Bone infarction refers to osteonecrosis of the diaphysis and epiphysis, often multiple and symmetrical, or occasionally single and well developed in the lower femur and upper tibia. Bone infarcts usually lack typical clinical manifestations and are seen in hospitals for localized joint pain or difficulty walking without typical signs and symptoms. Bone infarction commonly follows the use of large amounts of hormones, and the heavy use of immune preparations is also one of its causes, as well as alcoholism, fat metabolism disorders, pancreatitis, and trauma, but some other causes are not clear. Bone infarction can be examined by means of CT, and the diagnostic image is manifested by the local appearance of abnormal hypointense shadow, because the appearance of local infarction is mainly manifested by ischemia, and the treatment is mainly carried out by means of drugs. If the infarction and ischemia are prolonged, it will lead to local tissue necrosis, which will affect the motor function.