Most of the acute osteomyelitis can be completely cured after treatment and will not be transformed into chronic osteomyelitis, but chronic osteomyelitis can be caused when the treatment is not timely and complete, or when the treatment is inappropriate. The main reason is that the patient is not treated in time, the bacteria have infiltrated into the bone, causing serious damage to the bone, and then the antibiotics can not effectively reach the bone, the local antibiotic concentration is relatively low, can not control the infection, then it will be transformed into chronic osteomyelitis. In addition, if the patient is weak, has underlying diseases, and has a weak resistance to disease, the patient will also become chronic osteomyelitis. There are two situations whether to turn into chronic osteomyelitis: 1. time, if the acute osteomyelitis treatment is not cured for more than 6 weeks, the chance of turning into chronic osteomyelitis is higher; 2. the patient has pathological fracture, pathological fracture occurred during the period of acute osteomyelitis, fracture treatment time is longer 2-3 months later will also turn into chronic osteomyelitis.