Bone fracture healing process

Question 1

Bone fracture healing occurs in four overlapping stages. What is Stage 1:

Haematoma Formation

Answer 1

• Immediately after the fracture, blood vessels rupture, forming a haematoma.
• This provides a fibrin mesh that supports inflammatory cells, fibroblasts, and new capillaries.

Question 2

Bone fracture healing occurs in four overlapping stages. What is Stage 2:

Inflammation and Soft Callus Formation (Days 1–7):

Answer 2

• Inflammatory cells (e.g., macrophages) release cytokines.
• Fibroblasts and chondroblasts begin forming a soft callus of collagen and cartilage.

Question 3

Bone fracture healing occurs in four overlapping stages. What is Stage 3:

Hard Callus Formation (1–4 weeks):

Answer 3

• Osteoblasts replace the soft callus with woven bone.
• This hard callus stabilizes the fracture.

Question 4

Bone fracture healing occurs in four overlapping stages. What is Stage 4:

Bone Remodelling (months to years):

Answer 4

• Woven bone is gradually replaced with lamellar bone.
• Osteoclasts resorb excess bone, restoring the original shape and strength.