External fixation through a cast after a fracture is a common treatment method, and the time to remove the cast is considered to be 4-8 weeks. The specific time depends on the patient’s age, physical condition, the location of the fracture, the degree of fracture damage and the subsequent treatment care. The younger the relative age of the patient, the faster the fracture heals and the shorter the time to remove the cast, and the lesser the degree of fracture injury, the shorter the time to fix the cast. In the case of fractures occurring in children, treatment by manual repositioning and external fixation with a plaster rest can be considered in about 4 weeks to remove the cast and enhance functional exercise. In adult patients, internal fixation by surgical incision and external fixation with a cast will take 4-6 weeks before removal of the cast. If the patient is weak or suffering from underlying disease, it will take 6-8 weeks. Before removing the cast, it is necessary to examine by photograph and see obvious bone scab formation before considering.