ThoracoLumbar Fractures

Courtesy: Rishi Mugesh Kanna, Ganga Hospital, Coimbatore, India

 

Evaluation, Investigation, and Management of Thoracolumbar Spine Fractures

Initial Trauma Resuscitation and Transport

• Immobilize with a rigid cervical collar and a firm spine backboard with lateral head supports at the injury scene.
• Remove the backboard immediately upon arrival in the emergency resuscitation bay; prolonged immobilization creates pressure ulcers within thirty to sixty minutes.
• Differentiate between shock types during circulation assessment:
  • Neurogenic Shock: Caused by loss of sympathetic tone; presents with hypotension, bradycardia, and warm, well-perfused extremities. Managed primarily with sympathomimetic agents such as atropine.
  • Hypovolemic Shock: Caused by blood loss (e.g., associated pelvic fractures); presents with hypotension, tachycardia, and cool, poorly perfused extremities. Managed with aggressive crystalloid and blood volume resuscitation.
• Perform log-roll maneuvers with a minimum of three personnel to inspect the dorsal skin, palpate spinous processes from thoracic one to the sacrum for focal gaps or tenderness, and check for open wounds or Morel-Lavallée shear injuries.

Neurological Assessment and Injury Level Determination

• Follow the standardized neurological grading system excluding deep tendon reflexes:
  • Key Motor Groups Tested Against Resistance:
    • Cervical five: Elbow flexors
    • Cervical six: Wrist extensors
    • Cervical seven: Elbow extensors
    • Cervical eight: Finger flexors
    • Thoracic one: Finger abductors
    • Lumbar two: Hip flexors
    • Lumbar three: Knee extensors
    • Lumbar four: Ankle dorsiflexors
    • Lumbar five: Long toe extensors
    • Sacral one: Ankle plantarflexors
  • Sensory Assessment: Bilateral pinprick and light touch testing across all dermatomes from cervical two to sacral five.
• Evaluate sacral sparing (voluntary anal contraction, voluntary great toe movement, and perianal pinprick sensation at sacral four and five) to distinguish complete injuries from incomplete injuries with favorable recovery potential.
• Test the bulbocavernosus reflex to identify spinal shock (areflexic, flaccid paralysis). An intact reflex indicates spinal shock has resolved (typically within twenty-four to forty-eight hours), confirming baseline neurological findings.
• Establish diagnostic levels:
  • Motor Level: The lowest spinal segment with at least grade three over five muscle power, provided all higher levels are grade five over five.
  • Sensory Level: The most caudal dermatome with intact pinprick and light touch bilaterally.
  • Neurological Level of Injury: The most rostral segment with intact bilateral motor and sensory functions.
  • Spinal Cord vs. Vertebral Segment Correlation:
    • Lower cervical: One-vertebra offset
    • Upper thoracic: Two-vertebra offset
    • Mid-to-lower thoracic: Three-vertebra offset (e.g., thoracic ten neurological level corresponds to thoracic seven vertebral body)
    • Lumbar cord segments: Located between thoracic ten and eleven vertebral bodies
    • Conus medullaris: Located at the thoracic twelve to lumbar one junction

Diagnostic Imaging Modalities

• Plain Radiographs (Anteroposterior and Lateral):
  • Evaluate coronal alignment, asymmetric height loss, spinous process separation, widening of the interpedicular distance (indicative of burst fractures), and focal kyphosis.
• Computed Tomography:
  • Defines three-dimensional fracture morphology, posterior column disruption, lamina fractures, and pedicle integrity.
  • Reverse Cortical Sign: A retropulsed fragment flipped one hundred and eighty degrees with cancellous bone facing posteriorly. Contraindicates indirect reduction via ligamentotaxis and requires direct decompression.
  • Lamina Split Sign: Vertical laminar fracture warning of potential dural tears and entrapped nerve roots during decompressive laminectomies.
  • Whole-Body Computed Tomography: Recommended in high-energy trauma to exclude occult visceral and distracting skeletal injuries.
• Magnetic Resonance Imaging (Select Indications):
  • Indicated for neurological deficits (differentiating cord hematoma, transection, edema, or contusion), acute post-traumatic disc herniations, and occult posterior ligamentous complex injuries on fat-suppressed sequences.

Morphological Classification Principles

• Type A (Compression Injuries):
  • Involves the anterior and middle columns without posterior tension band failure. Subtypes range from single endplate wedge fractures to complete burst fractures involving both endplates with posterior vertebral wall compromise.
• Type B (Distraction Injuries):
  • Tension band failures, including pure bony Chance fractures (trans-osseous), osteoligamentous flexion-distraction disruptions, and hyperextension injuries.
• Type C (Translation Injuries):
  • Complete mechanical displacement or dislocation across coronal, sagittal, or axial planes representing severe instability.

Management Strategies and Surgical Techniques

• Conservative Management:
  • Indicated for neurologically intact, stable compression fractures and select burst injuries without posterior ligamentous complex disruption. Rigid external bracing may assist with symptomatic pain control but does not significantly alter progressive kyphosis outcomes.
• Posterior Stabilization:
  • Short-Segment Fixation: Encompasses one level above and one level below the fracture. Inclusion of intermediate pedicle screws directly into the fractured vertebra is mandatory to reduce cantilever stresses and prevent construct fatigue or collapse.
  • Long-Segment Fixation: Encompasses two levels above and two levels below the fracture. Indicated for gross translational dislocations, multi-level contiguous injuries, or severe bone fragmentation.
• Canal Decompression Approaches:
  • Indirect Decompression (Ligamentotaxis): Relies on distraction across an intact posterior longitudinal ligament to push retropulsed bone fragments back into the vertebral body. Ineffective in the presence of a reverse cortical sign.
  • Direct Decompression: Open posterior laminectomy with transpedicular fragment removal or formal open anterior corpectomy.
• Anterior Reconstruction:
  • Reserved for severe anterior column destruction, post-reduction gap collapse, or progressive deformity. Best performed via open thoracotomy or retroperitoneal thoracoabdominal approaches rather than lateral interbody approaches.
• Minimally Invasive Surgery:
  • Indicated for closed reduction and percutaneous pedicle screw fixation in select burst or distraction injuries without canal entrapment, reducing surgical site infection risks in polytrauma patients.

Adjunctive Considerations and Pharmacotherapy

• Systemic High-Dose Steroids: Historical protocols using high-dose methylprednisolone infusions are avoided due to lack of meaningful neurological efficacy and high complication rates, including severe gastrointestinal bleeding, systemic sepsis, and pneumonia.