Cervical Spine Fractures: Who Really Needs CT Angiography?

Blunt Cerebrovascular Injury: Are We Overscreening Low-Mechanism Trauma?

BACKGROUND AND PURPOSE

Screening patients with trauma for blunt cerebrovascular injury with neck CTA is a common practice, but there remains disagreement regarding which patients should be screened. We reviewed adult blunt cerebrovascular injury data from a level 1 trauma center to investigate whether screening is warranted in low-mechanism trauma.

MATERIALS AND METHODS

We reviewed all neck CTAs performed on adult trauma patients in the emergency department during the 2019 calendar year. Clinical and imaging risk factors for blunt cerebrovascular injury, trauma mechanism, initial neck CTA interpretations, results from subsequent CTA and DSA studies, antiplatelet and anticoagulant treatments, and outcome data were recorded.

RESULTS

One thousand one hundred thirty-six neck CTAs met the inclusion criteria, of which 965 (85%) were interpreted as having negative findings; 125, as having indeterminate findings (11%); and 46, as having positive findings (4%). Review of subsequent imaging and clinical documentation led to classification of 40 indeterminate studies (32%) as true-positives and 85 (68%) as false-positives. Blunt cerebrovascular injury was identified in 77 (12.6%) cases meeting and in 9 (1.7%) cases not meeting the expanded Denver criteria. The subset of 204 low-mechanism trauma cases (ground-level falls, blunt assaults, and low-impact motor vehicle collisions) not meeting the expanded Denver criteria (18% of the entire data set) could have been excluded from screening with 1 questionable injury and 0 ischemic strokes missed and 12 false-positive cases prevented.

CONCLUSIONS

We advocate reservation of blunt cerebrovascular injury screening in low-mechanism trauma for patients meeting the expanded Denver criteria. Further research is needed to determine the behavior of indeterminate cases and to establish criteria for separating true-positive from false-positive findings.

CT Scan in Subaxial Cervical Facet Injury: Is It Enough for Decision-Making?

STUDY DESIGN

Cross-sectional survey.

OBJECTIVES

Assessment of subaxial cervical facet injuries using the AO Spine Subaxial Cervical Spine Injury Classification System is based on CT scan findings. However, additional radiological evaluations are not directly considered. The aim of this study is to determine situations in which spine surgeons request additional radiological exams after a facet fracture.

METHODS

A survey was sent to AO Spine members from Latin America. The evaluation considered demographic variables, routine use of the Classification, as well as the timepoint at which surgeons requested a cervical MRI, a vascular study, and/ or dynamic radiographs before treatment of facet fractures.

RESULTS

There was 229 participants, mean age 42.9 ± 10.2 years; 93.4% were men. Orthopedic surgeons 57.6% with 10.7 ± 8.7 years of experience in spine surgery. A total of 86% used the Classification in daily practice. An additional study (MRI/vascular study/and dynamic radiographs) was requested in 53.3%/9.6%/43.7% in F1 facet injuries; 76.0%/20.1%/50.2% in F2; 89.1%/65.1%/28.4% in F3; and 94.8%/66.4%/16.6% in F4. An additional study was frequently required: F1 72.5%, F2 86.9%, F3 94.7%, and F4 96.1%.

CONCLUSIONS

Spine surgeons generally requested additional radiological evaluations in facet injuries, and MRI was the most common. Dynamic radiographs had a higher prevalence for F1/F2 fractures; vascular studies were more common for F3/F4 especially among surgeons with fewer years of experience. Private hospitals had a lower spine trauma cases/year and requested more MRI and more dynamic radiographs in F1/F2. Neurosurgeons had more vascular studies and dynamic radiographs than orthopedic surgeons in all facet fractures.

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.

Cervical fracture patterns associated with blunt cerebrovascular injures when utilizing computed tomographic angiography: a systematic review and meta-analysis

BACKGROUND CONTEXT

Prior studies have demonstrated an association between cervical spine fractures and blunt cerebrovascular injuries (BCVI) due to the intimate anatomic relationship between the cervical spine and the vertebral arteries. Digital subtraction angiography (DSA) has historically been the gold standard, but computed tomography angiography (CTA) is commonly used to screen for BCVI in the trauma setting. However, there is no consensus regarding which fracture patterns mandate screening. Over aggressive screening may lead to increased radiation, increased false positives, and overtreatment of patients which can cause unnecessary patient harm, and increased healthcare costs.

PURPOSE

The aim of this meta-analysis is to analyze which cervical spine fracture patterns are most predictive of BCVI when utilizing CTA.

STUDY DESIGN/SETTING

Systematic review and meta-analysis.

OUTCOME MEASURES

Odds ratios for specific cervical fracture patterns and risk of developing a BCVI.

METHODS

A systematic literature review of all English language studies from 2000-2020 was conducted. The year 2000 was chosen as the cut-off because use of CTA prior to 2000 was rare. Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Scopus, Global Index Medicus, and ClinicalTrials.gov were queried. Studies were included if they met the following criteria: (1) the diagnostic imaging modality was CTA; (2) investigated blunt cervical trauma; (3) noted specific cervical spine fracture patterns associated with BCVI; (4) odds ratios for specific cervical spine fracture patterns or the odds ratio could be calculated; (5) subjects were 18 years old or older. Studies were excluded if they: (1) included DSA or magnetic resonance imaging; (2) included penetrating cervical trauma; (3) included pediatric patients less than 18 years of age; (4) were not written in English. All statistical analysis was performed using R Studio (RStudio, Boston, MA, USA).

RESULTS

The initial search, after duplicates were removed, resulted in 10,940 articles for independent review. Six studies met the criteria for inclusion in the meta-analysis. Specific fracture patterns mentioned are isolated C1, C2, C3 fractures, any C1-C3 fracture, any C4-C7 fracture, two-level fractures, subluxation/dislocations, and transverse foramen (TF) fractures. Three studies were included in the meta-analysis for C1, C2, C1-C3, subluxations/dislocations, and TF fractures. Two studies were included in the meta-analysis for C3, C4-C7, and two-level fractures. The pooled odds ratio with 95% confidence interval for: C1 fractures and BCVI is 1.3 (0.8-2.1); C2: 1.6 (0.9-2.8); C3: 1.8 (0.9-3.6); C1-C3: 2.2 (1.1-4.2); C4-C7: 0.7 (0.3-1.7); Two-level: 2.5 (1.4-4.6); Subluxation/Dislocation: 2.9 (1.8-4.5); TF: 3.6 (1.4-8.9).

DISCUSSION/CONCLUSION

This study found that when utilizing CTA for screening of BCVI only fractures in the C1-C3 region, two-level fractures, subluxations/dislocations, and transverse foramen fractures were associated with increased incidence of a BCVI. Further refinement of protocols for CTA in the setting of blunt cervical trauma may help limit unnecessary patient harm from overtreatment and reduce healthcare costs.

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.

[Cervical fractures and disc lesions]

CLINICAL ISSUE

The head accounts for about 8% of the total body weight, and only modest ligaments stabilize the cervical spine. In children, the ratio head weight/body mass is even worse, so not surprisingly injuries to the cervical spine are common. This article reviews the most common classifications of different cervical fractures. In addition, ruptures of the ligaments and lesions to the intervertebral discs and the vertebral arteries are discussed.

PRACTICAL RECOMMENDATIONS

In high velocity trauma, it is vital to exclude lesions to the vertebral arteries and the cervical ligaments to prevent/minimize further harm and to accurately assess the stability of the cervical spine.

An Update in Imaging of Blunt Vascular Neck Injury

Traumatic injuries of the cervical carotid and vertebral arteries, collectively referred to as blunt cerebrovascular injury (BCVI), can result in significant patient morbidity and mortality, with one of the most feared outcomes being cerebrovascular ischemia. Systematic imaging-guided screening for BCVI aims for early detection to guide timely management. In particular, accurate detection of the severity and grade of BCVI is paramount in guiding initial management. Furthermore, follow-up imaging is required to decide the duration of antithrombotic therapy. In this article, classification of the grades of BCVI and associated imaging findings will be outlined and diagnostic pitfalls and mimickers that can confound diagnosis will be described. In addition, updates to existing screening guidelines and recent efforts of criteria modification to improve detection of BCVI cases will be reviewed. The advent of postprocessing tools applied to conventional computed tomography (CT) angiograms and new diagnostic tools in dual energy CT for improved detection will also be discussed.