backpain_pc_400_clr_2144Case: An 18 year old female was the restrained passenger in a motor vehicle crash moving at 65 mph. She complained of traumatic low back pain radiating to her abdomen. What is the most likely mechanism of injury, based on this video of CT images?

Poll Results

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Hyperflexion

Explanation

This is a Chance fracture. First described in 1948 by British radiologist George Quintin Chance, the eponymous fracture is a horizontal spinal fracture through the vertebral body and posterior elements (spinous process, laminae, and pedicles) of the thoraco-lumbar region.1

They are most commonly associated with a hyperflexion mechanism from motor vehicle accidents where the occupant is restrained by a lap belt.2

Though the fracture is quite uncommon, up to 33% of individuals with Chance fractures also have serious intra-abdominal injuries, predominantly hollow viscous injuries. When a patient with a Chance fracture also has an abdominal wall contusion, the risk of intra-abdominal injury rises to 85%.3

Master Clinician Bedside Pearls

Robert L. Rogers, MD, FACEP
Associate Professor of Emergency Medicine
Director, The Teaching Course
Department of Emergency Medicine
University of Maryland
Twitter: @EM_Educator

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1.
CHANCE G. Note on a type of flexion fracture of the spine. Br J Radiol. 1948;21(249):452. [PubMed]
2.
Magerl F, Aebi M, Gertzbein S, Harms J, Nazarian S. A comprehensive classification of thoracic and lumbar injuries. Eur Spine J. 1994;3(4):184-201. [PubMed]
3.
Tyroch A, McGuire E, McLean S, et al. The association between Chance fractures and intra-abdominal injuries revisited: a multicenter review. Am Surg. 2005;71(5):434-438. [PubMed]
Jeff Riddell, MD

Jeff Riddell, MD

Assistant Professor of Clinical Emergency Medicine
Co-Director, Medical Education Fellowship
LA County + USC Emergency Medicine Residency, Department of Emergency Medicine
Keck School of Medicine of the University of Southern California