The paper focuses on the incidence of tibia head fractures sustained in car-pedestrian accidents. The AIS scores for tibia fractures are presented, especially the differences between AIS 1990 and 2005 and its implications on the statistics. A review of the literature is given of which no conclusions to the true incidence of knee injury can be drawn. A sample of pedestrian accidents of the Medical University Hanover (MUH) is closely examined;​ however, no single parameter correlating with the risk of tibia head fractures in pedestrians can be identified statistically or technically. Nevertheless, biomechanical circumstances under which a tibia head fracture may occur can be identified. It is questionable whether those circumstances are reproduced by the current leg impactor tests.