Idiopathic femoral head necrosis

Idiopathic femoral head necrosis, also known as ischemic femoral head necrosis, is a common disease. The etiology of femoral head necrosis is diverse, but its common pathological mechanism is bone ischemia. Therefore, regarding the pathogenesis, blood supply Obstruction theory is the most easily accepted. According to this theory, due to various internal and external pathogenic factors, the nutritional blood flow of the bone tissue is reduced, the intravascular bone network is compressed or the outflow veins are blocked, causing local blood supply disturbances, and severe cases can cause ischemic necrosis of the bone tissue. . At the beginning of the disease, only a single major blood vessel is damaged. With the development of the disease, such as the residual circulating blood volume is not enough to maintain the normal blood supply of the bone cells in the damaged area, the bone marrow tissue will be damaged first, followed by osteonecrosis. Pathological examination showed emptiness in the bone cavity caused by lack of cellular components. Smaller lesions can heal spontaneously, which is difficult to find clinically. Repeated physiological repair activities cause sclerosis of the bone tissue in the diseased area. In patients with large lesions, only the necrotic bone tissue around the lesion is replaced by new bone tissue, while the necrotic cancellous bone in other parts is covered by the new bone tissue, which prevents it. The possibility of further growth of new bone tissue into alternative repair. With the further development of the disease, the subchondral bone plate and articular surface eventually collapsed. The joint space is narrow, and the typical osteoarthritis changes such as cystic changes and sclerosis of the bone tissue, and the joints are completely destroyed. Therefore, the key to treating idiopathic femoral head necrosis is early diagnosis and early treatment to promote local blood vessel regeneration and restore normal circulation to prevent articular surface collapse.