment and prognosis, it is different from that of adults, and he belongs to a self-healing disease with a slow course. The incidence varies from region to region, and the incidence in China is about 1 per 1,000. It is mostly seen in children aged 4-10 years old, with a male to female ratio of 4:1, of which 10% are bilateral. Etiology: The real cause of this disease is not fully understood. Infectious factors, due to the infection of the hip joint, the pressure in the joint capsule increases, which leads to venous stasis in the joint capsule, poor blood return, and impaired blood circulation in the femoral head, and ischemic necrosis occurs. Congenital factors, many scholars have found that there are congenital anomalies and defects in the nutrient vessels of the femoral head in children, especially in boys, in terms of anatomy. Genetic factors, 10%-20% of children have a positive family history, and the incidence of consanguineous marriage is high. Endocrine factors, it was found that the growth hormone mediator in the plasma of affected children is significantly lower than that of normal children of the same age, and in the blood of normal boys the growth hormone mediator is lower than that of normal girls, so the disease is more prevalent in boys. It is found that more children are obese, which may be related to the greater gravitational force on the femoral head. Symptoms: The onset of the disease is slow and the duration of the disease is long. Intermittent claudication and pain occur over several months, and the pain often radiates to the knee and inner thigh. Some children have knee pain at the beginning of the disease, but hip symptoms are not obvious. The symptoms of claudication and pain may increase with activity and decrease with rest. The hip joint has an abduction deformity with limited abduction and internal rotation. Some children may be asymptomatic or have mild symptoms in the early stages. There are three important clinical signs, namely obesity, reduced range of motion of the hip joint, and tightness of the intraskeletal muscles. In the later stages of the disease, the symptoms gradually resolve or even disappear, and the main manifestations on X-ray are increased density, small size, cystic degeneration, fragmentation of the femoral head, and widening and shortening of the femoral neck. Treatment: Different treatment methods should be used according to different pathological stages, and the commonly used treatment methods are non-surgical therapy and surgical therapy. Non-operative therapies include traction, hip herringbone cast fixation, weight-free brace and other methods. Surgical treatment includes drill hole decompression, tipped muscle graft, intraosseous vascular bundle graft, vascular bundle graft, synovectomy, periprosthetic muscle release, osteotomy, etc. Prevention: Since the cause of this disease is not clear yet, there is no reliable preventive measure. However, attention to the following aspects can have a positive effect on the prevention of this disease.