I. Definition: A bone infectious disease caused by the invasion of septic bacteria into bone tissue. It often recurs for many years and does not heal, seriously affecting the patient’s health and ability to work, and sometimes causing lifelong disability due to complications. It has been regarded as a difficult disease by medical practitioners for many generations. Chinese medicine is known as epiphyseal gangrene. Popularly known as iron bone tumor. Second, classification: 1, according to its route of infection can be divided into: (1) hematogenous osteomyelitis: the host’s own immunity, the body of other parts of the infection of purulent bacteria into the blood circulation, the reproduction of invasive bone tissue, and rapid multiplication and spread, triggering the disease. (2) Traumatic osteomyelitis: caused by traumatic wound infection, such as knife wounds, open fractures, or by aseptic operation during closed fracture surgery, etc., can cause pathogenic bacteria to invade bone tissue directly from the wound, causing osteomyelitis. (3) Infectious osteomyelitis: osteomyelitis is caused by the direct spread of septic lesions from the adjacent to the bone tissue, such as osteomyelitis caused by purulent dactylitis. 2, according to the development of the disease: (1) acute septic osteomyelitis:; (2) chronic septic osteomyelitis: from acute osteomyelitis to chronic inflammation is a process of gradual development of change, can not be mechanically divided by time. After the acute inflammation subsides, if there are dead bones, sinus tracts, and dead cavities, it is chronic osteomyelitis.