Femoral head necrosis is a disease in which the blood supply to the femoral head is interrupted or damaged, causing the death and subsequent repair of bone cells and bone marrow components, which subsequently leads to structural changes in the femoral head, femoral head collapse, and joint dysfunction. Femoral head necrosis, also known as ischemic necrosis of the femoral head, is a common and difficult to treat disease in the field of orthopedics. In the early and middle stages of femoral head necrosis, the femoral head is still intact, and minimally invasive surgery to preserve the head can achieve satisfactory results, thus avoiding or delaying the time of artificial joint replacement. At present, the head preservation surgical treatment for early and mid-stage femoral head necrosis at home and abroad mostly adopts bracing therapy to provide enough support to restore the stability of the femoral head and avoid or delay the collapse of the femoral head. Clinically commonly used support therapy: 1. Tantalum rod support: from the lower lateral side of the femoral ridge, through the femoral neck, the femoral head necrosis reconstruction rod (tantalum rod) is implanted into the osteonecrosis area below the weight-bearing area of the femoral head to provide a mechanical support to the bone structure of the femoral head necrosis area that may collapse. It is used to improve the bone structure of the osteonecrosis area, which has a good supporting effect on the femoral head that is about to collapse and can prevent or delay the collapse of the femoral head under normal walking conditions. It is one of the advanced techniques for the treatment of the first and second stages of femoral head necrosis. Trabecular metal (i.e. tantalum) is designed to intervene in stage I or II femoral head necrosis and can also be used in conjunction with bone grafting. As a bone replacement material, trabecular metal offers tremendous advantages in terms of physical properties. Tantalum rods have a high weight-bearing strength and a low modulus of elasticity, thus allowing for physiological weight-bearing conditions with minimal stress masking. It is a very structured biomaterial, and its pore size and large number of micropores support the formation of vascularization and the rapid and firm growth of soft tissues into it. 2.Autologous/allogeneic fibula support: On the basis of removing part of the dead bone of the femoral head, the autologous or allogeneic fibula will be slightly deflected after the central femoral stem 4cm below the greater trochanter and the fibula will be placed along the femoral neck in the direction of the femoral head, to under the diseased cartilage in the weight-bearing area of the femoral head, without crossing the articular surface, and can be combined with autologous or allogeneic cancellous bone graft on this basis. The advantage is that marrow core decompression reduces the excessive pressure in the femoral head, and when the closed marrow cavity is opened, the intraosseous hypertension is then relieved. The regeneration of capillaries is stimulated, intraosseous venous return is improved, blood supply is increased, intraosseous circulation is reestablished, and blood flow to the femoral head is improved; the cancellous bone particles filled by the removal of dead bone can induce the generation of a large number of osteoblasts, which has an obvious effect of inducing osteogenesis, effectively repairing bone defects, and promoting bone healing and regeneration. The fibular stem is implanted in the neck of the femoral head extending to the weight-bearing necrotic area of the femoral head, spanning the sclerotic area and the cystic degeneration area, so that the irregular fracture zone within the femoral head is stabilized and supported, providing effective mechanical support and preventing or delaying the collapse of the articular cartilage of the femoral head. This method is suitable for the early treatment of femoral head necrosis. 3.Autologous fibula support with vascular tip: Some scholars use autologous fibula support with vascular tip to obtain sufficient support while hoping to bring new blood supply to the femoral head through the anastomosis of blood vessels. 4, with vascularized greater trochanteric bone flap implantation: select the greater trochanteric bone flap with spinolateral femoral artery branches, cut the hip capsule open, dislocate the femoral head, groove at the cartilage denudation, thoroughly remove the accident to sclerosis with fresh blood seepage, select autologous or allogeneic cancellous bone for compression bone grafting, then put the taken greater trochanteric bone flap into the femoral head, suture the articular cartilage, and fill the iliac bone extraction with allogeneic iliac bone block The iliac bone is filled with allograft iliac bone. This method is suitable for patients with mild collapse in the middle stage and changes in the shape of the femoral head. The implantation of a vascularized bone block can significantly improve the inadequate blood supply in the femoral head. The vascularized bone block is alive and can be easily integrated with the bone in the recipient area when implanted, eliminating the need for a crawling replacement process. The implantation of cancellous bone in the cleared lesion area with adequate compression can reduce intraosseous pressure and improve venous return while preventing collapse of the weight-bearing area in the early postoperative period. Due to the good blood circulation, the growth of bone scab is also faster. At the same time, some experts and scholars at home and abroad have achieved certain clinical results in the treatment of early and mid-stage femoral head necrosis through titanium brace and memory metal brace, but their long-term efficacy is still waiting for a long time of follow-up observation. The above methods are the common surgical methods used in the treatment of early and mid-stage femoral head necrosis in clinical practice. It must be emphasized that bracing should be mastered with strict surgical indications, and at the same time, bracing is often combined with medullary decompression cancellous bone punching and bone grafting, which is the only way to cure or delay the course of femoral head necrosis.