Hangman's fracture
Encyclopedia
A Hangman's fracture is the colloquial name given to a fracture of both pedicles
Pedicle of vertebral arch
The pedicles are two short, thick processes, which project dorsally, one on either side, from the superior part of the vertebral body at the junction of its posterior and lateral surfaces. They connect the body of the spinal vertebra to the arch...

 or pars interarticularis
Pars interarticularis
The pars interarticularis, or pars for short, is the part of vertebra located between the inferior and superior articular processes of the facet joint. In the transverse plane, it lies between the lamina and pedicle. In other words, in the axial view, it is the bony mass between the facets that is...

 of the axis vertebra (C2).

The mechanism of the injury is forcible hyperextension
Anatomical terms of motion
The movement of body structures is accomplished by the contraction of muscles. Muscles may move parts of the skeleton relatively to each other, or may move parts of internal organs relatively to each other. All such movements are classified by the directions in which the affected structures are moved...

 of the head, usually with distraction of the neck. Traditionally this would occur during judicial hanging
Hanging
Hanging is the lethal suspension of a person by a ligature. The Oxford English Dictionary states that hanging in this sense is "specifically to put to death by suspension by the neck", though it formerly also referred to crucifixion and death by impalement in which the body would remain...

, when the noose
Hangman's knot
The hangman's knot or hangman's noose is a well-known knot most often associated with its use in hanging. For a hanging, the knot of the rope is typically placed under or just behind the left ear. When the condemned drops to the end of the rope, the force is supposed to break the neck...

 was placed below the condemned subject's chin. When the subject was dropped, the head would be forced into hyperextension by the full weight of the body, a sufficient force to cause the fracture. However, despite its long association with judicial hangings, one study of a series of such hangings showed that only a small minority of hangings produced a hangman's fracture.

Apart from hangings, the mechanism of injury - a sudden forceful hyperextension centered just under the chin - occurs mainly with deceleration injuries in which the victim's face or chin strike an unyielding object with the neck in extension. The most common scenario would be a frontal motor vehicle accident with an unrestrained passenger or driver, with the person striking the dashboard or windshield with their face or chin. Other scenarios would include falls, diving injuries, and collisions between players in contact sports.

Although a hangman's fracture is unstable, survival from this fracture is relatively common, as the fracture itself tends to expand the spinal canal at the C2 level. It is not unusual for patients to walk in for treatment and have such a fracture discovered on X-rays. Only if the force of the injury is severe enough that the vertebral body of C2 is severely subluxed from C3 does the spinal cord become crushed, usually between the vertebral body of C3 and the posterior elements of C1 and C2.

Treatment of hangman's fractures thus involve reducing any subluxations and stabilizing the spine in a fixed position, usually with a halo vest traction device, to allow the fracture to heal. In cases of non-union of the fracture, surgical stabilization and fusion is usually required.

In deliberate or suicidal hanging
Suicide methods
A suicide method is any means by which one or more persons purposely kill themselves. Suicide methods can be classified according to two modes of interrupting life processes: physical or chemical. Physical modes of interruption typically act by incapacitating the respiratory system or the central...

, asphyxia
Asphyxia
Asphyxia or asphyxiation is a condition of severely deficient supply of oxygen to the body that arises from being unable to breathe normally. An example of asphyxia is choking. Asphyxia causes generalized hypoxia, which primarily affects the tissues and organs...

 is much more likely to be the cause of death due to associated prevertebral swelling.

A common sign is a constricted pupil (Horner's syndrome
Horner's syndrome
Horner's syndrome is the combination of drooping of the eyelid and constriction of the pupil , sometimes accompanied by decreased sweating of the face on the same side; redness of the conjunctiva of the eye is often also present...

) on the ipsilateral side due to loss of sympathetic
Sympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...

 innervation to the eye, caused by damage to the sympathetic trunk
Sympathetic trunk
The sympathetic trunks are a paired bundle of nerve fibers that run from the base of the skull to the coccyx.-Structure:...

in the neck.
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