Spinal Trauma

In the absence of clinical pain along the spine, and with a normal neurologic examination in the awake and responsive patient, significant spinal injury is virtually excluded. However, many patients are obtunded or unassessable for other reasons and may need interim "spinal precautions".

5% of patients with TBI have associated spinal injury, but 25% of patients with spinal injuries have at least a mild TBI.

55% of spinal injuries happen in the cervical spine, 15% in the thoracic region, 15% in the thoracolumbar region, and 15% in the lumbosacral region.

Anatomy and Physiology

Spinal Tracts

Only three spinal tracts are clinically easy to assess:

Dermatomes

This is relevant for determining the sensory level of an injury (the lowest level on each side with normal sensory function).

Myotomes

Muscle strength is graded on a 6-pt scale (0-5; paralysis). The motor level of an injury is the lowest key muscle group with at least 3/6 muscle strength.

Describing Spinal Cord Injuries

Level

  1. Bony level refers to the specific vertebral body which is damaged.
  2. Neurologic level refers to the function of the spinal cord which is primarily determined by clinical examination. Often differs from the bony level because spinal nerves enter the foramina and ascend//descend before entering the spinal cord. May differ on each side - you must examine and document either side.
    1. Sensory level as above.
    2. Motor level as above.

Severity

  1. Incomplete/complete refers to partial function or lack of all function below a certain spinal level. Sacral reflexes (bublocavernous reflex or anal wink) do not qualify as sacral sparing of injury.
  2. Quadriplegia/paraplegia refers generally to a cervical vs thoracic injury.

Spinal Cord Syndromes

Spinal Cord Syndrome Description Mechanisms
Central cord syndrome Disproportionate upper limb weakness; varying degrees of sensory loss Hyperextension injury with prior cervical canal stenosis; forward falls with facial impact
Anterior cord syndrome Injury to the motor and sensory pathways; paraplegia and bilateral loss of pain and temperature sensation; intact dorsal column function Cord ischemia (poor prognosis)
Hemicord/Brown-Sequard syndrome Ipsilateral motor (corticospinal) and proprioception (dorsal column) loss; contralateral pain and temperature (spinothalamic) loss beginning one-two levels below the level of injury Penetrating trauma

Specific Spinal Injuries

Cervical Spinal Fractures

These result from combinations of axial loading, flexion, extension, rotation, lateral bending, and distraction injuries/forces. They are rare in children, but tend to present with upper C-spine injuries as opposed to lower C-spine injuries.

  1. Atlanto-occipital dislocation results from severe traumatic flexion and distraction; most patients die of brainstem destruction and apnea or have profound neurologic impairment. Common cause of death in babies with shaken baby syndrome.
  2. Atlas (C1) fractures are often associated with C2 fractures. The most common C1 fractures is a "burst/Jefferson" fracture secondary to axial loading leading to disruption of anterior/posterior ring disruption with lateral displacement of the lateral masses. Burst fractures are best seen on open-count C1-C2 XR and axial CT. They are generally not associated with spinal cord injury but should be treated as unstable. Unilateral or lateral mass fractures tend to be stable but err on the side of caution until evaluated by a specialist.
  3. C1 rotary subluxation is most often seen in children. It can occur spontaneously from trauma, after respiratory infection, or with rheumatoid arthritis. It presents as torticollis. Treatment consists of restricting the patient in the rotated position and refer them for further specialized treatment.
  4. Axis (C2) fractures represent 18% of cervical fractures. It is the largest cervcal vertebra and the most unusual in shape.
    1. Odontoid fractures occur in 60% of C2 fractures. The odontoid process is a peg-shaped bony projection of C2 that interfaces with the anterior arch of C1 and is held in place by the transverse ligament
      1. Type I (tip) are uncommon
      2. Type II (base of dens) are the most common
      3. Type III (base of dens with extension into axis body)
    2. Posterior element fracture ("hangman's fracture") involves the pars interarticularis (posterior element). Generally caused be an extension type injury. Patients need a rigid collar until specialist evaluation.
  5. C3 through C7 fractures and dislocations
    1. C5-C6 is the most vulnerable to injury as it is the area of greatest flexion and extension
    2. the most common level of cervical fracture is C5, and the most common level of subluxation is C5 on C6
    3. the incidence of neurologic injury increases dramatically with facet dislocations, and is much more severe with bilateral locked facets

Thoracic Spine Fractures

These can be classified into four broad categories:

  1. Anterior wedge compression fractures are caused by axial loading with flexion; these are usually minor/stable due to the limited amount of wedging possible and the rigidity of the rib cage.
  2. Burst injuries are caused by vertical axial compression.
  3. Chance fractures are caused by flexion about an axis anterior to the vertebral column; they are transverse fractures through the vertebral body. Associated with retroperitoneal and abdominal visceral injuries.
  4. Fracture-dislocations typically result from extreme flexion or severe blunt trauma causing disruption of the stabilizing posterior elements. Due to the canal being narrow in the thoracic region, fracture-subluxations commonly result in complete neurologic deficits.

Thoracolumbar Junction (T11 through L1) Fractures

Most often result from a combination of acute hyperflexion and rotation, are are generally unstable. Injury to L1 cord can cause conus medullaris syndrome (bladder and bowel dysfunction and decreased function of the lower extremities).

These patients are very susceptible to rotational movement so great care is required when logrolling them.

Lumbar Fractures

Similar types of bony injuries as the other regions of the spine, but the only part of the spinal cord here is the cauda equina, so the likelihood of complete neurologic deficit is much lower with lumbar injuries.

Blunt Carotid and Vertebral Artery Injuries

These can result from blunt neck trauma. Specific spinal indications in screening for these injuries include C1-C3 fractures, cervical spine fracture with subluxation, and fractures involving the foramen transversarium.

General Management of Spinal Trauma

Spinal Motion Restriction

Typically initiated by EMS and continued until injuries are excluded. Patients should be log-rolled (4x people minimum) when moved, and the long spinal board should be removed as soon as possible to prevent the formation of pressure ulcers.

A detailed neurologic examination can be safely deferred so long as the spine is protected if the patient is unstable. Keep the patient in spinal precautions until then.

IV Fluids

Persistent hypotension should raise the suspicion of neurogenic shock which classically presents with bradycardia. First-line pressors include phenylephrine, dopamine, norepinephrine. Avoid over-resuscitation as always.

Medications

There is not enough evidence to support the routine use of steroids in acute spinal cord injury.

Transfer

Consult a spinal/neurosurgical service and consider transferring the patient if required. Does the patient need intubation prior to transfer? Stabilize the spine during transfer with the necessary splints, backboards, and cervical collars. Avoid un-necessary delay.