Chest injuries sustained in severe traffic accidents by seatbelt wearers.

In Finland during the period 1972-1985, there occurred 3,468 severe traffic accidents in which one or more of the drivers or passengers sustained an injury leading to a fatal outcome within 30 days. Of the victims who had been wearing seatbelts, 207 had fatal and 73 had severe chest injuries. The four leading causes of fatalities resulting from chest injuries were ruptures of the aorta (37%), ruptures of the heart (28.4%), and bilateral lung contusions (31.1%) or lacerations (15.5%). Seatbelt wearers with heart ruptures more often had concomitant rib fractures, lung injuries, and sternum fractures than those who had sustained ruptures of the aorta. The side of rib fractures was associated with the victim's location in the car, drivers seated on the left having more right-sided and right front passengers more left-sided rib fractures. In addition to chest injuries, 87% of the victims had other concomitant injuries, the most common abdominal injuries being liver injuries (40.2%) and spleen ruptures (26.5%). In seatbelt wearers chest injuries with a fatal outcome appear to be caused by impacts of exceptional severity, since in more moderate accidents seatbelt wearing has proved to save lives.