Traumatic C2 spondylolisthesis.
50-85% secondary to motor vehicle accidents.
Extreme hyperextension at the level of the cervical spine causes fractures of both C2 pedicles and dislocation of C2-3 intervertebral disc, with damage to supporting ligaments and causing possible transaction of the spinal cord.
Management in patients without neurologic deficits is with external immobilization.
A major complication of nonsurgical management is incomplete consolidation of bone fragments, which will require surgery with metal implants, osseous grafts or screws.
In patients with neurologic deficits surgical fusion may be necessary.
Refers to fracture of both pedicles or pars interarticularis of the axis vertebra (C2).
Occurs mainly from falls, usually in the elderly, and motor accidents mainly due to impacts of high force causing extension of the neck and great axial load onto the C2 vertebra.
A Norway study suggested 60% of reported cervical fractures came from falls and 21% from motor-related accidents.
The C2 fracture accounts for almost 19% of all spinal fractures and 55% of cervical fractures.
Within C2 fractures, the hangman’s fracture accounts for 23% of occurrences while the odontoid or dens fracture accounts for 55% of such fractures.
Highest risk of C2 fractures are elderly people within the age group of 65-84 (39%) at risks of falls (61%) or motor accidents (21%) in metropolitan areas (94%).
The mechanism of the injury is forcible hyperextension of the head, usually with distraction of the neck.
Only a small minority of hangings produced a hangman’s fracture.
A sudden forceful hyperextension centered just under the chin.
A common sign of a Hangman’s fracture is a constricted pupil on the ipsilateral side due to loss of sympathetic innervation to the eye, caused by damage to the sympathetic trunk in the neck.
Injury occurs mainly with deceleration injuries in which the face or chin strikes an unyielding object with the neck in extension.
Most common process is a frontal motor vehicle accident with an unrestrained passenger or driver, with the person striking the dashboard or windshield with their face or chin.
Despite being an unstable fracture, survival from this fracture is relatively common.
In deliberate or suicidal hanging, asphyxia is much more likely to be the cause of death.
This type of fracture tends to expand the spinal canal at the C2 level.
Patients will frequently present for treatment and have this type of fracture discovered on X-rays.
If the injury is severe enough the vertebral body of C2 is subluxed from C3 and the spinal cord become crushed, usually between the vertebral body of C3 and the posterior elements of C1 and C2.
Treatments may be nonsurgical or surgical.