A medical term used to describe the orientation, as seen on an Xray,of a man's penis with respect to his lower extremity injury. A positive Throck-Morton sign is when the penis points to the side of the injury.
Senior Doctor: Mr. Jones has a femur and tibial fracture of his right leg.
Intern: Incidentally, I note on the x-ray that was taken of his pelvis that his johnson is pointing to the right - the same side as his injuries.
Senior Doctor: That, my young man, is a positive Throck Morton Sign.