Fracture/dislocation

Question 1

Long bone anatomy

Answer 1

Diaphysis - tube
Metaphysis - Flare part
Epiphysis - Joint surfaces

Question 2

What is an osteon?

Answer 2

As the functional and structural unit of compact bone, the osteon is responsible for the strength of the bone, the influx of nutrients into the bone, and waste removal from the bone.

Central canal with blood vessels, concentric lamellae, connective tissue

Runs longitudianl in cortex

Question 3

Growth plate zones

Answer 3

(1) Reserve zone; (2) proliferative zone; (3) zone of maturation; (4) zone of degeneration; (5) zone of provisional calcification; (6) hypertrophic zone.

Question 4

What plane has a better remodelling potentional

Answer 4

Flexion/extension

not rotation

Question 5

Phases of indirect bone healing

Answer 5

Inflammation (bleeding, clotting, fibrin stabilizes hematoma and macrofages clean dead tissue)
Soft callus - granulation phase (neo-vascularization, fibroblasts colonize hematome and produce collagen fibers, granulations tissue diff to fibrous tissue, then fibrocartilage from condroblasts invading from periosteum)
Hard callus - consolidation phase (fibrocartilage orginazes to woven bone, starts in periphery to center, 6-8w
Remodelling 18-14m

Question 6

Direct bone healing

Answer 6

Gap <2mm
No intermediate fibrous tissue
Minimal movement

Question 7

How to achieve interfragmentarey compression

Answer 7

Compression plate with eccentric hole for compression
Lag screw that relies on a gliding hole

Question 8

5 Modes of plating

Answer 8

Compression
Neutralization/protection (of ex lag screws)
Bridging
Buttress
Tension band

Question 9

Locking screws is used for what

Answer 9

Creating a internal “external fixator” with a fixed angel device not looking for compression

Used for bridge plating for complex fractures - aiming for healing with callus