Chapter 5- Fracture Healing

Question 1

What signs indicate that a fracture has united

Answer 1

• no pain on direct pressure to fracture site or when attempting to twist and bend fracture fragments
• no motion of fracture ends possible
• callus formation on X-ray

Question 2

When should an early callus be Visible on X-ray (therefore cast should be removed for assessment)

Answer 2

• 3 weeks in upper limb

- 6 weeks lower limb

Question 3

Classify the external callus

Answer 3

• hypertrophic: this is good but may lead to hypertrophic non-union if there is too much motion at fracture site
• atrophic: no callus forming

Question 4

What is wolffs law

Answer 4

Osteoblasts and osteoclasts constantly remodel the trabeculae and the bone according to the stresses acting on the bone

Question 5

Stages of fracture healing

Answer 5

Haematoma
Inflammatory phase 
Callus formation 
Callus consolidation 
Union 
Remodeling

Question 6

Factors delaying bone healing

Answer 6

• tissue hypoxia
• soft tissue damage
• bone loss
• type of bone (cortical bone heals slower than metaphyseal bone)
• infection, malignancy, diabetes, smoking, pvd,advancing age

Question 7

Factors enhancing bone healing

Answer 7

• hormonal and drug: growth hormone, thyroid hormone, calcitonin, anabolic steroids
• bone contact
• hyperbaric oxygen for compromised soft tissue

Question 8

With rigid internal fixation why is it difficult to tell radiologically whether the fracture has healed

Answer 8

• inhibits callus response outside the bone

- internal callus formation