The Significance of a Knee Injury in the Investigation of an Unsuspected Motor Vehicle-Pedestrian Collision.

Characteristic injury patterns have been described in pedestrians struck by motor vehicles. The common injury pattern seen in upright pedestrians consists of a triad of head, pelvis, and lower extremity trauma. There are several factors such as vehicular type, design, mass and speed, and impact surfaces that influence the type and distribution of these injuries. We report a case that illustrates the importance of examination of the knee at autopsy when the typical lower extremity diaphyseal fractures that are usually seen in a motor vehicle-pedestrian collision are absent.