Fracture Healing

Question 1

What are the 5 stages of fracture healing?

Answer 1

1. Haematoma - bleeding at fracture site + tissue damage, bone ends die back a few millimetres
2. Inflammatory reaction - inflam cells at haematoma
3. Callus - osteoblasts and osteoclasts, dead bone mopped up, woven bone appears in # callus
4. Consolidation - woven bone replaced by lamellar bone, # united
5. Remodelling - new bone remodelled to resemble old structure

HICCR

Question 2

How is # healing influenced by external splints?

Answer 2

• Prevent displacement
• Reduce pain
• Minimilise swelling - increase healing
• Maintain alignment - key for healing
• Reduce risk of non-union and malunion
• Allow control of gradual mobilisation

Question 3

3 steps of # management

Answer 3

1. Reduce
2. Hold
3. Rehabilitate

Question 4

Why is reduction important in #? aka restoring anatomical aligment

Answer 4

• Reduce bleeding
• Reduce traction on soft tissues = less swelling
• Reduce traction on traversing nerves = reduce risk of neuropraxia
• Reduce pressures on traversing blood vessels = restore any affected blood supply

Question 5

Why is hold important in # management? aka keeping# immbolised?

Answer 5

• Consider if traction is needed - eg if muscle pull is strong on bone apposing where it should stay
• Splints or plaster casts are examples
• Not circumferential in first 2 weeks to allow # to swell
• Allow healing

Question 6

How do intramedullary nails affect # healing?

Answer 6

• Allow stability and proper alignment
• Compression and distraction methods can bring bones back together and promote healing
• Minimise soft tissue destruction
• Early weight bearing
• Can promote callus formation
• Reduce implant related pain
• Minimise infection risk vs external

Question 7

How do screws and plates affect # healing?

Answer 7

• Alignment
• Load sharing so early weight bearing
• Minimise soft tissue destruction

Question 8

Factors contributing to non and malunion

Answer 8

• Inadequate immobilisation
• Poor blood supply - vascular injuries and smoking
• Infection
• Patient factors - advanced age, poor nutritional status, smoking, diabetes, OP
• Comminuted #
• Inadequate initial reduction

Question 9

What are bone morphogenetic proteins?

Answer 9

• Growth factors that play role in bone development and regeneration
• Stimulate the differentiayion of mesenchymal cells into osteoblasts
• Synthetic ones can be used to stimulate bone healing
• Can reduce need for bone grafts

Question 10

What is bone grafting?

Answer 10

• Bone is transplanted from another site (autograft) OR from a donor (allograft) OR synthetic source (alloplast)
• Can promote bone healing, fuse joints, fill bone defects

Question 11

The use of ultrasound in stimulating # healing

Answer 11

• Exogen can be used when there has been a failure of non union # healing (failure to heal within 9 months)
• Some evidence to suggest can be used in delayed healing (if no union within 3 months)

Question 12

Effects of smoking on # healing

Answer 12

• Reduced blood flow
• Reduced oxygenation
• Delayed inflammation and immune response - delay stages of # healing
• Impaired cellular proliferation
• Increased risk of infection
• Higher risk complications