Bone healing is a carefully orchestrated process within the body to both stabilize and heal bone as quickly as possible. The ultimate goal of bone healing is to return to previous anatomy and appearance. This whole process is done in three distinct steps-
Immediately following a fracture, the area forms a hematoma (or blood clot) to the area from bleeding bone and blood vessels. The vessels then constrict limiting further bleeding to the area. These extravascular blood cells then die and degenerate leaving a web or matrix of fibroblasts to support the healing process. Swelling during this stage is often utilized by the body to further immobilize the fractured area to facilitate healing.
Once the area is stabilized, the bone cells transform into chondroblasts (cartilage forming cells) that start replacing the matrix with hyaline cartilage. Similarly other bone cells are transformed into osteoblasts (woven bone forming cells) that replace the matrix and ultimately the hyaline cartilage with woven bone. This restores most of the bones original strength.
Additional cells transform into osteoclasts and the woven bone is resorbed and replaced with compact bone with similar appearance and strength to original bone in this area.