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