Week 5 CORTEXT - Fractures

Question 1

Transverse fractures

Answer 1

Occur with pure bending force where the cortex on one side fails in compression and the cortex on the other side in tension.
Transverse fractures may not shorten (unless completely displaced) but may angulate or result in rotational malalignment

Question 2

Oblique fractures

Answer 2

Occur with a shearing force (e.g. fall from height, deceleration.)
Oblique fracture patterns have the benefit of being able to be fixed with an interfragmentary screw. Oblique fractures tend to shorten and may angulate

Question 3

Spiral fractures

Answer 3

Occur due to torsional forces. Again interfragmentary screws potentially can be used. Spiral fractures are most unstable to rotational forces but can also angulate

Question 4

Comminuted fractures

Answer 4

fractures with 3 or more fragments.
Comminution is generally a reflection of a higher energy injury (or poor bone quality) and there may be substantial soft tissue swelling and periosteal damage with reduced bloody supply to the fracture site which may impair healing. Comminuted fractures are very unstable and tend to be stabilised surgically.

Question 5

Segmental fractures

Answer 5

Occurs when bone is fractured in two separate places. These injuries are very unstable and require stabilisation with long rods or plates.

Question 6

Angulation

Answer 6

Describes direction in which the distal fragment points towards and the degree of this deformity.
Medial (varus), lateral (valgus), anterior, posterior.
Can be measured in degrees from the longitudinal axis of diaphysis of long bone

Question 7

Clinical signs of fracture

Answer 7

Localised bony tenderness (not diffuse mild tenderness)
Swelling
Deformity
Crepitus

Question 8

Assessment of injured limb includes:

Answer 8

open or closed injury
distal neurovascular status
compartment syndrome
status of the skin and soft tissue envelope

Question 9

Investigations

Answer 9

Radiographs
Tomogram - moving x-ray
CT
MRI
Technetium bone scan

Question 10

Initial management

Answer 10

clinical assessment, analgesia, splintage/immoblisation and investigation

Question 11

Definitive fracture management

Answer 11

Depends on bone:

Undisplaced, minimally displaced and minimally angulated fractures which are stable = non-operatively with splintage and immobilsation and then rehab.

Displaced or angulated fractures = closed reduction and cast application

Unstable injuries = surgical stabilisation

Question 12

Complications

Answer 12

Early local - compartment syndrome, vascular injury with ischaemia, nerve compression or injury and skin necorisis

Early systemic = hypovolaemia, fat emboli, shock, ARDS, acute renal failure, SIRS, multi-organ dysfunction syndrome and death

Late local = stiffness, loss of function, chronic regional pain syndrome, infection, post traumatic osteoarthritis, DVT

Late systemic = pulmonary embolism

Question 13

Compartment syndrome

Answer 13

Requires urgent fasciectomy

Question 14

Nerve injuries

Answer 14

Neurapraxia
Axonotmesis
Neurotmesis

Question 15

Neurapraxia

Answer 15

Temporary conduction defect from compression or stretch. Resolves over time with full recovery (can take 28 days)

Question 16

Axonotmesis

Answer 16

sustained compression or stretch or from higher degree of force.
Nerve remains in continuity and internal structure intact, but the long nerve cell axons distally to point of injury die in process known as Wallerian degeneration.
Recovery is long for long nerves, regenerates at 1mm per day
Recovery is also variable and full power or sensation may not be achieved.

Question 17

Neurotmesis

Answer 17

complete transection of a nerve and is rare in closed injuries but can occur in penetrating ones.
No recovery without surgery, never get full recovery
Recovery variable.

Question 18

Colles fracture

Answer 18

acute median nerve compression/carpal tunnel syndrome

Question 19

Anterior dislocation of shoulder

Answer 19

axillary nerve palsy

Question 20

humeral shaft fracture

Answer 20

radial nerve palsy (in spinal groove)

Question 21

supracondylar fracture of elbow

Answer 21

median nerve injury (usually anterior interosseous branch)

Question 22

Posterior dislocation of hip

Answer 22

sciatic nerve injury

Question 23

“bumper” injury to lateral knee

Answer 23

common peroneal nerve palsy

Question 24

symptoms and signs of fracture healing

Answer 24

resolution of pain and function
absence of point tenderness
no local oedema
resolution of movement at fracture site

Question 25

Symptoms and signs of fracture NOT healing

Answer 25

ongoing pain
ongoing oedema
movement at fracture site
bridging callus seen on x-ray (CT better option to differentiate)

Question 26

How long does a tibia take to heal?

Answer 26

typically 16 weeks and sometimes over a year to unite

Question 27

How long does a femoral shaft take to heal?

Answer 27

Typically 3-4 months to heal

Question 28

What is a delayed union fracture?

Answer 28

one that has not healed within the expected time.

Infection can result, and has to be suppressed with antibiotics.

Question 29

Hypertrophic non union

Answer 29

can occur due to instability and excessive motion at the fracture site

Question 30

Atrophic non-union

Answer 30

can occur due to rigid fixation with a fracture gap, lack of bloody supply, chronic disease or soft tissue interposition