OsteonecrosisoftheFemoralHead (ONFH) is one of the unsolved difficult diseases in the field of orthopedics. Without timely and effective treatment, most patients’ disease will progress and eventually lead to severe osteoarthritis of the hip joint, making the patient incapable of working or even living on his own. As a mature and classical orthopedic treatment technology, total artificial hip replacement has achieved great success in the treatment of hip diseases, but for young and middle-aged ONFH patients, the application of artificial joint replacement has a high complication rate and the long-term effect is not ideal, and many patients have to undergo one or even several joint revision surgeries in their lifetime. The current joint revision surgery from the difficulty of surgery, intraoperative trauma to long-term results are still many problems. Therefore, the main goal of ONFH treatment in young adults should be to improve symptoms and function, preserve the femoral head as much as possible, delay joint replacement and eventually avoid artificial joint replacement efforts. In recent years, the prevalence of ischemic necrosis of the femoral head has increased significantly due to the popularity of high-speed transportation (trauma), irregular application of drugs (hormones), and changes in lifestyle and dietary habits (alcohol consumption), and the age of onset tends to be younger. However, for the treatment of this disease, there are many misunderstandings due to the lack of physicians’ own diagnosis and treatment level: on the one hand, many medical institutions and individual clinics cater to the patients’ fear of surgery and use Chinese herbal medicine for conservative treatment, resulting in many patients losing the best time to preserve the femoral head for surgery; on the other hand, many doctors carry out On the other hand, many doctors for patients with ischemic necrosis of the femoral head, artificial joint replacement, and did not fully consider the age and stage of the lesion, even for the age of only 17 ~ 18 years old ONFH patients also artificial joint replacement, so that the late complications are difficult to deal with. So improve the level of diagnosis and treatment of ONFH, strict control of the indications for treatment is one of the important issues we should emphasize. First, ONFH staging and treatment ONFH staging methods are many, widely accepted system in order of appearance FicatArlet system, Florida system, Pennsylvanis system, the Japanese Osteonecrosis Research Society system, the International Society for Research in Osteocirculation classification (ARCO) system and Pittsburgh (Pittsburgh) system. However, regardless of the staging method, the aim is to predict the natural progression of the lesion and to guide clinical treatment. To date, the FicatArlet system is still the most widely used clinical classification standard. Ficat I-II medullary decompression is a less controversial procedure, which aims to restore normal blood flow in the femoral head by reducing the pressure in the medullary cavity and alleviating the resulting pain. It is a simple procedure with minimal surgical trauma and few postoperative complications, and is suitable for patients in the early stages before the femoral head collapses. In recent years, in order to improve the efficacy and/or reduce the surgical trauma, some scholars have improved the operation technique of core decompression or combined the application of autologous or allogeneic osteogenic material transplantation with core decompression to further improve the therapeutic effect, and when osteoarthritic changes are apparent in stage IV of Ficat, artificial joint replacement becomes a reasonable treatment option. Arthroplasty includes total hip replacement, bipolar femoral head replacement and hip surface replacement, and bipolar femoral head replacement and hip surface replacement are not suitable for patients in this stage because the acetabulum is often involved. There are many treatment methods for medium-term cases (transitional stage, stage III) in which the femoral head has collapsed to different degrees, such as bone flap grafting with or without vascular tips, various osteotomies and arthroplasty, etc. Since the post-operative good rates of various procedures are reported to be different, how to choose a reasonable treatment plan has become the focus of controversy. Hasegawa et al. found that iliac flap transfer with rotating deep iliac vascular tip had better efficacy than inter-rotor rotational osteotomy in treating ischemic femoral head necrosis after 5 and 10 years of follow-up, and the 5-year and 10-year preservation rates of the femoral head were 85%/71% and 67%/61%, respectively. The 5-year and 10-year preservation rates of the femoral head were 85/71% and 67/61%, respectively. There were no serious complications in the flap group, whereas several major complications such as deep infection, inter-rotor fracture, pseudarthrosis and progressive collapse were found in the osteotomy group. Although osteotomy can slow down the collapse of the femoral head to some extent, this procedure is technically difficult, requires prolonged recovery time for bone healing, often causes lower limb inequality or claudication, has a high complication rate, and distorts the proximal femur to the detriment of later total hip replacement, so it should be used with clinical caution. Mont et al. applied a modified “living door” technique and BMP-rich allografts to treat ischemic femoral head necrosis, and 19 cases (21 hips) were treated with BMP-rich allografts. After a mean follow-up of 48 months (36-55 months), 86% (18 hips) were clinically successful. The smaller lesions were successful in all cases, while 3 of the 14 hips with larger lesions failed. This procedure is simpler than the vascularized bone grafting procedure, but the bone implanted after lesion removal needs to undergo a longer crawling replacement process to obtain sufficient support strength, so this procedure is suitable for cases with small ischemic femoral head necrosis lesions. 3.Bone graft with vascular tip Bone tissue flap graft with nutritive vascularity can be the main surgical treatment for preserving the femoral head because it starts from correcting the pathophysiological changes of ONFH, reconstructing the blood circulation of the femoral head and providing the living bone that can replace the necrotic bone, which has shown its superiority by clinical application and may become the main surgical treatment for preserving the femoral head. There are two types of such methods currently in use: one is free fibula grafting with anastomosis; the other is bone (membrane) flap transfer with vascular tip. Bone flap or periosteal flap transfer with a vascularized tip is more popular because it does not require microscopic anastomosis. Since there are more bone (membrane) flaps available around the hip joint for transposition, the following surgical methods belong to the second category: ① iliac flap transfer with a deep vascular tip of the rotating iliac vessels; ② iliac flap transfer with an ascending branch of the lateral femoral vessels; ③ greater trochanteric flap transfer with an ascending branch of the lateral femoral vessels; ④ femoral periosteal flap transfer with a descending branch of the lateral femoral vessels; ⑤ greater trochanteric flap transfer with a transverse branch of the lateral femoral vessels; ⑥ greater trochanteric flap transfer with a rotating (6) femoral head repair and reconstructive surgery with rotational medial femoral vascular deep branch or subgluteal vascular anastomosis branch of the greater trochanteric flap; (7) femoral head repair and reconstructive surgery with rotational lateral vascular transverse branch of the greater trochanteric flap combined with iliac (membrane) flap transfer. All of the above treatment methods with vascularized bone flap transfer have different surgical approaches and sampling parts, depending on the site of the lesion and the surgeon’s own experience. In 1005 cases (1226 sides) with a mean follow-up of 5.1 years, the femoral head was reconstructed with the use of the iliac flap with the ascending branch of the lateral femoral vessel, the greater trochanteric flap with the transverse branch of the lateral femoral vessel, the periosteal flap with the descending branch of the lateral femoral vessel, the iliac flap with the deep iliac vessel tip, and the greater trochanteric flap with the ascending branch of the lateral femoral vessel. The postoperative Harris hip function score improved significantly (mean 56.2 preoperatively and 85.8 postoperatively), with a clinical success rate of 89.4% (1041 hips) and an imaging success rate of 75.4% (878 hips). According to the Ficat osteonecrosis staging criteria, the excellent rate was 95.3% for stage II, 87.9% for stage III, and 60.8% for stage IV. In advanced cases with extensive osteonecrosis or severe collapse of the femoral head, where the cartilage of the articular surface of the femoral head is significantly defective or destroyed, the repair of the femoral head is often not completed by applying conventional bone flap or single bone flap transfer, and the long-term success rate of reconstructing the femoral head by applying a greater trochanteric bone flap with a vascular tip or combining with other periprosthetic bone (membrane) flap transfers can reach more than 60% [21]. Since this treatment method will not adversely affect total hip replacement even if it fails, repairing and reconstructing the femoral head in advanced cases is still a treatment option with a fallback when considering the huge psychological pressure and economic burden that young and middle-aged patients will face after artificial joint replacement. With the continuous development and improvement of the artificial joint preparation process and surgical operation technology, the age indication for joint replacement has been reduced to 55 years old, and the success rate of treatment measures to preserve the femoral head is relatively low for elderly patients older than 55 years old with poor osteogenic ability and less vascular condition than young adults. Therefore, for ONFH cases in this age group, total hip replacement is usually performed. For ONFH cases between 20 and 40 years of age, due to the high activity of the patients, it should be the clinician’s active direction to choose a treatment plan that can preserve the femoral head and not adversely affect the possible total hip replacement. For cases between 40 and 55 years old, if they are in the early stages of ONFH, they should also do their best to preserve the femoral head. If they are in the middle and late stages of ONFH, they should choose treatment measures that preserve the femoral head by combining the patient’s subjective wishes and technical conditions, or they can choose a less invasive and retractable arthroplasty, such as a hip surface replacement. When a decision is made to perform total hip replacement, the possibility of secondary revision should be fully considered in the preoperative prosthesis selection. In conclusion, although there are many treatment methods for ONFH, the treatment plan for intermediate and advanced cases has not been unified. How to preserve the femoral head as much as possible and avoid joint replacement or delay joint replacement under the premise of relieving symptoms and improving function should be a key consideration when choosing treatment options. The authors believe that before many issues such as the etiology of ONFH have been thoroughly revealed, it should be a priority for hip surgeons to accurately determine the course of the disease and the extent of involvement, and to use relatively simple and effective methods to stop the further development of the disease.