Vertebral artery injuries associated with cervical spine injuries: a review of the literature

Analysis of Cervical Angiograms in Cervical Spine Trauma Patients, Does it Make a Difference?

STUDY DESIGN

Retrospective review.

OBJECTIVE

To evaluate computed tomography angiogram (CTA) use for diagnosing blunt vertebral artery injury (BVAI) at a single institution, to assess the incidence of BVAI in the studied population, and determine if diagnosis affected care. We also wanted to evaluate if testing and treatment resulted in complications.

SUMMARY OF BACKGROUND DATA

BVAI is an example of a previously underdiagnosed injury. Ease of CTA has simplified vertebral artery evaluation. Injury to the vertebral or carotid arteries is diagnosed in approximately 0.1% of blunt trauma patients when there is high clinical suspicion, or when symptoms of central nervous system damage are apparent on initial examination. Routine screening of asymptomatic patients increases the incidence to approximately 1%.

MATERIALS AND METHODS

After IRB approval, the hospital trauma registry identified patients aged 18-89 presenting with cervical spine fracture from 2006 to 2011. A retrospective review of charts was completed. Data collection included demographic data, fracture pattern, and neurological findings. The indications for and the results of CTA was also reviewed. The type of treatment and any complications were recorded.

RESULTS

A total of 637 charts reviewed. A total of 108 subjects underwent CTA/magnetic resonance angiography; 15 diagnosed with VAI injury. Four received treatment. There were no complications from imaging or treatment of BVAI. Eight subjects without CTA evaluation presented with symptoms potentially related to injury on arrival. Three had neurological decline, although none were eligible for treatment. No routine diagnostic/treatment protocol for vertebral arteries was found at our institution.

CONCLUSIONS

Although neurological sequelae after VAI can be devastating, routine screening after cervical spine fracture may not be warranted. Beside cost, our study suggests it is rarely associated with symptoms, and the asymptomatic patient rarely receives treatment due to concomitant injuries. Our study reinforces the need for further research to establish protocols so that patient-appropriate, cost-effective evaluation and treatment can be provided.

Blunt vertebral vascular injury in trauma patients: ATLS® recommendations and review of current evidence

Blunt cerebrovascular injury (BCVI) encompasses two distinct clinical entities: traumatic carotid artery injury (TCAI) and traumatic vertebral artery injury (TVAI). The latter is the focus of our review. These are potentially devastating injuries which pose a diagnostic challenge in the acute trauma setting. There is still debate regarding the optimal screening criteria, diagnostic imaging modality and treatment methods. In 2012 the American College of Surgeons proposed criteria for investigating patients with suspected TVAI and subsequent treatment methods, caveated with the statement that evidence is limited and still evolving. Here we review the historical evidence and recent literature relating to these recommendations.

Factors affecting survival of patients in the acute phase of upper cervical spine injuries

INTRODUCTION

In recent years, on the one hand, the mortality rates of upper cervical spine injuries, such as odontoid fractures, were suggested to be not so high, but on the other hand reported to be significantly high. Furthermore, it has not been well documented the relationship between survival rates and various clinical features in those patients during the acute phase of injury because of few reports. This study aimed to evaluate survival rates and acute-phase clinical features of upper cervical spine injuries.

METHODS

We conducted a retrospective review of all patients who were transported to the advanced emergency medical center and underwent computed tomography of the cervical spine at our hospital between January 2006 and December 2015. We excluded the patients who were discovered in a state of cardiopulmonary arrest (CPA) and could not be resuscitated after transportation. Of the 215 consecutive patients with cervical spine injuries, we examined 40 patients (18.6%) diagnosed with upper cervical spine injury (males, 28; females, 12; median age, 58.5 years). Age, sex, mechanism of injury, degree of paralysis, the level of cervical injury, injury severity score (ISS), and incidence of CPA at discovery were evaluated and compared among patients classified into the survival and mortality groups.

RESULTS

The survival rate was 77.5% (31/40 patients). In addition, complete paralysis was observed in 32.5% of patients. The median of ISS was 34.0 points, and 14 patients (35.0%) presented with CPA at discovery. Age, the proportion of patients with complete paralysis, a high ISS, and incidence of CPA at discovery were significantly higher in the mortality group (p = 0.038, p = 0.038, p < 0.001, and p < 0.001, respectively).

CONCLUSIONS

Elderly people were more likely to experience upper cervical spine injuries, and their mortality rate was significantly higher than that in injured younger people. In addition, complete paralysis, high ISS, a state of CPA at discovery, was significantly higher in the mortality group.

Epidemiology and Outcomes of Vertebral Artery Injury in 16 582 Cervical Spine Surgery Patients: An AOSpine North America Multicenter Study

STUDY DESIGN

A multicenter retrospective case series was compiled involving 21 medical institutions. Inclusion criteria included patients who underwent cervical spine surgery between 2005 and 2011 and who sustained a vertebral artery injury (VAI).

OBJECTIVE

To report the frequency, risk factors, outcomes, and management goals of VAI in patients who have undergone cervical spine surgery.

METHODS

Patients were evaluated on the basis of condition-specific functional status using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) score, the Nurick scale, and the 36-Item Short-Form Health Survey (SF-36).

RESULTS

VAIs were identified in a total of 14 of 16 582 patients screened (8.4 per 10 000). The mean age of patients with VAI was 59 years (±10) with a female predominance (78.6%). Patient diagnoses included myelopathy, radiculopathy, cervical instability, and metastatic disease. VAI was associated with substantial blood loss (770 mL), although only 3 cases required transfusion. Of the 14 cases, 7 occurred with an anterior-only approach, 3 cases with posterior-only approach, and 4 during circumferential approach. Fifty percent of cases of VAI with available preoperative imaging revealed anomalous vessel anatomy during postoperative review. Average length of hospital stay was 10 days (±8). Notably, 13 of the 14 (92.86%) cases resolved without residual deficits. Compared to preoperative baseline NDI, Nurick, mJOA, and SF-36 scores for these patients, there were no observed changes after surgery (P = .20-.94).

CONCLUSIONS

Vertebral artery injuries are potentially catastrophic complications that can be sustained from anterior or posterior cervical spine approaches. The data from this study suggest that with proper steps to ensure hemostasis, patients recover function at a high rate and do not exhibit residual deficits.

Surgical management of post-traumatic atlantoaxial rotatory fixation due to C2 facet fracture: 5 clinical cases

PURPOSE

Report the results of surgical treatment of post-traumatic atlantoaxial rotatory fixation (AARF) due to C2 articular facet fracture in adults.

MATERIAL AND METHODS

The records of five patients treated since 2009 for AARF due to a C2 articular facet fracture were analyzed retrospectively. Three women and two men with an average age of 60 years (27-82) were included, one of whom initially had neurological deficits. In all cases, the surgical strategy consisted of posterior fixation: Harms-type in four cases and trans-articular with hooks in one case.

RESULTS

Dislocations due to fracture of the C2 articular facet are rare in adults; various treatment strategies have been described. In our experience, posterior screw fixation leads to satisfactory clinical and radiological outcomes. Fusion is not necessary in these cases because the dislocation is related to an asymmetric fracture without ligament damage.

CONCLUSION

Posterior fixation provides satisfactory reduction of these injuries and leads to satisfactory bone union. This surgical treatment can be performed early on after the trauma and is an interesting alternative to conservative treatment.

Update on traumatic acute spinal cord injury. Part 1

Traumatic spinal cord injury requires a multidisciplinary approach both for specialized treatment of the acute phase and for dealing with the secondary complications. A suspicion or diagnosis of spinal cord injury is the first step for a correct management. A review is made of the prehospital management and characteristics of the acute phase of spinal cord injury. Respiratory monitoring for early selective intubation, proper identification and treatment of neurogenic shock are essential for the prevention of secondary spinal cord injury. The use of corticosteroids is currently not a standard practice in neuroprotective treatment, and hemodynamic monitoring and early surgical decompression constitute the cornerstones of adequate management. Traumatic spinal cord injury usually occurs as part of multiple trauma, and this can make diagnosis difficult. Neurological examination and correct selection of radiological exams prevent delayed diagnosis of spinal cord injuries, and help to establish the prognosis.

Delayed bilateral vertebral artery occlusion after cervical spine injury: a case report

INTRODUCTION

There are considerable risks for the secondary spinal cord injury and the initial and/or delayed vertebral artery occlusion in cases of cervical fracture dislocation.

CASE PRESENTATION

An 86-year-old man was injured in a car accident and was diagnosed with no fracture or dislocation of the cervical spine by the emergency physician. However, he was transferred to our hospital 3 days later because he had motor weakness that was evaluated to be 32 points (out of 50 points) on the upper limb American Spinal Injury Association (ASIA) motor score and was diagnosed with spontaneously reduced fracture dislocation at C5/6. Magnetic resonance images revealed that the bilateral vertebral arteries were occluded, and there were some microinfarction lesions in the brain. On the first visit to his previous doctor, he was found to have a flow void in the right vertebral artery. This indicated that it was occluded during the waiting period at his previous doctor. On the day of his arrival at our hospital, the patient underwent a C5/6 posterior spinal fusion. Three months after surgery, he recovered to 46 points on the upper extremity ASIA motor score, and blood flow in the left vertebral artery was resumed.

DISCUSSION

Early reduction and stabilization are necessary for cervical spine fracture dislocation; however, it is important not only for the prevention of the secondary injury but also for the reduction of the risk of vertebral artery occlusion.

Rare case of bilateral traumatic internal carotid artery dissection

A 55-year-old man was working in a trench when the wall collapsed in on him, pinning him to the wall. On arrival in the emergency department the patient began reporting of right-sided headache. Neurological examination revealed left-sided reduced sensation with weakness. Whole-body CT scan showed right-sided flail chest and bilateral haemothorax as well as loss of flow and thinning of the distal right internal carotid artery (ICA) and loss of grey white matter differentiation in keeping with traumatic ICA dissection with a right middle cerebral artery (MCA) infarct. He was started on aspirin 300 mg once daily. 3 days postadmission the patient experienced worsening of vision and expressive dysphasia. CT angiogram showed bilateral ICA dissections extending from C2 to the skull base. The patient was managed conservatively in the stroke unit for infarction and was discharged home for follow-up in stroke clinic.

Predicting Blunt Cerebrovascular Injury in Pediatric Trauma: Validation of the "Utah Score"

Risk factors for blunt cerebrovascular injury (BCVI) may differ between children and adults, suggesting that children at low risk for BCVI after trauma receive unnecessary computed tomography angiography (CTA) and high-dose radiation. We previously developed a score for predicting pediatric BCVI based on retrospective cohort analysis. Our objective is to externally validate this prediction score with a retrospective multi-institutional cohort. We included patients who underwent CTA for traumatic cranial injury at four pediatric Level I trauma centers. Each patient in the validation cohort was scored using the "Utah Score" and classified as high or low risk. Before analysis, we defined a misclassification rate <25% as validating the Utah Score. Six hundred forty-five patients (mean age 8.6 ± 5.4 years; 63.4% males) underwent screening for BCVI via CTA. The validation cohort was 411 patients from three sites compared with the training cohort of 234 patients. Twenty-two BCVIs (5.4%) were identified in the validation cohort. The Utah Score was significantly associated with BCVIs in the validation cohort (odds ratio 8.1 [3.3, 19.8], p < 0.001) and discriminated well in the validation cohort (area under the curve 72%). When the Utah Score was applied to the validation cohort, the sensitivity was 59%, specificity was 85%, positive predictive value was 18%, and negative predictive value was 97%. The Utah Score misclassified 16.6% of patients in the validation cohort. The Utah Score for predicting BCVI in pediatric trauma patients was validated with a low misclassification rate using a large, independent, multicenter cohort. Its implementation in the clinical setting may reduce the use of CTA in low-risk patients.

Imaging of Spine Trauma

Imaging with computed tomography and magnetic resonance imaging is fundamental to the evaluation of traumatic spinal injury. Specifically, neuroradiologic techniques show the exact location of injury, evaluate the stability of the spine, and determine neural element compromise. This review focuses on the complementary role of different radiologic modalities in the diagnosis of patients with traumatic injuries of the spine. The role of imaging in spinal trauma classifications will be addressed. The importance of magnetic resonance imaging in the assessment of soft tissue injury, particularly of the spinal cord, will be discussed. Last, the increasing role of advanced imaging techniques for prognostication of the traumatic spine will be explored.

Management of Typical and Atypical Hangman's Fractures

Study Design Retrospective study of a prospectively maintained database. Objective Our aim was to retrospectively review management and outcomes of patients with low-grade hangman's fractures, specifically looking at differences in outcomes between collars and halo immobilization. We also studied fracture patterns and their treatment outcomes. Methods Forty-one patients with hangman's fractures were identified from 105 patients with axis fractures between 2007 and 2013. Typical hangman's fractures were defined as traumatic spondylolisthesis of the axis causing a bilateral pars interarticularis fracture. Fractures involving the posterior cortex of C2 on one or both sides or an asymmetrical pattern were defined as atypical. Results There were 41 patients with a mean age of 59 years, with 13 (31.7%) typical and 28 (68.2%) atypical fractures. There were 22 (53.6%) type 1 fractures, 7 (41.4%) type 2 fractures, and 2 (4.9%) type 2a fractures in this series. Cervical collars were used to manage 11 patients (27% of all patients with hangman's fractures) and halo orthosis was used in 27 (65.8%). Three (7.3%) patients underwent surgical fixation of the fracture. Bony union was achieved in all patients on radiologic follow-up. Permanent neurologic deficit occurred in one patient due to associated injuries. Neck pain and stiffness were reported more commonly in the atypical group, but this finding was not statistically significant. Conclusions The majority of hangman type fractures can be treated nonoperatively. We found no difference in outcomes between a rigid collar or halo immobilization for treatment of low-grade fractures. Radiologic follow-up is essential to identify cases of nonunion.

Intraspinal migration of a Kirschner wire as a late complication of acromioclavicular joint repair: a case report

BACKGROUND

Penetrating neck trauma involving foreign bodies is a rare event in European countries. Due to its relatively high mortality rate, the correct management strategy must be initiated from the beginning to prevent fatal complications. In the medical literature, there are only a few cases describing foreign bodies penetrating the cervical spine. Because of its rareness, many trauma centers lack the proper routine to adequately manage such injuries.

CASE PRESENTATION

This case report describes a 34-year-old white man of Central European descent with Kirschner wire migration and perforation of his vertebral foramen. He underwent acromioclavicular joint repair surgery 7 years ago, presented with a painful sensation around the area of his left clavicle and left side of his neck after a motorcycle accident. No neurological deficit was detected.

CONCLUSIONS

In such cases, a thorough radiological evaluation of the spinal cord and the surrounding vasculature is mandatory for a complete understanding of the extent of the injury and determining the proper surgical management. In cases of vertebral artery trauma both an endovascular and an open approach can be contemplated.

Screening via CT angiogram after traumatic cervical spine fractures: narrowing imaging to improve cost effectiveness. Experience of a Level I trauma center

OBJECT

Screening for vertebral artery injury (VAI) following cervical spine fractures is routinely performed across trauma centers in North America. From 2002 to 2007, the total number of neck CT angiography (CTA) studies performed in the Medicare population after trauma increased from 9796 to 115,021. In the era of cost-effective medical care, the authors aimed to evaluate the utility of CTA screening in detecting VAI and reduce chances of posterior circulation strokes after traumatic cervical spine fractures.

METHODS

A retrospective review of all patients presenting with cervical spine fractures to Northeast Ohio's Level I trauma institution from 2002 to 2012 was performed.

RESULTS

There was a total of 1717 cervical spine fractures in patients presenting to Northeast Ohio's Level I trauma institution between 2002 and 2012. CTA screening was performed in 732 patients, and 51 patients (0.7%) were found to have a VAI. Fracture patterns with increased odds of VAI were C-1 and C-2 combined fractures, transverse foramen fractures, and subluxation of adjacent vertebral levels. Ten posterior circulation strokes were identified in this patient population (0.6%) and found in only 4 of 51 cases of VAI (7.8%). High-risk fractures defined by Denver Criteria, VAI, and antiplatelet treatment of VAI were not independent predictors of stroke.

CONCLUSIONS

Cost-effective screening must be reevaluated in the setting of blunt cervical spine fractures on a case-by-case basis. Further prospective studies must be performed to elucidate the utility of screening for VAI and posterior circulation stroke prevention, if identified.

Strategy for endovascular coil embolization of a penetrating vertebral artery injury

Background:

Penetrating vertebral artery injuries (VAIs) are even rarer than carotid artery injuries. For anatomical reasons, the surgical management of VAI is difficult, and endovascular management often yields a good outcome. We report our strategy for the endovascular treatment of a patient with a penetrating VAI at the V2 segment of the left vertebral artery.

Case Description:

In a fall on a large rake, a 76-year-old man was stabbed in the left neck by three tines. Although he manifested no neurological deficits, computed tomography (CT) suggested penetrating VAI. Digital subtraction angiography confirmed VAI and extravasation, and he underwent endovascular coil embolization. Two microcatheters, inserted proximal and distal to the injury sites, were used for successful endovascular coil embolization. Postoperative magnetic resonance imaging - and single photon emission CT studies denied cerebral infarction and a decrease in cerebral perfusion. The patient exhibited no neurological deficits and was able to leave the hospital on foot.

Conclusion:

This is the rare documentation of a patient whose penetrating VAI was treated by simultaneous coil embolization and foreign body removal. Imaging studies confirmed the patency and perfusion of the intracranial artery. Our treatment strategy produced a good outcome in this unusual patient.

Risk factors for vertebral artery injuries in cervical spine trauma

Blunt cerebrovascular injuries (i.e. involvement of carotid and vertebral arteries) are increasingly being recognized in setting of cervical spine trauma/fractures and are associated with high incidence of stroke/morbidity and mortality. The incidence of vertebral artery injuries (VAI) is more common than previously thought and regular screening is seldom performed. However there exists no screening criteria and conflicting reports exists between spine and trauma literature. Many clinicians do not routinely screen/evaluate patients presenting with cervical spine trauma for potential VAI. This article provides a brief summary of existing evidence regarding the incidence of VAI in the background of cervical trauma/fractures. The type and fracture pattern that is associated with a high risk of VAI warranting mandatory screening/further work-up is discussed. A brief overview of diagnostic modalities and their respective sensitivity/specificity along with available treatment options is also summarized.

Treatment of osteoblastoma at C3-4 in a child: a case report

Background

Osteoblastoma is a rare and benign osteoid-producing primary bone tumor that affects mainly the long bones. 36% of these tumors are observed around the spine and the vast majority arises around the posterior.

Case presentation

This report describes a case of C3-4 osteoblastoma occurring in a 5-year-and-8-month-old Han Chinese child. The pathophysiology of symptom development, evaluations, and management are presented. Because of the close proximity of the osteoblastoma to the vertebral artery canal, the artery suffered a minor laceration intraoperatively. Hemostatic gelatin sponges were used to compress the bleeding site instantly and a tricortical iliac crest fixed with a screw was also used to add pressure to the gelatin sponges. Fusion on the other side was also used to stabilize the spine. To the best of our knowledge, this is the first report of a case of osteoblastoma at C3-4 with artery injury intraoperatively.

Conclusions

This case delineates the difficulties in diagnosing this tumor, the challenges and problems encountered during its surgical management, and the favorable prognosis after adequate treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-313) contains supplementary material, which is available to authorized users.

Does CT Angiography Matter for Patients with Cervical Spine Injuries?

BACKGROUND

Cervical injury can be associated with vertebral artery injury. This study was performed to determine the impact of computed tomography (CT) angiography of the head and neck on planning treatment of cervical spine fracture, if these tests were ordered appropriately, and to estimate cost and associated exposure to radiation and contrast medium.

METHODS

This retrospective review included all patients who underwent CT of the cervical spine and CT angiography of the head and neck from January 2010 to August 2011 at one institution. Patients were divided into those with and those without cervical spine fracture seen on CT of the cervical spine. We determined if the CT angiography of the head and neck was positive for vascular injury in the patients with a cervical fracture. Vascular injury treatment and alterations in surgical fracture treatment due to positive CT angiography of the head and neck were recorded. A scan was deemed appropriate if it had been ordered per established institutional protocol.

RESULTS

Of the 381 patients who underwent CT angiography of the head and neck, 126 had a cervical injury. Sixteen of the CT angiography studies were appropriately ordered for non-spinal indications, and twenty-three were inappropriately ordered. The CT angiography was positive for one patient for whom the imaging was off protocol and one for whom the indication was non-spinal. Nineteen patients had positive CT angiography of the head and neck; no patient underwent surgical intervention for a vascular lesion. Eleven patients underwent surgical intervention for a cervical fracture; the operative plan was changed because of vascular injury in one case. The CT angiography was positive for eleven of forty-eight patients who had sustained a C2 fracture; this group accounted for eleven of the nineteen positive CT angiography studies. Noncontiguous injuries occurred in nineteen patients; three had positive CT angiography of the head and neck. The approximate charge for the CT angiography was $3925, radiation exposure was approximately 4000 mGy/cm, and contrast-medium load was approximately 100 mL.

CONCLUSIONS

Positive CT angiography of the head and neck rarely altered surgical treatment of cervical spine injuries. This study supports the findings in the literature that C1-C3 spine injuries have an increased association with vertebral artery injury. CT angiography of the head and neck ordered off protocol had a low likelihood of being positive. Strict adherence to protocols for CT angiography of the head and neck can reduce costs and decrease unnecessary exposure to radiation and contrast medium.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Vertebral artery injury and severely displaced odontoid fracture: the case for early reduction

PURPOSE

To report a novel treatment method for vertebral artery occlusion. Vertebral artery injuries have a high association with specific cervical fractures including atlanto-axial fractures, displaced fracture patterns, and transverse foramen fractures. Optimal medical management of the occluded vertebral artery has yet to be determined; however, there is an extremely high complication rate with systemic anticoagulation in these patients. Furthermore, unlike appendicular skeleton fracture-dislocations with vascular injury, there is no clear consensus as to the optimal acute management of the displaced odontoid fracture with or without vertebral artery injury.

METHODS

We report on a severely displaced odontoid fracture that was found to have a vertebral artery injury. Medical records and imaging were reviewed.

RESULTS

An 82-year-old female presented to our hospital with a type IIb odontoid fracture after sustaining a ground-level fall. Pertinent physical exam findings were ecchymosis on the left side of her forehead and posterior cervical pain without neurologic deficits. An MRA showed an occluded left vertebral artery. The patient was placed in early cervical traction and the fracture was reduced within 12 h of presentation. Following surgical stabilization, an MR angiogram showed complete reperfusion of the vertebral artery without intimal tear.

CONCLUSION

To our knowledge, this is the first report of a displaced odontoid fracture in which cervical traction was used to restore the perfusion of the vertebral artery. Cervical traction may obviate the need for systemic anticoagulation and should be considered in patients who have an identifiable compression of the vertebral artery even if neurologically intact.

Contemporary management of combat-related vertebral artery injuries

BACKGROUND

Vertebral artery injuries (VAIs) following cervical trauma are uncommon. Advances in imaging technology and emerging endovascular therapies have allowed for the improved diagnosis and treatment of VAIs. We aimed to examine the contemporary management of combat-related penetrating VAIs during current US military operations.

METHODS

A retrospective review was performed on US casualties with combat-related VAIs evacuated to a single military institution in the US from September 2001 to 2010 for definitive management. Casualty demographics, mechanism of injury, location and type of VAI, neurologic sequela, associated injuries, method of diagnosis, and therapeutic management were collected.

RESULTS

Eleven casualties with a mean age of 26 years (mean [SD] ISS, 18 [7.0]) were found to have VAIs from gunshot wounds (6, 55%) or blast fragments (5, 45%). Cervical spine fractures (8, 72%), facial fractures (5, 45%), and spinal cord injury (3, 27%) were not uncommon. One casualty experienced a posterior cerebellar and parietal infarcts. All injuries were evaluated with digital subtraction angiography, 64-slice multidetector row computed tomography, or both. Casualties were noted to have vertebral artery occlusion (4, 36%), pseudoaneurysms (5, 45%), dissection (1, 9%), or arteriovenous fistula (1, 9%), with most injuries occurring in the V2 segment (6, 55%). Pseudoaneurysms were treated with coiling or stent-assisted coiling. Of 11 casualties, 6 were managed nonoperatively, half of whom with anticoagulation or antiplatelet therapy.

CONCLUSION

VAIs are infrequent in modern combat operations, occurring in only 3% of casualties experiencing arterial injuries and are often incidentally discovered during the delayed secondary evaluation of penetrating face and neck injuries at higher echelons of care. One should have a high index of suspicious for a VAI in a casualty with concurrent cervical spine fractures. Endovascular therapies using coils and covered stents have expanded the management options and simplified the treatment of combat-related VAIs.

LEVEL OF EVIDENCE

Therapeutic study, level V.

Current optimal assessment and management of carotid and vertebral spontaneous and traumatic dissection

Dissection of the internal carotid or vertebral artery has been recognized as a cause of stroke in young patients. It is disproportionate in its representation as a cause of stroke in this age group. Intimal tears, intramural hematomas, and dissection aneurysms may be the result of trauma or may occur spontaneously. Spontaneous dissection may be the result of inherent arterial weakness or in association with other predisposing factors. Clinical diagnosis is often difficult, but increased awareness and a range of modern investigations such as computerized tomography or magnetic resonance imaging may aid in diagnosis. Management options include antiplatelet therapy, anticoagulation, thrombolysis, and surgical or endovascular procedures. Prognosis is variable, and dissection may be asymptomatic but may lead to profound neurological deficit and death.

Cervical arterial injury after blunt trauma in children: characterization and advanced imaging

BACKGROUND

The incidence of cervical vascular injury (CVI) after blunt cervical trauma in children and adolescents is low. Potential harm from missed injury is high. Screening for CVI has increased with advances in noninvasive angiography, including computed tomographic angiography (CTA) and magnetic resonance angiography (MRA). We attempt to characterize CVI in children and adolescents and evaluate the utility of advanced imaging in CVI screening in this patient population.

METHODS

Clinical and radiographic records of consecutive patients aged 4 to 18 years with blunt cervical spine trauma from 1998 to 2008 were reviewed. Patient demographics, injury pattern, neurological findings, and treatment were recorded.

RESULTS

Sixty-one patients were identified. Nineteen underwent screening to evaluate for CVI, including 12 males and 7 females, mean age 13.5 years. The most common mechanism of injury was motor vehicle collision (n=11). Seven patients underwent MRA, 7 CTA, 3 had both studies, and 2 had traditional angiography. Seven patients had CVI, with an overall incidence of 11.5%. High-risk criteria (fracture extension to transverse foramina, fracture/dislocations or severe subluxations, or C1-C3 injury) were associated with increased rates of CVI. Neurological injury was found in 12/19 patients screened and 6/7 patients with CVI. Two of 7 patients underwent anticoagulation due to documented CVI. No delayed-onset ischemic neurological events occurred.

CONCLUSIONS

After blunt cervical spine trauma, certain fracture patterns increase the risk of CVI. CVI is common, with a minimum incidence of 7/61 or >10% of pediatric patients with blunt cervical spine injury. Over 1/4 of patients studied on the basis of high-risk criteria had injury. Advanced imaging with noninvasive angiography (CTA/MRA) should be strongly considered in pediatric patients with cervical spine trauma. The presence of CVI may prompt a change in management.

LEVEL OF EVIDENCE

Level IV-retrospective diagnostic study.

Vertebral artery injury in destabilized midcervical spine trauma; predisposing factors and proposed mechanism

BACKGROUND

By now it has been well established that vertebral artery injury (VAI) is associated with unstable cervical spine injuries resulting from blunt trauma. A more complete understanding of predisposing factors and the mechanism of injury in VAI should result in improved outcomes and reduced risk for patients with VAI associated with unstable cervical spine injury following blunt trauma. The authors report statistical outcome and hypothesis to more thoroughly examine the predisposing factors for VAI, of which management is controversial, in destabilized midcervical spine trauma.

METHODS

Ninety-one of 131 consecutive patients who underwent surgery for a traumatically destabilized subaxial cervical spine were included, and results were analyzed statistically by logistic regression.

RESULTS

Eighteen patients (19.8 % of 91 patients) had a VAI associated with midcervical spine trauma (C2-C6). In univariate statistical analysis, transverse foramen fracture (P = 0.002), facet dislocation (P = 0.014), and facet fracture (P = 0.001) were significant risk factors. However, only facet fracture was determined to be significant risk factor after multivariate analysis (P = 0.006, odds ratio 20.98). It is hypothesized that a VAI occurs in a midcervical spine injury when a facet fracture allows the bony compartment to impinge on the relatively narrow free space of the intervertebral foramen, which is also occupied by the cervical root.

CONCLUSION

A facet fracture is the most important risk factor for VAI in patients with a destabilized midcervical spine injury. Patients with a C2-C6 facet fracture may require a definitive evaluation with vertebral artery imaging.

Imaging evaluation of adult spinal injuries: emphasis on multidetector CT in cervical spine trauma

As computed tomography (CT) technology has evolved, multidetector CT has become an integral part of the initial assessment of many injured patients, and the spine is easily included in the total body screening performed in patients with severe blunt polytrauma. Despite all the advantages of multidetector CT, clearing the spine in which injury is suspected continues to be a daily challenge in clinical practice. The purpose of this review is to present the evidence and the controversies surrounding the practice of imaging in patients suspected of having spine injury. The discussion is centered on the increasing reliance on multidetector CT in the work-up of these patients but also considers the important contributions of clinical trials to select patient for appropriate imaging on the basis of risk and probability of injury. Available protocols, injury classification systems, and issues awaiting future research are addressed.

Stab wound with lodged knife tip causing spinal cord and vertebral artery injuries: case report and literature review

STUDY DESIGN

Case report and literature review.

OBJECTIVE

To report the case of a young patient who sustained a penetrating wound with a knife tip retained in his cervical vertebrae and to review the literature.

SUMMARY OF BACKGROUND DATA

Stab wound with foreign body retained, associated with spinal cord injury and vertebral artery injury, is not commonly reported. The timing and approach of surgical intervention are still controversial.

METHODS

A 17-year-old boy with a wound in the neck presented with diminishing feeling and dysfunction of the left leg and arm. Radiographs demonstrated a foreign body at the C4 level, and possible spinal cord and vertebral artery injuries were detected by computed tomography. Digital subtracted angiography showed a small lateral opening of the injured artery, which was successfully embolized. The knife tip was removed from the original wound without severe cerebrospinal fluid leakage or bleeding,

RESULTS

The patient achieved immediate improvement after the operation.

CONCLUSION

Cases of simultaneous spinal cord injury and vertebral artery injury in which the foreign body is retained are uncommonly reported. Digital subtracted angiography is necessary for cervical penetrating wounds and surgical approach should be individualized.

Whole-body computerized tomography and concomitant spine and head injuries: a study of 355 cases

The authors present a prospective study on the coexistence of spinal injury (SI) and severe traumatic brain injury (TBI) in patients who were involved in traffic accidents and arrived at the Emergency Department of Hospital das Clinicas of the University of Sao Paulo between September 1, 2003 and December 31, 2009. A whole-body computed tomography was the diagnostic method employed in all cases. Both lesions were observed simultaneously in 69 cases (19.4%), predominantly in males (57 individuals, 82.6%). Cranial injuries included epidural hematoma, acute subdural hematoma, brain contusion, ventricular hemorrhage and traumatic subarachnoid hemorrhage. The transverse processes were the most fragile portion of the vertebrae and were more susceptible to fractures. The seventh cervical vertebra was the most commonly affected segment, with 24 cases (34.78%). The distribution of fractures was similar among the other cervical vertebrae, the first four thoracic vertebrae and the lumbar spine. Neurological deficit secondary to SI was detected in eight individuals (11.59%) and two individuals (2.89%) died. Traumatic subarachnoid hemorrhage was the most common intracranial finding (82.6%). Spinal surgery was necessary in 24 patients (34.78%) and brain surgery in 18 (26%). Four patients (5.79%) underwent cranial and spinal surgeries. The authors conclude that it is necessary a judicious assessment of the entire spine of individuals who presented in coma after suffering a brain injury associated to multisystemic trauma and whole-body CT scan may play a major role in this scenario.

Clinical indications for arterial imaging in cervical trauma

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To evaluate the clinical indications for acquiring arterial imaging in cervical trauma.

SUMMARY OF BACKGROUND DATA

Cervical spine injuries are very common in high-energy trauma and are frequently seen at Level I trauma centers across the country. A clinical standard of care does not exist to indicate when further evaluation of the cervical vasculature is warranted after a documented cervical spine injury.

METHODS

After institutional review board approval, a retrospective study combining the data from 2 Level I trauma centers was undertaken. An evaluation of every arterial imaging procedure (computed tomography and magnetic resonance angiography) of the cervical spine was collected to further delineate indications and outcomes of these imaging modalities.

RESULTS

From 2005 to 2009, there were a total of 159 patients who underwent cervical arterial imaging at the 2 participating institutions for the indication of cervical trauma with concern for arterial injury. Thirty-six (22.64%) were found to have an injury after arterial imaging. There was a statistically significant correlation with displaced cervical injuries (P < 0.0153), which were defined as cervical dissociations or perched and/or jumped facets. The other statistically significant correlation was the presence of a neurological deficit (P < 0.001), defined as any presenting deficit on sensory or motor examination. Level of injury defined as axial (O-C2) versus subaxial (C3-C7), age, body mass index, and history of cigarette smoking were not statistically related to vascular injury.

CONCLUSION

Our retrospective evaluation indicates that there should be a lower threshold for obtaining arterial imaging with cervical injury patterns historically known to compromise the vasculature, which also have concomitant displaced cervical spine injuries and/or a neurological deficit.

Multi-detector row CT angiography of the neck in blunt trauma

Blunt cerebrovascular injury (BCVI) is uncommon but potentially catastrophic; 80% are caused by vehicle collisions. Ischemic events secondary to untreated BCVI are common, with high injury-specific mortality. This has led to implementation of screening programs based on mechanism of injury, clinical presentation, and injury patterns identified on noncontrast computed tomography (CT) imaging. The standard of reference for diagnosis is four-vessel digital subtraction angiography. Given its availably in trauma service institutions, use of multidetector CT angiography has increased. This article presents the evidence and the controversies surrounding its use. Available protocols, injury description, and grading, as well as potential pitfalls are reviewed.

Effect of heparin following cervical spinal cord injuries in rats

BACKGROUND

Risks of neurological deterioration after heparin administration following cervical spinal cord injury (SCI) in humans are unknown.

OBJECTIVE

To elucidate the safety of heparin following cervical SCI and investigate its potential neuroprotectant role.

METHODS

Sixty-two Sprague Dawley adult rats were subjected to mild (0.6 mm), moderate (0.9 mm), or severe (1.2 mm) C7-SCI. At each injury severity, intravenous heparin or saline was administered for 72 hours following SCI. Behavioral tests (Basso, Beattie, Bresnahan scores, Hargreave's) were performed before killing the rats at week 7. Half of the rats were killed at day 3, and the remainder at week 7 after SCI. Immunohistochemistry, Western blot analysis, and axonal retrograde tracing were conducted at both times.

RESULTS

Subpial hemorrhage was greater in heparin-treated animals compared with controls at all severities of SCI day 3 after injury. Counterintuitively, intraparencyhmal hemorrhage was minimal in the lesion epicenter following mild SCI in the heparin-treated animals compared with controls. India ink perfusion revealed greater preservation of microcirculation in heparin-treated animals compared with a reduction in control animals. A decrease in spinal cord perfusion correlated directly with an increase in hypoxia-inducible factor-1α expression. There was significant gray matter sparing, but no change in white matter volume after heparin treatment at week 7 in the mild SCI group. Beneficial effects on hemorrhagic volume, axon sparing, and functional recovery following heparin treatment were not observed in the moderate or severe SCI group.

CONCLUSION

Heparin treatment following SCI is safe at all degrees of injury. Heparin decreases platelet aggregation and microvascular occlusion, providing a potential neuroprotective effect following mild SCI.

Pediatric traumatic carotid, vertebral and cerebral artery dissections: a review

Traumatic cerebral dissections are rare but potentially dangerous conditions that through improved diagnostics have recently gained increased interest. However, there is still a significant lack of knowledge on the natural history, as well as on the best treatment options. Most of the literature on this topic consists of case reports and retrospective studies with no prospective randomized controlled studies. In our review, we highlight the fact that there is no level 1 evidence for the natural history of cerebral dissections or for the best treatment. We present 26 case studies derived from 70 pediatric patients affected by dissections, occlusions, and pseudoaneurysms.

Transient cortical blindness following a Hangman's fracture: a case report and review of literature

We describe a case with transient cortical blindness after trauma with no obvious structural damage to the vertebral artery in the presence of a C2 spondylolisthesis. A patient complaining of blindness in a setting of polytrauma should always alert the possibility of a cervical spine injury with vertebral artery ischaemia.

Blunt cerebrovascular injuries in acute trauma care: a screening protocol

INTRODUCTION

Blunt cerebrovascular injuries (BCVI) of the extra- or intracerebral vessels are frequently observed lesions which may lead to thrombembolic events with focal neurological deficits, stroke or death particularly in patients <60 years. However, a comprehensive standardised clinical algorithm for screening and management of these secondary injuries is still lacking.

MATERIALS AND METHODS

We developed a standardised screening protocol applicable for mild as well as severely injured patients. In this prospective cohort study, we evaluated the feasibility of this diagnostic algorithm in a level 1 trauma centre setting. Trauma patients who met the inclusion criteria underwent a computed tomographic angiography (CTA) as part of standard diagnostic procedure at admission. All suspicions or positive findings were reevaluated by a conventional four-vessel catheter angiography within the first 72 h after trauma. Within this period, anticoagulation with low-dose heparin was started. BCVI confirmation indicated a shift to systemic heparinisation with overlapping phenprocoumon therapy for at least 6 months. All patients were reevaluated after 6 months by another four-vessel angiography. Depending on the diagnostic findings, oral anticoagulation may be discontinued or continued for another 6 months.

RESULTS

A total of 44 patients (8 male, 6 female, age range 19-95 years) were included in the study. 20 BCVIs were detected in 16 patients (36.3%). The most common injuries identified were Biffl Type II (40%) and Type IV lesions (30%). 86.4% of the patients received a CTA upon admission, 93.2% of which were conducted within 12 h posttrauma. None of the patients had a secondary thrombembolic neurological event during the hospital stay or within 3 months postdischarge.

CONCLUSION

Our results indicate that implementation of the screening protocol can prevent strokes in patients without primary thrombembolic neurological deficits.

The incidence of noncontiguous spinal fractures and other traumatic injuries associated with cervical spine fractures: a 10-year experience at an academic medical center

STUDY DESIGN

Retrospective medical record review.

OBJECTIVE

The purpose of this study was to describe the incidence of other injuries that commonly occur in conjunction with cervical spine fractures and dislocations.

SUMMARY OF BACKGROUND DATA

Cervical spine fractures are often associated with other significant traumatic conditions, which may also require prompt diagnosis and management. However, the relative incidences of the injuries that occur in conjunction with various cervical spine fractures have not been well documented.

METHODS

The radiographic reports of all patients who underwent CT scans of the cervical spine at a single level 1 trauma center over a 10-year period were reviewed. The medical records of individuals with acute, nonpenetrating fractures of the cervical spine were further assessed for any associated traumatic pathology including noncontiguous spine injuries and those affecting other organ systems (i.e., head and neck, intrathoracic, intra-abdominal/pelvic, and nonspinal orthopedic disorders).

RESULTS

A total of 13,896 CT scans of the cervical spine were performed during this 10-year period of which 492 revealed acute fractures and/or dislocations. Of these subjects, 60% had sustained at least one additional injury. Overall, 57% were noted to have extraspinal injuries (34% head and neck, 17% intrathoracic, 10% intra-abdominal/pelvic, and 30% nonspinal orthopedic conditions) and noncontiguous spinal trauma was present in 19% of these cases (8% cervical injuries, 8% thoracic, and 6% lumbar). In general, the rates of associated injuries observed with occipital condyle and C7 fractures were significantly higher than those recorded for other cervical segments.

CONCLUSION

For patients with a known history of cervical spine trauma, the frequencies of associated injuries were similar across all levels of the cervical spine with the exception of the injuries to the craniocervical junctions. In practice, this means that injuries to the cervical spine can likely be grouped together when considering other possible associated injuries. Further elucidation of these injury patterns will likely be useful for facilitating the expedient evaluation and proper management of these individuals.

Cerebrovascular dissections: a review. Part II: blunt cerebrovascular injury

Traumatic cerebrovascular injury (TCVI) is present in approximately 1% of all blunt force trauma patients and is associated with injuries such as head and cervical spine injuries and thoracic trauma. Increased recognition of patients with TCVI in the past quarter century has been because of aggressive screening protocols and noninvasive imaging with computed tomography angiography. Extracranial carotid and vertebral artery injuries demonstrate a spectrum of severity, from intimal disruption to traumatic aneurysm formation or vessel occlusion. The most common intracranial arterial injuries are carotid-cavernous fistulae and traumatic aneurysms. Data on the long-term natural history of TCVI are limited, and management of patients with TCVI is controversial. Although antithrombotic medical therapy is associated with improved neurological outcomes, the optimal medication regimen is not yet established. Endovascular techniques have become more popular than surgery for the treatment of TCVI; endovascular options include stenting of dissections, intra-arterial thrombolysis for acute ischemic stroke caused by trauma, and embolization of traumatic aneurysms.

Vertebral artery injuries following cervical spine trauma: a prospective observational study

PURPOSE

The purpose of this study was to report on the incidence, diagnosis and clinical manifestation of VAI following cervical spine injuries observed in a prospective observational study with a standardized clinical and radiographical protocol.

METHODS

During a 16-year period, 69 (mean age: 43 ± 20.7 years; 25 female, 44 male) of 599 patients had cervical spine injury suspicious for VAI due to facet luxation and/or fractures extending into the transverse foramen. Diagnosis and management of these patients followed a previously published protocol (Kral in Zentralbl Neurochir 63:153-158, 2002). Digital subtraction angiography (DSA) was performed in all 69 patients. Injury grading of VAI was done according to Biffl et al. (Ann Surg 231:672-681, 2000). All patients with VAI were treated with anticoagulation (heparin followed by ASS) for 6 months.

RESULTS

In cases suspicious for VAI, the incidence of VAI detected by DSA was 27.5% (n = 19 of 69 patients). VAI Grade I occurred in 15.8%, Grade II in 26.3%, Grade IV in 52.6% and Grade V in 5.2%. Of 19 patients, 4 (21%) had clinical signs of vertebrobasilar ischemia. Two patients died in hospital after 4 and 21 days respectively. Of 69 patients, 33 (47.8%) with suspected VAI had unstable spine injuries and were treated surgically.

CONCLUSION

In patients with cervical spine fractures or dislocations crossing the course of the vertebral artery, VAI are relatively frequent and may be associated with significant morbidity and mortality. VAI were identified by DSA in 27.5%. Despite anticoagulation therapy, 5.8% became clinically symptomatic and 2.9% died due to cerebrovascular ischemia.

Blunt traumatic vertebral artery injury: a clinical review

Blunt traumatic vertebral injury (TVAI) is frequently associated with head and neck injury and is being detected with increasing frequency due to improved imaging of the trauma patient. In a few cases, it can lead to potentially fatal posterior circulation ischaemia There is debate in the literature regarding whether TVAI should be actively screened for and, if so, how. Management of TVAI may be conservative, medical (antiplatelet agents or anticoagulation), endovascular or open surgery. We review the literature concerning the mechanisms and presentation of TVAI following blunt injury and the current screening recommendations. Management strategies proposed are based on the radiological grade and clinical severity of TVAI, where high-grade symptomatic injuries and high-grade injuries in patients where anticoagulation is contraindicated are treated endovascularly and asymptomatic or low-grade injuries are managed with anticoagulation where it is not contraindicated. Follow-up is via CT angiography to assess for resolution of the injury.

Management of blunt extracranial traumatic cerebrovascular injury: a multidisciplinary survey of current practice

BACKGROUND

Extracranial traumatic cerebrovascular injury (TCVI) is present in 1-3% of all blunt force trauma patients. Although options for the management of patients with these lesions include anticoagulation, antiplatelet agents, and endovascular treatment, the optimal management strategy for patients with these lesions is not yet established.

OBJECTIVE

Multidisciplinary survey of clinicians about current management of TCVI.

METHODS

A six-item multiple-choice survey was sent by electronic mail to a total of 11,784 neurosurgeons, trauma surgeons, stroke neurologists, and interventional radiologists. The survey included questions about their choice of imaging, medical management, and the use of endovascular techniques. Survey responses were analyzed according to stated specialty.

RESULTS

Seven hundred eighty-five (6.7%) responses were received. Overall, a total of 325 (42.8%) respondents favored anticoagulation (heparin and/or warfarin), 247 (32.5%) favored antiplatelet drugs, 130 (17.1%) preferred both anticoagulation and antiplatelet drugs, and 57 (7.5%) preferred stenting and/or embolization. Anticoagulation was the most commonly preferred treatment among vascular surgeons (56.9%), neurologists (50.2%) and neurosurgeons (40.7%), whereas antiplatelet agents were the most common preferred treatment among trauma surgeons (41.5%). Overall, 158 (20.7%) of respondents recommended treatment of asymptomatic dissections and traumatic aneurysms, 211 (27.7%) did not recommend it, and 39.4% recommended endovascular treatment only if there is worsening of the lesion on follow-up imaging.

CONCLUSIONS

These data demonstrate the wide variability of physicians' management of traumatic cerebrovascular injury, both on an individual basis, and between specialties. These findings underscore the need for multicenter, randomized trials in this field.

A traumatic pseudoaneurysm of the vertebral artery

Although uncommon, vertebral artery pseudoaneurysms harbour significant risk of embolic stroke and their presence should be considered in cases of blunt cervical trauma. We illustrate a case of a traumatically ruptured vertebral artery pseudoaneurysm treated with coil embolisation.

Cerebrovascular Dissections—A Review Part I: Spontaneous Dissections

Spontaneous cerebrovascular dissections are subintimal or subadventitial cervical carotid and vertebral artery wall injuries and are the cause of as many as 2% of all ischemic strokes. Spontaneous dissections are the leading cause of stroke in patients younger than 45 years of age, accounting for almost one fourth of strokes in this population. A history of some degree of trivial trauma is present in nearly one fourth of cases. Subsequent mortality or neurological morbidity is usually the result of distal ischemia produced by emboli released from the injury site, although local mass effect produced by arterial dilation or aneurysm formation also can occur. The gold standard for diagnosis remains digital subtraction angiography. Computed tomography angiography, magnetic resonance angiography, and ultrasonography are complementary means o evaluation, particularly for injury screening or treatment follow-up. The annual rate of stroke after injury is approximately 1% or less per year. The currently accepted method of therapy remains antithrombotic medication, either in the form of anticoagulation or antiplatelet agents; however, no class I medical evidence exists to guide therapy. Other options for treatment include thrombolysis and endovascular therapy, although the efficacy and indications for these methods remain unclear.

Isolated transverse process fractures of the subaxial cervical spine: a clinically insignificant injury or not?: a prospective, longitudinal analysis in a consecutive high-energy blunt trauma population

STUDY DESIGN

Prospective single cohort study.

OBJECTIVE

To analyze the incidence, associated injuries, treatment outcomes and associated adverse events of isolated transverse process fractures (TPFs) of the subaxial cervical spine in a high-energy blunt trauma population.

SUMMARY OF BACKGROUND DATA

Currently, TPFs of the subaxial cervical spine are considered to be clinically insignificant. However, this hypothesis is based on clinical experience and has never been supported by research previously.

METHODS

During a 32-month period, routine computed tomography scans of the spine were obtained in high-energy blunt trauma patients. Patients with isolated TPFs of the subaxial cervical spine were prospectively identified. For each enrolled patient, gender, age, mechanism of injury, trauma severity, neurologic deficit, injury levels, affected structures, treatment, radiographic follow-up, functional outcome (Cybex goniometer, neck disability index), and patient satisfaction (10 point visual analog scale) were recorded.

RESULTS

Of 865 enrolled patients, 21 patients (2.4%) had 25 isolated TPFs of the subaxial cervical spine. The seventh vertebra was involved predominantly (76%). The initial treatment regimen was unrestricted movement in all patients. No associated adverse events were observed. A follow-up of 13 to 39 months was available in 14 patients. Follow-up showed a stable and intact subaxial cervical spine in all patients' radiographs, a patient satisfaction of 9.3 (SD 1.48), a Cybex measured range of motion in the sagittal plane of 109 degrees (SD 12.5, 95-129), the frontal plane of 70 (SD 17.8, 37-100) and the transverse plane of 144 (SD 12.5, 116-164), and a mean neck disability index score of 3.93 (SD 8.24).

CONCLUSION

The incidence of isolated TPFs of the subaxial cervical spine was 2.4%. Unrestricted movement resulted in satisfying functional, anatomic, and neurologic outcomes without associated adverse events. This study confirms that isolated TPFs of the subaxial cervical spine can be considered as clinically insignificant and do not require treatment.

What should an ideal spinal injury classification system consist of? A methodological review and conceptual proposal for future classifications

Since Böhler published the first categorization of spinal injuries based on plain radiographic examinations in 1929, numerous classifications have been proposed. Despite all these efforts, however, only a few have been tested for reliability and validity. This methodological, conceptual review summarizes that a spinal injury classification system should be clinically relevant, reliable and accurate. The clinical relevance of a classification is directly related to its content validity. The ideal content of a spinal injury classification should only include injury characteristics of the vertebral column, is primarily based on the increasingly routinely performed CT imaging, and is clearly distinctive from severity scales and treatment algorithms. Clearly defined observation and conversion criteria are crucial determinants of classification systems' reliability and accuracy. Ideally, two principle spinal injury characteristics should be easy to discern on diagnostic images: the specific location and morphology of the injured spinal structure. Given the current evidence and diagnostic imaging technology, descriptions of the mechanisms of injury and ligamentous injury should not be included in a spinal injury classification. The presence of concomitant neurologic deficits can be integrated in a spinal injury severity scale, which in turn can be considered in a spinal injury treatment algorithm. Ideally, a validation pathway of a spinal injury classification system should be completed prior to its clinical and scientific implementation. This review provides a methodological concept which might be considered prior to the synthesis of new or modified spinal injury classifications.

The vertebral artery and the cervical pedicle: morphometric analysis of a critical neighborhood

Object

The purpose of this retrospective study was to quantify the anatomical relationship between the vertebral artery (VA), the cervical pedicle, and its surrounding structures, including the incidence of irregularities. Additionally, data delineating a “safe zone,” and these data's application during instrumentation with transpedicular cervical screw fixation were considered. The anatomical proximity of the VA to the cervical pedicle prevents spine surgeons from preferring cervical pedicle screws (CPSs) over lateral mass screws at levels C3–6. Accurate placement of CPSs is often difficult to determine, because this definition can vary between 1 and 4 mm of lateral “noncritical” and “critical” pedicle breaches. No previous study in a western population has investigated the VA's proximity to the cervical pedicle, its percentage of occupancy in the transverse foramen (TF), and the incidence of irregular VA pathways.

Methods

One hundred twenty-seven consecutive patients who underwent CT angiography of the neck were enrolled in this study. The measurements included the following: medial pedicle border to VA; lateral pedicle border to VA; pedicle diameter (PD); sagittal diameter of the VA; coronal diameter of the VA; sagittal diameter of the TF; and coronal diameter of the TF. The cross-sections of the VA and the TF were measured to determine the occupation ratio of the VA. In addition, a safe zone was defined based on all lateral pedicle border to VA measurements in which the VA was within the TF. The level of entry of the VA into the TF as well as irregularities of the VA and the cervical pedicles were recorded.

Results

Vertebral artery dominance on the left side was seen in 69.3% of cases. The mean PD increased from 4.9 to 6.5 mm (from C-3 to C-7, respectively). Statistically significantly bigger PDs were seen in males. The mean PD at C-2 was 5.6 mm. Entry of the VA at C-6 was seen in approximately 80% of cases. The TF occupation ratio of the VA was found to be the greatest in C-4 and C-7 (37.1 and 74.2%, respectively). The safe zone increased from C-2 to C-6 (1.1 to 1.7 mm, respectively), but was only 0.65 mm at C-7. In 23.6% of cases, an irregular pathway of the VA or irregular anatomy of a cervical pedicle was seen, with the highest incidence of irregularities found at C-2.

Conclusions

Computed tomography angiography is a valuable tool that can help determine the relationships between cervical pedicles and the VA as well as irregular VA pathways. Pedicle diameter, safe zone, and occupational ratio of the VA in the foramen determine the risk associated with instrumentation and should be assessed individually. Based on the authors' measurements, C-4 and C-7 can be considered critical levels for CPS placement. Because of this and the high incidence of irregular VA pathways and different entry points, it may be helpful to review neck CT angiography studies before considering posterior instrumentation procedures in the cervical spine.