ABOUT FRACTURES: A fractured bone is the same thing as a broken bone. They occur because a bone area is unable to support the energy placed on it. That energy can be acute, as from a car crash or a two-story fall, or chronic and low-energy repetitive activity. The latter is responsible for stress fractures, an overuse injury commonly seen in athletes. The increased demand places on the bone causes it to remodel and become stronger in areas of higher stress, but if the repetitive demands become too great, a stress fracture can result.
HOW BONES HEAL: The 206 bones in the body renew themselves continually through a process known as remodeling, which is also how fractures heal. Complex chemical signals prompt cells called osteoclasts to break down and remove (by absorbing it) old bone. Other cells called osteoblasts deposit new bone. When a bone breaks, inflammatory cells rush to destroy invaders and isolate injured tissue, causing pain, swelling and heat at the breakage site for a few days. Tiny new blood vessels (capillaries) begin growing into the site, and new cells grow, too. New connective tissue bonds fractured bone ends and the remodeling process begins.