Patterns in deer-related traffic injuries over a decade: the Mayo clinic experience

Background: Our American College of Surgeons Level 1 Trauma Center serves a rural population. As a result, there is a unique set of accidents that are not present in an urban environment such as deer related motor vehicle crashes (dMVC). We characterized injury patterns between motorcycle/all-terrain vehicles (MCC) and automobile (MVC) crashes related to dMVC (deer motor vehicle crash) with the hypotheses that MCC will present with higher Injury Severity Score (ISS) and that it would be related to whether the driver struck the deer or swerved. Methods: The records of 157 consecutive patients evaluated at our institution for injury related to dMVC from January 1(st), 1997 to December 31(st), 2006 were reviewed from our prospectively collected trauma database. Demographic, clinical, and crash specific parameters were abstracted. Injury severity was analyzed by the Abbreviated Injury Scale score for each body region as well as the overall Injury Severity Score (ISS). Results: Motorcycle crashes presented with a higher median ISS than MVCs (14 vs 5, p < 0.001). Median Abbreviated Injury Score (AIS) of the spine for MCC riders was higher (3 vs 0, p < 0.001) if they swerved rather than collided. Seventy-seven percent of riders were not wearing a helmet which did not result in a statistically significant increase in median ISS (16 vs 10), head AIS (2 vs 0) or spine AIS (0 vs 0). Within the MVC group, there was no difference between swerving and hitting the deer in any AIS group. Forty-seven percent of drivers were not wearing seat belts which resulted in similar median ISS (6 vs 5) and AIS of all body regions. Conclusions: Motorcycle operators suffered higher ISS. There were no significant differences in median ISS if a driver involved in a deer-related motor vehicle crash swerved rather than collided, was helmeted, or restrained.