Cervicocranium and the aviator's protective helmet.
An analogy based on the likenesses of the APH-6 aviator's protective helmet and the hangman's noose has some interesting relationships to aircraft accident investigation and to the associated traumatic pathology. A superficial examination of the similarities might propose that the inferior edge of the helmet, when considered part of the continuous circle completed by the nape strap and the chin strap, forms a loop which can be likened to a hangman's noose. The analogy might be extended to the comparison of lesions made about the neck by the straps or the edge of the helmet compared with abrasions and contusions that might be associated with a rope encircling the same structures. Such a hangman's noose, when the knot is at the side of the head (subaural), produces fractures of the base of the skull tending to extend bitemporally through the basisphenoid. When the knot is anterior and beneath the chin (submental), the hangman's noose causes a fracture dislocation at the axis. Characteristically, the posterior arch is fractured and, interestingly enough, the odontoid process is not involved. Many of us anticipate that a fractured, displaced odontoid process is the prototype lesion which so precariously endangers the patient with cervical cord compromise and death similar to the hangman's fracture. More recent assessments of the mortality of the odontoid fracture suggest less than 10%.
D000060:Accidents, Aviation; D000337:Aerospace Medicine; D006260:Head Protective Devices; D006801:Humans; D011482:Protective Devices; D013124:Spinal Injuries / Q000209:etiology* / Q000473:pathology