Idiopathic femoral head necrosis, also known as ischemic femoral head necrosis, is a common disease caused by various intra- and extra-osseous pathogenic factors that reduce nutritional blood flow to bone tissue, compression of the intra-osseous vascular network or obstruction of outflow veins, resulting in impaired local blood supply, which can cause ischemic necrosis of bone tissue in severe cases. At the beginning of the disease, only a single major blood vessel is damaged. As the disease progresses, if the amount of residual circulating blood is insufficient to maintain the normal blood supply to the bone cells at the damaged area, the bone marrow tissue will be damaged first, followed by bone cell necrosis. Symptoms and signs Pain is the most common early symptom, with 50% of acute attacks characterized by hip discomfort in an indeterminate location, which may occur before or after a positive radiographic finding and may be associated with increased intraosseous pressure, tissue ischemia or microfractures. Eventually the joint surface collapses, resulting in further pain and limitation of lower extremity motion, especially internal rotation. Some patients develop intermittent claudication with symptoms similar to chronic peripheral vascular disease claudication, which decreases with rest and worsens with activity and weight bearing. Therefore, the following patients should be particularly alert: ① local pain of unknown origin, especially hip pain with occasional claudication; ② the contralateral hip has been clearly diagnosed as osteonecrosis, as non-traumatic osteonecrosis, bilateral lesions of the hip joint up to 30% to 80%; ③ there are obvious causative factors, such as long-term or short-term heavy application of steroid hormones, long-term heavy alcohol consumption, collagen disease (systemic lupus erythematosus, rheumatoid disease, etc.), sickle cell anemia, Gaucher tumor, decompression sickness, and a history of osteonecrosis induced by the aforementioned etiologies. There is a lack of a reliable and effective treatment for osteonecrosis. This pathological process, once initiated, is difficult to interrupt by external forces and generally takes 3 to 5 years. The degree of recovery is related to the early or late diagnosis and treatment, the size of the necrotic foci, the degree of necrosis and the appropriateness of treatment. Therefore, osteonecrosis should be diagnosed early and treated early, which will reduce or avoid the occurrence of deformity and obtain good results. Osteonecrosis once the bone shape deformation, can cause permanent damage, seriously affect the patient’s life and ability to work. 1, Western medical treatment (1) non-surgical treatment: ① restrict weight-bearing: strict restriction of weight-bearing or non-weight-bearing can restore the blood supply to the ischemic bone tissue and protect it from pressure, in order to control the development of the disease, prevent collapse, and promote the healing of the ischemic necrosis of the femoral head itself. It is mainly applied to patients who are not suitable for surgical treatment, such as the elderly, poor general condition, progressive stage of ischemic necrosis and patients with poor prognosis. It can be used to limit the load of the affected limb by relying on support such as cane and axillary cane until there is clinical indication for joint replacement. ②Dermal traction: Traction should be performed with the affected limb in an abducted and internally rotated position. This can not only relieve the spasm of the surrounding soft tissues, but also increase the capacity of the acetabulum to the femoral head, so that the pressure can be evenly distributed and avoid aggravation of femoral head necrosis or collapse and deformation due to stress concentration. The traction weight should be moderate and varies from person to person, generally 4kg for adults. traction once a day for 3-4h. ③ External shock wave: external shock wave has osteogenic effect and can promote fracture healing. ④Reduction and discontinuation of hormones: For patients with rheumatic diseases who are taking glucocorticoids, if possible, they should switch to other western drugs or switch to Chinese medicine treatment, while gradually reducing the dosage of hormones under medical advice, to eventually discontinuing them. (2) Surgical treatment: ① Treatment of preserved femoral head: A. Borehole decompression: mainly used for patients without joint surface collapse in the early stage, it is the simplest surgical method to treat femoral head necrosis. The mechanism of action is to reduce intraosseous pressure and promote venous reflux. The mechanism of action is to reduce intraosseous pressure, promote venous return, relieve trophoblastic vasospasm, and allow new blood vessels to grow into the ischemic area along the bone foramen. Some literature reports that the clinical efficiency can reach 90%, but most scholars fail to reach such ideal treatment results. B. Bone grafting: It is also called drilling and decompression bone grafting because it is necessary to drill holes before bone grafting. The mechanism of action is: a. drilling to decompress; b. bone grafting to provide mechanical support; c. bone grafting with myotome to increase the blood supply to the femoral head. There are many surgical methods, including cancellous bone grafting, cortical bone grafting, bone grafting with myotome, vascular anastomosis bone grafting and allogeneic bone cartilage grafting. In the early stage, central decompression and cortical bone implantation are often used to treat femoral head necrosis. C. Osteotomy: By changing the corresponding position relationship between the femoral head and the femoral stem can achieve: a. increase the weight-bearing area of the femoral head; b. reduce the pressure on the femoral head; c. move the femoral head necrosis lesion out of the weight-bearing area and reduce the local stress. In addition, osteotomy itself opens the medullary cavity, which can reduce the intraosseous pressure and improve the blood circulation of the femoral head. There are many osteotomy methods, such as flexion osteotomy, extension osteotomy and abduction, adduction and rotation osteotomy, etc., and their effects vary greatly. Arthroplasty: Hip arthroplasty includes metal cup arthroplasty, joint surface replacement, femoral head replacement and total hip arthroplasty. 2, Chinese medicine treatment The early stage of osteonecrosis is mainly manifested as local stiffness and discomfort, followed by increased pain. Restricted movement and muscle atrophy. In the view of Chinese medicine, the early stage is mainly bone paralysis, and the later stage is paralysis for a long time, and then develops into impotence paralysis. The causes are trauma, internal damage and external attack. Dietary care Dietary care: give high protein, high vitamin, calcium and iron rich and easy to digest food, diet should be diversified, keep balanced and rich in nutrition. Preventive care 1.Population prevention In production activities and daily life, pay attention to avoid serious trauma and cumulative stress injuries, such as heavy sports training, excessive long-distance running, etc. Workers involved in aviation or deep water operations, etc., should strictly master the operating procedures to prevent osteonecrosis caused by decompression sickness. Those who are frequently exposed to or apply radioactive substances in the fields of national defense, industry, and medicine should strengthen the management of radioactive substances and protective facilities for buildings and individuals. Clinical patients who must apply adrenocortical steroids or indomethacin-like drugs for treatment should strictly grasp the indications and principles of drug use, dosage, do not abuse and regular pelvic film. 2, individual prevention (1) primary prevention: create a good biomechanical environment, avoid over-concentration of stress, excessive intensity of activities. The workload and work rhythm should be controlled appropriately for the work with high activity and labor load, and pay attention to the combination of work and rest to eliminate or reduce the restrictive pressure on the epiphysis. Strengthen the protection against radioactive substances and radiation, and pay attention to the principles of medication against adrenocortical steroids and indomethacin. (2) Secondary prevention: The early diagnosis of femoral head epiphyseal necrosis can be made based on mild pain in the hip, small ossification center, uneven epiphyseal density, sclerotic cystic changes, etc., and widening of the medial gap of the hip joint. The affected limb should be traction in abduction and internal rotation position or abduction brace to maintain 40° abduction and mild internal rotation position, or plaster fixation to make the femoral head epiphysis incorporated into the acetabulum. For early stage patients with hip pain and flexion deformity, avoid weight-bearing and use hyperbaric oxygen therapy, and operate early if the symptoms are obvious. The affected limb can be traction, and when the pain disappears, it can be protected by a brace. (3) Tertiary prevention: epiphyseal drilling is commonly used in the first stage of aseptic necrosis of the femoral head to decompress and promote the reconstruction of necrotic epiphysis; in the second and third stages, synovectomy or total resection plus drilling of the femoral head or simultaneous implantation of blood vessels are commonly used, and in recent years, fetal cartilage implantation has also been reported to repair aseptic necrosis of the femoral head with good results. Salter’s pelvic osteotomy is feasible in cases of total femoral epiphysis involvement and subluxation, and sometimes pelvic osteotomy is performed together with subtrochanteric rotational osteotomy, and the hip is fixed with a “human” cast for 2-3 months after surgery, so that the femoral head can be better covered.