It can take from six to eight weeks for a bone to heal. Children can heal much more quickly than adults, according to Foot Health Facts.
When a bone is broken, blood begins to clot at the site of the fracture. This early clot lays the groundwork for reattaching and healing the fragments of bone. Cartilage, also known as soft cartilage, is replaced with hard callus. After these final steps, the bone goes through rigorous remolding, reforming and molding itself to its previous shape. Children go through this process much faster due to the fact that their bones are still maturing. Children have an abundance of bone-forming cells called osteoblasts. The number of these cells decrease from age 18 onward, according to HowStuffWorks.