Most displaced fractures of the lower arm can return to normal, and some patients will have sequelae after recovery, mostly related to the severity and treatment. Commonly, there are bone nonunion and deformity healing, nerve injury, dysfunction and so on. 1. Bone nonunion and deformity healing: It is mostly related to the fact that the fracture is not standardized, the fixation is not ideal, the plaster is loose and not replaced in time, etc., which can cause deformity healing of the fracture site. 2. Neurovascular injury: If the fracture is accompanied by neurovascular injury, after treatment, some patients will still have sensory dysfunction of the affected hand and decreased hand muscle strength. It can be observed for a period of time, if there is no improvement, it can be explored surgically. 3. Functional disorders: If the displaced fracture of the lower arm is poorly aligned, poorly repositioned or poorly fixed, it will affect the extension and rotation dysfunction of the joints and affect the limb activities. There may be other sequelae after the recovery of displaced small arm fracture, such as ulnar-radial joint separation, etc. It is recommended to standardize the treatment in time after the fracture, rehabilitation exercises, regular review to avoid sequelae.