Punched with a fist: the etiology of a fatal depressed cranial fracture.

We report a case in which a 33-year-old man was discovered unconscious following a fistfight with another man. Emergency neurosurgical efforts to repair a depressed temporoparietal skull fracture and associated brain injuries were unsuccessful. The forensic anthropologist and pathologist worked in tandem to sort out a complex combination of cranial evidence, including healed antemortem trauma, perimortem blunt force trauma, remote and recent neurosurgical intervention, and the craniotomy cut performed at autopsy. The victim had suffered head injuries and a right temporoparietal craniotomy ten years prior to death. The perimortem cranial fractures were centrally located within a surgically repaired roundel of bone involving portions of the right temporal and parietal bones. Reportedly, the victim was punched on the right side of his head as he was lying on the ground with the left side of his head against an asphalt surface. A primary question in the case was whether a blow with a fist could have produced the observed cranial injuries. To adequately answer that question, known data on the minimum amount of force required to fracture the temporoparietal region were compared to data on the amount of force generated by a blow with a fist. A biomechanics expert demonstrated that a single blow with a fist to the rigidly supported head of the victim could generate the required force to produce the observed fractures. The previous medical condition possibly predisposed the victim to the cranial fractures and contributed to the depressed nature of the fractures. Although depressed cranial fractures do not typically result from a blow with a fist, it was determined in this case that the fracture pattern was consistent with a punch to the head.