Difference between chance, burst and wedge spine fracture
Reading File
Finding Sources
Finding Sources
Searching PubMed
"thoracolumbar vertebral fracture" AND classification
Searching the Web
AO Spine thoracolumbar injury classification wedge burst chance fracture
Reading File
Reading File
Searching Images
diagram comparing thoracolumbar wedge compression burst fracture and Chance seatbelt fracture
Reading Web Page
https://surgeryreference.aofoundation.org/spine/trauma/thora…
Reading File
These are mainly thoracolumbar fractures. The key differences are the force, columns involved, and risk of instability/neural injury.
| Feature | Wedge (compression) fracture | Burst fracture | Chance fracture |
|---|---|---|---|
| Main force | Flexion + compression | Pure axial compression, such as fall onto feet | Flexion-distraction, classically lap-seat-belt injury |
| Vertebral shape | Anterior body collapses into a wedge | Vertebral body is crushed and fragments spread outward | Horizontal splitting injury through vertebra and/or posterior ligaments |
| Columns involved | Anterior column only | Anterior + middle columns | Usually middle + posterior columns, may include anterior wedging |
| Posterior vertebral wall | Intact | Fractured, fragments may retropulse into spinal canal | Can be involved, but defining feature is posterior tension-band failure |
| Stability | Usually stable if isolated | Potentially unstable | Usually unstable |
| Neurological risk | Low | Significant, due to retropulsed bone narrowing canal | Variable, can occur |
| Typical association | Osteoporosis or lower-energy flexion injury | High-energy trauma, commonly T12-L2 | Abdominal injury, especially with lap belt |
| AO Spine type | A1 wedge-compression | A3 incomplete burst or A4 complete burst | B1 if purely bony Chance injury; B2 if ligamentous/osseoligamentous posterior tension-band disruption |
Memory aid
- Wedge: front of vertebra is squashed.
- Burst: vertebra explodes outward, including the posterior wall.
- Chance: spine is pulled apart posteriorly in flexion over a seat belt.
Important imaging clues
- Wedge: reduced anterior vertebral height, but no posterior-wall fracture or canal fragment.
- Burst: posterior-wall break, widened interpedicular distance on AP radiograph, and retropulsed fragment on CT.
- Chance: transverse horizontal fracture line through posterior elements and vertebral body, or posterior ligament injury on MRI.
A simple anterior wedge compression injury is generally stable, while a burst injury has anterior and middle-column failure and may compress the cord or cauda equina. A Chance fracture is a flexion-distraction injury with posterior tension-band disruption and warrants active assessment for intra-abdominal injury. Schwartz’s Principles of Surgery, 11th ed., p. 1871. The AO Spine classification similarly distinguishes A1 wedge, A3/A4 burst, and B1 Chance injuries.
This is a shared conversation. Sign in to Orris to start your own chat.