Ischemic necrosis of the femoral head is a chronic disabling disease due to various etiological factors that destroy the blood circulation of the femoral head, eventually leading to the collapse of the femoral head and the dysfunction of the hip joint. The early manifestation of this disease is hip pain, which is aggravated by activities. In the late stage, the femoral head collapses, which seriously affects the function of the hip joint and reduces the quality of life of the patient, bringing great mental pressure and heavy economic burden to the patient and his family. Therefore, early diagnosis and treatment are especially important to prevent femoral head collapse and disability of patients. For the treatment of early to mid-stage ischemic necrosis of the femoral head, scholars at home and abroad believe that the ideal method should be to preserve the femoral head rather than replacing it. Therefore, preserving the femoral head is the main goal of treating early to mid-stage ischemic necrosis of the femoral head, and our team has summarized the efficacy of various “hip preservation” therapies after synthesizing various studies on them at home and abroad, so as to improve the quality of life of patients. To make the most accurate treatment decision. 1.Non-surgical treatment At present, non-surgical treatment is mostly comprehensive and conservative, including weight restriction, biophysical treatment and drug treatment. Weight restriction is the basis of non-surgical treatment, which requires patients to be bedridden or even absolutely bedridden. The efficacy of weight-bearing avoidance alone is not ideal and has been widely demonstrated in clinical practice. Biophysical methods include electromagnetic stimulation, extracorporeal shock wave technique, hyperbaric oxygen therapy and ion introduction, whose clinical therapeutic effects need to be further confirmed. Medication is the main adjunct to non-surgical treatment, including the use of painkillers, Chinese herbal medicine, anticoagulants, bisphosphonates, and lipid-lowering drugs. The main purpose is to dilate blood vessels, reduce intraosseous pressure and alleviate symptoms, but there is a lack of drug regimen with definite efficacy. Minimally invasive surgery (1) Interventional treatment It is simple, less traumatic and has fewer complications, and has been clinically proven to be an effective treatment method. (2) Arthroscopy Arthroscopic surgery can achieve the purpose of decompression of conventional surgery under minimally invasive, and joint cleaning is more thorough than conventional surgery, and can deal with osteoarthritis and synovial lesions at the same time, with obvious relief of symptoms in the short term after surgery, but its long-term efficacy has not been reported. 3, surgical treatment (1) osteotomy The principle of osteotomy is to remove the necrotic lesion from the main weight-bearing area and turn the normal part of the femoral head into a weight-bearing area to support the acetabulum. In addition, the osteotomy itself opens up the medullary cavity, which has the effect of reducing the intraosseous pressure and improving the blood supply to the femoral head. However, studies have shown that osteotomy alone is not effective and is not conducive to future arthroplasty, so this procedure should be chosen with caution and is currently only used as an alternative surgical option. (2) Core decompression The treatment principle of core decompression is to reduce intraosseous pressure, promote venous return, normalize bone microcirculation, stimulate vascular proliferation in the bone tract, and increase blood supply to the lesion area. It can relieve patients’ pain and delay hip replacement for more than 5 years, which is a commendable procedure for young patients. However, medullary decompression is prone to stress concentration and femoral head collapse, so simple medullary decompression of the femoral head is rarely used now. The development and maturation of medullary decompression + tantalum rod implantation and medullary decompression + autologous bone marrow cell transplantation have better solved the shortcomings of pure medullary decompression, thus achieving better clinical treatment results and becoming the preferred treatment for early to mid-stage femoral head necrosis. ①Medullary decompression + tantalum rod implantation, several studies and experiments at home and abroad have confirmed that this method can provide sufficient mechanical support for the subchondral bone plate of the necrotic femoral head and prevent the femoral head from collapsing, and the clinical application has also achieved satisfactory results. One of the disadvantages is that it cannot stop the progression of the disease, but it can significantly improve the symptoms in the early postoperative period and significantly delay the time of joint replacement. Although the porous tantalum rod implant is expensive, its early clinical results are encouraging, and the medium and long-term results remain to be further observed. ②Medullary decompression + autologous bone marrow mesenchymal cell transplantation. Normally, there is a lack of bone marrow hematopoietic cells in the adult femoral head, but there is red bone marrow in the proximal femur. MRI studies have found that the red marrow is prematurely converted to lipid marrow in patients with femoral head necrosis, leading to changes in the intramedullary hematopoietic system and eventually leading to femoral head necrosis. Therefore, autologous bone marrow MSC transplantation can promote the regeneration of osteoblasts and repair the necrotic bone cells, which can change the symptoms but not the root cause of ischemic necrosis of the femoral head, such as pure thrombolysis, alteration of local microcirculation or simple marrow core decompression in the early stage of clinical treatment. This has changed the status quo of the clinical treatment of ischemic necrosis of the femoral head, which was only treating the symptoms but not the root cause of the disease. Several famous foreign clinicians have proved through numerous clinical experiments that medullary decompression + autologous bone marrow mesenchymal cell transplantation is one of the best hip preservation surgeries for the treatment of early to mid-stage femoral head necrosis, and several hospitals in China have carried out this surgery with remarkable efficacy. In conclusion, our team believes that medullary decompression + autologous bone marrow mesenchymal cell transplantation has become the best choice for the treatment of early to mid-stage femoral head necrosis and has a wide clinical application prospect. (3) Vascularized bone flap transplantation Vascularized bone flap transplantation is also one of the best hip preservation surgeries for the treatment of early to mid-stage femoral head necrosis. The current mainstream adopts the method of anastomotic fibula transplantation, in which a normal fibula with blood flow is implanted to reconstruct the blood flow of the femoral head, thus improving the ischemic state of the necrotic femoral head and increasing the survival rate of bone graft. However, due to its complicated operation, high technical requirements and more postoperative complications, few people are currently treated by this surgical method.