Thoracic and lumbar fractures and dislocations

Pearls

• Injury to thoracic spine necessitates severe force
  • When spinal cord injury occurs usually complete
• Stable if two or more of the spinal columns are intact:
  • Anterior (anterior longitudinal ligament, annulus fibrosus, ant. half of the vertebral body)
  • Middle (posterior longitudinal ligament, posterior annulus fibrous, and post. half of vertebral body
  • Posterior (supraspinous and interspinous ligaments, facet joint capsule)
• Unstable if:
  • 50% loss of vertebral height
  • Kyphotic angulation around the fx:
    • >30deg for compression fx
    • > 25deg for burst fx
  • Neurologic deficit

Classification

Wedge Compression

• Only unstable if posterior ligament complex ruptures (requires a rotational force)
• Suspect instability and obtain CT if:
  • Severe compression (>50% loss of vertebral height)
  • Kyphosis >30o
  • Rotational component to the injury
  • Compression fx at multiple sites
  • Posterior cortex abnormality

Burst fracture

• Unstable
• Can occur with or without injury to posterior elements (posterior involvement increases risk for neuro deficits)
• Be certain not to mistakenly call a burst fracture a wedge fracture
  • Obtain CT if unsure

Flexion-distraction Injuries (lap belt)

• Obtain sagittally reconstructed CT if suspect lap-belt mechanism or flexion-distraction
• Unstable
• Intra-abdominal injuries more commonly associated than neuro deficits

Chance Fx

• Lap belt worn above the pelvic bones without a shoulder harness
  • Forceful flexion at the lap belt > compressive failure of the ant and middle columns
    • One or both articular processes fx > upper vertebrae anteriorly dislocates
• Imaging
  • Compression fx + increased posterior interspinous spaces caused by distraction

Translational

• Massive direct trauma to the back > failure of all 3 columns
• Almost invariably demonstrate neuro deficits

Source

UpToDate