Bone Growth & Repair Flashcards
Briefly describe the structure of cortical vs cancellous bone?
Cortical has circular concentric lamellae called osteons around haversian’s canals
Cancellous has trabeculae and marrow
Which type of bone resists what type of force, and in which one is longitudinal growth done?
Cortical bone resists bending & torsion
Cancellous bone resists compression, this is where the physis is
What are the 4 stages of fracture repair?
Inflammation
Soft Callus
Hard Callus
Bone Remodelling
What occurs during the inflammatory phase?
1) Fibroblasts chuff on in
2) Angiogenesis (induced by macrophages)
3) Mesenchymal & Osteoprogenitor cells appear
What can we give to accelerate the inflammatory phase?
Platelet concentrates & Growth factors e.g. IGF, VEGF, PDGF & TGF-B
What happens during the soft callus stage?
Swelling subsides and cartilage/fibrous tissue unites the bony fragments
What can we do during the soft callus stage?
Gold Standard is an Autogenous Cancellous Bone Graft
This is both osteoconductive & inductive
What are the disadvantages should we use allograft bone in the soft callus stage?
Not osteoinductive
Risk of disease transmission
What occurs during the hard callus stage?
Cartilage is converted to Woven bone
What occurs in the remodelling stage?
Woven bone converted to lamellar bone & the medullary canal is reconstituted
What could cause Delayed Union of a fracture?
- High energy injury
- Instability
- Infection
- Steroids & immunosuppressants
- Smoking
- Warfarin
- NSAIDs
- Ciprofloxacin
What can you do when a bone fracture fails/delays healing?
A different fixation
Dynamisation
Bone Grafting
