Femoral head necrosis is a gradually progressive disease that gets progressively worse over time, eventually reaching advanced stages of femoral head necrosis, but there is no strict intermediate maintenance of how long the disease will progress to advanced stages. This is because the development of osteonecrosis of the femoral head is related to many factors, such as the weight of the individual, the weight-bearing situation, the intermediate treatment, and even the perennial use of alcohol and large amounts of hormones and other dietary and medication aspects. It is important to carry out active treatment and not to allow the affected limb to bear weight, which may maintain no development for 3-5 years. In some patients, the head of femoral necrosis is not actively treated in the early stage, the weight is still large, and other factors are not controlled, it may develop to the advanced stage of necrosis in 0.5-1 year, which needs to be determined by comprehensive analysis, and there is no strict time limit.