Spinal Fractures

Question 1

Denis classification:

Answer 1

3 columns:
- ANT 2/3 of body *(+ant longitudinal ligament)
- POST 1/3 of body *(+post longitudinal ligament)
- From pedicles *(facet joints, articular processes, spinal processes, ligamentum flavum)

2 contiguous columns = unstable

Question 2

List the unstable C spine injuries:

Answer 2

Jumping Off Awnings Nearly Brings Frank Heavy Spinal Trauma

Jefferson’s
Odontoid
Atlantooccipital (sublux/disloc)
Neural arch C1 (unilat)
–> half Jeffersons
Burst
Facet dislocation (bilateral)
Hangman’s
Spinal subluxation
Teardrop

Question 3

Answer 3

Jefferson’s #

Burst of C1–>ant AND post arches
Axial load

Stability depends on transverse ligament
–> ? >6mm between peg and lat masses on peg view XR?

If intact, conservative Mx.

Risk to vertebral artery

Question 4

Describe the odontoid (peg/dens) fractures of C2:

Answer 4

Hyperextension, typically. But any AP force

Type 1:
- Tip avulsion
- Stable

Type 2:
Most common- 55%
- Through base
- Unstable
- Non-union risk
<12 yo, growth plate here!

Type 3:
- Into vertebral body too
- Unstable

Question 5

Answer 5

Hangman #

Hyperextension
–> Hanging
–> Struck on dashboard

Bilateral pedicles # and C2/C3 disruption

Question 6

Answer 6

Extension tear drop

These are avulsions
–> Anterior longitudinal ligament

Unstable (in extension)

Question 7

Answer 7

Flexion tear drop

REALLY BAD. Worst Cspine fracture.

These are crushes
–> Force transmits through whole depth
—> All ligaments interrupted
–> Anterior cord syndrome
–> Disc injury
…..

Do not confuse with extension teardrop on XR…..
- Look for other stuff: vertabral crush, translation*

Question 8

Answer 8

Clay-shovellers #

Spinous process avulsions by supraspinous ligament

Flexion

Stable, even if multiple

Question 9

Answer 9

Facet dislocation

Flexion (+rotation will cause unilateral)

In absence of fracture, the only way one vertebrae can move ANTERIOR on another, is facet joint disruption

Varying degrees: subluxed –> dislocated.
>25%- suggests bilateral

Unilateral = stable
Bilateral = unstable

Question 10

What cervical spine injuries are of concern in hyperflexion?

Answer 10

Flexion teardrop
Facet dislocation

Odontoid
Atlantooccipital dislocation**

Wedge
Clay Shoveller

Question 11

What cervical spine injuries are of concern in hyperextension?

Answer 11

**Hangman
Extension teardrop
Posterior neural arch C1

Odontoid
AO dislocation**

Question 12

APPROACH to the cervical xray:

Answer 12

3 views:
- PA
- Lateral
- Peg

4 ‘lines’
- Anterior
- Posterior
- Spinolaminal
- Spinous

Vertebral bodies:
- #
- Height loss (>25% unstable)
- Anterolistheses (# or facet)
- Retrolisthesis (crush, flexion tear, Hangman)
- Teardrop (DDx FLEX from ext)

Facet joints
- Crowded/ rotated towards = facet sublux/disloc (>25% likly bilat- unstable)

Spinous processes
- Clay-shoveller

Prevertebral swelling
Normal =
- Kids: <2/3 corresponding vertebra
- Adults: <7mm at C2, <2cm at C6

Peg view
- #
- Asymmetry, or widening (>6mm) between peg and lat mass

Question 13

What is the normal thickeness of prevertebral soft tissues?

Answer 13

<7mm at C2
<20mm at C6

Kids: <1/3 corresponding vertebra to C4, <one whole width, C4 onwards

Question 14

Answer 14

Crush fracture

Stable <50%

Axial load, flexion
OR
Insufficiency
–> Vit D, Ca, PTH, BMD etc.

Question 15

Answer 15

Burst #

Axial load/ flexion

Often unstable, can be stable

Question 16

Answer 16

Chance #
AKA Seatbelt Injury

Distraction

Thoracolumbar junction

Splitting of spinous process, extending into vetebral body**

ALWAYS GO LOOKING FOR VISCERAL INJURY

Question 17

Causes of atlanoccipital instability:

Answer 17

incl. odontoid

Down’s, Marfan’s, osteogenesis imperfecta
Rheumatoid, ank spond, SLE
Retropharyngeal abscess, URTI