A 24-year-old rear seat passenger wearing only a lap belt is in a head-on collision. Radiographs show a horizontal fracture line running through the L2 vertebral body, pedicles and spinous process. Which mechanism produced this fracture?

• A Rotational shear injury
• B Axial compression injury
• C Hyperextension-shearing injury
• D Flexion-distraction injury ✓

Explanation

The Chance fracture is a flexion-distraction injury: the lap belt acts as a fulcrum so the spine fails in tension across all three columns, producing a horizontal fracture through the body, pedicles and posterior elements. Because it is a three-column injury it is mechanically unstable and is strongly associated with hollow viscus and mesenteric injuries of the abdomen from the same belt force.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.