Ischemic necrosis of the femoral head can occur after a femoral neck fracture, whether it heals or not. In general, the necrosis rate can reach 20%-35% after femoral neck fracture, and necrosis can occur 2-3 months after the injury, and sometimes at the latest 4 years after the femoral head necrosis starts. For femoral neck fractures with no displacement or minimal displacement and tight insertion, the femoral head is relatively easy to heal and the rate of femoral head necrosis is relatively low due to less damage to the blood flow of the joint capsule. For subtrochanteric, trochanteric, and transcranial fractures with large displacement, the blood flow to the joint capsule and femoral head is severely damaged, which seriously affects the blood supply to the femoral head and has a high chance of ischemia and necrosis of the femoral head. If the maintenance is good, the pressure on the femoral head is low, the weight-bearing is reduced or not, and the strenuous exercise is avoided, the necrotic bone can be restored by vascular crawl replacement.