A fracture without exposed bone ends is called a closed fracture, which means that after a fracture occurs, the bone at the location of the fracture is relatively sharp, and it is easy for the force of the injury to be too great to stab the broken end of the fracture out of the body, and then you can see the end of the bone after the fracture, and the broken end of the fracture does not puncture the skin, and most of the fracture belongs to a closed fracture. However, there are some exceptions, for example, if a pelvic fracture results in damage to the bladder, urethra, or rectum, this is not considered a closed fracture. There are also cases where no bone is visible at the fracture site, but there may be damage to the lower layers of the skin, and over time, if there is degeneration or necrosis of the skin, this would not be considered a closed fracture. If a closed fracture is determined, the bone at the fracture must not be exposed, but a fracture with no exposed bone ends is not necessarily a closed fracture. There is a difference in treatment between a non-closed fracture and a closed fracture, so it is important to choose the appropriate treatment for each case.