The scab formation phase is the second stage of fracture healing and is known as the primary scab formation phase. This phase lasts until about twelve weeks after the fracture, during which the fracture gradually grows an abundant scab through osteogenesis, and the scab growth gradually heals the fractured segment. Ideally, the fracture will be clinically healed by the end of the crust formation period. During this period, with systematic and proper fracture treatment, the fracture will have significant and abundant bone scab growth and the fracture line will be significantly blurred or even disappear.