The growth process of the fracture is divided into three periods: First, the growth period of the primitive bone scab, formed about 4-6 weeks after the injury, the early stage is due to the hematoma at the end of the fracture appeared to be mechanized, and then there is a gradual proliferation of fibrous tissues, and finally slowly will form the primitive bone scab. Photographs can be seen at the fracture end of the fracture line blurring, part of the periosteal reaction. Secondly, during the growth period of bony scabs, usually about 4-8 weeks or 4-12 weeks after the injury, the scabs will obviously start to grow, and the fracture line can be seen to be very blurred, and the ends of the fracture will be obviously wrapped by the scabs. Third, the shaping period of the fracture, after the bone scab grows and stabilizes, the whole bone begins to shape, and finally the marrow cavity is connected, within 8-12 months.