13 Spinal Trauma and Fractures • 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). Table 13.1 Incomplete spinal cord injury manifestations
13.1 General Principles
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 |
– 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.
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.
Fig. 13.1 Coronal section. CT scan demonstrating type III occipital condyle fracture.
– 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.
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.
– 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.
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.
Fig. 13.4 Axial section. CT scan showing a comminuted Jefferson fracture involving the anterior and posterior C1 arches.
∘ 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.
Fig. 13.5 (a) Lateral view. Plain radiograph demonstrating a hangman fracture at C2. (b) Axial section. CT scan demonstrating a comminuted hangman fracture of C2.
– 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.
