Assess alignment of the vertebrae as assessed by intact anterior spinal, posterior spinal, and spinolaminar lines (it should be possible to draw a smooth curved line touching all 7 cervical vertebrae at each of these locations without interruption).
Any soft-tissue swelling or disruption of normal lines, in the setting of trauma, suggests occult fracture or ligamentous injury.
In children under 8, ligamentous laxity of the upper C-spine can cause anterior displacement of C2 on C3, a normal variant called pseudosubluxation, which can be confused with an acute ligamentous injury. Up to 4 mm is normal in children <8yo.
—Check Swishuk’s line (the line drawn in the additional image between the anterior aspects of the spinous processes of C1 and C3—in pediatric pseudosubluxation, it will be within 2 mm of the anterior aspect of the C2 spinous process).
((((pic in case 7 additional images))))
In general: If both spinal columns are disrupted, the spine will move as 2 separate pieces, and there is high likelihood of that movement’s causing or worsening spinal cord injury. If only 1 column is disrupted, the other column resists further movement, and the likelihood of a spinal cord injury occurring is less and depends on the strength of the intact ligaments.
Unstable fractures: Jefferson Bit Off a Hangman’s Thumb: Jefferson burst fracture (C1), Bilateral facet dislocation, Odontoid fractures (C2), Hangman fracture (C2), Teardrop fracture
- Jefferson burst fracture: C1, axial load
- Odontoid fracture: high cervical pain radiating to the occiput
- Hangman fracture: C2, extreme hyperextension
The Hangman’s fracture, or spondylolysis of C2, occurs when the cervicocranium (skull, atlas, and axis) is thrown into extreme hyperextension as a result of abrupt deceleration. Bilateral fractures of the pedicles of the axis (C2) occur with or without dislocation. Although a hangman’s fracture is unstable, cord damage is often minimal because the AP diameter of the neural canal is greatest at the C2 level, and the bilateral pedicular fractures permit the spinal canal to decompress itself.
-Deficits on neurologic exam are more likely due to associated head injury or vertebral artery injury than to damage to the spinal cord directly
-concomitant C spine injuries (esp C1-C3) are common – look for them
-immobilize and consult spine specialist ASAP
- A flexion teardrop fracture results when severe flexion forces cause anterior displacement of a wedge-shaped fragment (resembling a teardrop) of the anteroinferior portion of the involved vertebral body. This fracture involves complete disruption of the ligamentous structures at the level of the injury. This leads to a highly unstable fracture.
Flexion injuries can cause unstable injuries such as atlantoaxial dislocation, bilateral facet dislocations, and teardrop fractures, as well as stable injuries, such as spinous process avulsions (e.g. clay shoveler’s fracture) or simple wedge fractures.
–Unilateral facet dislocations typically present with ipsilateral radiculopathy (the affected superior facet displaces into the neural foramen) and less than 50% anterior vertebral body displacement on lateral radiographs
—considered stable, but a significant percentage have associated cord injury
—Head often held deviated away from the side of the injury, unable to straighten
—may be palpable malalignment of spinous processes
–Bilateral facet dislocations often have frank neurologic deficit with greater than 50% vertebral body displacement on x rays
—unstable, majority have cord injury
—may have bony stepoff
-mgmt: immobilize in hard collar, but if spine locked, do not force it. Use sandbags, towel rolls, and tape instead
-call spine specialist (NSG) for closed reduction in ED prior to going to OR
-perform serial neurologic exams – neurologic deficit may worsen after closed reduction (from disc protrusion)
(((pic case 2))))
C2 (axis) fracture
-odontoid/dens fractures: Types I (tip), II (base), & III (body of C2)
—type III is unstable (involves C2 ring)
—consult ortho/NSG for mgmt for all of these
-The lateral masses of C1 should align perfectly with the lateral masses of C2 (blue lines). The medial aspect of the C1 lateral masses should be equidistant to the odontoid (letter A – in this case asymmetrically widened on the right). A distance of >7mm from a C1 lateral mass to the dens indicates transverse ligament rupture or C1 burst (Jefferson) fracture
(((pic case 3, diagnosis))))
Transverse spinous process fracture:
-there is a significant association between transverse process fractures and intraabdominal injury (given high energy mechanism), so these fractures should be regarded as possible markers for abdominal organ injuries, even though the spine is stable
-obtain CT abd/pelv with recon of T/L spine to look for intraabd injuries and other associated spine fractures
-if isolated, pain control and early mobilization
Lower spine fractures:
-it is important to distinguish a burst fracture from a simple compression fracture. In a simple compression fracture, the compression should only involve the anterior aspect of the vertebral body. In a burst, the posterior vertebral body is also compressed (and thus more likely to injure spinal cord).
–unstable if neuro deficit, >50% loss of vertebral body height, >20 degrees angulation at the thoracolumbar junction, canal compromise
—–dispo determined by ability to control pain. These pts can go home with TLSO brace or to rehab
–If there is loss of height of the posterior portion of the vertebral body or retropulsed bone, the diagnosis is burst fracture. Burst fractures are unstable!