bone repair

Question 1

how bones break

Answer 1

repetitive force
single force
- load
- rate
- direction
- bone properties
- soft-tissue forces

Question 2

classifications of fractures

Answer 2

broken 
fractured
cracker/hairline
greenstick
buckle
avulsion

’ a soft itssue injury complicated by a broken bone’

Question 3

why classify?

Answer 3

Immortality
Information sharing (#)
Guide treatment
Guide prognosis
Research
	allow direct comparison

Question 4

anatomical, mechanism and descriptive classification of a fracture

Answer 4

Anatomical
	Proximal, Mid, Distal
	Intra/extra-articular
	Displaced/Undisplaced
	Open/closed
	Simple/Multifragmentary
Mechanism of injury
	Bending
	Shearing
	Compression
	Rotation
Comprehensive (descriptive)
	AO Muller

Question 5

displacement

Answer 5

S hortening- distance
T ranslation- %
A ngulation- degrees
R otation- degrees

Question 6

diagnosis and imaging

Answer 6

History - mechnism
Examination
	look
	Feel
	Move
Investigations
	Xray
	USS
	CT
	MRI

Question 7

XRays

Answer 7

2D representation of 3D structure
Rule of 2s
	2 views
		AP and Lateral
	2 Joints
		Above and Below
	2 Times
		Before and After

Question 8

ultrasound scan USS

Answer 8

Haematoma
Joint effusion
Tendon/Vascular injury

Question 9

CT

Answer 9

3D reconstruction
Joint surface
Comminution
Angiogram

Question 10

MRI

Answer 10

Associated injuries
	Ligament
	Cartilage
	Tendon
Occult fractures
Stress fracture
	The “dreaded black line”

Question 11

treatment principles

Answer 11

4 Rs
Resuscitate
Re-align
	Joint surface anatomical
Restrict
	Minimise further soft tissue damage
	Stable biological fixation
Rehabilitate
	Early weight bearing

Question 12

bone healing

Answer 12

How do I want this to heal?
	Primary
	Secondary (with callus)
Adjuncts
	Osteo conductive
	Osteo inductive
	Osteo genic

How should I fix this?
Absolute stability
Relative stability

Question 13

perren’s Strain theory

Answer 13

Perren’s Strain Theory
Amount of fracture movement relative to fracture gap
Different tissues tolerate different amounts of movement
Up to 100% - Granulation tissue
Up to 17% - Fibrous Connective tissue
2-10% - Fibrocartilage
< 2% - Bone

Within range for bone
fracture ends resorbed
strain reduced
leads to differentiation of callus

Above threshold bone forming
process impaired
leads to non-union

Question 14

principles of fixation

Answer 14

Manipulation
Restore
	Length
	Rotation
	Stability
	Articular surface

Question 15

treatment options

Answer 15

Non-surgical
	Analgesia
	Cast/splint/sling
Surgical
	Internal fixation
			K-wires
			Plate/screws
			Intramedullary nail
	External fixation

Question 16

external fixation

Answer 16

temporary procedure

correction of deformity

Question 17

LC-DCP

Answer 17

allows linear compression across fracture gap .
footprint on bone reduced ~ 50%
minimises periosteal compression

Question 18

compression plate biomechanics

Answer 18

Fracture reduced to plate
Relies on large friction forces
Rigid fixation / absolute stability
Direct healing with no callus
Prone to failure

Question 19

locking plate

Answer 19

Angular and Axial Stability
Flexible Internal Fixation
Fixed angle construct

Question 20

locking plate biomechanics

Answer 20

Surrogate cortex
Angular and Axial stability
No friction (Bone/Plate) required
Periosteal blood flow unrestricted
Flexible elastic fixation with fragments splinted (Biological fixation)
Indirect Healing similar to external splinting Ex-fix and IM devices
Load shared across each bone/screw interface
Cut-out of screws is now or nothing

Question 21

LCP

Answer 21

Combination Holes
Linear compression
Angular and axial stability

Question 22

IM nail

Answer 22

Minimise soft tissue injury

Only available for certain fractures

Question 23

what influences fracture healing

Answer 23

Injury factors
	Energy
	Environment
Patient factors
	Compliance
	Comorbidities
Surgical factors
	Suitability
	Stability

Question 24

fracture complications

Answer 24

Immediate
	Haemorrhage
Short term
	Compartment syndrome
	Neurological injury
	Fat embolus
Mid term
	Infection
	Delayed/non-union
Long term
	Loss of function
	Growth disturbance
	Arthritis

Question 25

fat embolism syndrome FES

Answer 25

serious manifestation of fat embolism occasionally causes multi system dysfunction, the lungs are always involved and brain is next

Question 26

special cases

Answer 26

Growth plate injury
Non-accidental injury
Fragility fractures

Question 27

hip fractures

Answer 27

Increasingly common
Rising socio-economic burden
	£3.6-£5.6 Billion per annum (2033)
8-10% die within 30 days
15-30% die within 1 year
75% die within 5 years
1/3 return to premorbid function
1/4 need full-time Nursing Home care
Up to 50% deaths avoidable