Cervical spine x-ray interpretation

Background

Lateral film

Disruption of one column is generally stable. Disruption of two or more is unstable.

  • Make sure that the C7-T1 junction is adequately visualized
    • Cervical Spine Radiographic series contains 3 views
      • Anteroposterior
      • Lateral
      • Open mouth odontoid view
  • Look for alignment of four parallel vertical columns that follow a slightly lordotic curve without any step offs
    • Anterior Vertebral Line: anterior to the vertebral body alternating with intervertebral disks surrouded by anulus fibrosus and anterior longitudinal ligament
    • Posterior Vertebral Line: posterior to the vertebral body alternating with intervertebral disks surrouded by anulus fibrosus and posterior longitudinal ligament
    • Spinolaminar Line- anterior edge of the spinous process
    • Posterior Spinous Line-spinous process, nuchal ligament, interpsinous and supraspinous ligaments, and ligamentum flavum

Pediatric

  • In patients less than 7 years old, most common mechanism for C-Spine injury was from motor vehicle crashes with injuries in the axial (occiput-C2) region
  • In patients 8-15 years old, sports and motor vehicle crashes account for the most common mechanisms with injuries in the sub axial C3-C7) region. Most pediatric fractures occur higher than C3 (from proportionally larger head)[1]
  • Pseudosubluxation of C2-C3 is common (~40%) in children <8yr
    • To distinguish from true dislocation or fracture:
      • Draw line from cortex of post arch of C1 to cortex of posterior arch of C3 (Swischuk line)
      • This line should pass through or be <2mm ant to posterior arch of C2

Measurements (Normal)

  • Predental space (anterior aspect of odontoid to post aspect of ant ring of C1)
    • Adult <3mm
    • Peds <5mm
    • Widening of space suggests Jefferson burst fracture of C1
  • Anterior soft tissue
    • Distance between ant border of C2 and post pharynx should be <6mm in adults and peds
    • Distance between ant border of C6 and post trachea should be <22 mm in adults
      • Should be <14mm in children <15yr or less than width of vertebral body at each level
  • Bones
    • Vertebral body: Anterior height should be no more than 3mm shorter than posterior height

Lateral View

  • Alignment
    • Disruption in the anterior, posterior, or spinolaminal lines
  • Bones
    • Obvious fracture
    • Disruption of ring of C1
    • Double facet sign indicates fractured articular facet
    • Loss of vertebral height
  • Cartilage
    • Intervertebral disc space height and length should be uniform
      • Narrowing: disc herniation or adjacent vertebral fracture
      • Widening: posterior ligamentous injury
  • Soft tissue
    • Widening of the prevertebral soft tissue suggests fracture

AP View

  • Alignment of spinous processes
  • Distance between spinous processes
  • Uniformity and height of vertebrae

Odontoid View

  • Spacing of dens and lateral masses
  • Lateral alignment of C1 and C2
  • Uniformity of bones

X-ray vs CT

  • Plain radiographs may be appropriate in low-risk patients
  • High risk patients requiring CT:
    • Closed head injury
    • Neurologic deficits
    • High energy trauma
    • Unreliable examination
    • Pain out of proportion to exam
    • Inadequate plain films

See Also

References