In general, a cast is required until the fracture is stabilized by the formation of a bone scab, and the earlier the cast is fixed, the more stable the fracture will be and the easier it will heal, at least 6-8 weeks after the fracture. The purpose of cast fixation after fracture is to maintain the stability of the fracture end and to avoid the possibility of delayed or deformed healing due to continued activity and displacement of the fracture end. Therefore, prompt repositioning and fixation is required to promote fracture healing after a fracture, which cannot be further repositioned if it is prolonged. Fixation alone is only meant to further prevent displacement, and the point of fixation is still to avoid excessive movement that may cause displacement of the fracture. However, if the fracture is already formed by bone scabs and the broken end is already stable, it is not necessary and usually a cast is needed within 6-8 weeks.