The human body has 206 bones that make up the skull, trunk, spine, scapula, pelvis and limb bones. The bones are connected to each other by joint capsules and ligaments, which make up the joints. Fractures or dislocations occur when bones and joints are struck by violence that exceeds the elastic tolerance of the bone. However, if the bone itself is already diseased, such as inflammation, tumor, osteoporosis, etc., fracture may occur with slight movement of the diseased limb, which is called pathological fracture. Some fractures are caused by the concentration of minimally invasive stress in a certain place and repeated action, such as long-distance marching or long-distance running, which can cause fractures in both toes and tibia, called fatigue fractures. After a fracture there are usually local symptoms such as bruising and swelling with pressure pain and limited movement of the limb. In addition to these general symptoms, the fracture itself may also have its own specific symptoms: local deformity, such as shortening, angulation or rotation of the injured limb; local frictional sound or frictional sensation of collision between the fractured ends: pseudo-articular activity, i.e., joint-like activity where there is no joint. However, some fractures such as cleft fractures and i-branch fractures in children do not have the above special symptoms and should be distinguished. When the fracture end punctures the skin or mucous membrane and is open to the outside world, it is called an open fracture, and bacteria and foreign bodies can easily enter the body through the wound and cause infection. A fracture with intact skin or mucosa is called a closed fracture. When the fracture has occurred for more than 3 weeks, it is called an old fracture and is not easily repositioned by manipulation due to the presence of scar tissue and bone scabs between the dislocated fracture ends. The principle of treatment for fractures and dislocations is to first reset the fracture to restore its original anatomical form and then use external or internal fixation to maintain the correct position after reset until the fracture heals. Experts suggest that when a fracture or joint dislocation is suspected, the injured limb can be temporarily fixed with splints, pieces of wood, bark, etc., and then quickly sent to a hospital for further examination and treatment.