Ischemic necrosis of the femoral head is a pathological process in which osteocytes, bone marrow hematopoietic cells and adipocytes in the femoral head are affected by one or more factors, either alone or in combination, causing cellular necrosis. The common triggering factors of the disease include ① trauma to the hip such as femoral neck fracture or hip dislocation, ② alcohol abuse, ③ application of corticosteroids (hormones), ④ decompression sickness, ⑤ radiation injury, ⑥ streptocytosis, ⑦ systemic lupus erythematosus and so on. The pathology is characterized by ischemic necrosis of the femoral head due to impaired blood circulation and the consequent repair reaction, and the necrosis and repair reaction are intertwined, eventually leading to the collapse of the femoral head and degenerative arthritis of the hip joint. The disease occurs in men between 20 and 50 years of age, and some patients are affected bilaterally at the same time. The disease starts slowly and is easily missed and misdiagnosed without obvious symptoms at the beginning of the disease. In the early stage, the hip is mildly painful and the joint movement is normal or mildly restricted. With the increase of claudication and hip pain, the affected hip shows flexion, inversion, contracture deformity, and limited abduction and internal rotation. The manifestations of osteoarthritis appear in the late stage. MRI is the most accurate imaging method for diagnosing ischemic necrosis of the femoral head, especially in the early stages of osteonecrosis when only bone marrow changes are present, with an accuracy of over 90%. The International Society for Bone Circulation Research recommends a 5-stage classification of the disease based on the extent and degree of femoral head lesions. Treatment includes both non-surgical and surgical treatments. Early and aggressive treatment can help reverse or stop the disease from continuing to progress. Patients should be careful to avoid weight bearing in their daily life and try to take bed rest and crutches to reduce the stresses acting on the joint and to allow ideal repair of the necrotic femoral head before it collapses. Vasoactive drugs and lipid-lowering medications help to improve the blood supply to the femoral head. Pulsed electromagnetic fields help to improve symptoms and stop the disease from progressing. The disease belongs to the Chinese medical term “osteodystrophy”, which is an evidence of deficiency of the root and the symptoms. Blood stasis and phlegm are the symptoms, and deficiency of liver, kidney and qi and blood is the root cause. Treatment is mostly based on breaking down blood stasis, nourishing blood, strengthening the spleen, and tonifying the liver and kidney, and applying blood-activating, blood-nourishing, and tendon-strengthening drugs for internal use, together with external treatments such as herbal fumigation and steam baths to promote new bone regeneration and improve joint function. Surgical treatment is applicable to patients with stage II or above, including medullary decompression, bone grafting, superior femoral osteotomy, surface replacement arthroplasty and artificial total hip arthroplasty. Medullary decompression osteotomy can (1) interrupt the vicious cycle of ischemia and intraosseous hypertension, (2) remove the necrotic bone that prevents revascularization, (3) fill the defect with fresh osteoinductive cancellous bone, and (4) fill the defect with a viable cortical bone column to support the subchondral bone surface and accelerate the revascularization process. This procedure is effective in relieving pain, improving joint function, reversing the pathological process or delaying the time to total hip replacement. Artificial total hip arthroplasty is the only surgical option available for patients with advanced disease. It improves the patient’s quality of life by relieving pain and improving joint function.