Bone infarction, in the early stage, may not have any clinical manifestations, only in the combination of other problems in the imaging examination, can be found in the local phenomenon of bone infarction, with the expansion of the scope of the infarction, the local pain, especially in the activity of the pain is more obvious, when resting occurs hidden pain, many patients due to the pain is obvious, in the continuation of strenuous exercise in the pathologic fracture only to find out. It is not accompanied by numbness and weakness of the limbs, and the common parts of bone infarction are femoral head, talus and navicular bone, and its main cause is local ischemia and hypoxia, and ischemic necrosis occurs when the bony structure loses nutrients, and its typical symptom is pain, and it is easy to complicate the dysfunction of the joints, for example, when there is aseptic necrosis of the femoral head, which will cause hip dysfunction and limp, and the more severe the necrosis is, the more typical the symptom is. The more severe the necrosis, the more typical the symptoms.