Possible XOR fallacy – Case report of combined foramen sternale with an osseous sternal knife stab injury

This case report details a sternal finding that first was reported as penetrating knife stab wound. It was one in a series of 24 otherwise relatively superficial skin stab wounds allegedly performed by a single assailant within the scope of a single attack. The effort required to penetrate the sternum with a knife appears to be considerably higher than to inflict relatively superficial skin and soft tissue penetration. This initially raised suspicion of another person contributing to the attack, or, a different weapon being used. After reviewing the clinical CT scans, we identified the combination of a preexisting sternal foramen with a marginal fracture and concluded that the sternal “penetration” was in keeping with the depth of the other 23 stab wounds. None of the injuries were lethal, the victim survived the attack. Assuming that a knife penetration fracture of a sternum and a foramen sternale are mutually exclusive constitutes an exclusive-OR fallacy (XOR fallacy).