13 Spinal Trauma and Fractures

10.1055/b-0039-166422

13 Spinal Trauma and Fractures

Ankur S. Narain, Fady Y. Hijji, Philip K. Louie, Daniel D. Bohl, and Kern Singh

13.1 General Principles

Background:
- Cervical injury occurs in 2 to 3% of blunt trauma cases.
- Thoracolumbar injury represents 75 to 90% of spinal trauma.
- Sacral fractures often present with pelvic injuries (30–45%).
Initial management:
- Primary survey and neurologic assessment:
  - ABCDE: Airway, Breathing, Circulation, Disability, Exposure.
- Secondary survey:
  - Evaluate for spinal shock: check bulbocavernosus reflex:
    - Intact if anal sphincter contraction is observed in response to squeezing the glans penis or pulling on a Foley catheter.
  - Evaluate for neurologic shock:
    - Loss of sympathetic tone leads to circulatory collapse.
    - Signs include hypotension, relative bradycardia:
      - Utilize vasopressors, fluid resuscitation as necessary.
  - Determine neurologic level of the injury:
    - Defined by lowest level with intact sensation and 3+/5 motor strength.
  - Assessment of degree of neurologic injury:
    - Magnitude of spinal cord involvement ( Table 13.1 ).
    - American Spinal Injury Association (ASIA) impairment scale ( Table 13.2 ).
- Standard imaging:
  - Orthogonal radiographs: anteroposterior (AP) and lateral of cervical, thoracic, and lumbar spine.
  - Computed tomography (CT) scan: sagittal and coronal reconstructions:
    - Improves visualization of occipital-cervical and cervicothoracic junctions, bony structures, and occult fractures.
  - Magnetic resonance imaging (MRI):
    - Required in cases of neurologic impairment.
    - Improves visualization of ligamentous structures.
    - Short tau inversion recovery (STIR) sequence heightens demonstration of edema.

**Table 13.1** Incomplete spinal cord injury manifestations
Syndrome	Deficits	Etiology
Anterior cord syndrome	Paraplegia (bilateral) Pain and temperature	Injury to the anterior spinal artery
	(bilateral) Urinary retention
Central cord syndrome	Motor weakness (bilateral – arms > legs)	Hyperextension injury (i.e., syringomyelia)
Posterior cord syndrome	Vibration and proprioception (bilateral)	Tabes dorsalis, epidural metastases
Brown-Séquard	Motor (ipsilateral) Vibration and proprioception (ipsilateral) Pain and temperature 2–3 levels below lesion (contralateral)	Trauma: knife or bullet wound

**Table 13.2** Summary of the American Spinal Injury Association (ASIA) impairment scale
ASIA grade	Type of injury	Definition
A	Complete	Complete loss of motor and sensory function
B	Incomplete	Motor function preserved below level of injury
C	Incomplete	Motor function preserved, but key muscles below the level of injury have a muscle grade < 3
D	Incomplete	Motor function preserved, but key muscles below the level of injury have a muscle grade > 3
E	Normal	No deficits

13.2 Cervical Trauma and Fractures

13.2.1 Occipital Condyle Fracture

(Fig. 13.1)

Background and etiology:
- Caused by high-energy trauma:
  - Axial compression or rotation.
  - Lateral bending.
  - Direct blow.
- Anderson and Montesano classification system:
  - Type I (15%): collapse due to axial compression; stable.
  - Type II (50%): basilar skull fracture; stable.
  - Type III (35%): avulsion injury near alar ligament attachment; potentially unstable.
Presentation:
- High cervical neck pain and stiffness.
- Motor paresis.
- Possible cranial nerve deficit.
Imaging:
- Plain radiographs: avoid traction:
  - Open-mouth odontoid view.
  - AP and lateral views often inadequate due to superimposition of nearby structures (maxilla, occiput, mastoid processes).
- CT scan: cranial CT including views of the craniocervical junction.
Management:
- Based on presence of ligamentous injury and craniocervical stability:
  - Stable: cervical orthosis.
  - Unstable: occipitocervical fusion; rigid posterior segmental stabilization with instrumentation from the occiput to C2/C3.

13.2.2 Atlanto-Occipital Dissociation

(Figs. 13.2, 13.3)

Background and etiology:
- Traumatic: due to high-energy, rotational or flexion–extension force causing ligamentous injury.
- Acquired: due to bony dysplasia or ligament and soft-tissue laxity (i.e., Down’s syndrome).
- Results in separation of the spinal column from the occiput.
Presentation:
- Neurologic deficits and possible quadriparesis.
- Cardiorespiratory derangement.
- Commonly fatal due to brainstem destruction.
Imaging:
- Plain radiography and CT scan: lateral/sagittal views:
  - Harris’ lines: suggestive of injury if:
    - Basion-dens interval (BDI) is greater than 10 mm.
    - Basion-axial interval (BAI) is greater than 12 mm.
    - Atlantodental interval (ADI) is greater than 3 mm.
    - Powers’ ratio: C–D/A–B.
      - A–B: distance from anterior arch to opisthion.
      - C–D: distance from basion to posterior arch.
      - Powers’ ratio greater than 1: indicative of anterior subluxation/dislocation.
      - Powers’ ratio less than 1: indicative of posterior dislocation, odontoid fracture.
  - Wackenheim’s line:
    - Line from the posterior surface of clivus to the upper cervical canal:
      - Line behind odontoid: posterior dissociation.
      - Line in front of odontoid: anterior dissociation.
- MRI:
  - Used to evaluate for spinal cord and ligamentous injury.
Management:
- Stable: fluoroscopy-guided reduction and halo vest; avoid traction.
- Unstable: operative posterior fusion from the occiput to at least C2.

**Fig. 13.2** Lateral view. Depiction of measurements comprising the Powers ratio. A, anterior arch of C1; B, basion; C, posterior arch of C1; O, opisthion. (Reproduced with permission from Khanna AJ, ed. MRI Essentials for the Spine Specialist. New York, NY: Thieme; 2014.)

**Fig. 13.3** Sagittal section. CT scan showing a case of atlanto-occipital dissociation with a widened basion-dens interval.

13.2.3 Atlas (C1) and Jefferson’s Fractures

(Fig. 13.4)

Background and etiology:
- Due to hyperextension and axial loading causing fracture of the anterior or posterior arch of C1:
  - Combination fracture of the anterior and posterior arches is known as a Jefferson’s fracture.
Presentation:
- Typically presents without neurologic deficits.
- In severe fractures, possible medullary dysfunction can occur.
Imaging:
- Plain radiographs:
  - Open-mouth odontoid view:
    - Spence rule: greater than 7 mm composite overhang between lateral masses of C1 and C2 (39% sensitivity).
  - Lateral:
    - Atlantodental interval:
      - Less than 3 mm: normal.
      - 3–5 mm: injury to transverse ligament with intact alar and apical ligaments.
      - Greater than 5 mm: injury to transverse, alar ligament, and tectorial membrane.
- CT scan: coronal and sagittal reconstructions:
  - Further delineate fracture pattern.
  - Aids in identifying associated injuries in the cervical spine.
  - CT angiography (CTA) to rule out vertebral artery injury.
- MRI:
  - Used to assess transverse of atlantal ligament (TAL).
  - Significant for possible surgical planning.
Management: based on the patency of the TAL:
- TAL intact: rigid cervical orthosis.
- TAL incompetent: C1–C2 fusion.

13.2.4 Traumatic Spondylolisthesis of C2 (Hangman’s Fracture;)

(Fig. 13.5)

Background and etiology:
- Associated with high-velocity trauma.
- Mechanistic pattern: hyperextension → compression → rebound flexion:
  - Results in bilateral fracture of the lamina and pedicles.
- Second most common axis fracture (38%).
Presentation:
- Asymptomatic if nonangulated and nondisplaced.
- Cerebellar findings (nausea, vomiting, ataxia, asymmetric neurological examination) if vertebral artery injury is present.
Imaging:
- Plain radiography:
  - Flexion and extension views to evaluate for subluxation.
- Levine and Edwards radiographic classification:
  - Type I: less than 3-mm displacement.
  - Type II: greater than 3-mm displacement and greater than 11-degree angulation.
  - Type IIa: less than 3-mm displacement and greater than 11-degree angulation.
  - Type III: associated facet dislocation.
- CT scan with coronal and sagittal reconstructions:
  - Bilateral lamina and pedicle fracture.
  - Anterolisthesis of C2 on C3.
  - CTA to rule out vertebral artery injury.
Management:
- Dependent on classification:
  - Type I: halo brace for 12 weeks.
  - Type II: reduction via cervical traction and halo brace for 10 to 12 weeks.
  - Type IIa: reduction in extension followed by halo brace; avoid traction.
  - Type III: anterior C2–C3 or posterior C1–C3 fusion.

13.2.5 C2 Dens Fracture

(Fig. 13.6)

Background and etiology:
- Caused by hyperflexion or hyperextension:
  - Elderly: falls.
  - Young patients: blunt trauma.
Presentation:
- Neck pain and tenderness to palpation.
- Neurologic deficits usually not present.
Imaging:
- Radiographs: AP, lateral, and open-mouth odontoid views:
  - Anderson and D’Alonzo imaging classification:
    - Type I: avulsion fracture at the tip.
    - Type II: at the odontoid base.
    - Type III: within the C2 body.
  - Rule out os odontoideum:
    - Appears similar to a type II fracture.
    - Possible failure of fusion at base of odontoid, may be residual of an old traumatic process.
- CT scan with sagittal and coronal reconstructions:
  - CTA required to determine vertebral artery location prior to operative therapy with posterior instrumentation.
- MRI:
  - Used to assess integrity of the cruciate ligament.
Management:
- Type 1 fractures: stable; treated with rigid cervical collar.
- Type 2 fractures: most unstable, requires surgical treatment:
  - Anterior odontoid screw fixation.
  - Posterior C1–C2 instrumented fusion.
- Type 3: stable; treated with halo brace or rigid cervical collar.