Analysis of perimortem trauma in hanged individuals from the Lisbon Identified Skeletal Collection

Hanging consists of the external pressure of the neck by a ligature through suspension of the body. It may cause death by asphyxiation, vascular change, cerebral ischaemia, anoxia or bone trauma. Skeletal trauma by hanging occurs predominantly at the axis, but may likewise take place at the cranial base, other upper cervical vertebrae, and hyoid bone. Six individuals from the Lisbon Identified Skeletal Collection, whose cause of death was by hanging, were macroscopically analyzed for perimortem trauma at the cranium and cervical area. Only one female individual of 53 years exhibited perimortem fractures. The trauma observed at the sixth cervical vertebra and the cranium was inconsistent with the fracture pattern expected for hanging. The individual also had a craniotomy, suggesting the perimortem blunt trauma arose on the autopsy procedure, which was confirmed by the medical-legal report. Hanging not always results in skeleton trauma as methods of hanging can differ in drop length, knot position, and ligature material. This study emphasizes the difficulty in inferring death by hanging in non-identified skeletons, particularly in suicides.