Dead bone is caused by the cessation of the local metabolism of bone tissue. According to clinical medicine, with the change of environment and diet, the high incidence of dead bone disease has caused many people to have the phenomenon of dead bone, and in the face of this phenomenon, we need to go to the hospital in time for a comprehensive examination and treatment. When going to the hospital we need to do the following clinical examinations: a. Hemodynamic examination: 1. Intramedullary pressure determination: Under local or general anesthesia, a trocar needle is inserted directly into the medullary cavity of the intertrochanteric region of the femur to determine the intramedullary pressure in the lesion area. This method can detect abnormal changes in bone tissue earlier than conventional X-ray and nuclear bone scan examination, and is valuable for early diagnosis of dead bone. 2.Intra-medullary venous radiography: injecting contrast into the medullary cavity through the intra-medullary pressure measuring cannula, taking continuous X-ray films, observing the travel and emptying of the contrast in the medullary cavity, thus examining the vascular travel structure, which can provide a basis for the early diagnosis of dead bone. Histopathological examination: It can be used as a basis for confirming the diagnosis of dead bone. At present, it is rarely used alone, but is often used simultaneously with bone marrow decompression and bone grafting.