Fracture healing can usually be divided into three periods, starting with the period of hematoma inflammation and mechanization, which usually occurs within two weeks after the fracture. The hematoma is gradually replaced by granulation tissue at the fracture end. At two weeks, a fibrous crust may appear at the fracture end, and from four weeks onwards, the fibrous crust is gradually replaced by a bony crust, at which point the fracture enters the primary crust formation phase, when the fracture acquires initial stability. From eight to twelve weeks after the fracture, the bony crust is gradually replaced by the Hafers bone plate, at which time the strength of the fracture can be increased, known as the bone plate shaping period, and clinical healing is usually achieved three months after the fracture.