A Chance fracture is a flexion-distraction spinal injury, classically a horizontal bony fracture crossing the posterior elements and vertebral body. It often occurs near the thoracolumbar junction after an accident and may involve spinal instability and associated abdominal injuries.
The flexion-distraction mechanism
During forceful forward bending, the posterior spinal structures can pull apart under tension. The classic bony pattern is classified as an AO type B1 injury. Associated ligament disruption changes the assessment; injuries described as seat-belt injuries do not all have the same structural pattern.
Recognizing a traumatic emergency
Substantial back pain after a collision or fall requires urgent assessment. Abdominal seat-belt bruising or belly pain may signal an associated internal injury. Weakness, numbness, urinary retention or saddle numbness requires immediate emergency assistance. Do not try walking or bending simply to test whether the back is safe.
Investigations
Trauma assessment considers spinal and abdominal injuries together. CT defines the fracture path and alignment; MRI may clarify ligament and neurological involvement. The neurological examination is repeated when appropriate. A normal isolated radiograph does not necessarily exclude a clinically important injury after significant trauma.
Treatment and healing
Specialists choose between immobilization for selected bony injuries and surgical stabilization when the injury pattern or subsequent course requires it. Follow-up checks alignment and bone healing. Return to activity also depends on associated abdominal injuries, rather than improvement in back pain alone.
Role of TAGMED care
A suspected or recent fracture requires hospital assessment first. TAGMED must not use traction or manipulation across an unhealed injured segment. Gradual supportive care can only be considered after clearance from the treating team, with careful respect for prescribed loading and movement restrictions.
Frequently asked questions
Is this an ordinary wedge fracture?
No. Posterior distraction makes the injury mechanism different.
Can someone still walk with it?
Sometimes, but walking ability does not establish stability or safety.
Why examine the abdomen?
The same mechanism can cause internal abdominal injuries.
Is surgery always needed?
No. Selected bony fractures may be immobilized and closely monitored.
When can sport resume?
After healing is confirmed and specialist clearance considers all associated injuries.
Conceptual diagram: assessment must consider the spine and associated injuries.
Medical references
- AO Foundation. B1 Transosseous tension band disruption / Chance fracture.
- American Academy of Orthopaedic Surgeons. Fractures of the Thoracic and Lumbar Spine.
- National Institute for Health and Care Excellence. Spinal injury: assessment and initial management — Recommendations.
References document the topic; their inclusion does not imply endorsement of TAGMED services by those organizations.
Educational information from The Spine Page. This entry does not replace an individual assessment. Documentary version: October 12, 2026. Sylvain Desforges, B.Sc., D.O., N.D., osteopath and naturopath.
TAGMED clinic contact details
These contact details do not replace emergency care. For severe or rapidly progressive symptoms, go to an emergency department; call 911 when needed.
Clinique TAGMED — Terrebonne
1150, rue Lévis, Suite 200
Terrebonne (Québec) J6W 5S6
450‑704‑4447
Clinique TAGMED — Montréal
1140, avenue Beaumont
Mont-Royal (Québec) H3P 3E5
1‑877‑672‑9060