Femoral head necrosis has the following characteristics: First, it is mostly seen in young patients with early joint dysplasia, long-term application of hormones and long-term heavy alcohol consumption, or people who work more strenuously, especially those who work in a squatting position for a longer time. Second, the early features are the appearance of pain in the groin area, aggravated by exertion and cold, and later not relieved by rest, the pain is gradually obvious, and at the same time can radiate around the hip joint, and even on the upper thigh and the front, when there is pain when the leg is crossed or internal retraction. Third, continued development can appear obvious joint pain, affecting activities, pain is more obvious, go to the hospital for examination, which can be done by taking pictures and MRI. Early MRI examinations are clearer, and in later stages the films can be seen.