Ischemic necrosis of the femoral head is a disease with insidious onset. Patients suddenly develop symptoms, often months or even years after the actual disease, and once symptoms appear, it is a sign that the disease has progressed to a certain level. In other words, the course of the disease has been relatively long. In clinical practice, we can often meet patients with bilateral ischemic necrosis of the femoral head, one side is symptomatic or even very severe, while the other side has shown osteonecrosis on MRI, but has not yet developed symptoms. Often months or years pass before the symptoms appear. In other words, the onset of ischemic necrosis of the femoral head can be bilateral and symmetrical or asymmetrical, with one side being stage II or III, while the other side can be stage I or II or even stage III. The extent of necrosis in each stage (I-III) can also be inconsistent, and the necrotic area can be A (< 15%), B (15-30%), or C (> 30%) of the total area of the femoral head. Once ischemic necrosis of the femoral head occurs, the extent of osteonecrosis is relatively fixed and generally does not expand continuously. Instead, the degree of lesion will keep developing, that is, the degree of lesion will keep developing along the direction of stage I → stage II → stage III → stage IV. At this point, without interventional treatment, it is difficult for the lesion to remain stationary, and it is unlikely to be reversed, that is, it is unlikely to see the possibility of sclerotic bone formation in the area of femoral head necrosis. Therefore, interventional treatment of ischemic necrosis of the femoral head should be carried out as early as possible. Among the interventional treatments, all surgical attempts to preserve the femoral head necrosis from progressing are called joint preservation surgery or head-conserving surgery. The efficacy of early head preservation treatment depends to a large extent on the degree of progression of the osteonecrosis, that is, the stage and extent of the osteonecrosis. The earlier the osteonecrosis is detected and treated, the greater the chance of recovery. Therefore, we advocate that therapeutic measures should be taken as early as possible, even if no symptoms are present and the necrosis is well defined, and that treatment should be aggressive in order to maximize the recovery of osteonecrosis. At present, among various early interventional treatment methods, the efficacy of head-preserving surgery is significantly better than various conservative methods of taking medication.