The shortening of the arm after a crack fracture of the elbow joint may be related to elbow dislocation and adolescent epiphyseal injury. If the elbow joint fracture occurs, the arm is obviously shorter than the opposite side, which may be accompanied by posterior dislocation of the elbow joint, which can be clearly diagnosed by radiography or CT examination, and conservative or surgical treatment can be chosen according to the results of the examination. If the elbow joint fracture in adolescents after a longer period of time, such as half a year or a year after the arm becomes shorter, it may be related to the epiphyseal injury at the time of fracture. The epiphysis is the point of growth and development of the bone. If the bone is damaged during the fracture, the epiphysis grows too slowly or stops growing, causing the arm to be shorter than the opposite side. If there are symptoms of a shortened arm after an elbow fracture, it is recommended that the patient go to the hospital for a complete examination and receive regular treatment.