1. Non-surgical therapy: ① weight-bearing restriction, ② skin traction, ③ electrical stimulation, ④ hormone reduction 2. Surgical therapy: ① treatment to preserve the femoral head: A. Drilling and 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. Li Jun, Department of Orthopedics, Peking University First Hospital, Beijing, China B. Marrow core decompression + bone grafting: The mechanism of action is: a. drilling to decompress; b. bone grafting to provide mechanical support; c. bone grafting with myotubes to increase the blood supply to the femoral head. There are many surgical methods, including cancellous bone grafting, cortical bone grafting, bone grafting with myotubes, vascular anastomosis bone grafting and allogeneic bone cartilage grafting. C. Osteotomy: By changing the corresponding position between the femoral head and the femoral stem, it can: a. increase the weight-bearing area of the femoral head; b. reduce the pressure on the femoral head; c. move the necrotic 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. D. Other methods: For those patients who are not suitable for arthroplasty, arthrofusion and Girdlestone hip arthroplasty can be considered. ②Arthroplasty: Hip arthroplasty includes metal cup arthroplasty, joint surface replacement, femoral head replacement and total hip arthroplasty.