TALAR NECK FRACTURE BY A NOVEL MECHANISM- THE BIOMECHANICS OF VEHICLE AIRBAG TRAUMA

We present the case of a 19-year-old woman who sustained a right talar neck fracture when the car in which she was travelling was involved in a high-speed collision. She was a front seat passenger travelling with her feet up on the dashboard, and was injured when the passenger airbag deployed. Front airbags are designed to provide protection from impact injury by having the occupant “fall” into the already-inflated device, and in order to inflate quickly enough they rely on an explosive exothermic reaction. It is postulated that an inflating airbag has similar properties to a blast wave produced by an explosion, and thus if a person is in direct contact with an inflating rather than inflated airbag, they may sustain high energy transfer injuries, not dissimilar to blast wave injuries. Although airbags have undoubtedly lead to safer motoring, it is well known that they can cause serious injury in normal usage, and injuries to the face, neck, chest and abdomen have been well documented. They should not be thought of as entirely benign devices.