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)
• 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

• Blunt neck trauma
• Cervical spine clearance
• Canadian cervical spine rule
• NEXUS cervical spine rule
• X-ray interpretation (main)