If a joint dislocation occurs in the arm, it usually loses its function of movement, such as a dislocated elbow joint, which completely loses its function of flexion, extension and rotation. The characteristic manifestation of joint dislocation is elastic fixation, which means that the joint is fixed in an abnormal position and the function of the joint is lost, and the joint can be restored to its normal form and activity immediately after the resetting. The elbow joint should be fixed in a long-arm cast for three weeks after dislocation, which is conducive to the self-repair of the joint capsule and helps to avoid the occurrence of secondary dislocation.