Stages in the Healing of a Bone Fracture

First Stage

Hematoma formation. Torn blood vessels hemorrhage. A mass of clotted blood (hematoma) forms at the fracture site. Site becomes swollen, painful, and inflamed.

Fourth Stage

Bone remodeling. Excess material on the bone shaft exterior and in the medullary canal is removed. Compact bone is laid down to reconstruct shaft walls.

Third Stage

Bony callus formation. New bone trabeculae appear in the fibrocartilaginous callus. Fibrocartilaginous callus converts into a bony (hard) callus. Bone callus begins 3-4 weeks after injury,

Second Stage

Fibrocartilaginous callus forms. Granulation tissue (soft callus) forms a few days after the fracture. Capillaries grow into the tissue and phagocytic cells begin cleaning debris.