Thoracic and lumbar fractures and dislocations

Pearls

• 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:
    • >30o for compression fx
    • > 25o for burst fx
  • Neurologic deficit

Classification

• Wedge compression fracture
  • 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