A novel classification for atypical Hangman fractures and its application: A retrospective observational study

Understanding cervical spine instability: a finite element study on atypical hangman's fractures

Recent reports have highlighted a notable prevalence of atypical hangman's fractures, yet their biomechanical aspects remain underexplored. Using a validated finite element model, this study assesses changes in rotation-moment characteristics of the upper cervical spine due to fractures involving the superior and inferior articular process, pars interarticularis, and lamina. The results revealed that fractures affecting the superior articular process and pars interarticularis led to significant instability, particularly in axial rotation and extension. However, atypical hangman's fractures did not necessarily produce greater instability than Levine-Edwards type II hangman's fractures.

Atypical Hangman's Fractures: An Institutional Study of 51 Patients With Atypical Traumatic Spondylolisthesis of C2

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Atypical hangman's fractures are associated with increased risk for neurologic injury due to involvement of the posterior cortex of the axis body. We present the largest single-center cohort of atypical hangman's fractures with the goal of guiding treatment decisions and outcomes based on fracture classification.

METHODS

We performed a retrospective analysis of all patients with atypical hangman's fractures treated at a single Level I trauma center between January 2010 and September 2023. 51 patients met inclusion criteria and demographic, treatment, and radiographic data were recorded and compared across the Type I and II fracture groups.

RESULTS

Final treatment modalities varied significantly between the groups (P < 0.01), with hard cervical collar and invasive halo immobilization being the most prevalent treatments for fracture Types I and II respectively. One Type I fracture patient and four Type II fracture patients failed non-operative treatment, requiring surgery. Across both groups, posterior cervical fusion (73%) was the most common surgical approach. Median length of stay varied significantly between the two fracture groups (2.0 (1.0-7.0) vs 5.0 (3.0-8.0) days; P = 0.01). Irrespective of fracture type, longer hospital length of stay was associated with increased patient age (IRR = 1.02; P < 0.01), non-white race (IRR = 2.47; P = 0.01), injury caused by MVC (IRR = 1.93; P < 0.01), and the presence of non-spine orthopedic injuries (IRR = 1.72; P = 0.03).

CONCLUSIONS

While atypical Type I hangman's fractures may be managed effectively non-operatively with a hard cervical collar, atypical Type II fractures managed with a hard cervical collar are at greater risk of requiring subsequent surgical intervention.

Management of C2 fractures following multiple classifications, a narrative review

Introduction

Classifications are helpful for surgeons as they can be a resource for decision-making, often providing the individual indicators that may deem a case necessary for surgery. However, when there are multiple classifications, the decision-making might be compromised. That is the case with C2 fractures. For this reason, this study was designed to review the different classifications of axis fractures.

Research question

What are the most commonly used classifications for C2 fractures, and how do these classifications compare in terms of clinical utility?

Methods

A systematic literature review following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Guidelines was performed. Three different Pub-med searches (https://pubmed.ncbi.nlm.nih.gov/) were done to isolate the most common C2 fracture classifications of odontoid process fractures, the posterior element of the axis and axis body fractures.

Results

The search isolated 530 papers. Applying the inclusion and exclusion criteria yielded seven papers on axis body fractures, six on odontoid fractures, and ten on "hangman's fractures." Most of the classifications proposed are modified versions of the classic ones: Benzel's for body fractures, Anderson and D'Alonzo's for odontoid fractures, and Effendi's for "hangman's fractures." The proposal by AO Spine of a different classification seems promising and had good early results of interobserver and intraobserver agreement.

Discussion and conclusion

Currently, no classification is universally accepted or widely used. The emergence of the AO Spine Upper Cervical Injury Classification system seems promising as it encompasses radiological and clinical elements.

Analysis of the clinical characteristics of adult patients with hangman's fractures: A retrospective study based on multicenter clinical data

Background

There are few reports on the clinical characteristics of adult patients with hangman's fractures.

Methods

The clinical data of adult patients were collected from the hangman's fracture database of 7 medical centers. Data on patients who met the inclusion and exclusion criteria were retrospectively analyzed. Data, including gender, age, mechanism of injury, fracture classification, and treatment, were statistically analyzed.

Results

A total of 216 eligible patients (160 males and 56 females, with a mean age of 49.7 years) were selected. There was no statistically significant difference in gender distribution of different age groups. The male-to-female ratio was similar in the young group (18–44 years) and the middle-aged group (45–64 years) (both about 3:1) but decreased in the elderly group (65 years and above) (about 2:1). Overall, high-energy injury was the main mechanism of injury. There was a statistically significant difference in the percentage of patients with high-energy injury in various age groups (the highest in the young group, and the lowest in the elderly group). Overall, unstable fracture was the main fracture type, with a higher proportion in the young and elderly groups than that in the middle-aged group, but there was no statistically significant difference. From the perspective of treatment options, the percentage of patients receiving surgery was higher in the young and elderly groups than that in the middle-aged group.

Conclusion

Hangman's fracture is predominant in males of all age groups, with high-energy injury as the main mechanism of injury. Unstable fracture is common fracture type. The percentage of patients receiving surgery in the young and elderly groups is higher than that in the middle-aged group, which may be correlated with the high incidence of unstable fracture and the life characteristics of the patients in the young and elderly age groups.

Analysis of the clinical characteristics and predisposing factors for neurological deficit with Hangman fractures

BACKGROUND

Hangman fracture is the second most common injury of the upper cervical spine, and neurological deficit with Hangman fracture is not rare. To our knowledge, few reports have statistically analyzed the predisposing factors for this injury. The objective of this study was to describe the clinical characteristics of neurological deficit associated with Hangman fracture and evaluate its risk factors.

METHODS

In this retrospective study, 97 patients with Hangman fractures were included. Data on the age, sex, injury etiology, neurological deficits, and associated injuries were obtained and evaluated. The pretreatment parameters, anterior translation and angulation of C2/3, presence of the posterior vertebral wall (PVW) fractures of C2, and presence of spinal cord signal changes were measured. Twenty-three patients with neurological deficits after Hangman fractures comprised group A, and 74 patients without neurological deficit comprised group B. Student's t-test or a nonparametric test and the chi-square test were used to evaluate the differences between groups. Binary logistic regression analysis was used to identify the risk factors for neurological deficit.

RESULTS

Among the 23 patients in group A, 2 were American Spinal Injury Association (ASIA) scale B, 6 were C, and 15 were D, and spinal cord magnetic resonance imaging signal change was observed at the level of C2-C3 disc, C2, or both. Patients with the combination of PVW fractures and ≥ 50% significant translation or angulation of C2/3 were significantly more likely to have a neurological deficit. Both factors remained significant in binary logistic regression analysis.

CONCLUSIONS

Neurological deficit after Hangman fractures always presents clinically as a partial neurological impairment. The combination of PVW fractures with ≥ 1.8 mm of translation or ≥ 5.5° of angulation of C2/3 was the predisposing factor for neurological deficit with Hangman fractures.

Detailed observation of anatomical location and pattern in Hangman's fracture based on computed tomography three-dimensional reconstruction

OBJECTIVE

To observe the precise anatomical location and pattern of the fracture lines in Hangman's fracture.

METHODS

Three-dimensional computed CT images of 210 patients with Hangman's fracture were collected. According to the involvement of anatomical structures, the injuries were classified into facet joint injury and pure bony injury. The C2 ring was also divided into: anterior, middle, and posterior elements. The anatomical structures involvement and fracture patterns were observed.

RESULT

Total 520 anatomical structures injuries were involved in 210 patients Hangman's fractures, including 298 facet joints injuries (57.3%) and 222 bony injuries (42.7%). The most common facet joints injury was superior articular facet injury of C2, and the most common pure bony injury was pediculoisthmic component fracture. The injuries of anterior element (60.6%) were more common than that of middle (20.4%) or posterior (19.0%) element. One injury in anterior element on one side and another injury located in the anterior, middle or posterior element other side was the most common fracture pattern. Injury of middle element on one side with another injury located in the middle or posterior element could be also observed.

CONCLUSION

In Hangman's fractures, fracture lines could occur in any part of C2 ring. Facet joints injuries were more common than pure bony injuries, and the injuries of anterior element were also more common than that of middle or posterior element. The high prevalence of facet joints injuries means that most of Hangman's fractures may be involved with intra-articular injuries.

Is it feasible to treat unstable traumatic spondylolisthesis of the axis via posterior fixation without fusion?

BACKGROUND

Few studies reported treatment of unstable traumatic spondylolisthesis of the axis using posterior fixation without fusion. The aim of this study was to evaluate the results and feasibility of posterior fixation without fusion in treating unstable traumatic spondylolisthesis of the axis.

METHODS

Eleven patients with traumatic spondylolisthesis of the axis were included in this study, and posterior fixation without fusion using screw-rod system was performed for them. The clinical outcomes were assessed using the Visual Analog Scale (VAS), the Neck Disability Index (NDI), and the Odom's grading system. Plain radiography was used to measure the displacement and angulation of C2-C3, and cervical lordosis. Plain radiography and computed tomography were also used to observe the bony fusions of fracture lines and postoperative spontaneous fusion of C2-C3.

RESULTS

The mean follow up time was 24.6 months (range, 12-72 months). The VAS and NDI scores were significantly improved at the final follow-up compared with those before operation (P < 0.05), and according to Odom's criteria, 90.9% (10/11) of patients rated their level of satisfaction as excellent or good. The angulation and displacement of C2-C3, and cervical lordosis were significantly improved after operation compared with those before operation (P < 0.05), and at the final follow-up, and these radiological parameters were maintained. All patients achieved solid bony fusions of fracture lines. No operative segment instability was found in all patients during the follow-up period. Spontaneous fusion at bilateral C2-C3 facet joints was found in 11 cases, and anterior and/or posterior bony bridge of intervertebral bodies at C2-C3 was found in 9 cases.

CONCLUSIONS

Posterior fixation without fusion may be a feasible and effective option for unstable traumatic spondylolisthesis of the axis.

Case of pedicle lag screw fixation for oblique axis body and pars fractures with displacement

Background:

Multiple axis fractures with instability are rare and appropriate treatment modalities have not been established.

Case Description:

A 33-year-old male presented with severe neck pain, bilateral upper-extremity numbness, and brisk reflexes in both lower extremities of 14 days’ duration after a car accident. The cervical CT revealed an oblique C2 body fracture and asymmetrical neural ring fractures, while the MRI showed a normal C2-3 disk. As traction failed to reduce the fracture, the patient underwent an anterior retropharyngeal approach to release the fracture fragments, followed by posteriorly passing bilateral C2 pedicle lag screws. Eight months later, the patient exhibited full range of motion across the C1-2 level with fusion of the previously noted fractures.

Conclusion:

A 33-year-old male with an unstable C2 body fracture and asymmetrical neural ring fractures successfully underwent an anterior retropharyngeal approach to release the fracture fragments, followed by posteriorly passing bilateral C2 pedicle lag screws to achieve stability/fusion.

Spine trauma: Radiological approach and new concepts

The spine is the main stabilizer and load bearer of the axial skeleton. It is also important for the protection of neural structures, such as the spinal cord, nerve roots, and cauda equina. In the healthy skeleton, most injuries are a consequence of high-energy trauma and can lead to severe dysfunction, such as tetraplegia or paraplegia. In order to avoid such disabilities, it is important to recognize details that will guide treatment, and that will determine the necessity or not to have surgery. Familiarity with radiography, CT, and MRI in evaluating spine trauma is necessary, as, in some cases, all three methods will be useful in determining management and surgical planning. The most important factor in determining management in the thoracolumbar spine is the posterior ligamentous complex (PLC). Therefore, familiarity with its anatomy, primary and secondary signs of its injuries, is essential for radiologists in the emergency setting. Spine fractures are a very heterogeneous group of disorders. Management can be both conservative and surgical. It is important for radiologists to be aware of classifications and patterns for these injuries.

Proposal of New Radiological Classification and Treatment Strategy for Transverse Fractures of the C2 Axis Body

OBJECTIVE

To investigate the characteristics of transverse fractures of the C2 axis body diagnosed on sagittal computed tomography (CT) and to propose new classification and appropriate treatment strategies.

METHODS

A retrospective study was performed by enrolling 49 patients (26 men and 23 women) with transverse fractures of the C2 axis body who were treated at four national trauma centers of tertiary university hospitals from January 2000 to December 2017. The mean age of the patients was 60.8 years (ranging from 21 to 90 years). We classified 49 transverse fractures of the C2 body into three types based on fracture trajectories involving superior articular facet (SAF) and lateral cortex (LC) of the C2 body on coronal CT as follows: Type 1, involvement of C2 SAF on both sides; Type 2, unilateral involvement of C2 SAF on one side and LC on the other side; Type 3, involvement of LC on both sides. The characteristics, treatment methods, and results of 49 transverse fractures of the C2 body were analyzed. Mean follow-up was 12.6 months (ranging from 12 to 26 months).

RESULTS

Twenty-six (53.1%) patients were Type 1, 21 (42.9%) were Type 2, and 2 (4.0%) were Type 3. Correlation coefficients for intra-observer and inter-observer reliabilities of classification were 0.723 and 0.598 (both, P < 0.001), respectively. About 40.8% (7 Type 1 and 13 Type 2) of the patients had fracture displacement >3 mm; Incidence of fracture displacement >3 mm was higher in Type 2 than Type 1 (61.9% vs 26.9%, P < 0.05). About 79.6% (20 Type 1, 17 Type 2 and 2 Type 3) of the patients were treated conservatively, and 20.4% (6 Type 1 and 4 Type 2) underwent surgery. At last follow-up, 47 out of 49 patients achieved fusion; overall fusion rate was 95.9%. All conservatively treated Type 1 and Type 3 patients achieved fusion. Out of 17 conservatively treated Type 2 patients, 15 achieved fusion but two developed nonunion; however, two nonunion patients opted not to undergo surgery. Subgroup analysis showed that Philadelphia brace caused nonunion significantly in fracture displacement >3 mm compared to Minerva brace/Halovest (100% vs 0%, P < 0.05). All surgically treated Type 1 and 2 patients achieved fusion. In terms of clinical outcomes, neck pain visual analog scale and neck disability index were significantly improved (both, P < 0.01). According to Odom's criteria, 93.9% (46/49) of the patients achieved satisfactory outcomes. No major complications occurred.

CONCLUSIONS

The majority of transverse fractures of C2 body can be treated conservatively. However, surgery or rigid Minerva brace/Halovest should be considered for Type 2 transverse fractures of the C2 body with fracture displacement >3 mm.

Atypical hangman's fracture with concomitant subaxial fracture-dislocation treated with circumferential fusion of C2-C5-a case report

INTRODUCTION

Atypical hangman's fractures are coronally-oriented vertical fractures of the posterior body of C2. Though these are not uncommon injuries, there is a paucity of data investigating the management of these fractures, especially when they occur in association with subaxial fracture dislocations.

CASE PRESENTATION

A 50-year-old male suffered a cervical extension injury when he dove into a shallow swimming pool while intoxicated. Initial examination demonstrated 2/5 strength in the right deltoid and biceps and 3/5 strength in the left deltoid and biceps with no motor or sensory function distal to the C5 level. Cervical CT scan revealed a C2 atypical hangman's fracture and a C4 right-sided facet fracture with traumatic spondylolisthesis at C4/5. We performed C2-C5 anterior cervical discectomy and fusion followed by a C3-C5 posterior instrumented fusion. At the patient's two year postoperative visit, the patient has had minimal improvement in neurologic function with 4/5 strength in bilateral deltoids and biceps and 2/5 strength in right wrist extension. Radiographs show a solid arthrodesis on flexion-extension radiographs.

DISCUSSION

To our knowledge, this is the first case report discussing the operative management of an atypical hangman's fracture with a concomitant subaxial fracture-dislocation. This case report adds to our current knowledge by demonstrating a novel anterior-posterior approach for treating these complicated injuries.

Failure of C2-3 anterior arthrodesis for the treatment of atypical Hangman's fractures: A three case series

Background

Hangman's fractures (HF) are defined by bilateral fractures of pars interarticularis of the axis. Most can be treated with a collar. However, the treatment strategies for atypical HF (AHF) involve the pedicles, are unstable, and require fusion. Here, we present three cases of AHF that failed anterior arthrodesis warranting repeat anterior (one case), and posterior fusions (three cases).

Case Description

One female and two males, ranging from 48 to 69 years of age, presented with AHF. All three were originally treated with C2-3 anterior cervical discectomy/fusion, and all three failed (e.g., resulted in pseudarthrosis/ anterolisthesis/instability). The first patient required a secondary C3 corpectomy/C2-4 arthrodesis, with C1-C4 posterior instrumentation. The latter two patients required secondary C1-C3 posterior fusions. For all three patients, 3-12 months follow-up X-rays confirmed the excellent alignment of the instrumentation and bony fusion.

Conclusion

Anterior arthrodesis can be utilized to treat AHF, but often fail when addressing AHF. All AHF warranted secondary posterior fusions (e.g., C1-C3 two cases; and C1-C4 one case) and a subset may additionally require more extensive anterior fusions (e.g., C2-C4 with corpectomy of C3).

Treatment of Axis Ring Fractures: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU)

STUDY DESIGN

Narrative literature review and expert recommendation.

OBJECTIVE

To establish treatment recommendations for axis ring fractures based on the knowledge of the experts of the Spine Section of the German Society for Orthopaedics and Trauma.

METHODS

This recommendation summarizes the knowledge of the experts of the Spine Section of the German Society for Orthopaedics and Trauma with regard to the treatment of axis ring fractures based on a narrative literature review.

RESULTS

Typical "hangman's fractures" with bilateral separation of the neural arch from C2 and atypical "hangman's fractures" with irregular fracture morphology are described. Computed tomography is the "gold" standard used to detect and analyse these fractures adequately. Furthermore, the detection of vertebral artery integrity is necessary. To classify axis ring fractures, the Levine-Edwards or Josten classification is recommended. In particular, the integrity of the C2/3 disc and the integrity of the anterior longitudinal ligament are used to determine the treatment strategy. While Levine-Edwards type I and type IIA (Josten type 1 and 2) fractures should be treated conservatively, Levine type II and type III (Josten type 3 and 4) fractures should be treated operatively. Levine-Edwards type II fractures will be predominately treated by anterior C2/3 fusion. Levine-Edwards type III fractures have to be primary reduced, if an anterior fusion is planned (anterior cervical discectomy and fusion [ACDF] C2/3). If a closed reduction of a type III fracture is impossible, an open reduction and posterior fixation/fusion is the treatment of choice.

CONCLUSION

Conservative treatment is predominantly reserved for Levine-Edwards I and IIA fractures. Operative treatment should be performed in case of Levine-Edwards II and III fractures.