The sternum is the central bone of the human body, the trunk bone, and the only skeletal structure in the midline of the anterior chest of the body. The sternum may be in a cartilaginous state during the growth phase and throughout life. The adult sternum is composed of three bones: the top is the sternal hilt, which is shaped like a relatively irregular hexagon; the middle is the sternal body, which accounts for more than half of the length of the sternum, and the sternal hilt is formed by the arrangement of four pieces of cartilage in the growing adolescent, which will fuse into a whole hard bone structure only after the age of 25; the bottom is the sternal process, which is shaped like the tip of an iron sword. The lowermost part is the sternal process, which is shaped like the tip of an iron sword, hence the name. The entire sternum is also shaped like the handle of an iron sword, slightly inclined in the front of the body’s chest, protecting the organs in the chest cavity.