Normal Views

C-Spine Evaluation

Fractures and Dislocations

• Dens

• C1 (Jefferson Burst Fx)

• C2 (Hangman's Fx)

• Burst

• Teardrop Flexion

• Compression

Facet Dislocation - Subluxation

• Anterior Subluxation

• Unilateral Locked Facets

• Bilateral Locked Facets

• Clay Shoveler's Fracture

• Atlanto-Axial Subluxation

• Os Ondontoidum

• Limbus Vertebrae

• Retropharyngeal Abscess

LINES OF LIFE:  There are 4 basic parallel lines to evaluate alignment that help determine c-spine injuries.

1. Anterior vertebral body line

2. Posterior vertebral bodyline

3. Spinal Laminar line

4. Posterior spinous process

Exception to #2 is in children, where there is often a physiological offset of 2 to 3mm of C2 on C3 or C3 on C4.

Note, in absence of disk disease, the distance between adjacent anterior and posterior vertebral body is uniform at all levels.  A gap at one level suggests ligamentous injury (e.g. anterior if gap is found anteriorly etc).  An abnormal fanning of the spinous processes would support posterior Ligamentous injury. 

It is important to evaluate the facets.  Since Lateral films are not usually positioned perfectly, there is often overlap of the left and right facets at each level. These should be fairly uniform in the absence of rotation. An abrupt change indicates an abnormal rotation.  

Further, the inferior articular surface of the facet should be in full contact with the more distal element’s Superior articular facet.  The absence of such full contact indicates a subluxed, perched, or locked facet. 

• Inspect C1-C2 Area

• Atlantodental distance

  • Adults:  <3mm

  • Children <5mm

• No change with flexion/extension

Some Indications of C-Spine Instability:

• Subluxation greater than 3.5mm. 

• Angular deformity of more than 11 deg.

• Compression fx more than 25% loss of vertebral body height

• Narrowing of the disk space.

• Widening of the interspinous distance

• Facet joint widening

Note:  On AP view, the distance between spinous processes should not be more than 1.5X the distance of subjacent processes.

The posterior aspect of the dens to posterior arch of C1 should be more than 17mm. If not = neurological damage.

PEARLS

• 20% of spinal fractures are multiple

• 5% of spinal fractures are at discontinuous levels

• Most spinal fractures occur in upper (C1-C2) or lower (C5-C7) regions

• Spinal cord injury occurs

  • At time of trauma 85%

  • At a late complication 15%

• Any signs/symptoms of cord injury require MRI, if available.

• Get CT in patients with unexplained Prevertebral  soft tissue swelling, if available.

Lines of Life