Spinal injuries

5% of patients with spinal injury have worsening/new neurological symptoms after arriving in ED
- Typically due to ischaemia or progression of spinal cord oedema
- Can also result from excessive movement of the spine
- Ok to wait for spinal clearance if there are other more pressing pathologies around
- Don't keep patients on long backboards while awaiting clearance
- Avoid hypotension in spinal patients, even though that can be difficult in the setting of neurogenic shock

Clearing the spine can be straightforward

Exclude neurological deficit
Exclude midline pain/tenderness
Absent intoxication
No distracting injuries

Anatomy

Three columns - vertebral bodies and posterolateral pedicles
- Anterior column: anterior longitudinal ligament, most of vertebral body (ant 2/3), ant fibres of annulus fibrosis and nucleus pulposis
- Middle: posterior cortex of vertebral body and posterior longitudinal lig and post fibres of annulus fibrosis
- Posterior: pedicle, llamina, facet joints, spinous process, interspinous/supraspinous ligaments, ligamentum flavum
- In general, a single-column injury is stable
- A middle column injury usually implies a 2 or 3 column injury, implying instability
- Instability requires two column injury AT THE SAME LEVEL
Cervical spine most vulnerable to injury - 55% of spinal injuries begin here
Cervical canal wide from foramen magnum to lower C2 - if patients survive initial injury, likely to be neurologically intact - can also die at the scene from apnoea from phrenic nerve injury
C3 and below - small spinal canal - likely spinal cord injury
Children >12yo have fairly similar spines to adults
Spinal cord - foramen magnum to L1, then cauda equina

Terminology

Complete spinal cord injury - no demonstrable sensory or motor function below a certain level
Incomplete - some degree remains
Neurogenic shock - loss of vasomotor tone and sympathetic innervation to the heart (T6 and above)
- Results in bradycardia, lack of sympathetic response to hypovolaemia
Spinal shock - flaccidity and loss of reflexes that occurs immediately after spinal cord injury
Central cord syndrome - disproportionately greater loss of motor strength in upper extremities than lower extremities
- Occurs after hyperextension when there is pre-existing cervical canal stenosis
- Common after a fall forwards onto face in elderly patient
Anterior cord syndrome - loss of motor, pain and temperature innervation, but preservation of position, vibration and temperature sensation (dorsal column)
- Common after cord ischaemia
Brown-Sequard syndrome - hemisection of the cord - ipsilateral motor loss (corticospinal tract) and loss of position sense (dorsal column), contralateral loss of pain and temperature sensation beginning one to two levels lower (spinothalamic tract)
Unstable injury - radiographic injury or any neurologic deficits (at least initially)

Clinical assessment

Time of assessment
Use ASIA worksheet
Sensation - light touch and pinprick
Reflexes - triceps, brachioradialis, patellar, Achilles
Four-extremity motor evaluation focusing on C5-T1 and L2-S1 myotomes
Rectal exam

Documenting injury

Level
- Bony level is the vertebra that is damaged
- Neurological level if the most caudal segment of spinal cord that has normal sensory and motor function on both sides of the body
  - Motor level - normal means at least 3/5 power
Examination
- 10 different muscle groups bilaterally rated 0-5, and add the 20 scores to determine total ASIA motor score
- Sensation on a 0-2 scale all dermatomes
- Combination of ASIA impairment scale with motor score is best description of neurologic status after SCI
- See bottom for ASIA worksheet

Syndromes

Central cord syndrome
- Contusion/ischaemia/haemorrhage in central part of the spinal cord, associated with traumatic injury in the cervical or upper thoracic spine
- Tetraparesis with arms weaker than legs, and burning hands
- Variable amount of sensory loss that does not affect the face
Cervicomedullary syndrome
- Injury from lower medulla to C4
- Respiratory difficulty
- Spinal shock
- Sensory deficit C1-C4
- Facial sensory loss from damage to ascending tract of spinal trigeminal nerve
Anterior cord syndrome
- Incomplete spinal injury - vascular compromise in the anterior spinal artery distribution, and subsequent ischaemic injury to anterior two-thirds of the cord
- Can occur after blunt trauma mechanisms or ischaemic injuries
- Loss of motor function and pain and temperature sensation below the level of injury
- Preservation of vibration and light touch
- Low chance of recovery
Posterior cord syndrome
- Rare
- Tetraparesis
- Profound sensory loss with preservation of pain and temperature
Brown-Sequard
- Incomplete spinal cord syndrome resulting from hemitransection, usually from penetrating injuries
- Ipsilateral paralysis
- Ipsilateral vibration and loss of light touch
- Contralateral pain and temperature loss
Conus medullaris syndrome
- Burst fractures T12/L1
- Paraparesis along with loss of bowel and bladder function
- Sensory loss in legs
- Sparing perianal sensation

Specific injuries

Atlanto-occipital dislocation
- Mostly die at scene due to apnoea
- Common cause of death in shaken baby syndrome
Atlas (C1) fracture
- 40% are a/w C2 fracture
- Commonly burst fracture - axial loading
- Uncommon to be a/w spinal cord injury, but are certainly unstable, keep in collar
- Unilateral fractures are uncommon
C1 rotary subluxation
- Most often seen in children
- Doesn't take much force sometimes
- Patient presents with torticollis
- Restrict motion with head in rotated position and refer
C2 fractures
- 18% of all C-spine fractures
- Odontoid fractures
  - Normally positioned in contact with anterior arch of C1, held in place by transverse ligament
  - Type 1 fracture - odontoid tip
  - Type 2 - base
  - Type 3 - extend into body of C2
- Posterior element fracture (Hangman's)
  - Involves posterior elements of C2 - pars interarticularis
  - Usually caused by extension
  - Rigid collar and refer
C3-C7
- C5-6 is most flexible, therefore most vulnerable to injury
- Incidence of neurologic injury is much higher with facet dislocations
Thoracic
- Anterior wedge compression
  - Axial loading with flexion
  - Rarely more than 25%
  - Mostly kept stable by rigidity of ribcage
  - Mostly treated with a rigid brace
- Burst injuries
  - Vertical-axial compression
  - Probably needs fixation
- Chance fractures
  - Transverse fractures through vertebral body
  - Caused by flexion about an axis anterior to the vertebral column - MVA with poorly-placed seat belt
  - Can be a/w retroperitoneal and abdominal injuries - pancreas, duodenum
  - Probably needs fixation
- Fracture-dislocations
  - Relatively uncommon
  - Nearly always extreme flexion or severe blunt trauma to spine, which disrupts the posterior elements
  - Commonly results in complete neurological deficits
  - Probably needs fixation
Thoracolumbar junction fractures (T11-L1)
- Combination of acute hyperflexion and rotation
  - Falls from height, restrained drivers at high speed
- Usually unstable
- Beware of spinal cord injury at L1 (bladder/bowels/lower limbs)
- Extremely vulnerable to rotational forces, be careful when logrolling
Lumbar
- Similar to thoracic injuries
- Lower risk of spinal cord injury than thoracic
Penetrating injuries
- Usually stable
Blunt carotid/vertebral artery injuries
- Indications for screening (carotid angio and generally COW, but can be decided by radiology reg):
  - C1-C3 fractures
  - Cervical spine fracture with subluxation
  - Fractures involving foramen transversarium
  - Bruising to neck is soft, but can be indicated
  - Spinous process fractures probably doesn't need one
  - Base of skull fractures indicated

Applying a cervical spine collar

Supine
Someone else stands behind the head and stabilise either side of head
Slide the posterior part of the collar behind the neck
Bring the anterior part round the front and place chin in the chin holder
Secure the collar - allow mouth opening

Process for clearing C-spine

Apply Canadian or Nexus rules
Wait for CT report if indicated
- Obvious bony deformity
- Loss of alignment of posterior aspect of vertebral bodies
- Increased distance between spinous processes
- Narrowing of vertebral canal
- Increased prevertebral soft-tissue space
If CT report clear, reassess
- Awake, alert, sober patient
- No neck pain or midline tenderness
- Voluntarily move from side to side, flex, extend. If no pain, C-spine is cleared.
If ongoing pain/midline tenderness/any neurological deficit, probably needs MRI
If fracture detected, 10% have a further spinal injury - should image whole spine

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