Print Friendly, PDF & Email

Spinal trauma – Imaging and management

 

Canadian C-spine rules

  • Are any of the following present such that clinical clearance is inappropriate? Yes: radiography. No: proceed
    • Glasgow coma scale (GCS) <15
    • Presence of distracting injuries
    • Intoxication
  • Are ≥1 high-risk factors present that mandate radiography? Yes: radiography. No: proceed
    • Age >65 years
    • Dangerous mechanism*
    • Paraesthesia in extremities
  • Are ≥1 low-risk factors present which allow clinical clearance to be attempted? No: radiography. Yes: proceed
    • Simple rearend motor vehicle collision (MVC)**
    • Sitting in Emergency Department
    • Ambulatory at any time since
    • Delayed onset of neck pain
    • Absence of midline cervical spine tenderness
  • Able to actively rotate neck 45 degrees left and right? No: radiograph. Yes: cervical spine cleared clinically

 

  • *Dangerous mechanism includes:
    • Fall from height ≥1 metre or 5 stairs
    • Axial loading to head e.g. diving
    • MVC involving
    • High speed (≥60 mph)
    • Rollover
    • Ejection
    • Pedestrian or cyclist struck by a motor vehicle

 

  • **Simple rearend motor vehicle collision excludes:
    • Pushed into oncoming traffic
    • Collision with bus or large truck
    • Rollover
    • High speed

 

National Emergency X-Radiography Utilization Study (NEXUS) criteria:

  • Provided all of the following are absent, cervical spine can be cleared clinically; if ≥1 are present then radiography is required
    • Focal neurological deficit
    • Midline spinal tenderness
    • Reduced level of consciousness
    • Intoxication
    • Distracting injury

 

Which rules to use?

  • Both have their advantages and disadvantages
  • The Canadian C-spine rules are useful in the context of midline tenderness because clinical clearance can still be attempted provided ≥1 other low-risk factors are present
  • The NEXUS criteria are useful in the context of age >65 and dangerous mechanism because these do not mandate radiography
  • Ultimately, the decision of whether or not imaging is required is a clinical one; if in doubt, it is best to ere on the side of caution and proceed to imaging
    • However, remember that imaging is not without its disadvantages such as radiation, discomfort and pressure sores from ongoing immobilisation, inconvenience to the patient, increased workload for radiographers

 

Primary imaging modality

  • CT cervical spine should be used if any of the following are present
    • Elderly patients
    • Patients with known or presumed cervical spine degenerative disease
    • GCS <13
    • Intubated patients
    • Inadequate plain film series
    • Suspicion or certainty of abnormality on plain film series
    • Patients being scanned for head trauma and/or multi-region trauma as well
  • In the absence of the above, 3-view plain radiographs (lateral, anteroposterior and odontoid peg) should be adequate

 

 

Cervical spine radiograph interpretation

  • ABCD approach
    • Adequacy and alignment
    • Bones
    • Cartilage and other soft tissues
    • Dens and disc spaces
  • Lateral view
    • Identify C1-7 and the superior border of T1
    • If the superior border of T1 cannot be identified, the film is inadequate and a swimmer’s view should be requested
    • Check the alignment of the following three lines; each should be smooth and unbroken
      • Anterior vertebral line (along the anterior margins of the vertebral bodies)
      • Anterior spinal line (along posterior margins of the vertebral bodies)
      • Posterior spinal line (along the bases of the spinous processes); this may show a step at C2 but should not be >2 mm posterior to line
    • Check that Wackenheim’s line drawn along the clivus passes posterior to the peg; if it intersects the peg, suspect atlanto-occipital dislocation
    • Check that the anterior cortex of the peg
      • Closely opposes the anterior arch of C1; this gap should be <3 mm in adults and <5 mm in children
      • Is continuous with the anterior cortex of the C2 body; displacement implies a fracture
    • Check that the posterior cortex of the peg is continuous with the posterior cortex of the C2 body; displacement implies a fracture
    • Check that Harris’ ring (white ring projected over the base of the peg and part of the C2 body) is normal; it is normal for this ring to appear incomplete over its superior and/or inferior borders but disruption of the anterior and/or posterior margins implies a fracture through the base of the peg or the body of C2
    • Examine all vertebrae for preservation of height, width and integrity of the bony cortex; joints spaces should be uniform
    • Check that the vertebral soft tissues are normal (C1-4 <7 mm and C5-7 <22 mm); any bulges indicate haemorrhage and suggest injury
  • Anteroposterior (AP) view
    • Check that the spinous processes are in a straight line
    • Check that the space between adjacent spinous processes is approximately equal
  • Odontoid peg view
    • Check that the lateral margins of C1 align vertically with those of C2; lateral displacement of the former compared to the latter implies a burst fracture, or Hangman’s fracture
    • Check that the spaces on each side of the peg are approximately equal; if not, suspect C1 rotary subluxation
    • Check for a fracture line across the base of the peg; it is very common to see a thin black line (Mach band) across the top or base of the peg which is an optical illusion from superimposition; the gap between the two upper incisors can also cause an apparent vertical fracture

 

Thoracic and lumbar spine radiograph interpretation

  • Lateral view
    • Identify three columns
      • Anterior
        • Anterior longitudinal ligament
        • Anterior annulus fibrosus
        • Anterior 2/3 vertebral body
      • Middle
        • Posterior longitudinal ligament
        • Posterior annulus fibrosus
        • Posterior 1/3 vertebral body
      • Posterior
        • Facet joints
        • Pedicles
        • Posterior ligaments
          • Ligamentum flavum
          • Interspinous ligament
          • Supraspinous ligament
    • Examine all vertebrae for preservation of height, width and integrity of the bony cortex; joints spaces should be uniform
    • Check for loss of height or wedging of the vertebral bodies which suggests a compression fracture
    • The posterior margin of each vertebral body should be slightly concave; loss of this concavity may be associated with a wedge fracture
  • AP view
    • Examine all vertebrae for preservation of height, width and integrity of the bony cortex; joints spaces should be uniform
    • Check that the spinous processes are in a straight line
    • Check that the space between adjacent spinous processes is approximately equal
    • Check the width between pedicles; normally pedicles gradually splay apart but sudden widening suggests a fracture
    • Check the paraspinal lines on a thoracic spine radiograph
      • Right paraspinal line should not be visible
      • Left paraspinal line should be closely applied to vertebral bodies with the vertical shadow of the descending aorta lateral to it
      • Any displacement or bulging should be regarded as a haematoma from a vertebral body fracture

 

Initial management of spinal trauma:

  • Manage patients with a dangerous mechanism of injury from an ABCDE perspective
  • Patients with suspected or confirmed spinal trauma should have their spine immobilised in a neutral position
  • This can be with manual inline stabilisation (MILS) initially followed by triple immobilisation (collar, blocks and tape) at the earliest opportunity
  • If airway compromise is suspected, a jaw thrust can be applied simultaneously with MILS; head-tilt and chin-lift manoeuvres are contraindicated as these may exacerbate spinal trauma
  • Patients requiring intubation and ventilation may have their triple immobilisation removed but this must be substituted with MILS applied by an assistant

 

Further management of spinal trauma

  • Give analgesia for pain e.g. morphine 1-10 mg IV
  • For agitated patients who are unable to cope with immobilisation, every effort should be made to relieve the cause of agitation e.g. analgesia for pain; sedation with or without intubation and ventilation may be necessary
  • Patients should not be forcibly restrained by immobilisation as this is likely to exacerbate injury
  • Spinal boards are for extrication and transport purposes only; on arrival to the Emergency Department, patients should be log-rolled for removal from the board and examination of the back with or without digital rectal examination
  • During prolonged immobilisation consider IV maintenance fluid and toileting with bedpans

 

Click here for medical student OSCE and PACES questions about Spinal trauma 

Common Spinal trauma exam questions for medical students, finals, OSCEs and MRCP PACES

 

Click here to download free teaching notes on Spinal trauma: Spinal trauma – Imaging and management

Perfect revision for medical students, finals, OSCEs and MRCP PACES