Occlusion of the lumbar spine canal during high-rate axial compression

BACKGROUND CONTEXTWhile burst fracture is a well-known cause of spinal canal occlusion with dynamic, axial spinal compression, it is unclear how such loading mechanisms might cause occlusion without fracture.PURPOSETo determine how spinal canal occlusion during dynamic compression of the lumbar spine is differentially caused by fracture or mechanisms without fracture and to examine the influence of spinal level on occlusion.STUDY DESIGNA cadaveric biomechanical study.METHODSTwenty sets of three-vertebrae specimens from all spinal levels between T12 and S1 were subjected to dynamic compression using a hydraulic loading apparatus up to a peak velocity between 0.1 and 0.9 m/s. The presence of canal occlusion was measured optically with a high-speed camera. This was repeated with incremental increases of 4% compressive strain until a vertebral fracture was detected using acoustic emission measurements and computed tomographic imaging.RESULTSFor axial compression without fracture, the peak occlusion (O_max) was 29.9±10.0%, which was deduced to be the result of posterior bulging of the intervertebral disc into the spinal canal. O_max correlated significantly with lumbar spinal level (p<.001), the compressive displacement (p<.001) and the cross-sectional area of the vertebra (p=.031).CONCLUSIONSSpinal canal occlusion observed without vertebral fracture involves intervertebral disc bulging. The lower lumbar spine tended to be more severely occluded than more proximal levels.CLINICAL SIGNIFICANCEClinically, intermittent canal occlusion from disc bulging during dynamic compression may not show any radiographic features. The lower lumbar spine should be a focus of injury prevention intervention in cases of high-rate axial compression.     

Neurologic recovery from thoracolumbar burst fractures: is it predicted by the amount of initial canal encroachment and kyphotic deformity?

BACKGROUND: The association between neurologic recovery and initial compromise of spinal canal and sagittal alignment has been rarely documented. This study was performed to better understand whether the degree of neurologic recovery from thoracolumbar burst fractures is affected and predicted by initial compromise of spinal canal and sagittal alignment. METHODS: Eighty-seven patients who underwent conservative or surgical treatment for thoracolumbar burst fractures between 1993 and 2001 were prospectively followed up for 3 to 10 years (average, 5.5 years). They were assessed for neurologic deficit and improvement as defined by the scoring system of ASIA, the stenotic ratio of spinal canal and kyphosis angle. RESULTS: The ASIA score in 52 patients with neurologic deficit averaged 34.0 (range, 0-50) on admission and 46.1 (range, 27-50) at final follow-up. All these patients except 2 with neurologic deficit experienced improvement with an average recovery rate of 72.7% (range, 0%-100%). No statistically significant difference (P > .05) in the stenotic ratio of spinal canal or kyphotic deformity was demonstrated among the patients with no neurologic deficit, with incomplete lesions, and with complete lesions. The stenotic ratio of spinal canal or kyphosis angle was not significantly correlated with initial and final ASIA score and recovery rate (P > .05). CONCLUSIONS: The neurologic recovery from thoracolumbar burst fractures is not predicted by the amount of initial canal encroachment and kyphotic deformity. When deciding on the treatment for patients with thoracolumbar burst fractures, both neurologic function and spinal stability should be taken into account.     

Vertebral artery occlusion after acute cervical spine trauma

STUDY DESIGN: A retrospective study of vertebral artery injury diagnosed during the last 6 years in our institution. OBJECTIVES: To determine the clinical and radiologic features of vertebral artery injury. SUMMARY OF BACKGROUND DATA: Extracranial occlusion of the vertebral artery associated with cervical spine fracture is uncommon and can cause serious and even fatal neurologic deficit due to back lifting and cerebellar infarction. Magnetic resonance imaging and magnetic resonance angiography are extremely helpful in the examination of acute injuries of the cervical spine. METHODS: Magnetic resonance imaging and magnetic resonance angiography were performed at the time of injury. RESULTS: The authors reviewed six patients with cervical spine fractures who were diagnosed with a unilateral occlusion of the vertebral artery by means of magnetic resonance imaging/magnetic resonance angiography. One patient had signs of vertebrobasilar insufficiency and another with complete cord lesion had cerebellar and back lifting infarctions. Surgical anterior spinal fusion was performed in five patients, and one was treated by traction and orthosis. At the time of discharge, five patients had no vertebrobasilar symptoms, and the patient who experienced vertebrobasilar territory infarctions showed no progression of the neurologic damage. CONCLUSIONS: Vertebral artery injury should be suspected in cervical trauma patients with facet joint dislocation or transverse foramen fracture. Magnetic resonance imaging/magnetic resonance angiography is a helpful test to rule out vascular injury. Vertebral artery injury affects the extracranial segment at the same level as the cervical fracture. This is a retrospective review that did not permit drawing conclusions about the effects of early surgical stabilization in the treatment of cervical spine injuries with associated vertebral artery injury; however, surgical stabilization may avoid propagation and embolization of the clot located at the site of the lesion.     

The significance of thoracolumbar spinal canal size in spinal cord injury patients

STUDY DESIGN: A prospective, consecutive case series. OBJECTIVES: To determine the relation between spinal canal dimensions and Injury Severity Score and their association with neurologic sequelae after thoracolumbar junction burst fracture. SUMMARY OF BACKGROUND DATA: There is a relation in the cervical spine between spinal canal dimension and its association with neurologic sequelae after trauma. A similar relation at the thoracolumbar junction has not been conclusively established. METHODS: Forty-three patients with thoracolumbar junction burst fractures (T12-L2),13 with and 30 without neurologic deficit, were included. Computed tomographic scans were used to measure the sagittal and transverse diameters and the surface area of the spinal canal at the level of injury, as well as one level above and one level below the fracture level. Injury severity score was calculated for both groups. Statistical analysis comparing those with a neurologic deficit to those without was performed by Student's t test. RESULTS: The ratio of sagittal-to-transverse diameter at the level of injury was significantly smaller in patients with a neurologic deficit than in those without a neurologic deficit (P < 0.05). The mean transverse diameter at the level of injury was significantly larger in patients with neurologic deficit than in the neurologically intact patients (P < 0.05). The surface area of the canal at the level below the injury was significantly larger in the patients with a neurologic deficit than in those without a deficit (P < 0.05). Patients with a neurologic deficit had a statistically higher Injury Severity Score when admitted than those without a neurologic deficit (P < 0.0001), although the difference became insignificant after the neurologic component of the scoring system was eliminated. CONCLUSION: There are no anatomic factors at the thoracolumbar junction that predispose to neurologic injury after burst fracture. The shape of the canal after injury, however, as determined by the sagittal-to-transverse diameter ratio, was predictive of neurologic deficit.     

Does neurological recovery in thoracolumbar and lumbar burst fractures depend on the extent of canal compromise?

STUDY DESIGN: Prospective study. OBJECTIVES: Forty-five consecutive cases of thoracolumbar and lumbar burst fractures treated non-operatively were analyzed to correlate the extent of canal compromise at the time of injury with (i) the initial neurologic deficit and (ii) with the extent of neurological recovery at 1 year. The effect of spinal canal remodeling on neurological recovery was also analyzed. SETTING: University teaching hospital in south India. METHODS: The degree of spinal canal compromise and canal remodeling were assessed from computed tomography scans. The neurologic status was assessed by Frankel's grading. RESULTS: The mean canal compromise in patients with neurologic deficit was 46.2% while in patients with no neurological deficit it was 36.3%. The mean spinal canal compromise in patients with neurological recovery was 46.1% and 48.4% in those with no recovery. The amount of canal remodeling in patients who recovered was 51.7% and 46.1% in the patients who did not recover. None of these differences was statistically significant. CONCLUSION: This study shows that there is no correlation between the neurologic deficit and subsequent recovery with the extent of spinal canal compromise in thoracolumbar burst fractures.     

Management of thoracolumbar fractures with accompanying neurological injury.

The optimal surgical approach for spinal canal reconstruction of thoracolumbar fractures is controversial, and the relationship between spinal canal reconstruction and neurological recovery remains unclear. To address these issues, 22 consecutive cases of thoracolumbar fracture with accompanying neurological deficit were reviewed. Neurological status was graded at the time of admission, postoperatively, and at a mean of 15 months postinjury. By using preoperative and postoperative radiographs and computed tomographic scans, the degree of spinal canal compromise was quantified in the sagittal, coronal, and axial planes. All fractures were stabilized by posterior instrumentation and fusion, and in 10 injuries, retropulsed vertebral body fragments were further reduced by posterolateral decompression. Spinal canal dimensions, neurological function, and operative approach were compared by using nonparametric statistical analysis. The greater the initial spinal canal compromise, the more severe the neurological deficit (P = 0.04). With injuries involving L1 and above, this relationship increased (P = 0.003). The extent of spinal canal reconstruction failed to correlate with neurological recovery. Compared with spinal instrumentation alone, transpedicular decompression showed no benefit in terms of postoperative canal dimensions or neurological outcome. On the basis of this experience, transpedicular decompression offers no advantage over spinal instrumentation alone. The relationship between initial spinal canal encroachment and neurological deficit demonstrates that the degrees of bony and neurological injury directly reflect the kinetic energy transferred at the time of impact. The lack of correlation between the extent of spinal canal reconstruction and neurological recovery suggests that ongoing neural compression/distortion contributes little to the overall neurological injury.     

A biomechanical analysis of spinal instrumentation systems in thoracolumbar fractures. Comparison of traditional Harrington distraction instrumentation with segmental spinal instrumentation

A total of 61 biomechanical tests were performed on 25 cadaveric spinal segments to investigate the comparative strengths of three instrumentation systems: 1) conventional Harrington distraction instrumentation (HRI), 2) segmentally wired Harrington distraction rods, and 3) Luque segmental spinal instrumentation (SSI). In type I testing in which axial preload was applied to normal specimens, and then progressive rotation until ultimate failure followed, five of six Harrington systems failed at the bone-metal interface. In contrast, all six Luque SSI vertebral segments disrupted in a location removed from the bone-metal interface. In Type-II testing (six specimens) in which axial loading of experimentally produced unstable burst fractures was applied, the most stable fixation in resisting compressive loads was segmentally wired Harrington distraction rods (P less than 0.001). In Type-III testing (six specimens), there was axial preloading, then progressive rotation applied to translational fracture-dislocations and this showed that the ability to resist torsion was lowest with plain HRI, slightly improved by segmentally wired HRI, and the stiffest system was Luque SSI (P less than 0.05). The three methods of testing cadaveric segments provided a relevant laboratory model for investigation of spinal instrumentation systems in thoracolumbar fracture stabilization. The results compare favorably with other biomechanical studies, information derived from in vitro and ex vivo animal models and clinical experience with failures of fixation. The biomechanical advantages of segmentally wired Harrington distraction instrumentation in resisting axial loads seem to justify this method of fixation in unstable burst fractures. Similarly, the use of Luque segmental spinal instrumentation with L-rods coupled together is the best method of achieving rotational stability in translational injuries (fracture-dislocations). However, the above biomechanical considerations should be balanced against the increased operative time, more exacting technical expertise required, and possible risk of iatrogenic neurologic sequelae in implementing segmental fixation in unstable thoracolumbar fracture management.     

Dural lacerations and thoracolumbar fractures

In the pre-CT era, Miller et al. reported the presence of dural lacerations (DL) and herniations of the cauda equina in a group of patients with thoracolumbar fractures that involved separation of the pedicles, as detailed on plain radiographs. Recently, these injuries have been well characterized on CT scan. We retrospectively reviewed our series of thoracolumbar burst fractures to assess the predictive value of CT for the presence of a DL, and the clinical significance of this finding. Twenty-five patients with 27 levels of injury were assessed. Dural lacerations were noted in eight (32%) of the cases. These were significantly associated with posterior element fractures noted on axial CT, and with motor neurologic deficits. There was no correlation between the presence of a DL and the degree of spinal canal compromise. Dural lacerations occur relatively frequently in patients with thoracolumbar fractures that require operative management. Their presence should be of particular concern in those cases with a motor deficit on presentation and a posterior element fracture on axial CT scan.     

Non-contiguous spinal fractures

A retrospective review of 817 spinal fracture patients revealed a 6.4% (52/817) incidence of non-contiguous spine fractures. Seventy-three per cent of the non-contiguous injuries were comprised of combinations of injuries in the cervical and thoracic regions or in the thoracic and lumbar regions. Forty-five per cent of fractures were a combination of compression fractures, 40% a combination of a compression fracture and a major spine fracture (i.e., one more likely to cause a neurologic deficit), and 15% a combination of major fractures.     

Is the anterior spinal artery occluded in severe cervical compressive myelopathy?

Purpose: The goal of this study was to identify whether the anterior spinal artery (ASA) is occluded in severe cervical compressive myelopathy (CCM) according to computed tomography angiography (CTA); occlusion was defined as spinal canal sagittal diameter compression of more than 80%.Study design: A retrospective study.Setting: Xinqiao Hospital, Chongqing, China.Participants: The sample comprised 11 patients with spinal canal sagittal diameter compression of more than 80%.Interventions: The patient underwent CTA of the ASA after admission. Covisualization of the ASA and the artery of Adamkiewicz was used to identify the ASA.Outcome Measures: Spinal cord compression and decompression were determined with 1.5-Tesla magnetic resonance imaging. The neurologic status was evaluated according to the classification of the American Spinal Injury Association (ASIA).Results: No ASA occlusion was found in all 11 severe CCM patients who presented with chronic or acute onset. All patients demonstrated improved neurological status after the anterior cervical decompression and fusion procedure.Conclusion: ASA occlusion was not observed in CCM patients with spinal canal sagittal diameter compression of more than 80%.     

Pathoanatomical and surgical findings in cervical spinal injuries

The pathomorphology of normal and degenerated human cervical spines that had been subjected to trauma was studied in detail by surface-cryoplaning of frozen autopsy specimens. Four cervical spines that had been surgically fused were also sectioned after removal of the metal. In young individuals, disc ruptures occurred that resulted in compromise of the vertebral canal. In degenerated spines, vertebral endplate ridges were frequently fractured. These injuries resulted in encroachment on the spinal cord as well as on the nerve roots in the foramen. Osteophytes from the uncinate processes also contributed to stenosis at the nerve root exist. These pathoanatomical findings were corroborated by intraoperative observations in patients. The high incidence of compressive lesions anteriorly in the cervical spine underscores the need to consider both anterior and posterior surgery in many of these patients.     

Dynamics of interpedicular widening in spinal burst fractures: an in vitro investigation

Background contextSpinal burst fractures are a significant cause of spinal instability and neurologic impairment. Although evidence suggests that the neurologic trauma arises during the dynamic phase of fracture, the biomechanics underpinning the phenomenon has yet to be fully explained. Interpedicular widening (IPW) is a distinctive feature of the fracture but, despite the association with the occurrence of neurologic deficit, little is known about its biomechanics.PurposeTo provide a comprehensive in vitro study on spinal burst fracture, with special attention on the dynamics of IPW.Study designExperimental measurements in combination with computed tomography scanning were used to quantitatively investigate the biomechanics of burst fracture in a cadaveric model.MethodsTwelve human three-adjacent-vertebra segments were tested to induce burst fracture. Impact was delivered through a drop-weight tower, whereas IPW was continuously recorded by two displacement transducers. Computed tomography scanning aided quantifying canal occlusion (CO) and evaluating sample anatomy and fracture appearance. Two levels of energy were delivered to two groups: high energy (HE) and low energy (LE).ResultsNo difference was found between HE and LE in terms of the residual IPW (ie, post-fracture), maximum IPW, or CO (median 20.2%). Whereas IPW was not found to be correlated with CO, a moderate correlation was found between the maximum and the residual IPW. At the fracture onset, IPW reached a maximum median value of 15.8% in approximately 20 to 25 milliseconds. After the transient phase, the pedicles were recoiled to a median residual IPW of 4.9%.ConclusionsOur study provides for the first time insight on how IPW actually evolves during the fracture onset. In addition, our results may help shedding more light on the mechanical initiation of the fracture.     

Unilateral cervical facet fractures with subluxation: injury patterns and treatment

STUDY DESIGN: This is a retrospective study of patients with unilateral cervical facet fractures from a Level I academic trauma center. OBJECTIVE: We sought to examine fracture patterns involving only the facets, to examine the incidence of associated neurologic and vascular injuries, and to determine optimum management strategies for these injuries. SUMMARY OF BACKGROUND DATA: Most of the literature regarding unilateral cervical facet injuries has resulted from studies evaluating dislocated locked facets, "fracture-dislocations," or fractures of the lateral mass and pedicle. METHODS: We retrospectively reviewed our experience with unilateral fractures of the facets, identifying 25 cases over a 5-year period. Presenting history, neurologic examination, imaging findings, method of reduction, interval to surgery, type of surgery, and evaluation for vascular injuries were recorded. Fusion was assessed by plain radiographs and computed tomography scans at follow-up. RESULTS: All 25 patients were treated operatively. Ten of the fractures involved the superior articular process, 13 involved the inferior articular process, and 2 cases involved both. The most commonly affected level was at C6/7. Twenty-one of the 25 patients underwent anterior stabilization, 3 underwent posterior stabilization, and 1 underwent anterior-posterior stabilization. Eleven patients underwent diagnostic 4-vessel angiography, revealing 2 patients with vertebral artery injuries. Average follow-up was 11.5 months. There were no identifiable nonunions. CONCLUSIONS: We conclude the following: (a) anterior discectomy and fusion with a static (constrained) plating system is appropriate treatment for this type of injury, (b) in the absence of significant neurologic deficit with residual canal or foraminal stenosis, preoperative closed reduction is not necessary, (c) a small percentage of these patients will have vertebral artery injury, thus warranting screening with 16-slice computed tomographic angiography.     

Z-plate instrumentation in thoracolumbar spinal fractures.

Anterior decompression enables direct access and good canal clearance of the injury level in thoracolumbar spinal fractures, and decompressing the neural elements is shown to be an important factor for neurologic improvement and pain relief in many cases. In this study, results with anterior decompression and Z-plate instrumentation in thoracolumbar spinal fractures are reviewed. Nineteen patients with old spinal fracture (average: 3 years) and neural compression, and 15 patients with fresh thoracolumbar fractures with neurologic deficit and/or major anterior spinal canal obstruction had anterior decompression and Z-plate instrumentation with anterior fusion. Stabilization was protected with thoracolumbar thermoplastic braces for six months. Preoperative kyphotic deformity averaged 20.9 degrees (range: 7 degrees to 64 degrees), while it was an average of 8.0 degrees (range: -12 degrees to 35 degrees) postoperatively. Medullary canal compromise was 41% an average (range: 13% to 67%) and postoperatively it had an average value of 6% (range: 0% to 18%). Patients were followed up an average of 30 months (range: 25 to 36 months). The unchanged positions of bone grafts and statistically insignificant loss of correction in the sagittal plane are accepted as evidence for bony fusion in all patients. Z-plate instrumentation provides stable fixation. Additionally, the technique can be performed easily and has the added benefit of being MRI-compatible.     

Angiographic detection of carotid and vertebral arterial injury in the high-energy blunt trauma patient

BACKGROUND AND OBJECTIVE: Injury to the carotid and vertebral arteries is an identified risk to patients after blunt high-energy cranio-cervical trauma with an associated risk of thromboembolic stroke. We sought to determine the incidence, features, and risk factors of arterial injury using selective cerebral angiography in a high-risk trauma patient subset. METHODS: Blunt trauma patients with a high-energy mechanism were selected to undergo screening cerebral angiography if they met one of the following criteria: (1) cervical spine hyperextension/hyperflexion injury, (2) skull-base or facial fracture, (3) lateralizing neurologic deficit, ischemic deficit, or cerebral infarction, or (4) hemorrhage of arterial origin. RESULTS: Of 69 screened patients 20 were found to have a vascular injury (28.9%), including 13 carotid and 15 vertebral; 9 of the 20 patients with vascular injury were symptomatic (45%). The most frequent injuries were intimal dissections (8/28), pseudoaneurysms (6/28), and vessel occlusions (5/28); 8 lesions were intracranial and 20 cervical. Displaced facial fractures (P<0.02) but not skull-base fracture were predictive of carotid injury; multilevel cervical spine fractures (P<0.001) and transverse foraminal fractures (P<0.02) were associated with vertebral injury. CONCLUSIONS: Cerebral angiography in a selected group of trauma patients was found to yield a significant rate of carotid and vertebral arterial injury, a finding that had implications to subsequent clinical management.     

Spinal cord injury without radiographic abnormality in children--the SCIWORA syndrome

Spinal cord injury in children frequently occurs without fracture or dislocation. The clinical profiles of 55 children with spinal cord injury without radiographic abnormalities (SCIWORA) are reported in detail to illustrate features of this syndrome. No patient had vertebral fracture or dislocation on plain films and tomographies. There were ten upper cervical (C1-C4), 33 lower cervical (C5-C8), and 12 thoracic cord injuries; of these, 22 were complete or severe lesions and 33 were mild lesions. The mechanism of the neural injury probably relates to the inherent elasticity of the juvenile spine, which permits self-reducing but significant intersegmental displacements when subjected to flexion, extension, and distraction forces. The spinal cord is therefore vulnerable to injury even though the vertebral column is spared from disruption, and this vulnerability is most evident in children younger than 8 years. All but one of the 22 children with profound neurologic injuries were younger than 8 years (p less than 0.000001), whereas 24 of 33 children with mild injuries were older. Younger children were also more likely to have severe upper cervical lesions (p less than 0.05); lower cervical lesions were distributed evenly through the ages of 6 months to 16 years. Thoracic injuries most commonly resulted from distraction or crushing. Distraction invariably involved violent forces, and crush injuries were usually caused by children being run over while lying prone, when the spinal column was acutely bowed towards the spongy abdominal and thoracic cavities. Fifteen children had delayed onset of neurologic deficits; nine of these had transient warning symptoms of paresthesia, subjective paralysis, and Lhermitte's phenomenon 30 minutes to 4 days before the onset of deterioration. Eight other children suffered a second SCIWORA 3 days to 10 weeks after the initial SCIWORA. The spines in these children were presumably rendered incipiently unstable by the initial injury and thus were susceptible to additional, often more severe, neurologic trauma. The long-term neurologic outcome in children with SCIWORA is solely determined by their admission neurologic status. Realistically, the outcome can thus only be improved by: 1) ruling out occult fractures and subluxation which will require surgical fusion; 2) identifying patients likely to have delayed deterioration; and 3) preventing recurrent SCIWORA. Our experience and recommendations in these regards are discussed.     

The efficiency of ultrasound guided spinal fracture reposition

Summary To calculate canal compromise and decrease of midsagittal diameter caused by retropulsion of fragments into the spinal canal we analyzed the pre- and postoperative computed tomographies of 32 patients with unstable thoracolumbar burst fractures treated by USS (universal spine system). Our intention was to examine the efficiency of ultrasound guided repositioning of the dispaced fragments which was performed in all 32 cases. We found a clear postoperative enlargement of canal area (ASP preoperatively 55 %, postop. 80 %) and midsagittal diameter (MSD preop. 58 %, postop. 78 %). 10 of 13 patients presented a postoperative improvement of neurological deficit, no neurological deterioration occured. Fractures with neurological deficit showed more canal compromise (52 %) and less midsagittal diameter (MSD compromise 51 %) than those without (40 % or 39 %). There was no correlation between the percentage of spinal canal stenosis and the severity of neurological deficit. Below L 1 the spinal canal is greater than between Th 11 and L 1, so a more important spinal stenosis is tolerated. In case of unstable burst fractures with neurological deficit the ultrasound guided spinal fracture reposition is an effective procedure concerning the necessary improvement of spinal stenosis: an additional ventral approach for the revision of the spinal canal is unneeded. In fractures without neurologic deficit the repositioning of the displaced fragments promises an avoidance of long-term damages such as myelopathia and claudicatio spinalis.      

Functional recovery after near complete traumatic deficit of the cervical cord lasting more than 24 h.

Two young men presented with a complete cervical cord deficit associated with bilateral C4-C5 dislocation and 11 mm encroachment (sagittal narrowing) of the spinal canal in one case and near complete cervical cord deficit due to a crush fracture of the C7 vertebral body with 9 mm axial compression and 50% antero-posterior encroachment of the canal in the other case. There was no improvement within the first 24 h. Both patients left the hospital walking after open surgical realignment and complete cord decompression.     

胸腰椎爆裂骨折损伤部位和椎管内占位程度与神经损伤的关系

目的探讨胸腰椎爆裂骨折骨折部位及椎管内骨块占位程度与神经损伤的关系。方法对213例胸腰椎爆裂骨折根据骨折部位及CT测出的椎管内骨折骨块占位程度与神经损伤进行分析评定。结果神经损伤组椎管骨折骨块占位程度明显高于无神经损伤组;在有神经损伤情况下,骨折部位椎管内骨块占位程度腰段大于胸腰段;神经损伤程度与椎管内骨块占位程度无显著相关。结论胸腰椎爆裂骨折椎管内骨块占位压迫是神经损伤的重要因素;神经损伤与骨折部位和椎管内骨块占位程度联合相关。     

Liberalized screening for blunt carotid and vertebral artery injuries is justified

BACKGROUND: Current literature suggests that blunt carotid injuries (BCIs) and vertebral artery injuries (BVIs) are more common than once appreciated. Screening criteria have been suggested, but only one previous study has attempted to identify factors that predict the presence of BCI/BVI. This current study was conducted for two reasons. First, we wanted to determine the incidence of BCI/BVI in our institution. Second, we wanted to determine the incidence of abnormal four-vessel cerebral angiograms ordered for injuries and signs believed to be associated with BCI/BVI and thus to determine whether the screening protocol developed was appropriate. METHODS: From August 1998, we used liberalized screening criteria for patients who were prospectively identified and suspected to be at high risk for BCI/BVI if any of the following were present: anisocoria, unexplained mono-/hemiparesis, unexplained neurologic exam, basilar skull fracture through or near the carotid canal, fracture through the foramen transversarium, cerebrovascular accident or transient ischemic attack, massive epistaxis, severe flexion or extension cervical spine fracture, massive facial fractures, or neck hematoma. Four-vessel cerebral angiograms were used for screening for BCI/BVI. RESULTS: Over the 18-month study period, 48 patients were angiographically screened, with 21 patients (44%) being identified as having a total of 19 BCIs and 10 BVIs. Nine patients had unilateral carotid artery injuries and three patients had bilateral carotid artery injuries. Vertebral artery injuries were unilateral in six patients. One patient had bilateral carotid artery injuries and a unilateral vertebral artery injury. One patient had a unilateral carotid artery injury and a unilateral vertebral artery injury, and one patient had a unilateral carotid artery injury and bilateral vertebral artery injuries. During the same study period, 2,331 trauma patients were admitted, with 1,941 (83%) secondary to blunt trauma. The overall incidence of BCI/BVI was 1.1%. The frequency of abnormal angiograms ordered for cerebrovascular accident or transient ischemic attack, massive epistaxis, or severe cervical spine fractures was 100%. The frequency of abnormal angiograms ordered for the other indications was as follows: fracture through foramen transversarium, 60%; unexplained mono- or hemiparesis, 44%; basilar skull fracture, 42%; unexplained neurologic examination, 38%; anisocoria, 33%; and severe facial fractures, 0%. CONCLUSION: The liberalized screening criteria used in this study were appropriate to identify patients with BCI/BVI. This study suggests BCI/BVI to be more common than previously believed and justifies that screening should be liberalized.