Fracture Repair

Question 1

What are the four stages of fracture repair?

Answer 1

1) Haematoma formation
2) Fibrocartaliginous Callus formation
3) Bony Callus formation
4) Bone remodelling

Question 2

What happens in haematoma formation?

Answer 2

• Mass of clotted blood forms
• Bone cells at the fracture edge die
• Swelling and Inflammation
• Phagocytic cells remove dead tissue

Question 3

What happens in fibrocartaliginous callus formation?

Answer 3

Pro Callus of granulation tissue forms (fibroblasts and capillaries)

• Fibroblasts produce collagen fibres which span break. Others differentiate into chondroblasts, forming a sleeve of hyaline cartilage
• Osteoblasts invade fracture site, put down spongy trabeculae

Question 4

What happens in bony callus formation?

Answer 4

Firbrocartaliginous callus undergoes endochondral ossification and intramembranous ossificatioon

Question 5

What happens in bone remodelling?

Answer 5

Cancellous bone remoddled into cortical bone

Final shape same as before as same mechanical stressors

Question 6

Outline the entire process of fracture repair

Answer 6

1) Haematoma formation
- Mass of clotted blood forms
- Bone cells at the fracture edge die
- Swelling and Inflammation
- Phagocytic cells remove dead tissue
2) Fibrocartaliginous Callus formation
- Pro Callus of granulation tissue forms (fibroblasts and capillaries)
- Fibroblasts produce collagen fibres which span break. Others differentiate into chondroblasts, forming a sleeve of hyaline cartilage
- Osteoblasts invade fracture site, put down spongy trabeculae
3) Bony Callus formation
Firbrocartaliginous callus undergoes endochondral ossification and intramembranous ossificatioon
4) Bone remodelling
Cancellous bone remodeled into cortical bone
Final shape same as before as same mechanical stressors