If a bone fracture does not hurt upon inspection by a doctor, it is most likely healed, according to C. Noel Henley, M.D. This typically occurs after about six weeks, depending upon the type and location of the fracture. X-rays can also determine whether or not a bone has healed.
As the bone heals, calcified blood clots, or callus, form near the points of fracture, states Dr. Henley. This callus is new bone and is also a sign of healing. Callus forms after the initial healing process begins, where blood vessels within the fractured bone cause blood to pool and clot. The clotted blood contains proteins and cells that create a framework on which new bone can grow.