Thoracic and lumbar fractures and dislocations

Background

• Injury to thoracic spine necessitates severe force
  • thoracic spine has enhanced stiffness secondary to articulations with the rib cage
  • When spinal cord injury occurs usually complete
  • thoracic spinal canal is narrower than in other regions, increased risk of cord injury
• Important to evaluate for thoracic spine injuries and aortic injuries in the setting of blunt chest trauma with mediastinlal widening
• Follows the three column model - 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 fracture:
    • >30' for compression fracture
    • > 25' for burst fracture
  • Neurologic deficit

Classification

Compression (wedge)

• Only unstable if posterior ligament complex ruptures (requires a rotational force)
• Mechanism: axial loading and flexion
• Unlikely to cause cord damage
• Suspect instability and obtain CT if:
  • Severe compression (>50% loss of vertebral height)
  • Kyphosis >30deg
  • Rotational component to injury
  • Compression fracture at multiple sites
  • Posterior cortex abnormality

Lumbar burst fracture

• considered unstable
• Mechanism: axial load with failure of the anterior and middle columns
• Can cause cord damage

Flexion-Distraction Injuries (lap belt)

• Mechanism: seat belt serves as axis of rotation with failure of middle and posterior columns
• increased height of posterior vertebral body

factor of the posterior wall of the vertebral body posterior opening of the disk space

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

Chance Fracture

• most common at T12-L2 due to spinal curvature and mechanism
• Unstable
• Seat Belt Injury: lap belt worn above the pelvic bones without a shoulder harness
• Mechanism: minor anterior vertebral compression with failure of the middle and posterior columns
• usually missed diagnosed as anterior compression fracture- (which is usually stable) versus this fracture is unstable.
  • Associated with intra-abdominal injury (rectus sheath hematoma, intestinal perforation)
    • One or both articular processes fracture > upper vertebrae anterior dislocates/subluxation

fracture dislocations

• Unstable
• Most damaging of all injuries
• Mechanism: multiple can be compression, flexion, distraction, rotation or shearing forces causing failure of anterior, middle and posterior columns

Minor Thoracic and Lumbar Spine Fractures

• Transverse process fracture
• Spinous process fracture
• Pars interarticularis fracture

Imaging

• Indications to Image Thoracic and Lumbar Spine after Trauma
  • Mechanism
    • Gunshot, High energy trauma, Motor vehicle crash with rollover or ejection, Fall >10 ft or 3 m, Pedestrian hit by car
  • Physical Exam
    • Midline back pain, Midline focal tenderness, Evidence of spinal cord or nerve root deficit
  • Associated injuries
    • Cervical fracture, ribe fracture, aortic injuries, hollow viscus injuries
• Plain radiographs or CT scan to evaluate for body abnormality
• Can reformat Chest and Abdomen CT to look at thoracic, lumbar spine
• MRI is diagnostic test of choice to evaluate patients with nerve injury
• CT myelography alternative when MRI unavailable
• anterior vertebral body compression fracture with extension through middle of vertebral body into posterior wall
• Compression fracture + increased posterior interspinous spaces caused by distraction

10% of patients with a spine fracture have second fracture in a different segment

Management

• • type and screen/cross, labs including pancreatic enzymes if thoraco-lumbar location
  • consult ortho or neurosurgery (institution dependent)
  • spinal precautions
  • emergency operative repair unless medically unstable

Translational

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

Differential Diagnosis

Lower Back Pain

• Spine related
  • Acute ligamentous injury
  • Acute muscle strain
  • Disk herniation (Sciatica)
  • Degenerative joint disease
  • Spondylolithesis
  • Epidural compression syndromes
    • Spinal cord compression (non-traumatic)
    • Cauda equina syndrome
    • Conus medullaris syndrome
    • Epidural abscess (spinal)
    • Epidural hematoma (spinal)
  • Thoracic and lumbar fractures and dislocations
  • Cancer metastasis
  • Spinal stenosis
  • Transverse myelitis
  • Vertebral osteomyelitis
  • Ankylosing spondylitis
  • Spondylolisthesis
  • Discitis
  • Spinal Infarct
• Renal disease
  • Kidney stone
  • Pyelonephritis
  • Nephrolithiasis
• Intra-abdominal
  • Abdominal aortic aneurysm
  • Ulcer perforation
  • Retrocecal appendicitis
  • Large bowel obstruction
  • Pancreatitis
• Pelvic disease
  • PID
• Other
  • Retroperitoneal hemorrhage/mass
  • Meningitis

Management

LUMBAR

• Stable Fractures - TLSO brace as directed by Neurosurg

CT IF:

• Compression
• Wedge
• >50% height (rule out middle column & burst)

See Also

• Spinal Cord Trauma
• Vertebral fractures

External Links

• EAST Guidelines for screening for thoracolumbar injuries