Traumatic spondylolisthesis of the axis.

Hanging, a common method of execution, began in antiquity and continues to this date. Unfortunately, the exact cause of a victim's demise was not always obvious, and many victims died as the result of asphyxiation from the hangman's noose. In the latter part of the 19th century, scientific curiosity led to autopsy studies of the cervical spine; Paterson in 1890 first described the lethal lesion. Experimental work in 1913 demonstrated that when the hangman's knot was placed beneath the chin, death rapidly occurred because of a traumatic spondylolisthesis of the second cervical vertebra. This knot placement then became standard as the most efficient method of execution. It was not until the mid-20th century that the similarity between judicial and civilian injury was recognized. The reports were infrequent, and most of the pars interarticularis fractures resulted from automobile accidents in which the victim was thrown forward and struck his or her face against the windshield which caused sudden violent hyperextension. The similarity between civilian and vehicular injuries was recognized in 1965 by Schneider who, together with his associates, reported eight cases; it was this group who introduced the term "hangman's fracture". Garber presented his thoughts on this subject, noting that there was a difference between the forces generated by judicial hanging and those caused by motor vehicle accidents and other similar civilian injuries. The former results in axial loading and hyperextension, and, rarely, in flexion or axial loading. Since the lesion occurs at the pars interarticularis of C2, Garber suggested that a more appropriate term might be traumatic spondylolisthesis of the axis.