Bones break when subjected to abnormal stresses. The process of repair begins as soon as the fracture occurs. Blood vessels in Haversian canals, periosteum, and marrow tend to rupture from fractures. Blood then flows into the fracture zone forming a hematoma that coagulates as blood vessels are sealed off. When periosteum is torn and pulled from the broken bone, it stimulates an osteogenic layer of periosteum to form a callus, which is a fracture repair tissue that forms a natural splint. Osteoblasts then respond, usually within two days, and the callus is mineralized into the primary bone callus, which takes six weeks to form. Later, this woven bone callus is converted to lamellar bone. If the orientation of the broken bone ends is
