If you break a bone, you go to the doctor and you get a cast. We tend to think of bones as these rigid support systems, but they’re actually made of living tissue. Bones are constantly breaking down and remodeling themselves to adapt to your lifestyle. If you go from playing video games on your couch to marathon running, your bones are going to change to compensate. If you just started marathon running and break a bone, you’re not out of luck. It produces tons of new cells at the site of the break to rebuild the bone over time.
If you have cancer, a genetic defect, or if something really bad happens – like, a break is so bad that than the body can’t heal it on its own, scientists finally have a way to repair bones that befall these situations too.