Hangman's fracture is the colloquial designation for a both-sided lesion of the axis vertebra, notably of its left and right pars interarticularis. It is the result of a cervical trauma.
Presentation
Patients suffering only from HF may not experience more discomfort than neck pain and this applies even to the more unstable HF types. Some patients claim neck muscle tension or spasms. Neurological deficits are uncommon because the spinal cord is usually not compromised. Indeed, a HF may even widen the spinal canal at the level of the axis vertebra.
However, HF most frequently result from falls, motor vehicle or sports accidents that may have exposed the (cervical) spine to additional mechanical forces. It is not uncommon to find multiple fractures in one patient. Thus, damage to the spinal cord may occur independent from HF but will most certainly dominate the clinical presentation. Head trauma may yield similarly severe consequences.
Patients who sustained a trauma will also show abrasions, lacerations and other wounds. Fractures are not necessarily limited to the axial skeleton.
Entire Body System
- Bullet Wound
The compounding may come from within (by a bone protruding through the skin) or from without (e.g., by a bullet wound communicating with the bone). See illustration. [medical-dictionary.thefreedictionary.com]
Musculoskeletal
- Neck Pain
Complications, neck pain, neurological improvement, and fusion rate were assessed. RESULTS: The LSR technique was used for C2-C3 pedicle fixation and fusion in all the patients. [ncbi.nlm.nih.gov]
At no point did the patient complain of worsening neck pain or the onset of new symptoms, and her neurological examination remained normal. [barrowneuro.org]
Neurologic
- Confusion
Congenital defects of C2 are rare and can be confused with Hangman's fractures. CT has been advocated as aiding in differentiation between an acute fracture and congenital defects. [ncbi.nlm.nih.gov]
Traumatic spondylolisthesis of C2 (hangman fracture) A great deal of confusion surrounds the exact pathology of this fracture. [emedicine.medscape.com]
On the left images of an unrestrained passenger, who was ejected from a vehicle and found confused and combative at the scene. He was intubated and taken to a hospital, where he was found to be quadriplegic. [radiologyassistant.nl]
- Screaming
“As the prisoner felt the hangman’s fingers position the noose tightly beneath his left jaw he screamed to some obscure deity to save him before vomiting into the cloying white linen of the hood encasing his head. [stridentpublishing.co.uk]
Workup
HF are identified and classified based on the results of diagnostic imaging. While computed tomography scans and magnetic resonance imaging will yield the desired results, plain radiography is often sufficient [8]. With regards to the latter, anteroposterior, laterolateral and special odontoid views are required to thoroughly evaluate the lesion [9]. Oblique views are not generally recommended, but may be of help to improve the image of posterior parts of the axis vertebra. It has been reported that some HF visible on plain radiographic images have been missed in computed tomography scans. Thus, plain radiography is the diagnostic measure of first choice. Computed tomography may, however, be applied to assess the extent of injury. Strong suspicion for cervical spine fractures that cannot be confirmed in plain radiographic images also indicate computed tomography exams. Employment of magnetic resonance imaging is limited to evaluation of soft-tissue damage, e.g., injury of intervertebral discs and neural tissue. Such an examination is mandatory in patients presenting with neurological deficits.
Treatment
Treatment depends on the specific type of HF:
- HF type I. A cervical collar to increase stability of the cervical spine is often sufficient for treatment of this type of HF. External fixation may be an alternative option.
- HF type II. In general, patients should undergo cervical traction with skull tongs. Therapy may then be changed to an external fixation with a halo, which should be maintained for another few months. In mild cases of HF type II, i.e., minor subluxation and angulation, this switch may take place after as little as one week of tong traction. The halo then needs to be worn for up to four months. In more severe cases, tong traction needs to be continued for up to six weeks. The precise point in time when a switch from tong traction to a halo is acceptable depends on the individual case.
If the response to this conservative therapy is not satisfactory, a surgical intervention and stabilization of the upper cervical spine by anterior cervical plating or insertion of transpedicular screws may be necessary [10] [11]. - HF type IIA. Fracture reduction by sole conservative treatment is unlikely. Closed reduction under fluoroscopic guidance is a minimally invasive surgical intervention often applied to improve that situation. In some cases, anterior cervical plating or insertion of transpedicular screws may be required though. Subsequently, external fixation is necessary.
- HF type III. This type of fracture most often requires surgical stabilization to avoid further displacement of vertebra fragments and subsequent damage to the spinal cord. Lateral plates, interspinous compression and bilateral oblique wiring as well as transpedicular screws are usually applied. Post-operative stabilization with a halo may be recommendable.
Prognosis
Prognosis for HF is good. Only in rare cases do patients present spinal cord injuries that may be associated with permanent quadriplegia. However, patients who present with HF have often been involved in a serious accident and that same accident may have provoked several other injuries that may be considerable more severe than the HF itself. Such comorbidities may significantly worsen the prognosis.
Etiology
This condition is named for its classic etiology, the hanging of a convict on the gallows. The interaction between the noose that forced the convict to maximally extend their neck, but that also maintained him attached to the gallows, and the force of gravity that accounted for distraction of the cervical spine caused HF to many unfortunate individuals.
Luckily, few people are hanged today. Those that end up in that same position may still sustain that type of fracture (and also cardiovascular and respiratory arrest). Although these individuals most likely won't ever present to a physician, HF are still seen today. Similar mechanical forces may act on the cervical spine of an unrestrained passenger of a motor vehicle is forced into hyperextension either upon striking the dashboard or during severe whiplash injury. Falls may also lead to HF. Moreover, athletes doing hard contact sports such as American football or rugby or divers may sustain HF [3].
Epidemiology
It has been estimated that one out of five spinal fractures corresponds to a cervical spine fracture [4]. The majority of those affect the axis vertebra, but do not necessarily involve its pars interarticularis. Incidence rates regarding the cervical fractures in trauma patients vary from study to study and range between 1 and 4% [5].
Pathophysiology
People presenting with HF sustained a severe trauma that typically involved hyperextension of the head and distraction of the cervical spine [6]. These movements put considerable strains on cervical vertebrae, intervertebral discs and joining ligaments, particularly on the second and third vertebra of the cervical spine. As has been described above, hyperextension exposes the anterior longitudinal ligament to increased mechanical stress. Flexion, in contrast, stresses the posterior longitudinal ligament. Both movements result in compression and possibly damage of the intervertebral disk and this condition may leave both vertebrae out of their physiological range of angulation.
These traumatic events have been associated with hanging for a long time. And indeed, some people who found themselves in this situation sustained HF. Surprisingly, forensic science has recently shown that only a small share of hangings truly caused HF [7]. Luckily, they are also rare in falls, motor vehicle and sports accidents. All these situations may, however, have the patient moving rapidly with a maximally extended head. If this movement is suddenly stopped by the patient colliding with an immobile object that hits them under the chin, the neck will be forced into hyperextension. Inertia will continue to drag their body weight into the direction of the abruptly stopped movement, thus distracting the cervical spine.
Prevention
Accident prevention in professional and recreational activities, while doing sports or riding in a motor vehicle are the best measures to avoid HF. Some activities may require wearing neck protection. From a healthwise point of view, contact sports like American football and rugby cannot be recommended. With regards to motor vehicles, wearing a seat belt decreases the risk of HF significantly.
Summary
The term hangman's fracture (HF) refers to the traumatic separation of both pars interarticularis of the second vertebra of the cervical spine, the axis vertebra [1]. This kind of fracture results from hyperextension and subsequent distraction of head and thorax.
These are precisely the movements that occur forcibly when someone is hanged: The noose forces the convict's head into a position of overextension. Simultaneously, the convict's own body weight is pulling downwards while the noose maintains head and neck attached to the gallows, a situation that results in distraction of the cervical spine. Somewhat surprisingly, in this scenario, the fractured vertebra is not the cause of death. Fatal damage to the medulla oblangata or asphyxia due to strangling are the most likely causes of death, and this also applies to deliberate or suicidal hanging as it might still be seen today.
Nowadays, HF rarely result from hanging but rather from motor vehicle or sports accidents.
All these situations may be associated with different mechanical forces and may provoke distinct grades of HF. They are classified according to the following system [2]:
- HF type I. Describes a stable fracture that occurred after axial loading and hyperextension. The intervertebral disc and both the anterior and the posterior longitudinal ligaments between C2 and C3 remain intact and allow for a maximal subluxation of 3 mm.
- HF type II. The initial forces are similar to those described in HF type I. However, hyperextension is followed here by rebound flexion, which contributes to cervical spine damage. The anterior longitudinal ligament may remain largely intact, but the posterior longitudinal ligament and the intervertebral disc suffered severe damage during head flexion. Thus, the subluxation is greater than in HF type I and there is an angulation >11° between both vertebrae. The fracture is no longer stable.
- HF type IIA. Here, flexion is combined with distraction. Similar to what has been described for HF type II, flexion provokes considerable lesions of the posterior longitudinal ligament and the intervertebral disc, thus leaving both vertebrae with severe angulation and the fracture unstable.
- HF type III. This is the most severe type of HF. Flexion is followed by hyperextension and axial loading. Both longitudinal ligaments are injured, the intervertebral disk is dislocated. Intervertebral facet joints may also be dislocated. This fracture is unstable.
Patient Information
Hangman's fracture (HF) is the colloquial name for an injury of the second vertebra of the cervical spine, the axis vertebra. Per definition, someone who sustained a HF presents with a fracture of both pars interarticularis of this vertebra. The latter term refers to specific anatomic parts of the bone.
Causes
As the colloquial name of this condition suggests, this fracture may occur while someone is hanged on the gallows. Here, the noose placed around the convict's neck forces their cervical spine into hyperextension while additional forces act on it: As soon as the convict falls down, their weight pulls down their body, but head and neck are still attached to the gallows. Thus, distraction forces put an additional strain on the spine. The axis vertebra breaks.
Nowadays, HF result from falls, motor vehicle and sports accidents that cause similar situations. Someone may fall down, hit an immobile object with their chin. Their neck will be forced into hyperextension, inertia accounts for distraction of the cervical spine. An individual riding in a car without wearing a seat belt may hit the dashboard with their chin during an accident and suffer the same fracture.
Symptoms
Surprisingly, symptoms associated with a HF are very mild. Most patients claim neck pain, some experience neck muscle tension or spasms. Additional fractures may significantly aggravate the situation.
Diagnosis
HF are identified and evaluated in radiographic images. Additional diagnostic measures such as computed tomography scans or magnetic resonance imaging may be required if the physician suspects lesions not visible in plain X-ray images, e.g., injuries of intervertebral disks or neural tissue.
Treatment
Depending on the severity of the fracture, possible subluxation and displacement of vertebra fragments, conservative or surgical measures will need to be applied. Mild cases may merely require spine traction and wearing a cervical collar, while more complicated fractures need to be stabilized with plates and screws. The decision for a specific therapeutic scheme is based on the risk of spinal cord damage.
References
- Roy-Camille R, Bleynie JF, Saillant G, Judet T. [Odontoid process fractures associated with fractures of the pedicles of the axis (author's transl)]. Rev Chir Orthop Reparatrice Appar Mot. 1979; 65(7):387-391.
- Levine AM, Edwards CC. The management of traumatic spondylolisthesis of the axis. J Bone Joint Surg Am. 1985; 67(2):217-226.
- Yilmaz F, Akbulut S, Kose O. An unusual presentation of an atypical hangman's fracture. J Emerg Trauma Shock. 2010; 3(3):292-293.
- Leucht P, Fischer K, Muhr G, Mueller EJ. Epidemiology of traumatic spine fractures. Injury. 2009; 40(2):166-172.
- Pratt H, Davies E, King L. Traumatic injuries of the c1/c2 complex: computed tomographic imaging appearances. Curr Probl Diagn Radiol. 2008; 37(1):26-38.
- Pathria MN. Physical injury: Spine. In: Resnick D, ed. Diagnosis of Bone and Joint Disorders. Vol 4. Philadelphia, PA: W.B. Saunders Co.; 2002:2964-2967.
- James R, Nasmyth-Jones R. The occurrence of cervical fractures in victims of judicial hanging. Forensic Sci Int. 1992; 54(1):81-91.
- Conneely M, Park J, Demos TC. Radiologic case study. Cervical spine trauma: unstable fractures, C2-C7 injuries, and imaging guidelines. Orthopedics. 2008; 31(8):818.
- Koller H, Acosta F, Tauber M, et al. C2-fractures: part I. Quantitative morphology of the C2 vertebra is a prerequisite for the radiographic assessment of posttraumatic C2-alignment and the investigation of clinical outcomes. Eur Spine J. 2009; 18(7):978-991.
- Wang MY. Cervical crossing laminar screws: early clinical results and complications. Neurosurgery. 2007; 61(5 Suppl 2):311-315; discussion 315-316.
- Ying Z, Wen Y, Xinwei W, et al. Anterior cervical discectomy and fusion for unstable traumatic spondylolisthesis of the axis. Spine (Phila Pa 1976). 2008; 33(3):255-258.