Spinal injuries in road accidents victims : quali- quantitative analysis on a population of 614 cases

Introduction: our goal is to analyze carefully the features of spinal injuries found at the autopsy of road accidents victims. We want to describe, when possible, specific injury patterns and eventually to find out the connection between these patterns and specific crash dynamics. One more reason for this study comes from the high frequency of spinal lesions, as testified in many clinical series, as well in many necroscopic series. Moreover, we all know that necroscopic evidences can result useful for drawing successful street law innovations. Methods: we started from the “Street Crashes Database”, available in our Institute. From the whole population of 2550 street victims, we chose 614 cases having spinal lesions documented at autopsy: these cases represent the population of the present study. We divided our population according to age classes, vehicle and (for cars and motorbikes) position of the victim and spinal site of lesion (upper and lower cervical, upper and lower thoracic, lumbo-sacral and multiple site injuries). Starting from such preliminary subdivisions, we made different cross-examinations to define spinal injury patterns for car occupants, bikers and pedestrians and to describe the most peculiar crash dynamics causing specific spinal site injuries. We considered also the features of extra-medullary injuries of all our cases. Results: 24,1% of street victims recorded in our database presents one or more spinal lesions. About 50% of our 614 cases has got a spinal injury at a lethal site (upper cervical tract: C1-C4). 38% of our population is represented by car occupants, 30% by bicycle and motorbike riders and 23,7% by pedestrians (being the others truck occupants). 45.6% of all our cases is composed by pure cervical injuries, while pure thoracic injuries account for 29.7, pure lumbo-sacral for 5.8% and multiple site injuries for 18.9%. 30% of motorcycle riders, present in our database, reports spinal injuries versus 27% of bicycle riders and 18,5% of moped riders. Motorcycle and moped riders spinal injuries tend to occur mostly at cervical site (42%), while bicycle riders lesions tend to occur at thoracic site (43%). 28% of car drivers reports spinal injuries versus 19% of car passengers and such lesions tend to occur mostly at cervical site (58% for drivers and 61% for front seat passengers). 25.4 % of the database pedestrians present spinal lesions; these lesions tend to occur with similar frequencies at cervical and thoracic site (36,1% versus 34%). 50,4% of pure cervical injuries occur in car occupants; 40,6% of pure thoracic lesions and 44,4% of pure lumbo-sacral lesions occur in two-wheels vehicle bikers. Conclusions: our study demonstrates the existence of different spinal injury patterns for different kinds of street users (car occupants, bikers, pedestrians). Moreover the present results allow us to hypotize, starting from knowledge of the specific injuried site and eventually of the associated extra-medullary injuries, the probable causative dynamics. We think that such a study is able to offer the forensic pathologist another concrete instrument to use in the effort to understand exactly a crash genesis.