Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
An external callus is a temporary bony structure that forms around the outside of a bone fracture during the healing process. It stabilizes the fracture like a natural splint, allowing new bone tissue to grow and eventually replace it.
Related terms
Fracture: A break in bone tissue, which can range from a thin crack to a complete break.