A blurred fracture line usually refers to a fracture where a bone scab has formed but has not fully healed. Fracture healing process can be generally divided into three stages: hematoma mechanization period, scab formation period, scab shaping period. 1. hematoma mechanization period: 2~3 weeks after the fracture, pain and swelling caused by hematoma, symptoms are relieved after hematoma absorption. x-ray shows that the cortical bone is interrupted or discontinuous. 2. Scab formation period: 5~8 weeks after the fracture, the pain disappears, and moderate rehabilitation exercises can be carried out. With the gradual growth of the bone scab, the X-ray shows a blurred fracture line and high density shadow. 3. Scab shaping period: 8~12 weeks after the fracture, the patient can do weight-bearing exercise. x-ray shows that the fracture line disappears, and bone trabeculae appear. If local pain, swelling and other symptoms, it is recommended to consult a doctor in time to avoid delay.