Introduction
Anatomy: The thoracic spine is inherently stable due to the rib cage and costovertebral ligaments.
The "Critical Zone": The T4-T9 region has a narrow canal and a tenuous blood supply (watershed area), making spinal cord injury (SCI) more common in displaced fractures.
Stability: Thoracic fractures often require higher energy (e.g., MVA, falls from height) compared to lumbar fractures.
Classification (AO Spine Thoracolumbar)
The AO system categorizes fractures based on the mechanism and morphological stability:
Type A: Compression Injuries
A0: Minor injury (transverse process or spinous process fracture).
A1: Wedge/Compression. Involves superior or inferior endplate; posterior wall intact.
A2: Split. Coronal split through both endplates; posterior wall intact.
A3: Incomplete Burst. Involves one endplate and the posterior wall.
A4: Complete Burst. Involves both endplates and the posterior wall.
Type B: Tension Band Injuries
B1: Transosseous tension band failure (Chance Fracture). Monosegmental, horizontal fracture through the pedicles/lamina.
B2: Posterior ligamentous complex (PLC) disruption. Bony or ligamentous failure of the tension band.
B3: Hyperextension injury. Often seen in Ankylosing Spondylitis (AS) or DISH.
Type C: Translation Injuries
Description: Displacement or dislocation in any plane (Anterior, posterior, or lateral).
Stability: Highly unstable; usually associated with complete SCI.
Clinical Evaluation
Log-roll: Essential to examine the entire spine for "step-off" or midline tenderness.
Neurological Exam: Precise ASIA scoring is critical. Check for Bulbocavernosus reflex to differentiate between spinal shock and complete injury.
Respiratory Assessment: High thoracic fractures can impair intercostal muscle function.
Imaging
X-Ray: Look for loss of vertebral height, increased interspinous distance (suggests PLC injury), and "widened mediastinum" (may indicate thoracic aorta injury in high-energy trauma).
CT Scan: Gold standard for bony morphology and canal compromise.
MRI: Required to assess PLC integrity, disc herniations, and spinal cord edema/hemorrhage.
Treatment Decision Making: TLICS Score
The Thoracolumbar Injury Classification and Severity Score (TLICS) guides surgical management:
Morphology: Compression (1), Burst (2), Translation/Rotation (3), Distraction (4).
PLC Integrity: Intact (0), Suspected/Indeterminate (2), Disrupted (3).
Neurological Status: Intact (0), Nerve root (2), Complete SCI (2), Incomplete SCI (3), Cauda Equina (3).
Injury Morphology
Morphology Type | Points | Description |
Compression | 1 | Loss of anterior vertebral body height; posterior wall intact. |
Burst | 2 | Failure of both anterior and posterior walls of the vertebral body. |
Translation / Rotation | 3 | Horizontal displacement or rotational malalignment (Highly Unstable). |
Distraction | 4 | Failure of the tension band (e.g., Chance fracture). |
Posterior Ligamentous Complex (PLC) Integrity
PLC Status | Points | Clinical Findings |
Intact | 0 | No widening of spinous processes; no MRI evidence of injury. |
Indeterminate | 2 | Suspected injury based on isolated spinous process fracture or MRI edema. |
Disrupted | 3 | Clear widening of interspinous distance; palpable "step-off." |
Neurological Status
Clinical Presentation | Points | Priority |
Intact | 0 | Normal motor and sensory exam. |
Nerve Root Injury | 2 | Deficit localized to a specific dermatome/myotome. |
Complete SCI | 2 | No motor or sensory function below the level of injury. |
Incomplete SCI | 3 | Partial motor or sensory function preserved (Highest surgical urgency). |
Cauda Equina Syndrome | 3 | Bowel/bladder dysfunction; saddle anesthesia. |
Treatment Recommendation Based on Total Score
Total Score | Recommendation | Management Approach |
0 – 3 Points | Non-operative | Bracing (TLSO), early mobilization, and serial X-rays. |
4 Points | Indeterminate | Surgeon's discretion; consider PLC status and patient comorbidities. |
5+ Points | Operative | Decompression and instrumented stabilization (usually posterior). |
Surgical Management
Goals: Neurological decompression, restoration of alignment, and stable fixation.
Approaches:
Posterior Instrumented Fusion: Most common; uses pedicle screws and rods.
Anterior Decompression: Indicated if there is significant ventral cord compression that cannot be reached posteriorly.
Long-segment vs. Short-segment: Thoracic fractures usually require long-segment fixation (two levels above and two levels below) due to the high kyphotic stresses.
Pits & Pearls
Pearl: In a Chance Fracture (Type B1), the most common associated injury is intra-abdominal (e.g., bowel perforation or solid organ injury). Always order a CT Abdomen/Pelvis.
Pitfall: Assuming a compression fracture is stable without checking the PLC. If the interspinous distance is widened on X-ray, it is a Type B injury and likely needs surgery.
Tip: For patients with Ankylosing Spondylitis, any minor trauma is a fracture until proven otherwise by CT/MRI.