Adult ischemic necrosis of the femoral head (ANFH) is a common orthopedic disease in which the blood supply to the femoral head is disrupted by different etiologies, resulting in necrosis of the bone and cartilage of the femoral head. Its pathogenesis is complex, mainly due to trauma, hormone application, excessive alcohol consumption, hematologic disorders, decompression disease and other causes that lead to damage to the local trophoblastic vessels of the femoral head, which in turn leads to bone ischemia, degeneration, necrosis, trabecular fracture and collapse of the femoral head and hip joint dysfunction. At present, there are various methods to treat femoral head necrosis, mainly divided into non-surgical treatment and surgical treatment. Some progress of ANFH treatment in recent years is summarized as follows. 1.The goal of non-surgical treatment is to hope that the ischemic necrosis of the femoral head can repair itself and prevent the femoral head from collapsing. It is applicable to Ficat stage I and II cases. 1.1 Avoiding weight-bearing The principle is to use various measures such as bed rest or lower limb traction to reduce or avoid weight-bearing on the femoral head, so as to facilitate the femoral head to repair itself and rebuild blood flow. Such measures include partial non-weight-bearing and complete non-weight-bearing, i.e., the patient is required to be bed-ridden or even absolutely bed-ridden. Even without weight bearing, the femoral head is still subjected to considerable muscle tension, which can still cause the femoral head to collapse. Therefore, some people think that there is no difference between weight-bearing, non-weight-bearing and partial weight-bearing. Some foreign scholars have calculated the follow-up results of 182 hips in 21 hospitals, showing that the improvement rate of clinical signs after reducing weight-bearing is only 35% in stage I, 31% in stage II and 13% in stage III. Continuous traction on the lower extremity can reduce the pressure on the surface of the femoral head, and the effect is significantly better than bed rest alone. 1.2 Pharmacological treatment has provided new ideas for pharmacological prevention and early treatment of ANFH by applying lipid-lowering and vasodilating drugs for the treatment of hormonal and alcoholic femoral head necrosis in response to the etiological theory of fat metabolism disorder and intravascular coagulation. Vasodilators such as scopolamine, dihydroergotoxine, and vincristine can dilate blood vessels to increase blood flow and have an enhanced ameliorative effect on ischemia. Statin lipid-lowering drugs are HMG-CoA reductase inhibitors, which have been widely used in clinical practice and proved to be effective in hypercholesterolemia. pritchet observed 284 patients who needed hormone therapy and took statins at the same time as starting high doses of hormones. after a mean follow-up of 7.5 years, only 3 patients (1%) had osteonecrosis, suggesting that statins can prevent the occurrence of osteonecrosis. Russo et al. reported 45 cases of osteonecrosis of the femoral head, and after 6 months of follow-up with extracorporeal shock wave treatment, 39 of them had disappearance of pain and normalization of abnormal signal in the lesion area as shown by MRI. 1.4 Hyperbaric oxygen therapy (HBO) is a non-invasive physical therapy that promotes femoral head repair by increasing the partial pressure of oxygen and improving cellular hypoxia, and has been widely used in clinical practice. Numerous studies have shown that HBO combined with other non-surgical or surgical treatments is one of the best options for treating early ANFH. Reis et al. reported 12 patients with stage I ANFH treated with HBO 100 times (0.2-0.24 mPa, 90 min/time, 6 times a week), 81% of the patients recovered normal MRI examinations, while only 17% of the control group recovered. 1.5 Interventional therapy applies the Seldinger technique to directly and rapidly inject a variety of effective drugs into the blood vessels supplying blood flow to the femoral head (such as the spiral internal and external femoral arteries) under the surveillance of TV X-ray to dilate the blood vessels and subsequently dissolve the fat emboli, which increases the number of blood vessels in the subchondral area of the femoral head and thickens the diameter of the vessels, improves blood supply, reduces intraosseous pressure, and promotes the resorption of necrotic bone and the formation of new bone. Most of the reported interventional therapies are effective. Interventional therapy has the advantages of minimally invasive, reproducible, accurate localization, fast results and few complications. It is currently an effective method for the treatment of ANFH. 1.6 Stem cell therapy In recent years, the rise and development of stem cell engineering technology has provided the theoretical basis and rationale for stem cell therapy for ischemic necrosis of femoral head. Bone marrow mesenchymal stem cells (BMSCs) are stem cells with multi-directional differentiation potential derived from mesoderm, which mainly exist in connective tissue and organ mesenchyme throughout the body, with the most abundant in bone marrow tissue. Recent studies have shown that BMSCs have the ability to differentiate into osteoblasts, chondrocytes, neuronal cells, adipocytes, cardiomyocytes, etc. under certain induction conditions after isolation and culture in vitro. Wang et al. used trans-angiogenin-1 (Ang-1) BMSCs, which have the effects of promoting vascular endothelial cell growth and enhancing angiogenesis and metabolism, to observe their effects on bone repair and blood supply reconstruction in vivo. The results showed that the appropriate local supplementation of trans-Ang-1 BMSCs could promote early microcirculatory reconstruction, thus enhancing blood supply and creating a microenvironment for vascular regeneration, which contributed to the early repair of ischemic necrotic areas of the femoral head. 2. Surgical treatment 2.1 Core decompression (CD) is a surgical procedure designed based on the pathological basis of increased intramedullary pressure in ANFH. The main purpose is to reduce the high pressure in the femoral head neck, improve blood circulation, and create conditions for revascularization and reossification in the femoral head. The initial CD technique was to use a 0.8-1M diameter circular saw sleeve under X-ray fluoroscopic guidance to drill into the necrotic area via the femoral rotor, with widely varying clinical outcomes reported, with excellent rates ranging from 33% to 90%. In recent years, many physicians have improved this technique by using a fine needle with a diameter of 3.5L to drill multiple holes, and found that the clinical outcome improved, especially the collapse rate of the femoral head was significantly reduced. kim reported in the 2003 ARCO annual meeting a group of 3-year follow-up results, using a fine needle to drill multiple holes, the collapse rate was 14.3%, much lower than the 45% collapse rate of the traditional thick bad saw sleeve. sternberg reported 328 cases of 406 hip femoral head necrosis treated with marrow core decompression and bone grafting with a minimum follow-up of 2 years, 36% of patients eventually underwent total hip replacement and 60% had no progression of disease within 2 years. The authors also emphasized the importance of measuring the size of the necrotic area and pointed out that the size of the necrotic area is more important in determining the outcome of treatment than staging. At present, it is believed that this method is mainly suitable for cases with Ficate stage I and II and lesion extent less than 30%, and the effect is less satisfactory for stage III and IV with larger lesion extent. If for various reasons, a larger operation cannot be done, central decompression can be applied as a palliative therapy to relieve pain. 2.2 Trans-femoral neck junction opening bulb-shaped lesion removal and compression bone grafting This procedure is called lightbulb surgery and was first introduced by Rosenwasser in 1994, who reported that 15 cases of ANFH treated with this method had a joint preservation rate of 81% at 10 to 15 years follow-up. This technique has been widely used, especially in recent years, new techniques such as bone substitute material, bone forming protein (BMP) and autologous bone marrow stem cells have been introduced, which has improved the success rate of the procedure. This procedure is mainly suitable for cases with large lesions in Ficate II and III stages. 2.3 Bone grafting with a vascularized tip There are many methods of bone grafting with a vascularized tip, and the bone graft can come from the ilium, greater trochanter, fibula, etc. Bone grafting with vascular tips is a treatment method for the pathological changes of ANFH, which can effectively achieve intra-femoral head decompression, rapidly restore blood flow in the femoral head, support the weight-bearing area and induce osteogenesis.Leung treated ANFH with iliac flap grafting with deep vascular tips of the rotating ilium, and followed up 18 patients with 21 cases of ischemic necrosis of the femoral head for 4-12 years, and the results showed good results for early and middle stage lesions. The results showed good results for early and mid-stage lesions and good results for pain relief in advanced cases, but were not satisfactory for maintaining the integrity of the femoral head and still had a certain rate of collapse. Bone grafting with avascular tip is suitable for patients with severe Ficat II and III osteonecrosis or extensive osteonecrosis that cannot be easily healed by bone grafting without blood supply. The disadvantages are that the operation is complicated, long, traumatic, more complications in the donor area, more common vascular anatomical variants, the mechanical strength of the femoral head can be weakened by scraping away the dead bone, and weight-bearing restriction for 6 to 12 months after the operation. 2.4 Osteotomy for ANFH aims to remove the necrotic part of the femoral head from the main weight-bearing area, so that the weight-bearing stress is supported by the healthy part of the femoral head and its biomechanical environment is changed to prevent the collapse of the non-collapsed femoral head and to prevent further collapse of the existing mildly collapsed one, thus improving clinical symptoms and joint function. There are two major types of femoral osteotomies used to treat ANFH: intertrochanteric osteotomy and transtrochanteric rotational osteotomy. seheider compared the various osteotomies for the treatment of femoral head necrosis and found that rotational osteotomy had the highest complication rate (55%), while flexion osteotomy had a better outcome than rotational osteotomy. Within 5 years after surgery, 21 of the 29 rotational osteotomies had total hip replacement, whereas only 17 of the 63 flexion osteotomies had total hip replacement. Patients who underwent osteotomy should avoid weight-bearing for 0.5 to 1 year after surgery. Osteotomy is technically demanding and can further destroy the blood supply to the femoral head, making the repair of the necrotic area more difficult. If the osteotomy fails, it will increase the difficulty of hip arthroplasty in the future, so the procedure should be chosen carefully. 2.5 (1) Only the degenerated cartilage and subchondral dead bone of the femoral head are removed, which has a small impact on the acetabulum and is less traumatic. The normal bone of the femoral head neck is preserved and does not affect the long-term hip fusion or total hip replacement; (2) the femoral bone is preserved and the femoral stem is avoided, thus reducing the total amount of foreign body implants and the chance of infection; (3) the limited surface replacement is free of polyethylene wear particles and does not cause aseptic osteolysis. Hungerford et al. used femoral head surface replacement for Ficate stage III and IV ischemic necrosis of the femoral head, and after a mean follow-up of 10.5 years, the outcome was excellent in 62% of cases (Harris score). The authors concluded that femoral head surface replacement can be used as an intermediate treatment for ischemic necrosis of the femoral head in young stage III and IV Ficat, without significant acetabular lesions and without any good treatment other than artificial total hip replacement, and can delay the age of total hip replacement. 2.6 Artificial joint replacement For patients with advanced Ficate stage III or IV, total hip replacement is the best choice to relieve patients’ pain and restore the function of the joint to the maximum extent. There are two types of total hip prostheses, cemented and uncemented, both of which have advantages and disadvantages with similar long-term outcomes. xenakis followed up 28 patients with 36 hips who received uncemented total artificial hip replacement for femoral head necrosis with an average follow-up of 11.2 years and a prosthetic survival rate of 93.4%, with significant improvement in mean pain score, walking ability, and joint mobility. The authors concluded that despite imaging changes in some patients during the follow-up period, 93.4% of the prostheses survived for more than 11 years, indicating that non-cemented total hip replacement is the best treatment option for patients with advanced femoral head necrosis.Fyda reported 36 cases of cemented total hip replacement for 48 hips with femoral head necrosis with at least 10 years of postoperative follow-up and 8 revisions during the follow-up period ( 6 cases of aseptic loosening, 1 case of infection, and 1 case of recurrent joint dislocation), with a 10-year revision rate of 22.9%. After comparing and analyzing with related literature, the authors concluded that there is a high rate of prosthesis loosening after cemented total hip arthroplasty for femoral head necrosis, and it is mostly on the femoral side. However, with the application of modern bone cement technology, the loosening rate of the prosthesis has been significantly reduced, especially the cemented femoral stem prosthesis has achieved satisfactory results, making the bone cement prosthesis popular again. In summary, the treatment of ANFH has been reported in many domestic and international literature, and the basic principles are to increase the local blood supply to necrotic bone tissue, induce bone reconstruction, repair necrotic bone tissue, etc. No single method is suitable for the treatment of ischemic necrosis of the femoral head in all cases. The current consensus is to choose different treatment methods according to different necrosis types, different ages, different occupational requirements and different economic conditions. It is important that the surgical treatment of ANFH should be diagnosed as early as possible and effective treatment should be selected to delay or avoid premature arthroplasty before femoral head collapse occurs.