Etiology Traumatic factors: for example, non-healing fracture and femoral head necrosis after femoral neck or femoral head fracture; ischemic necrosis of the femoral head caused by hip dislocation. Non-traumatic: long-term application of hormones due to rheumatic or other diseases; or long-term alcohol abuse causing femoral head necrosis. There are also some occupations, such as divers, which can also cause femoral head necrosis because of the long-term experience of post-diving pressurization and post-disembarkation decompression. Idiopathic: This is femoral head necrosis in which no clear cause can be found. Clinical manifestations Progressive pain and limitation of movement of the hip joint. In the early stage, the pain is intermittent, aggravated by exertion, and improves after rest. Patients in the early stage of femoral head necrosis often say that they cannot cross their legs and that cross-legging hurts. With the development of the disease, the pain gradually becomes continuous, and the pain is more obvious at night. Limping will occur when the pain is severe. After joint destruction, the range of motion of the hip joint is significantly limited. ECT and MRI have early diagnostic value, and radiographic changes are usually stage II. Staging: usually divided into four stages Stage I: clinical manifestation of hip pain, but no change in X-ray film Stage II: hip pain, cystic change of femoral head or crescentic sign visible in X-ray film, but no collapse of femoral head Stage III: hip pain, uneven density and collapse of femoral head visible in X-ray film Stage IV: arthritic stage, obvious collapse of femoral head, narrowing of joint space and subchondral bone sclerosis seen in X-ray Treatment Stage I and II: femoral head The morphology of the femoral head is still intact, so head-preserving treatments can be taken, such as avoiding weight-bearing and applying drugs to improve the blood supply to the femoral head. However, clinical observation shows that the drug treatment of femoral head necrosis is almost ineffective, so it is better not to listen to the fictitious prescriptions and spend a lot of money not only to cure the disease, but also to cause damage to liver and kidney function due to the toxic reaction of drugs. At present, the most effective treatment for femoral head necrosis stage I and II is femoral head marrow core decompression, free bone grafting or bone flap transplantation with vascular tip, stem cell transplantation, etc. The cure rate can reach 60%-80%. Stage III and IV: At this time, the morphology of the femoral head has been destroyed beyond repair, especially for patients in stage IV, only artificial total hip arthroplasty can be performed.