Hangman's fracture

The execution technique of hanging, introduced by the Angle, Saxon, and Jute Germanic tribes during their invasions of the Roman Empire and Britain in the 5th century, has remained largely unchanged over time. The earliest form of a gallows was a tree on which prisoners were hanged. Despite the introduction of several modifications such as a trap door, the main mechanism of death remained asphyxiation. This created the opportunity for attempted revival after the execution, and indeed several well-known cases of survival following judicial hanging have been reported. It was not until the introduction of the standard drop by Dr. Samuel Haughton in 1866, and the so-called long drop by William Marwood in 1872 that hanging became a standard, humane means to achieve instantaneous death. Hangmen, however, fearing knot slippage, started substituting the subaural knot for the traditional submental knot. Subaural knots were not as effective, and cases of decapitation were recorded. Standardization of the long drop was further propagated by John Berry, an executioner who used mathematical calculations to estimate the correct drop length for each individual to be hanged. A British committee on capital sentences, led by Lord Aberdare, studied the execution method, and advocated for the submental knot. However, it was not until Frederic Wood-Jones published his seminal work in 1913 that cervical fractures were identified as the main mechanism of death following hanging in which the long drop and a submental knot were used. Schneider introduced the term “hangman's fracture” in 1965, and reported on the biomechanics and other similarities of the cervical fractures seen following judicial hangings and those caused by motor vehicle accidents. ¹⁾. Strictly speaking, the fracture is misnamed and should more correctly be called “hangee” fracture. As a historical note, there are four methods of judicial hanging, and the process is more complicated than may be evident at first glance ²⁾.

Hangman fracture, also known as traumatic spondylolisthesis of the axis, is a C2 fracture which involves the pars interarticularis of C2 on both sides, and is a result of hyperextension and distraction.

Hangman's fracture classification.

Hangman's fracture clinical features.

This is known as a 'judicial lesion' as these are the forces delivered by a noose, which, contrary to most ill-informed depictions, was placed with the knot towards the side of the neck, next to the angle of the mandible/mastoid process.

This fracture is virtually never seen in suicidal hanging. Indeed, it was not even seen in many of those who were judicially hanged; asphyxiation being the usual mode of death. Major trauma in hyperextension, such as a high-speed motor vehicle accident, is, in fact, the most common association – especially in fatal cases.

Cervical CT: with sagittal & coronal reconstructions should be done to fully assess the fracture.

CTA: should be done to evaluate the vertebral arteries if the fracture extends through foramen transversarium (especially Levine Type IA) and in patients with symptoms suggestive of stroke. Some recommend CTA for all C2 fractures—.

Angiography or MRA may be done as an alternative to CTA.

Radiographic features

Bilateral lamina and pedicle fracture at C2

Usually associated with anterolisthesis of C2 on C3

Extension of the fracture to the transverse foramina should be sought, raising the possibility of vertebral artery injury.

MRI: cervical MRI should be done to look for C2–3 disc disruption (a marker for instability (Levine grade II) which usually requires surgical stabilization). Findings may include abnormal increased signal intensity on MRI (best seen on sagittal FLAIR images or T2WI).

X-rays: lateral C-spine X-rays show the fracture in 95% of cases. Also demonstrates C2 angulation and/or subluxation. Most fractures pass through the pars or the transverse foramen,55 7% go through the body of C2. Instability can usually be identified as marked anterior displacement of C2 on C3 (guideline55: unstable if displacement exceeds 50% of the AP diameter of C3 vertebral body), excessive angulation of C2 on C3, or by excessive motion on flexion-extension films. Patients suspected of having Levine Type I fractures and are neurologically intact should have physician-supervised flexion-extension X-rays to rule out a reduced type II fracture.

Hangman’s fracture treatment.

Fifteen patients with unstable hangman's fractures with age ranging from 17 years to 81 years were operated using CT-based navigation from September 2011 to march 2016. Patient's age, sex, mechanism of injury, associated injuries and neurological status were noted. Clinical outcome, accuracy of screw insertion, preoperative and postoperative displacement and angulation of C2 over C3 and bony fusion were assessed.

Overall 76 screws were inserted including 30 screws in C2 pedicle with 2 (2/60 , 6.7%) malplaced screws in C2 pedicle. Mean follow-up period was 34 ± 18 months (range 7-80 months). Mean hospital stay was 12.8 ± 2.4 days. Mean preoperative and postoperative displacements were 4.1 mm and 1.8 mm respectively with a mean reduction of 2.3 mm. Mean preoperative angulation was 11.2° and the postoperative angulation was 2.1° with a mean reduction of 7.1°<b>.</b> Bony fusion was achieved and rotation was preserved at C1-C2 joint in all cases.

Intraoperative O-arm-based navigation is a safe, accurate, and effective tool for screw placement in patients with unstable hangman fracture and achieves good anatomical reduction ³⁾.

Mirvis et al. retrospectively evaluated their radiographic experience with this injury in 27 patients over a 24-month period. Lateral cervical spine studies and computed tomography (CT) scans (21 patients) were analyzed. CT studies provided better delineation of the fracture in all 21 patients and significant additional information in five patients (24%). Seven patients (26%) suffered initial neurologic sequelae in association with the C-2 injury. Nine patients had additional sites of fracture, including seven with associated C-1 ring disruption (26%). Extension of the fracture line into the transverse vertebral artery foramen led to vertebral artery injury and cerebellar embolization in one patient. Angiography may be necessary to detect intimal injury to the vertebral arteries when the fracture extends through the transverse foramina and to indicate the need for anticoagulation when clinically feasible ⁴⁾.

A three month old infant with a subtle hangman's fracture which might have been confused with primary spondylolysis. The traumatic nature of the defect was confirmed by serial plain films and CT. In addition to showing the value of serial studies, Parisi et al. believe that this is the youngest confirmed case of hangman's fracture reported till 1991 ⁵⁾.