The principles of treatment for extremity fractures are reduction, fixation and functional exercise. The goal is to restore good movement and weight-bearing function of the limb. 1. Reset The purpose of reset is to restore the normal anatomy of the fracture site as much as possible, and the methods are closed manual reset and open surgical reset. However, under the premise of functional alignment, the limb can still recover better function through reasonable functional exercise during treatment and bone remodeling after fracture healing. Although incisional reduction is more traumatic, the reduction effect is really effective, and after giving strong internal fixation, the patient can perform functional exercises early, which helps the affected limb to obtain the maximum functional recovery. 2.Fixation Fixation is to provide a stable healing environment for the fracture site and to maintain the result of repositioning. The main methods of fixation are external fixation and internal fixation; external fixation is commonly used for small splint fixation, plaster fixation, and external fixation frame fixation. If there is no other special treatment, after external fixation, the patient can often go home to recuperate, but then must pay attention to observe the peripheral blood flow and sensory movement of the affected limb, if the fingers or toes continue to swell and pain, numbness, blue color, or peripheral joint movement disorders, then must quickly go to the hospital for appropriate examination, as well as early detection of possible osteofascial compartment syndrome and nerve injury, and make the appropriate treatment. Internal fixation commonly used are plates, screws, wires, intramedullary pins, power condyles, power hips, etc. For fractures with defects, it is often necessary to give autologous bone or allogeneic bone graft, which helps the fracture to heal. 3.Functional exercise Functional exercise is to avoid a series of complications such as joint adhesions and muscle contractures caused by long-term fixation, especially external fixation, so that the function of the limb can be well restored. Modern fracture therapy places great emphasis on functional exercise, which not only can avoid the above-mentioned side effects of fixation, but also can promote the swelling of the acute phase of the fracture and promote the healing of the fracture. In addition, fracture healing takes a long time, so whether patients and their families can correctly understand and apply functional exercises for limb fractures is very important for patients to get the best recovery of limb function.