Fracture Healing and Methods to Stimulate Fracture Healing
DNB Orthopaedics • May 2024 • Paper I • 10 Marks
Introduction
Fracture healing is a complex biological and mechanical process by which continuity, strength and function of a broken bone are restored.
Unlike most tissues, bone can heal by regeneration with restoration of near-normal structure rather than by permanent scar formation.
Fracture healing depends on two major pillars:
Biology + mechanical environment.
Types of Fracture Healing
Primary / Direct Bone Healing
Occurs under conditions of absolute stability with very small interfragmentary strain and little or no callus formation.
Secondary / Indirect Bone Healing
Occurs under relative stability and proceeds through hematoma, callus formation, mineralization and remodeling.
A. Stages of Secondary Fracture Healing
Fracture ↓ Hematoma + inflammation ↓ Granulation tissue ↓ Soft callus ↓ Hard callus / woven bone ↓ Remodeling ↓ Lamellar bone + restored architecture
1. Hematoma and Inflammatory Phase
Immediately after fracture, disruption of periosteal, endosteal and medullary blood vessels leads to formation of a fracture hematoma.
Events
- Local hemorrhage and clot formation
- Temporary local hypoxia
- Necrosis of bone immediately adjacent to the fracture ends
- Recruitment of neutrophils, macrophages and inflammatory cells
- Removal of necrotic tissue and…