I. What is femoral head necrosis? Femoral head necrosis is also known as aseptic necrosis of the femoral head, or ischemic necrosis of the femoral head. Osteonecrosis is caused by damage to the bone trophoblastic vessels for a variety of reasons, further leading to ischemia, degeneration, and necrosis of the bone. Femoral head necrosis is a lesion caused by localized poor blood flow to the femoral head for a variety of reasons, leading to further ischemia, necrosis, trabecular fracture, and collapse of the femoral head. Further development can lead to hip dysfunction, which can seriously affect the quality of life and labor ability of patients, and can lead to lifelong disability if not treated in time. Second, what are the causes of femoral head necrosis? Traumatic: Fracture of the femoral head or femoral neck after hip trauma, hip fracture or dislocation, or injury to the vascular branch without fracture or dislocation can cause local ischemia of the femoral head, which can further develop into necrosis. Non-traumatic : 1, long-term or large application of glucocorticoids accounted for 43%; 2, alcohol poisoning; 3, decompression sickness, diving, flight personnel in the case of high pressure, increased dissolved nitrogen in the blood and tissues, environmental pressure is reduced, the excess nitrogen has been dissolved need to be gradually discharged through the lungs, if the pressure is reduced too quickly, nitrogen can not be discharged, that is, free out in the body, the formation of bubbles, resulting in gas embolism, gas embolism In the blood vessels, the blood flow is blocked and the local blood supply to the femoral head becomes poor, resulting in ischemic necrosis. 4, other : hypertension, diabetes, arteriosclerosis, obesity, gout, radiation therapy, burns, can also cause necrosis of the femoral head. Third, what is the main discomfort of femoral head necrosis? Femoral head necrosis is characterized by hip pain and claudication as the main clinical manifestations. The pain is mostly progressive. In the early stage, there can be no clinical symptoms, only found when taking CT films or x-ray films, but also can be the first to appear hip or knee pain, and in the hip and the involutional muscle pain leg root pain, appear earlier. Pain can be continuous or intermittent, such as bilateral lesions can appear alternating pain. The pain is often aggravated by prolonged standing and activity, and can be alleviated by taking painkillers and resting in bed. Patients may have limited hip joint activities, mainly abduction and internal rotation, so patients may show that they cannot cross their legs, have difficulty getting on and off the bicycle, but can still ride the bicycle, and in severe cases, the hip joint flexion and extension are also limited, showing that they cannot squat. Fourth, what clinical treatment methods are commonly used for femoral head necrosis? 1, non-surgical treatment (1) avoid weight-bearing: including partial weight-bearing and non-weight-bearing; (2) drug therapy; (3) other treatment methods: such as electrical stimulation therapy, bloodletting therapy, hyperbaric oxygen therapy, etc. 2, surgical treatment (1) central decompression; (2) osteotomy; (3) bone grafting; (4) bone graft with blood supply; (5) hip replacement: for advanced patients, total hip replacement is the best choice. V. Why necrosis of the femoral head should be treated early? Femoral head necrosis is a progressive disease, such as no special treatment, 70% to 80% of patients in the x-ray film and clinical progress of the disease performance. The natural course of femoral head necrosis includes two aspects, namely, progressive collapse of the femoral head and secondary osteoarthritis of the hip joint. If it progresses to severe osteoarthritis, only artificial total hip replacement can be performed. Since the disease mostly occurs in young adults, the aim of treatment is to preserve the femoral head as much as possible before collapse and delay the time of artificial joint replacement, in addition to improving clinical symptoms. On the contrary, if you are afraid of surgery and take various kinds of blood-activating and pain-relieving drugs, or take some special drugs orally, you will miss the time of surgery, and when the femoral head develops into the collapsed stage or osteoarthritis stage, it will be more difficult to treat. If you do not receive timely and regular treatment, you will miss the best time for treatment, plus weight bearing, such as walking, climbing, carrying things, etc., causing the femoral head to collapse, forming osteoarthritis, the final result is that the patient is disabled.