Final answer:
The four major healing stages of a simple fracture are hematoma formation, fibrocartilaginous callus formation, bony callus formation, and remodeling. These stages are part of the body's natural process to repair a broken bone and restore its strength and integrity.
Step-by-step explanation:
The healing stages of a simple fracture follow a series of progressive steps that include:
- Hematoma formation: Blood vessels in the broken bone tear, leading to a clot or hematoma at the fracture site.
- Fibrocartilaginous callus formation: Capillaries grow into the hematoma while fibroblasts and osteoblasts begin to reform bone, creating a fibrocartilaginous callus.
- Bony callus formation: The fibrocartilaginous callus is converted into a bony callus of spongy bone, joining the broken bone ends together firmly.
- Remodeling: The bony callus is remodeled, with excess material removed, and compact bone added to resemble the bone's original structure.
Bone remodeling is a critical phase where the bone adapts to stresses and achieves strength comparable to the unbroken bone. This process can take several months to complete.