Predictors of Vertebral Artery Injury in Isolated C2 Fractures Based on Fracture Morphology Using CT Angiography

A Systematic Review and Meta-Analysis of Vertebral Artery Injury After Cervical Spine Trauma

STUDY DESIGN

Systematic Review and Meta-Analysis.

OBJECTIVE

Identify the incidence, mechanism of injury, investigations, management, and outcomes of Vertebral Artery Injury (VAI) after cervical spine trauma.

METHODS

A systematic review and meta-analysis were conducted in accordance with the PRISMA guidelines (PROSPERO-ID CRD42021295265). Three databases were searched (PubMed, SCOPUS, Google Scholar, CINAHL PLUS). Incidence of VAI, investigations to diagnose (Computed Tomography Angiography, Digital Subtraction Angiography, Magnetic Resonance Angiography), stroke incidence, and management paradigms (conservative, antiplatelets, anticoagulants, surgical, endovascular treatment) were delineated. Incidence was calculated using pooled proportions random effects meta-analysis.

RESULTS

A total of 44 studies were included (1777 patients). 20-studies (n = 503) included data on trauma type; 75.5% (n = 380) suffered blunt trauma and 24.5% (n = 123) penetrating. The overall incidence of VAI was .95% (95% CI 0.65-1.29). From the 16 studies which reported data on outcomes, 8.87% (95% CI 5.34- 12.99) of patients with VAI had a posterior stroke. Of the 33 studies with investigation data, 91.7% (2929/3629) underwent diagnostic CTA; 7.5% (242/3629) underwent MRA and 3.0% (98/3629) underwent DSA. Management data from 20 papers (n = 475) showed 17.9% (n = 85) undergoing conservative therapy, anticoagulation in 14.1% (n = 67), antiplatelets in 16.4% (n = 78), combined therapy in 25.5% (n = 121) and the rest (n = 124) managed using surgical and endovascular treatments.

CONCLUSION

VAI in cervical spine trauma has an approximate posterior circulation stroke risk of 9%. Optimal management paradigms for the prevention and management of VAI are yet to be standardized and require further research.

The Incidence, Characteristics and Outcomes of Vertebral Artery Injury Associated with Cervical Spine Trauma: A Systematic Review

STUDY DESIGN

Systematic Review.

OBJECTIVES

Vertebral Artery Injury (VAI) is a potentially serious complication of cervical spine fractures. As many patients can be asymptomatic at the time of injury, the identification and diagnosis of VAI can often prove difficult. Due to the high rates of morbidity and mortality associated with VAI, high clinical suspicion is paramount. The purpose of this review is to elucidate incidence, diagnosis, treatment and outcomes of VAI associated with cervical spine injuries.

METHODS

A systematic search of electronic databases was performed using 'PUBMED', 'EMBASE','Medline (OVID)', and 'Web of Science, for articles pertaining to traumatic cervical fractures with associated VAI.

RESULTS

24 studies were included in this systematic review. Data was included from 48 744 patients. In regards to the demographics of the focus groups that highlighted information on VAI, the mean average age was 46.6 (32.1-62.6). 75.1% (169/225) were male and 24.9% (56/225) were female. Overall incidence of VAI was 596/11 479 (5.19%). 190/420 (45.2%) of patients with VAI had fractures involving the transverse foramina. The right vertebral artery was the most commonly injured 114/234 (48.7%). V3 was the most common section injured (16/36 (44.4%)). Grade I was the most common (103/218 (47.2%)) injury noted. Collective acute hospital mortality rate was 32/226 (14.2%), ranging from 0-26.2% across studies.

CONCLUSION

VAI secondary to cervical spine trauma has a notable incidence and high associated mortality rates. The current available literature is limited by a low quality of evidence. In order to optimise diagnostic protocols and treatment strategies, in addition to reducing mortality rates associated with VAI, robust quantitative and qualitative studies are needed.

Pediatric Spine Trauma

Pediatric spine has growth potential with incomplete ossification, and also unique biomechanics which have important implications for trauma patients. This article intends to review various aspects of pediatric spine trauma including epidemiology, anatomy and biomechanics, and clinically relevant details of each type of injury based on the location and mechanism of injury. With the appropriate but not superfluous treatment, pediatric spine trauma patients can have better chance of recovery. Therefore, as a spine surgeon, understanding the general concept for each injury subtype together with the debate and progress in the field is inevitable.

Low-dose three-dimensional CT angiography for the evaluation of posterolateral protrusion of the vertebral artery over the posterior arch of the atlas: a quantitative anatomical comparison study of the rotational and neutral positions

AIM

To investigate the changes in relevant anatomical parameters of posterolateral protrusion of the vertebral artery (VA) between head-neck rotational and neutral positions using low-dose three-dimensional computed tomography angiography (3D-CTA).

MATERIALS AND METHODS

Low-dose 3D-CTA images obtained for various craniocervical diseases in 36 non-dominant VA side patients with neutral, left and right head-neck rotational positions were evaluated. The relevant parameters from superior and inferior views, including external diameter (ED), internal diameter (ID), transverse diameter (TD), heights and diameters of posterolateral protrusion of the VA over the posterior arch of the atlas in the neutral and rotational positions, were recorded and compared.

RESULTS

There was no significant differences in the rotational angle (left/right: 31.23 ± 6.60/29.94 ± 6.09°, p>0.05). There were no significant differences in heights and diameters of bilateral VA between rotational and neutral positions (all p>0.05). The contralateral ID, ED, and TD of the rotational positions were significantly shorter than those of the neutral position (all p<0.05), while there were no significant differences in the three ipsilateral diameters (all p>0.05).

CONCLUSIONS

Posterolateral protrusion of the VA is not uncommon in the population, and surgeons should be aware of its presence, especially the increased possibility of injury to the VA caused by head-neck rotation, during the operation; thus, preoperative evaluation by low-dose 3D-CTA should be considered.

Patient specific predictive factors of vertebral artery injury following blunt cervical spine trauma

OBJECTIVE

Determine patient and injury characteristics predictive of vascular injury (VAI) in blunt cervical spine (BCS) trauma to identify high-risk patients and propose an alternative screening protocol.

METHODS

Patients presenting between 2014 and 2018 with BCS injury and cervical spine CT imaging were included. Demographics and injury characteristics of BCS injuries were collected. Univariate and multivariate analyses to determine risk factors for VAI were performed. Once factors associated with greater odds of VAI were identified, this information was used to create an alternative protocol for indicating CTA in patients who sustained BCS injury.

RESULTS

A total of 475 patients were included. CTA of the neck was performed in 55.5% patients. In patients who received CTA, 18.2% had a contraindication to receiving anti-platelet therapy, and 25% were already receiving anti-coagulation therapy as an outpatient medication. VAI was found in 13.2% patients. In patients with VAI, 48.5% were already receiving anti-coagulation as outpatient medication. Acute kidney injury was found in 10.5% patients who had received CTA. Factors associated with greater odds of having VAI included transverse foramen involvement(p = 0.0001), subluxation/displacement/dislocation of fracture(p = 0.03), high energy mechanism(p = 0.02), SLIC score > 4(p = 0.04), and concomitant lumbar spine injury(p = 0.03). Using Modified Hawkeye Protocol, 40.2% of patients were indicated to receive a CTA, and 17 VAI were identified. Compared to Denver Criteria, CTAs were performed in 73 less patients(p = 0.04).

CONCLUSIONS

Updated protocols utilizing evidence-based clinical parameters to predict chance of VAI may avoid unnecessary advanced imaging and contrast load to patients in the setting of BCS trauma.

Development and first application testing of a new protocol for CT-based stability evaluation of the injured upper cervical spine

PURPOSE

For trauma surgeons, the evaluation of the stability of the upper cervical spine may be demanding. The aim of this study was to develop a protocol for decision-making on upper cervical spine stability in trauma patients based on established parameters obtained by CT imaging as well as testing the protocol by having it applied by trauma surgeons.

METHODS

A structured literature search on upper cervical spine stability was performed. The best evaluated instability criteria in CT imaging were determined. Based on these parameters a protocol for stability evaluation of the injured upper cervical spine was developed. A first application testing was performed. In addition to the assessment of instability, the time required for the assessment was analyzed.

RESULTS

A protocol for CT-based stability evaluation of the injured upper cervical spine based on the current literature was developed and displayed in a flow chart. Testing of the protocol found the stability of the cervical spine was correctly assessed in 55 of 56 evaluations (98.2%). In one test run, a stable upper cervical spine was judged to be unstable. Further analysis showed that this case was based on a measurement error. The assessment time of CT-images decreased significantly during repeat application of the protocol (p < 0.0001), from 336 ± 108 s (first case) to 180 ± 30 s (fourth case).

CONCLUSION

The protocol can be applied quickly and safely by non-specialized trauma surgeons. Thus, the protocol can support the decision-making process in CT-based evaluation of the stability of the injured upper cervical spine.

The Utility of Short-Interval Repeat Computed Tomography Angiogram After Blunt Cerebrovascular Injury in Adults

Introduction

Blunt cerebrovascular injury (BCVI) can lead to thromboembolic events. The necessity of short-interval noninvasive vascular imaging after the initial diagnosis is controversial. This retrospective cohort assesses the utility of short-interval computed tomography angiography (CTA) after an initial diagnosis of BCVI. 

Methods

We retrospectively reviewed patients with BCVI managed at our institution from 2016 to 2019 who underwent a short-interval (one to three weeks) repeat CTA after initial diagnosis. We excluded patients with age <18 years, penetrating injury, and previous neck irradiation. We collected baseline data and performed logistic regression to identify predictors of BCVI imaging outcomes. 

Results

The study cohort comprised 38 patients with a mean age of 45 years with 68% males. Motor vehicle crash (MVC) was the most common mechanism of 79% injury. Unilateral vertebral artery (VA) was the most common vessel that is 66% injured, and grade I 36% was the most common dissection on initial CTA. Grades III and IV dissection 33% were the most common in the short-interval CTA. Shift analysis showed a significant improvement in Biffl grades I on the short-interval CTA (p = 0.0001). Antiplatelet therapy or anticoagulation (AC) was administered to 82% of patients after the initial diagnosis. The rates of early (<2 weeks) and delayed (two weeks to three months) ischemia were 5% and 0%, respectively, and endovascular stenting was performed in 8%. 

Conclusion

BCVI grades I and II are more frequent than high-grade injuries. Short-interval non-invasive vascular imaging can detect changes of BCVI which can affect the management paradigm. It also can select patients who will benefit from endovascular intervention and avoid stroke. Besides, the short-interval non-invasive vascular imaging will not incur additional cost or increase exposure to radiation.

Cervical Spine Fractures: Who Really Needs CT Angiography?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Compare a novel two-step algorithm for indicating a computed tomography angiography (CTA) in the setting of a cervical spine fracture with established gold standard criteria.

SUMMARY OF BACKGROUND DATA

As CTA permits the rapid detection of blunt cerebrovascular injuries (BCVI), screening criteria for its use have broadened. However, more recent work warns of the potential for the overdiagnosis of BCVI, which must be considered with the adoption of broad criteria.

METHODS

A novel two-step metric for indicating CTA screening was compared with the American College of Surgeons guidelines and the expanded Denver Criteria using patients who presented with cervical spine fractures to a tertiary-level 1 trauma center from January 1, 2012 to January 1, 2016. The ability for each metric to identify BCVI and posterior circulation strokes that occurred during this period was assessed.

RESULTS

A total of 721 patients with cervical fractures were included, of whom 417 underwent CTAs (57.8%). Sixty-eight BCVIs and seven strokes were diagnosed in this cohort. All algorithms detected an equivalent number of BCVIs (52 with the novel metric, 54 with the ACS and Denver Criteria, P = 0.84) and strokes (7/7, 100% with the novel metric, 6/7, 85.7% with the ACS and Denver Criteria, P = 1.0). However, 63% fewer scans would have been needed with the proposed screening algorithm compared with the ACS or Denver Criteria (261/721, 36.2% of all patients with our criteria vs. 413/721, 57.3% with the ACS standard and 417/721, 57.8%) with the Denver Criteria, P < 0.0002 for each).

CONCLUSION

A two-step criterion based on mechanism of injury and patient factors is a potentially useful guide for identifying patients at risk of BCVI and stroke after cervical spine fractures. Further prospective analyses are required prior to widespread clinical adoption.

LEVEL OF EVIDENCE

4.

Best practice guidelines for blunt cerebrovascular injury (BCVI)

Blunt cerebrovascular injury (BCVI) is a non-penetrating injury to the carotid and/or vertebral artery that may cause stroke in trauma patients. Historically BCVI has been considered rare but more recent publications indicate an overall incidence of 1-2% in the in-hospital trauma population and as high as 9% in patients with severe head injury. The indications for screening, treatment and follow-up of these patients have been controversial for years with few clear recommendations. In an attempt to provide a clinically oriented guideline for the handling of BCVI patients a working committee was created. The current guideline is the end result of this committees work. It is based on a systematic literature search and critical review of all available publications in addition to a standardized consensus process. We recommend using the expanded Denver screening criteria and CT angiography (CTA) for the detection of BCVI. Early antithrombotic treatment should be commenced as soon as considered safe and continued for at least 3 months. A CTA at 7 days to confirm or discard the diagnosis as well as a final imaging control at 3 months should be performed.

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.

Fractures of the axis: a review of pediatric, adult, and geriatric injuries

Fractures of the second cervical vertebra (C2, axis) are common in adult spine surgery. Those fractures occurring in younger adult patients are often associated with high-energy mechanism trauma, resulting in a "Hangman's Fracture." Management of these fractures is often successful with nonoperative means, though surgery may be needed in those fractures with greater displacement and injury to the C2-C3 disc. Older patients are more likely to sustain fractures of the odontoid process. The evidence supporting surgical management of these fractures is evolving, as there may be a mortality benefit to surgery. Regardless of treatment, longer-term mortality rates are high in this patient population, which should be discussed with the patient and family at the time of injury. Pediatric patients may suffer fractures of the axis, though differentiation of normal and pathologic findings is necessary and more difficult with the skeletally immature spine.