1- Principles of bone healing

Question 1

What are the 3 phases of bone healing

Answer 1

inflammatory, reparative, remodeling

Question 2

Lysis of osteocytes & cells of dead tissue in the inflammation stage stimulates what?

Answer 2

The attraction of inflammatory cells & macrophages = clears away necrotic material

Question 3

Name the the main steps of the inflammatory stage of bone healing

Answer 3

1. A blood clot is formed at the fracture site
2. Phagocytes attracted and clean site
   - occurs within a couple of hours of injury

Question 4

What is soft callus? & what phase does it occur in?

Answer 4

Fibrous/cartilage tissue (soft bone) which replaces the blood clot caused in the inflammatory phase
Is quite elastic & soft = starts to stabilise the fracture site
Restorative phase

Question 5

Describe the process of hard callus formation

Answer 5

As fracture is stabilised & blood supply is restored, newly formed cartilage is substituted by bone tissue by endochondral ossification

Question 6

When does hard callus formation begin?

Answer 6

2 weeks after fracture > 6-12th weeks later

Question 7

What type of bone healing Is it when we repair fractures surgically?

Answer 7

First intention - minimal bone callus formation
Direct formation of bone tissue in a fracture line

Question 8

Name 3 conditions first intention bone healing needs

Answer 8

Good blood supply
Immediate stabilisation
Perfect reduction of fracture edges
Absence of micromovements
Absence of infection

Question 9

What is second intention bone healing?

Answer 9

The natural type of healing
Takes longer

Question 10

what is healing by first intention healing

Answer 10

is characterised by the direct formation of bone tissue in a fracture line without the creation or production of bone callus.