Etiology of spinal cord injury: MVC (42%), falls (27%), violence (15%, mainly GSW).
Spinal stability: ability of spine to limit patterns of displacement that may damage spinal cord or nerve roots. Denis system: 3 lines: anterior portion of vertebral body; middle is posterior portion of vertebral body; posterior – boney complex of posterior vertebral arch. If 2 lines disrupted – unstable. Unstable also considered if cervical vertebral body compression > 25% or >50% in thoracic/lumbar.
Corticospinal Tract: descending motor pathway. Crosses from brain at medulaa so left sided lesion causes left sided weakness. Ipsalateral symptoms with spinal cord lesion.
Spinothalamic Injury: pain and temperature. If this region of spinal cord gets damaged, loss of pain/temperature on CONTRALATERAL side.
Dorsal columns: vibration/proprioception. Damage causes ipsalateral symptoms.
Anterior Cord Syndrome: damage to corticospinal and spinothalamic tracts causing loss of motor and pain/temp bilaterally below lesion. Caused by damage to anterior cord due to flexion or thrombosis. Poor prognosis.
Central Cord Syndrome: Older patients with cervical spondylosis with hyperextension. Damages corticospinal and spinothalamic tracts with upper extremities affected more than lower extremitites. Prognosis good though fine motor likely long term affected.
Brown-Sequard Syndrome: hemisection of cord. Ipsalateral loss of motor, proprioception/vibration, contralateral pain/temp. Due to penetrating injury. Best prognosis.
Complete Spinal Cord Lesions: absence of sensory/motor below level of injury. Includes loss of function to level of lowest sacral level. Priapism implies complete spinal cord injury. Incomplete if any sensory, motor, or both functions are partially present. Even if rectal tone or sacral sensation at anal region present, its consider incomplete.
Spinal Shock: Looks like complete and cannot differentiate until it resolves. Can persist for days/weeks. Bulbocavernous reflex: first reflex to return as shock resolves. Squeeze penis/clitorus causing anal tightening – can also be done by pulling on foley.
Neurogenic Shock: injury to spinal cord at cervical or thoracic vertebral causing loss of sympathetic arterial tone. Causing peripherally vasodilation, hypotensive with relative bradycardia. Flaccid with areflexia. If some neuro symptoms at all below, likely not neurogenic shock. This is diagnosis of exclusion. Treatment with IV fluids, MAP > 90. May need positive inotropes, atropine for significant bradycardia.
Penetrating Injuries: transperitoneal and transintestinal GSW to spine needs IV broad spectrum antibiotics. most are managed non-operatively. If progressive neuro deficits, will need surgical decompression. Bullet remova does not significantly improve neuro deficits of patients with stable cervical or thoracic spine. Bullet removal at T11-L2 may significantly improve motor recovery in both incomplete and complete spinal injuries.
Cervical Spine Injuries
NEXUS: National Emergency X-Radiography Utilization Study. No imaging of cervical spine if all 5 excluded. 99.6% sensitive, 12.9% specific. N (neuro deficit/paresthesis), E (Etoh), X (Xtreme injury/distracting injury), U (Unable to provide history, AMS), S (Spinal tenderness, midline).
Canadian Cervical Spine Rule for Radiography: 100% sensitive, 42.5% specific for ‘clinically important’ cervical spine injuries. Answer 3 questions: First one is making sure there are no high risk factors: age >65, dangerous mechanism (fall from >3ft, axial load, high speed MVC > 60mph, rollover, ejection, recreation vehicle or bicycle, paresthesis in arms). If all negative, next question requires any of the following to provide with safely doing ROM of the neck in the ED: simple rear-end, patient able to sit up in the ED, ambulatory at scene, delayed onset of neck pain, absence of midline tenderness. If ANY of these +, can procede to next question. Third question: Can patient rotate their neck 45 degrees to the left and to the right. If able to do this, no imaging necessary.
CT preferred over xray; CT doesn’t exclude ligamentous injury. Flex-Ext xray view used to assess spinal stability though not useful in the acute setting. High false positive/negative rate. If step off of 3.7mm or angulation > 11, considered unstable. If CT negative and still having persistent pain, recommend hard collar with f/u in 3-5 days with PCP or trauma surgeon.
Newer literature showing potential to clear with negative CT C-spine. EAST guidelines (2015) recommended obtunded patients with negative CT neck can have collar removed. New study of 10,000 pts showed only 3 missed injuries with negative CT c-spine and all had initial neuro exams likely consistent with central cord syndrome (Inaba, 2016).
If C1-C3 or transverse foramen fracture noted, 22% associated with vertebral artery dissection or thrombosis – likely need to get MRA or CTA.
Anterior subluxation: Hyperflexion sprain/rupture. Ligament failure. Can be unstable though rarely have associated neuro deficits.
Bilateral facet dislocation: Disruption of all ligaments secondary to hyperflexion. Vertebral body dislocated anteriorly at least 50% of its width. Unstable. Usually neuro deficits. Forward movement causes inferior facets of upper vertebrae to pass up and over the superior facets of lower vertebrae.
Simple Wedge Fracture: superior endplate of vertebral body. Usually stable. If posterior displacement, consider burst and unstbale. Posterior ligament usually intact.
Spinous Process Avulsion (Clay-Shovelers) Fracture: Lower cervical, usually C7. Intense flexion. Stable. named after abrupt head flexion that clay miners experienced when lifting shoveful of clay and the clay stuck to shovel.
Flexion Teardrop Fracture: Anteroinferior pattern with complete ligament disruption. can cause anterior cord syndrome with neuro deficits. Highly unstable.
Occipitoatlantal Dissocation/Dislocation: skull displaced anteriorly or posteriorly. Usually death. If subluxed, look for basion/dens interval (BAI – basion anxial interval) > 12mm. Extremely unstable.
C2 (Odontoid) Fracture: 3 types: Type I is avulsion which is stable. Type II is most common type, odontoid body fracture – unstable. Type III is superior portion of body of C2 secondary to force with some angulation. Unstable as well.
Unilateral facet dislocation: Vertebral body will be displaced <50% of its width. Stable.
Vertebral Compression Injuries
Jefferson (burst) Fracture: C1 (Atlas) fracture. Axial load. Outward displacement of lateral masses on open-mouth view. Severe causes transverse ligament disruption. Usually unstable. Predental space (space on lateral xray between posterior C1 and anterior dens) < 3mm.
Burst Fracture: Retropulsion. Stable since usually ligaments intact though can be unstable if retropulsion penetrates spinal cord causing anterior cord syndrome.
Hyperextension Dislocation: Usually facial trauma and central cord syndrome. May look normal on CT though with lots of soft tissue swelling from it being ‘reduced.’ Unstable.
Anterior Arch of Atlas Avulsion Fracture: Stable.
Posterior Arch of Atlas Fracture: Potentially unstable.
Extension Teardrop Fracture: Anteroinferior vertebral body avulsion fracture. Unstable.
Laminar Fracture: stable.
Traumatic Sponylolisthesis of Axis: Hangman’s Fracture. Fracture of both pedicles of C2 allows it to displace on C3. Unstable though rarely have neuro deficits. Called Hangmans because judicial haning had knot in front causing hyperextension.
Uncinate Fracture: lateral flexion injury. Lateral superior edge of vertebral body. Can cause tranverse fracture. Ipsalateral neuro deficits. Stable.
Occipital Condyle Fracture: high-velocity injury, neuro impairment common. Neuro deficit or avulsion requires surgery.
Pillar Fracture: isolated vertical/oblique fracture though lateral mass. Extension/rotation injury. Unstable/stable depends on injury/severity.
Spinal Orthoses in cervical spine – restricts flexion/extension in middle/lower though lateral bending and rotational movements were poorly controlled. Hard collars include Philadelphia, Miami J. Gold standard is halo cervical immobilization: vest, halo ring pinned to skull and upright posts.
Thoracic Spine Injuries
Thoracic spine is rigid (T1-T10) and usually not injuried. If fracture, usually severe forces applied. Spinal cord narrowing at thoracic region though.
Thoracolumbar Spine Injuries
T11-L2 is transitional zones prone to stress/injury.
Compression Fracture: usually stable unless >50% compressed. Burst Fracture causes retropulsion of fragments and usually unstable.
Flexion-Distraction Fracture (Chance): seat-belt injury usually when lap-belt used only. Increased posterior vertebral body height, posterior wall body fracture, posterior opening of disc space. Look for anterior compression fracture of T11-L2 in ‘restrained’ patient. Usually unstable.
Immobilization of upper thoracic not always necessary but can provide additional comfort. Thoracolumbar jnction and lumbar regions are difficult to immobilize – remind patient to restrict movement.
Sacral fractures usually associated with pelvic fractures. If central sacral canal involved, can cause bowel/bladder issues.
Coccyx fracture can be made clinically with rectal exam. Don’t necessarily need xrays. Treatment symptomatically with analgesics and use rubber doughnut pillow.
Tintinalli, Seventh Edition, Chapter 255: Spine and Spinal Trauma
Rosens, Chapter 36: Spinal Trauma
Normal CT C-spine? MRI?, Eric Morley, AAEM 2017