Bilateral fractures of transverse processus: a diagnostic sign of overrun?

Injuries caused by traffic accidents can be complex and extensive. Due to the highly dynamic course of actions, reconstructive questions may be challenging to investigators. Differentiation of a single collision from an overrun is a central question. We hypothesized that the existence of spine fractures such as spinous and transverse processus fractures may be helpful to distinguish both. The postmortem CT-data of pedestrian fatalities were analyzed in a retrospective manner. A group finally assessed as being overrun (n=13; 7 m, 6 f, 18-86 y, mean 65 y) and a control group being hit but not overrun (n=11; 7 m, 4 f, 31-89 y, mean 61 y) were compared. Secondarily, the CT results were compared to the localization of fractures detected in routine autopsy. Cases in the overrun group showed 1-31 fractures of processus (mean 14.6) and 9 cases presented with bilateral fractures of partly opposite transverse processus. In the control group there were 6 cases without any fractures and 5 cases showed 1-9 injuries (mean 1.7). There were no bilateral fractures of transverse processus in the control group. Autopsy only detected fractures of spinous processus in 4 cases from the overrun group. Bilateral fractures of transverse processus are a possible sign for an overrun. Unilateral fractures of the transverse processus are not specific. Post-mortem CT is more sensitive for the evaluation of vertebral processus than conventional autopsy.