Bones have a strong regenerative capacity, and after a fracture, most of them are able to heal, but healing requires several conditions: 1. there should be a proper alignment surface, the fracture should not be separated or misaligned too much, if the fracture is not in contact and there is a large defect in the middle, it is difficult to heal such a fracture; 2. there should be a stable environment, the fracture should be in contact and needs to be fixed stably so that the fracture ends are in constant contact A stable environment can be created by external fixation or internal fixation; 3. It takes time, usually 100 days for the fracture, and it takes about two to three months for the scab to grow, and some parts, such as the navicular fracture or the fracture at the junction of the middle and lower 1/3 of the tibia, may take longer to heal due to the ischemia of the fracture segment; 4. There should be blood vessels for blood supply and proper coverage of the surrounding soft tissues such as muscle fascia so that the fracture will heal faster.