Magnetic resonance imaging in acute spinal cord trauma

Quantifying Intraparenchymal Hemorrhage after Traumatic Spinal Cord Injury: A Review of Methodology

Intraparenchymal hemorrhage (IPH) after a traumatic injury has been associated with poor neurological outcomes. Although IPH may result from the initial mechanical trauma, the blood and its breakdown products have potentially deleterious effects. Further, the degree of IPH has been correlated with injury severity and the extent of subsequent recovery. Therefore, accurate evaluation and quantification of IPH following traumatic spinal cord injury (SCI) is important to define treatments' effects on IPH progression and secondary neuronal injury. Imaging modalities, such as magnetic resonance imaging (MRI) and ultrasound (US), have been explored by researchers for the detection and quantification of IPH following SCI. Both quantitative and semiquantitative MRI and US measurements have been applied to objectively assess IPH following SCI, but the optimal methods for doing so are not well established. Studies in animal SCI models (rodent and porcine) have explored US and histological techniques in evaluating SCI and have demonstrated the potential to detect and quantify IPH. Newer techniques using machine learning algorithms (such as convolutional neural networks [CNN]) have also been studied to calculate IPH volume and have yielded promising results. Despite long-standing recognition of the potential pathological significance of IPH within the spinal cord, quantifying IPH with MRI or US is a relatively new area of research. Further studies are warranted to investigate their potential use. Here, we review the different and emerging quantitative MRI, US, and histological approaches used to detect and quantify IPH following SCI.

The Role of Magnetic Resonance Imaging to Inform Clinical Decision-Making in Acute Spinal Cord Injury: A Systematic Review and Meta-Analysis

The clinical indications and added value of obtaining MRI in the acute phase of spinal cord injury (SCI) remain controversial. This review aims to critically evaluate evidence regarding the role of MRI to influence decision-making and outcomes in acute SCI. A systematic review and meta-analysis were performed according to PRISMA methodology to identify studies that address six key questions (KQs) regarding diagnostic accuracy, frequency of abnormal findings, frequency of altered decision-making, optimal timing, and differences in outcomes related to obtaining an MRI in acute SCI. A total of 32 studies were identified that addressed one or more KQs. MRI showed no adverse events in 156 patients (five studies) and frequently identified cord compression (70%, 12 studies), disc herniation (43%, 16 studies), ligamentous injury (39%, 13 studies), and epidural hematoma (10%, two studies), with good diagnostic accuracy (seven comparative studies) except for fracture detection. MRI findings often altered management, including timing of surgery (78%, three studies), decision to operate (36%, 15 studies), and surgical approach (29%, nine studies). MRI may also be useful to determine the need for instrumentation (100%, one study), which levels to decompress (100%, one study), and if reoperation is needed (34%, two studies). The available literature consistently concluded that MRI was useful prior to surgical treatment (13 studies) and after surgery to assess decompression (two studies), but utility before/after closed reduction of cervical dislocations was unclear (three studies). One study showed improved outcomes with an MRI-based protocol but had a high risk of bias. Heterogeneity was high for most findings (I² > 0.75). MRI is safe and frequently identifies findings alter clinical management in acute SCI, although direct evidence of its impact on outcomes is lacking. MRI should be performed before and after surgery, when feasible, to facilitate improved clinical decision-making. However, further research is needed to determine its optimal timing, effect on outcomes, cost-effectiveness, and utility before and after closed reduction.

Characterization of 3-Dimensional Printing and Casting Materials for use in Magnetic Resonance Imaging Phantoms at 3 T

Imaging phantoms are used to calibrate and validate the performance of magnetic resonance imaging (MRI) systems. Many new materials have been developed for additive manufacturing (three-dimensional [3D] printing) processes that may be useful in the direct printing or casting of dimensionally accurate, anatomically accurate, patient-specific, and/or biomimetic MRI phantoms. The T1, T2, and T2* spin relaxation times of polymer samples were tested to discover materials for use as tissue mimics and structures in MRI phantoms. This study included a cohort of polymer compounds that was tested in cured form. The cohort consisted of 101 standardized polymer samples fabricated from: two-part silicones and polyurethanes used in commercial casting processes; one-part optically cured polyurethanes used in 3D printing; and fused deposition thermoplastics used in 3D printing. The testing was performed at 3 T using inversion recovery, spin echo, and gradient echo sequences for T1, T2, and T2*, respectively. T1, T2, and T2* values were plotted with error bars to allow the reader to assess how well a polymer matches a tissue for a specific application. A correlation was performed between T1, T2, T2* values and material density, elongation, tensile strength, and hardness. Two silicones, SI_XP-643 and SI_P-45, may be usable mimics for reported liver values; one silicone, SI_XP-643, may be a useful mimic for muscle; one silicone, SI_XP-738, may be a useful mimic for white matter; and four silicones, SI_P-15, SI_GI-1000, SI_GI-1040, and SI_GI-1110, may be usable mimics for spinal cord. Elongation correlated to T2 (p = 0.0007), tensile strength correlated to T1 (p = 0.002), T2 (p = 0.0003), and T2* (p = 0.003). The 80 samples not providing measurable signal with T1, T2, T2* relaxation values too short to measure with the standard sequences, may be useful for MRI-invisible fixturing and medical devices at 3 T.

Growth and alignment of the pediatric subaxial cervical spine following rigid instrumentation and fusion: a multicenter study of the Pediatric Craniocervical Society

OBJECTIVE The long-term effects of surgical fusion on the growing subaxial cervical spine are largely unknown. Recent cross-sectional studies have demonstrated that there is continued growth of the cervical spine through the teenage years. The purpose of this multicenter study was to determine the effects of rigid instrumentation and fusion on the growing subaxial cervical spine by investigating vertical growth, cervical alignment, cervical curvature, and adjacent-segment instability over time. METHODS A total of 15 centers participated in this multi-institutional retrospective study. Cases involving children less than 16 years of age who underwent rigid instrumentation and fusion of the subaxial cervical spine (C-2 and T-1 inclusive) with at least 1 year of clinical and radiographic follow-up were investigated. Charts were reviewed for clinical data. Postoperative and most recent radiographs, CT, and MR images were used to measure vertical growth and assess alignment and stability. RESULTS Eighty-one patients were included in the study, with a mean follow-up of 33 months. Ninety-five percent of patients had complete clinical resolution or significant improvement in symptoms. Postoperative cervical kyphosis was seen in only 4 patients (5%), and none developed a swan-neck deformity, unintended adjacent-level fusion, or instability. Of patients with at least 2 years of follow-up, 62% demonstrated growth across the fusion construct. On average, vertical growth was 79% (4-level constructs), 83% (3-level constructs), or 100% (2-level constructs) of expected growth. When comparing the group with continued vertical growth to the one without growth, there were no statistically significant differences in terms of age, sex, underlying etiology, surgical approach, or number of levels fused. CONCLUSIONS Continued vertical growth of the subaxial spine occurs in nearly two-thirds of children after rigid instrumentation and fusion of the subaxial spine. Failure of continued vertical growth is not associated with the patient's age, sex, underlying etiology, number of levels fused, or surgical approach. Further studies are needed to understand this dichotomy and determine the long-term biomechanical effects of surgery on the growing pediatric cervical spine.

Acute Thoracolumbar Spinal Cord Injury: Relationship of Cord Compression to Neurological Outcome

BACKGROUND

Spinal cord injury in the cervical spine is commonly accompanied by cord compression and urgent surgical decompression may improve neurological recovery. However, the extent of spinal cord compression and its relationship to neurological recovery following traumatic thoracolumbar spinal cord injury is unclear. The purpose of this study was to quantify maximum cord compression following thoracolumbar spinal cord injury and to assess the relationship among cord compression, cord swelling, and eventual clinical outcome.

METHODS

The medical records of patients who were 15 to 70 years of age, were admitted with a traumatic thoracolumbar spinal cord injury (T1 to L1), and underwent a spinal surgical procedure were examined. Patients with penetrating injuries and multitrauma were excluded. Maximal osseous canal compromise and maximal spinal cord compression were measured on preoperative mid-sagittal computed tomography (CT) scans and T2-weighted magnetic resonance imaging (MRI) by observers blinded to patient outcome. The American Spinal Injury Association (ASIA) Impairment Scale (AIS) grades from acute hospital admission (≤24 hours of injury) and rehabilitation discharge were used to measure clinical outcome. Relationships among spinal cord compression, canal compromise, and initial and final AIS grades were assessed via univariate and multivariate analyses.

RESULTS

Fifty-three patients with thoracolumbar spinal cord injury were included in this study. The overall mean maximal spinal cord compression (and standard deviation) was 40% ± 21%. There was a significant relationship between median spinal cord compression and final AIS grade, with grade-A patients (complete injury) exhibiting greater compression than grade-C and D patients (incomplete injury) (p < 0.05). Multivariate logistic regression identified mean spinal cord compression as independently influencing the likelihood of complete spinal cord injury (p < 0.01).

CONCLUSIONS

Traumatic thoracolumbar spinal cord injury is commonly accompanied by substantial cord compression. Greater cord compression is associated with an increased likelihood of severe neurological deficits (complete injury) following thoracolumbar spinal cord injury.

LEVEL OF EVIDENCE

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

Therapy of an incomplete spinal cord injury by intrathecal injection of EPO and subcutaneous injection of EPO, vitamin C and G-CSF

Spinal cord injury is a rare disease with an incidence about 40 cases per million population in the USA. The most common reasons are traffic accidents, falls, violence and sports. A 53-year-old male patient presented with an incomplete tetraparesis as a result of a spinal cord injury after the accident. It was not possible to treat him with steroids because he was out of the therapeutic time period of 8 hours when he presented to the hospital. The main problem of spinal cord injuries is the secondary injury caused by inflammation and swelling of the spinal cord. To avoid this, the patient was experimentally treated with erythropoietin (EPO) intrathecal and EPO, granulocyte-colony-stimulating factor and vitamin C subcutaneous after his initial spinal cord relief surgery. These drugs might be able to relieve this secondary reaction but were never applied for this indication in human before. This study shows that it could be a promising treatment for spinal cord injuries with potential therapeutic benefits.

Myelopathy

Myelopathy is an inclusive term, referring to pathology leading to a neurologic deficit related to the spinal cord. The clinical diagnosis of myelopathy requires a detailed history and physical examination to define the clinical syndrome. Neuroimaging is indicated in most instances of new-onset myelopathy. It is indicated also when the worsening of a myelopathy is unexplained. Advances in neuroimaging have proved to play a vital role in diagnosis. Appropriate diagnosis and treatment are dependent upon an adequate imaging evaluation to establish the presence of mechanical stability, extrinsic spinal cord compression, or an intramedullary lesion. The most frequent etiology of myelopathy is related to degenerative disease of the spine from osteophyte or extruded disc material causing compression of the spinal cord in the cervical or thoracic spine. The next common etiologies are spinal cord compression due to extradural masses caused by metastatic disease to bone or blunt trauma. In these cases, emergency imaging should be performed to assess the nature of the lesion causing the myelopathy and plan the most appropriate treatment. Also urgent imaging should be performed when an abscess in the spinal canal is suspected. Less urgent is imaging of primary neoplasms of the meninges, roots, or spinal cord, as well as noninfectious inflammatory processes, such as multiple sclerosis, and neurodegenerative, vascular, nutritional, or idiopathic disorders leading to myelopathy. Although a survey of the entire spinal cord can be performed with imaging, it is more appropriate to define from the clinical findings what levels of the spine and spinal cord should be imaged. This approach helps limit the likelihood of false-positive imaging findings that may encourage needless attempts to fix what is not broken. Similarly, the most appropriate imaging study and protocol should be selected in order to provide a timely and accurate diagnosis. To do so requires detailed knowledge regarding the strengths and limitations of the multiple imaging modalities available. This chapter outlines an approach to proper study selection based on the likely etiology of myelopathy from the clinical findings. Chapters 33-39 cover these disorders in detail.

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.

Multidimensional Analysis of Magnetic Resonance Imaging Predicts Early Impairment in Thoracic and Thoracolumbar Spinal Cord Injury

Literature examining magnetic resonance imaging (MRI) in acute spinal cord injury (SCI) has focused on cervical SCI. Reproducible systems have been developed for MRI-based grading; however, it is unclear how they apply to thoracic SCI. Our hypothesis is that MRI measures will group as coherent multivariate principal component (PC) ensembles, and that distinct PCs and individual variables will show discriminant validity for predicting early impairment in thoracic SCI. We undertook a retrospective cohort study of 25 patients with acute thoracic SCI who underwent MRI on admission and had American Spinal Injury Association Impairment Scale (AIS) assessment at hospital discharge. Imaging variables of axial grade, sagittal grade, length of injury, thoracolumbar injury classification system (TLICS), maximum canal compromise (MCC), and maximum spinal cord compression (MSCC) were collected. We performed an analytical workflow to detect multivariate PC patterns followed by explicit hypothesis testing to predict AIS at discharge. All imaging variables loaded positively on PC1 (64.3% of variance), which was highly related to AIS at discharge. MCC, MSCC, and TLICS also loaded positively on PC2 (22.7% of variance), while variables concerning cord signal abnormality loaded negatively on PC2. PC2 was highly related to the patient undergoing surgical decompression. Variables of signal abnormality were all negatively correlated with AIS at discharge with the highest level of correlation for axial grade as assessed with the Brain and Spinal Injury Center (BASIC) score. A multiple variable model identified BASIC as the only statistically significant predictor of AIS at discharge, signifying that BASIC best captured the variance in AIS within our study population. Our study provides evidence of convergent validity, construct validity, and clinical predictive validity for the sampled MRI measures of SCI when applied in acute thoracic and thoracolumbar SCI.

Successful delayed non-operative management of C2 neurosynchondrosis fractures in a pediatric patient: a case report and review of management strategies and considerations for treatment

Upper cervical synchondrosis fractures are the most common types of cervical fractures in the pediatric population less than 7 years of age (Blauth et al (Eur Spine J 5:63-70, 1996); Connolly et al (Pediatr Radiol 25(Suppl1):S129-133, 1995); Mandabach et al (Pediatr Neurosurg 19(5):225-232, 1993); Schippers et al (Acta Neurochir 138:524-530, 1990)) The vast majority occur through the dentocentral or basilar synchondrosis. We present the second reported case in recent literature of a unilateral neurosynchondrosis fracture. The patient, a 4-year-old male, was initially managed conservatively with a rigid cervical collar for a period of 3 months. Despite multiple counseling sessions with family, the patient remained poorly compliant with cervical immobilization. After 3 months, imaging demonstrated partial fusion with persistent anterolisthesis of C2 on C3. The decision was made to place the child in external halo fixation as an attempt to achieve fusion prior to committing to internal surgical fixation and the associated sequelae. Immobilization with a hard cervical collar is often first line treatment. In the case of failed fusion, debate exists regarding surgical fixation in children. Occipito-atlanto-axial fusion leads to permanent loss of a significant degree of flexion, extension, and rotatory movement. The pediatric population has a strong propensity to fuse; however, compliance is often a barrier to conservative treatment due to age-related behavioral practices. We demonstrate that even with initial failed fusion and progression of deformity while in a cervical collar, conservative management with external halo fixation can potentially obviate the need for internal fixation.

A Case of Delayed Myelopathy Caused by Atlantoaxial Subluxation without Fracture

We report a case of delayed myelopathy caused by atlantoaxial subluxation without fracture. The patient was a 38-year-old male who became aware of weakness in extremities. The patient had a history of hitting his head severely while diving into a swimming pool at the age of 14 years old. At that time, cervical spine plain X-ray images showed no fracture, and the cervical pain disappeared after use of a collar for several weeks. At his first visit to our department, X-ray images showed an unstable atlantoaxial joint. After surgery, weakness of the extremities gradually improved. At 6 months after surgery, bone union was completed and the symptoms disappeared. This case shows that atlantoaxial ligament injuries are difficult to diagnose and may easily be missed. A high level of suspicion is important in such cases, since neurological compromise or deterioration may occur many years after the injury.

Imaging techniques in spinal cord injury

BACKGROUND

Spinal imaging plays a critical role in the diagnosis, treatment, and rehabilitation of patients with spinal cord injury (SCI). In recent years there has been increasing interest in the development of advanced imaging techniques to provide pertinent microstructural and metabolic information that is not provided by conventional modalities.

METHODS

This review details the pathophysiological structural changes that accompany SCI, as well as their imaging correlates. The potential clinical applications of novel spinal cord imaging techniques to SCI are presented.

RESULTS

There are a variety of novel advanced imaging techniques that are principally focused on the microstructural and/or biochemical function of the spinal cord, and can potentially be applied to traumatic SCI, including diffusion tensor imaging, magnetic resonance spectroscopy, positron emission tomography, single-photon emission computed tomography, and functional magnetic resonance imaging. These techniques are presently in various stages of development, including some whose applications are primarily limited to laboratory investigation, whereas others are being actively used in clinical practice.

CONCLUSION

Advanced imaging of the spinal cord has tremendous potential to provide patient-specific physiological information about the status of cord integrity and health. Advanced spinal cord imaging is still at early stages of development and clinical implementation but is likely to play an increasingly important role in the management of spinal cord health in the foreseeable future.

Internal stabilization of a flexion-distraction injury of the upper cervical spine of a toddler: a new technique and literature review

STUDY DESIGN

A case report and literature review.

OBJECTIVE

To present a new and simple technique of fixation without fusion of a rare unstable Salter-Harris type I injury in the upper cervical spine of a 23-month-old toddler.

SUMMARY OF BACKGROUND DATA

Surgical treatment of unstable pediatric cervical spine injuries most commonly involves posterior fusion with internal fixation, usually posterior wiring.

METHODS

Detailed description of the surgical procedure carried out for fixating an unstable flexion-distraction injury in a 23-month-old toddler, with severe head injury and pneumothorax, is presented.

RESULTS

A rare unstable flexion-distraction injury in the upper cervical spine of a toddler was successfully treated with a posterior Number 2 Vicryl (polyglactin 910; ETHICON Division of Johnson & Johnson) suture fixation, with good healing of the ligaments and end plates, without fusion. Preservation of motion was achieved without obvious instability at 28 months postsurgery.

CONCLUSION

In selected cases of cervical spine injuries in the young pediatric population, simple stabilization of the spine using degradable Number 2 Vicryl (polyglactin 910) sutures with minimal exposure can provide sufficient stability until healing occurs. Advantages are that fusion is avoided and motion preserved.

Clinical diagnosis and prognosis following spinal cord injury

Spinal cord injury (SCI) is a sudden, life-altering event. Injury severity and accompanying recovery vary considerably from individual to individual. The most important determinant of prognosis is whether an injury is clinically complete or incomplete. While approximately 10-20% of complete injuries convert to incomplete during the first year post-injury, the magnitude of motor recovery following complete SCI is limited or absent. Robust functional motor recovery (e.g., weight-bearing, ambulation) distal to the zone of injury is rare. Recovery following incomplete SCI is particularly variable, and anywhere from 20% to 75% of individuals will recover some degree of walking capacity by 1 year post-injury. This is related to presenting injury severity (American Spinal Injury Association Impairment Scale grade); however, even 20-50% of individuals who present as motor complete, sensory incomplete will walk in some capacity by 1 year post-injury. Regardless, for both complete and incomplete injuries, the majority of recovery is observed during the initial 9-12 months, with a relative plateau reached by 12-18 months post-injury. Magnetic resonance imaging (MRI) provides valuable adjunct information when a bedside clinical assessment cannot be completed. The presence of intramedullary hemorrhage and extended segments of edema have been associated with clinically complete SCI.

Diagnostic and prognostic role of MRI in spinal trauma, its comparison and correlation with clinical profile and neurological outcome, according to ASIA impairment scale

Aims and objectives:

To evaluate the role of magnetic resonance imaging (MRI) as a non-invasive diagnostic tool in patients with acute and chronic spinal trauma and to compare and correlate the MRI findings with those of patients’ clinical profile and neurological outcome according to ASIA impairment scale to assess prognostic and clinical value of MRI.

Materials and Methods:

Sixty two patients of spinal trauma formed the study group in a prospective fashion. The patients undergoing MR imaging and magnetic resonance images were analyzed and correlated with findings on neurological examination according to American Spinal Injury Association (ASIA) impairment scale (AIS) at the time of MRI examination and subsequently at sub-acute interval to assess neurological outcome.

Statistical Analysis:

Sample profile was described in terms of 95% confidence limit and proportion. To describe strength of association between extent of spinal cord injury and outcome, odd's ratio, bivariate and multi variant analysis, was used. Pearson's chi square (χ) ² statistics was applied to test the association between two categorical variables. Data were analyzed using statistical software package, STATA 9.2 and the difference was considered to be significant if ‘P’ value was <0.05.

Observation and Results:

The cord edema without hemorrhage was the most common MR finding (41.5%). The others were sizable focus of hemorrhage within the cord (33%), epidural hematoma (5.0%), and normal cord (26%). Majority of MR findings correlated well with clinical profile of the patient according to ASIA impairment scale. This study demonstrated that patients with presence of sizable focus of haemorrhage had larger cord edema and more severe grade of initial ASIA impairment scale( AIS) with poor recovery at follow up (P=0.032).Improvement in upper extremity was more than lower extremity. Severe cord compression was also associated with poor neurological outcome; however it was not statistically significant (P=0.149).

Conclusions:

With this study the authors concluded that various MRI findings in acute spinal cord injury correlated well with the initial clinical findings and on follow-up according to ASIA impairment scale. MRI is useful for initial diagnosis of acute spinal cord injury and its prognostication for predicting neurological recovery.

Pediatric cervical spine injuries: a comprehensive review

INTRODUCTION

Cervical spine injuries can be life-altering issues in the pediatric population. The aim of the present paper was to review this literature.

CONCLUSIONS

A comprehensive knowledge of the special anatomy and biomechanics of the spine of children is essential in diagnosis and treating issues related to spine injuries.

Magnetic resonance imaging of intramedullary spinal cord lesions: a pictorial review

Magnetic resonance imaging is the current imaging modality of choice in the evaluation of patients presenting with myelopathic symptoms in the search for spinal cord lesions. It is important for the radiologist to recognize and differentiate nonneoplastic from the neoplastic process of the spinal cord as the differentiation of the 2 entities is extremely crucial to the neurosurgeon. This article presents a broad spectrum of benign intramedullary spinal abnormalities including syrinx, contusion, abscess, infarction, myelitis, multiple sclerosis, sarcoid, cavernoma, and arteriovenous malformation. Rare intramedullary neoplasms including dermoid tumor, astrocytoma, ependymoma, hemangioblastoma, lymphoma, ganglioneuroblastoma, and metastases are also illustrated. The clinical presentation and magnetic resonance signal characteristics as well as the differential diagnosis of the intramedullary lesions are discussed. The potential pitfalls in the differentiation of tumors from nonneoplastic disease of the spinal cord are also elucidated.

Traumatic cervical cord transection without facet dislocations--a proposal of combined hyperflexion-hyperextension mechanism: a case report

A patient is presented with a cervical spinal cord transection which occurred after a motor vehicle accident in which the air bag deployed and the seat belt was not in use. The patient had complete quadriplegia below the C5 level and his imaging study showed cervical cord transection at the level of the C5/6 disc space with C5, C6 vertebral bodies and laminar fractures. He underwent a C5 laminectomy and a C4-7 posterior fusion with lateral mass screw fixation. Previous reports have described central cord syndromes occurring in hyperextension injuries, but in adults, acute spinal cord transections have only developed after fracture-dislocations of the spine. A case involving a post-traumatic spinal cord transection without any evidence of radiologic facet dislocations is reported. Also, we propose a combined hyperflexion-hyperextension mechanism to explain this type of injury.

Transient focal spinal cord hyperemia after resection of spinal meningioma: case report

OBJECTIVE

Transient postoperative focal hyperemia in the spinal cord is rare. We report 2 patients with transient focal hyperemia after the resection of a spinal meningioma that led to temporal neurological deterioration followed by complete recovery.

CLINICAL PRESENTATION

Two patients presented with cervical meningiomas at the C7 and C1-C2 levels. Preoperatively, both patients experienced gradual exacerbation of spastic tetraparesis. Magnetic resonance imaging revealed isointensity on T1-weighted images and high intensity on T2-weighted images with homogeneous enhancement.

INTERVENTION

Both patients underwent complete tumor removal. A histopathological examination revealed a meningothelial meningioma in both patients. Postoperative magnetic resonance imaging revealed transient focal hyperemia of the cervical cord.

CONCLUSION

Both patients manifested transient focal hyperemia of the spinal cord after acute decompression by resection of a spinal meningioma.

Cervical spine injuries in children: attention to radiographic differences and stability compared to those in the adult patient

The relative rarity of pediatric cervical spine injuries can impede rapid response and efficient care of this patient population. An understanding of the unique anatomical, radiographic, and biomechanical characteristics of the pediatric cervical spine is essential to the appropriate care of these challenging patients. Patterns of injury, diagnosis, and issues related to operative and nonoperative management are discussed with a focus on the developing spine. Our aim is to improve the understanding of traumatic cervical spine injuries in children for all practitioners involved with their care.

Unstable upper pediatric cervical spine injuries: report of 28 cases and review of the literature

OBJECTIVE

Traumatic lesions of upper cervical spine are rare in children. To evaluate their experience with this lesions and factors affecting outcome, authors conducted a retrospective study of 28 cases of upper pediatric cervical spine injuries treated in the last 25 years.

MATERIALS AND METHODS

To help in treatment of these lesions, we studied our series and reviewed the literature. Patients were divided into three groups: 0 to 2, 3 to 8, and 9 to 16 years, and managed according to status at presentation and type of injury.

RESULTS

Seven patients were managed surgically and 21 nonsurgically (3 halo braces, 18 hard collars or molded braces). Patients in the younger age group sustained more neurological injuries than the others. In group 1, 33% present a fracture/luxation of C0/C1 or odontoid. In group 2, 80% had sustained fracture/luxations of C2. In group 3, 60% present odontoid fractures. At late follow-up review, solid fusions were demonstrated in all patients. Neurological deterioration occur in six patients. The mortality rate was 12%. Compared with other authors' report, incidence of this lesions increased but not the number of those managed surgically.

CONCLUSIONS

Management must be tailored to the patient's age, neurological status, type, and level of injury. Compared with other author's experience, fusion and instrumentation procedures were used less frequently. Signs of medullary compression, significant spine deformation, dynamic instability, and age higher than 8 years are the criteria for surgery. The criteria for instability in children are different from those used in adults because the residual spinal growth is a major concern. The best treatment is therefore preventive.

MRI findings in spinal cord penetrating injury: three case reports

Stab wounds of the spinal canal are rare and constitute an uncommon cause of spinal cord injury. They are usually responsible for an immediate neurological deficit that requires emergency therapeutic management to minimize the extent of neurological deficit and to prevent further loss of neurological function. Magnetic resonance imaging (MRI) is used to evaluate damage to the spinal cord, including contusions, hematoma and compression of extramedullary origin. We report the MRI findings in three patients admitted for spinal canal penetrating injury with neurological symptoms.

Acute cervical traumatic spinal cord injury: MR imaging findings correlated with neurologic outcome--prospective study with 100 consecutive patients

PURPOSE

To prospectively evaluate whether quantitative and qualitative magnetic resonance (MR) imaging assessments after spinal cord injury (SCI) correlate with patient neurologic status and are predictive of outcome at long-term follow-up.

MATERIALS AND METHODS

The study included 100 patients (79 male, 21 female; mean age, 45 years; age range, 17-96 years) with traumatic cervical SCI. Ethics committee approval and informed consent were obtained. The American Spinal Injury Association (ASIA) motor score was used as the outcome measure at admission and follow-up. The ASIA impairment scale was used to classify patients according to injury severity. Three quantitative (maximum spinal cord compression [MSCC], maximum canal compromise [MCC], and lesion length) and six qualitative (intramedullary hemorrhage, edema, cord swelling, soft-tissue injury [STI], canal stenosis, and disk herniation) imaging parameters were studied. Data were analyzed by using the Fisher exact test, the Mantel-Haenszel chi(2) test, analysis of variance, analysis of covariance, and stepwise multivariable linear regression.

RESULTS

Patients with complete motor and sensory SCIs had more substantial MCC (P=.005), MSCC (P=.002), and lesion length (P=.005) than did patients with incomplete SCIs and those with no SCIs. Patients with complete SCIs also had higher frequencies of hemorrhage (P<.001), edema (P<.001), cord swelling (P=.001), stenosis (P=.01), and STI (P=.001). MCC (P=.012), MSCC (P=.014), and cord swelling (P<.001) correlated with baseline ASIA motor scores. MSCC (P=.028), hemorrhage (P<.001), and cord swelling (P=.029) were predictive of the neurologic outcome at follow-up. Hemorrhage (P<.001) and cord swelling (P=.002) correlated significantly with follow-up ASIA score after controlling for the baseline neurologic assessment.

CONCLUSION

MSCC, spinal cord hemorrhage, and cord swelling are associated with a poor prognosis for neurologic recovery. Extent of MSCC is more reliable than presence of canal stenosis for predicting the neurologic outcome after SCI.

Predicting neurologic recovery in cervical spinal cord injury with postoperative MR imaging

STUDY DESIGN

Prospective, nonrandomized, observational cohort study.

OBJECTIVES

To determine whether the presence of spinal cord hemorrhage and length of hematoma on magnetic resonance imaging (MRI) is predictive of recovery in cervical spinal cord injury (SCI).

SUMMARY OF BACKGROUND DATA

A clear picture of the location, extent, and severity of traumatic cervical cord injury can be obtained with MRI. Several prognostic studies looked for an association between the degree of SCI, as depicted by MRI, and neurologic outcome. Up to now, an association between the length of hemorrhage and the extent of SCI and motor recovery could not be demonstrated.

METHODS

Twenty-nine patients with acute traumatic cervical spinal cord injury underwent surgery within 2 to 9 hours. MRI was performed within 2 weeks of injury. Neurologic impairment was classified using the ASIA classification. The effects of hemorrhage and length of hematoma on changes in the neurologic impairment were assessed at time of MRI and at median follow-up in 35 months (range, 24-65 months).

RESULTS

Patients with hemorrhage were much more likely to have a complete injury at time of follow-up (odds ratio = 2.33, 95% confidence interval, 1.42-3.82). Patients admitted with complete SCI, ASIA A, showed a median length of hematoma of 10.5 mm and a median length of edema of 66.5 mm and no change at follow-up. Patients with incomplete SCI showed a median length of hematoma of 4 mm and small edema. Presence of hemorrhage less than 4 mm was associated with good prognosis.

CONCLUSION

This study indicates that presence of hemorrhage of less than 4 mm was not associated with complete SCI and showed good prognosis.

Cervical spine trauma in children: a review

Injuries of the cervical spine are relatively rare in children but are a distinct clinical entity compared with those found in adults. The unique biomechanics of the pediatric cervical spine lead to a different distribution of injuries and distinct radiographic features. Children younger than 9 years of age usually have upper cervical injuries, whereas older children, whose biomechanics more closely resemble those of adults, are prone to lower cervical injuries. Pediatric cervical injuries are more frequently ligamentous in nature, and children are also more prone to spinal cord injury without radiographic abnormality than adults are. Physical injuries are specific only to children. Radiographically benign findings, such as pseudosubluxation and synchondrosis, can be mistaken for traumatic injuries. External immobilization with a halo brace can be difficult and is associated with a high complication rate because of the thin calvaria in children. Surgical options have improved with the development of instrumentation specifically for children, but special considerations exist, such as the small size and growth potential of the pediatric spine.

Neurologic recovery according to early magnetic resonance imaging findings in traumatic cervical spinal cord injuries

The aim of this study was to determine the usefulness of early magnetic resonance imaging findings in predicting neurologic recovery at or below the injured level in traumatic cervical spinal cord injuries. Thirty patients with traumatic cervical spinal cord injuries were included. All of the patients received a magnetic resonance imaging and a neurologic examination in the emergency room, within 7 days of injury and at 6 months following the injury. To quantify neurologic recovery below the injured level, we modified clinical scales, particularly the motor ratio and the sensory ratio. We used the neurologic level to quantify recovery around the injured level. We assessed neurologic recovery according to MRI patterns and lesion extents. The pure hemorrhagic MRI pattern was not observed. In edematous and mixed types, the improvement of neurologic levels was not significantly different. The motor ratio and sensory ratio improved significantly more in edematous type patients than in mixed type patients. Based on MRI lesion extent, the improvement of neurologic levels was not significantly different, and motor ratio and sensory ratio improved significantly more in those with one or two segments involved than in those with more than two segments involved. In conclusion, early MRI pattern and lesion extent after traumatic cervical spinal cord injury may provide important information to help predict neurologic recovery, especially below the injured level.

Spinal Cord Injury without Radiographic Abnormality in Children, 2 Decades Later

OBJECTIVE:

Much new research has emerged since1982, when the original description of spinal cord injury without radiographic abnormality (SCIWORA) as a self-contained syndrome was reported. This article reviews new and old data on SCIWORA, from the past 2 decades.

METHODS:

This article reviews what we have learned since 1982 about the unique biomechanical properties of the juvenile spine, the mechanisms of injuries, the profound influence of age on injury pattern and outcome, the magnetic resonance imaging (MRI) features, and management algorithms of SCIWORA.

RESULTS:

The increasing use of MRI in SCIWORA has yielded ample evidence of damage in virtually all nonbony supporting tissues of the juvenile vertebral column, including rupture of the anterior and posterior longitudinal ligaments, intervertebral disc disruption, muscular and interspinal ligament tears, tectorial membrane rupture, and shearing of the subepiphyseal growth zone of the vertebral endplates. These findings provide the structural basis for the postulated “occult instability” in the spine of a patient after SCIWORA. MRI also demonstrated five classes of post-SCIWORA cord findings: complete transection, major hemorrhage, minor hemorrhage, edema only, and normal. These “neural” findings are highly predictive of outcome: patients with transection and major hemorrhage had profoundly poor outcome, but 40% with minor hemorrhage improved to mild grades, whereas 75% with “edema only” attained mild grades and 25% became normal. All patients with normal cord signals made complete recovery.

The large pool of clinical data from our own and other centers also lends statistical power to uphold most of our original assertions regarding incidence, causes of injury, pathophysiology, age-related changes in the malleability of the spine, vectors of deformation, and the extreme vulnerability of young children to severe cord injury, particularly high cervical cord injury. Thoracic SCIWORA has been identified as an important subset, comprising three subtypes involving high-speed direct impact, distraction from lap belts, and crush injury by slow moving vehicles. Computation of the sensitivities of MRI and somatosensory evoked potentials in detecting SCIWORA shows that both tests were normal in 12 to 15% of children with definite, persistent myelopathy; all of these children were nevertheless braced for 3 months because of their clinical syndrome. Children with transient deficits but abnormal MRI and/or somatosensory evoked potentials were also braced, but the 60% with transient deficits and normal MRI and somatosensory evoked potentials were not braced. This is a change from our original policy in 1982 of bracing all children with persistent or transient deficits, brought on by our new MRI and electrophysiology data.

CONCLUSION:

Injury prevention, prompt recognition, use of MRI and electrophysiological verification, and timely bracing of SCIWORA patients remain the chief measures to improve outcome.

Pediatric spinal cord injury without radiographic abnormality (SCIWORA): the absence of occult instability and lack of indication for bracing

STUDY DESIGN

A retrospective review of medical records and imaging studies of children diagnosed with spinal cord injury without radiographic abnormality (SCIWORA) or SCIWORA-like symptoms at Children's Hospital of Pittsburgh between 1965 and 1999 was undertaken.

OBJECTIVES

To evaluate the existence of occult segmental spinal instability and a role for bracing as treatment for SCIWORA, we contrasted the Children's Hospital of Pittsburgh experience with literature reports on SCIWORA.

SUMMARY OF BACKGROUND DATA

There is a great deal of confusion and conflicting evidence regarding pediatric SCIWORA in the literature. Previous reports from our institution reported unique findings, including the only description of serious, recurrent SCIWORA in the literature. These findings have frequently been cited as the justification for long-term immobilization in all cases of SCIWORA.

METHODS

All records on patients coded as spinal cord injury without fracture or dislocation (ICD-9 code 952.xx) were reviewed. Children 17 years of age or younger with traumatic spinal cord injury and normal plain radiographic findings were included. Penetrating trauma, infection, or metabolic diseases were excluded.

RESULTS

A total of 189 patients were diagnosed with SCIWORA at our institution over the 35-year review period. These patients differed from those reported in the literature with respect to a higher incidence, older age, less involved neurologic injury, and more low-energy mechanisms, such as sports and falls. There were no cases of a patient with SCIWORA who deteriorated and developed a permanent neurologic deficit after having either recovered or plateaued from an initial SCIWORA. All recurrent SCIWORA recovered to normal neurologic function. Bracing did not demonstrate any benefit in preventing these minor recurrent SCIWORAs.

CONCLUSION

We identified no cases of serious, recurrent SCIWORA at our institution from 1965 to 1999. A case-by-case evaluation is required for the treatment of spinal cord injury without apparent spinal column injury, and bracing is not uniformly indicated.

Simultaneous fracture of every cervical vertebra: a case study

STUDY DESIGN

The case of a 14-year-old boy who sustained simultaneous fractures of every cervical vertebra in a high-energy snowmobile accident is reported.

OBJECTIVE

To describe a case of multiple cervical spine fractures and their management.

SUMMARY OF BACKGROUND DATA

Injuries from all-terrain vehicles and off-road vehicles, including snowmobiles, are increasing in severity and frequency. The reported case illustrates a result of high-impact loading in which the driver struck his head after being thrown from a snowmobile at high speed.

METHODS

The 14-year-old boy in the reported case fractured C1-C7, but had no neurologic sequelae.

RESULTS

The fractures were treated with a halo vest after traction and reduction of the displaced odontoid fracture. All the fractures healed with no residual cervical instability.

CONCLUSIONS

This case report is the first to describe a patient of any age who sustained simultaneous fractures of every cervical vertebra. Treatment with a halo vest was successful in protecting the cervical spine until healing was complete.

Management of acute central cervical spinal cord injuries

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

Intensive care unit (or other monitored setting) management of patients with acute central cervical spinal cord injuries, particularly patients with severe neurological deficits, is recommended. Medical management, including cardiac, hemodynamic, and respiratory monitoring, and maintenance of mean arterial blood pressure at 85 to 90 mmHg for the first week after injury to improve spinal cord perfusion is recommended. Early reduction of fracture-dislocation injuries is recommended. Surgical decompression of the compressed spinal cord, particularly if the compression is focal and anterior, is recommended.

Immediate spinal cord decompression for cervical spinal cord injury: feasibility and outcome

BACKGROUND

The effect of immediate surgical spinal cord decompression on neurologic outcome after spinal cord injury is controversial. Experimental models strongly suggest a beneficial effect of early decompression but there is little supportive clinical evidence. This study is designed to evaluate the feasibility and outcome of an immediate spinal cord decompression treatment protocol for cervical spinal cord injury in a tertiary treatment center.

METHODS

To address this issue, 91 consecutive patients with acute, traumatic cervical spinal cord injury (1990-1997) were prospectively studied. Sixty-six patients (protocol group) underwent emergency magnetic resonance imaging (MRI) to determine the presence of persistent spinal cord compression followed, if indicated, by immediate operative decompression and stabilization. Twenty-five patients were managed outside the treatment protocol because of contraindication to magnetic resonance imaging, need for other emergency surgical procedures, or admitting surgeon preference (reference group). The protocol and reference groups had similar sex and age distributions, admitting Frankel grades, levels of neurologic injury, and Injury Severity Scores.

RESULTS

Twenty-seven percent of patients seen were not enrolled in the treatment protocol because of the need for other emergent surgical treatment, contraindication to MRI, and specific surgeon bias regarding the "futility" of emergent treatment. The neurologic outcome for the patients in the reference group were similar to that in the previously reported literature. Fifty percent of protocol patients, compared with only 24% of reference patients, improved from their admitting Frankel grade. Eight protocol patients (12%), but no reference patients, improved from complete motor quadriplegia (Frankel grade A or B) to independent ambulation (Frankel grade D or E). Protocol patients required shorter intensive care unit stays, and shorter total hospital stays than reference patients. In the treatment protocol group, spinal cord decompression, confirmed by MRI, was achieved with immediate spinal column alignment and skeletal traction in 32 patients (46%). Thirty-four patients (54%) required emergent operative spinal cord decompression because of MRI-documented persistent spinal cord compression.

CONCLUSION

We conclude that immediate spinal column stabilization and spinal cord decompression, based on magnetic resonance imaging, may significantly improve neurologic outcome. The feasibility of such a treatment protocol in a tertiary treatment center is well demonstrated. Additional multicenter trials are necessary to achieve definitive conclusions regarding clinical efficacy.

Chest wall trauma

Sufficient trauma to the chest can result in injury to the bony thorax and soft tissues of the chest wall, increasing patient morbidity and mortality. Fractured ribs can lacerate the pleura, lung, or abdominal organs. Fractures to upper ribs, clavicle, and upper sternum can signal brachial plexus or vascular injury. Paradoxical movement of a flail chest can impair respiratory mechanics, promote atelectasis, and impair pulmonary drainage. Most patients with thoracic spine fracture-dislocations have complete neurologic deficits. Scapular fractures, associated with other injuries in almost all patients, are frequently overlooked on supine chest radiographs. Sternal fractures, associated with clinically silent myocardial contusion, are best visualized on chest computed tomography (CT). Severe trauma to the chest wall can be associated with large chest wall hematomas or collections of air within the chest wall that can communicate with the intrathoracic space. CT scanning can easily distinguish chest wall from parenchymal or mediastinal injury, whereas this differentiation my not be possible with chest radiography.

Pediatric cervical spine injuries: report of 102 cases and review of the literature

OBJECT

To evaluate and review their experience with pediatric cervical injuries and factors affecting outcome, the authors conducted a retrospective clinical study of 102 cases (65% boys, 35% girls) of pediatric cervical spine injuries treated in the last decade. This study is an extension of and comparison with their earlier experience.

METHODS

Patients were divided into two age groups-birth to 9 years (Group I) and 10 to 16 years of age (Group 2)- and managed according to status at presentation and type of injury. Thirty patients were managed surgically and 72 non-surgically (42 wore a halo brace and 30 wore hard collars or custom-molded braces). Motor vehicle accidents were the most common cause of injury, and 40% were associated with head injury. Patients in the younger-age group (Group 1) sustained more neurological injuries than the older patients in Group 2, and most injuries were in the upper cervical spine. Of the 38 children in Group 1, in 39% a subluxation was present and in 29% a fracture or fracture/subluxation was demonstrated. Of the patients in Group 2, 80% had sustained fractures or fracture/subluxations. Vertebral fractures were the most common radiological findings (32%). At late follow-up review (mean 5 years), solid fusions were demonstrated in all patients. Neurological deterioration did not occur in any patient. The mortality rate was 16%. Compared with the authors' earlier report, the incidence of cases with pediatric cervical injuries increased, as did the number managed surgically. Various fusion techniques were used, and neurological and fusion outcomes improved as compared with the previous report.

CONCLUSIONS

The prognosis of neurological recovery from pediatric cervical spine injuries is related to the severity of the initial neurological injury. Management must be tailored to the patient's age, neurological status, and type and level of injury. Compared with our earlier experience, fusion and instrumentation procedures were used more frequently. Different types of fusion and instrumentation procedures can be performed safely in children and produce good outcomes.

Indirect posterior reduction and fusion of the traumatic herniated disc by using a cervical pedicle screw system

OBJECT

In this study the authors retrospectively review 16 patients with traumatic disc herniation secondary to middle and lower cervical spine injuries who underwent a single posterior reduction and fusion procedure in which a cervical pedicle screw system was used. The study was undertaken to evaluate whether the procedure effectively reduced the disc herniation and whether it can be safely conducted without performing anterior decompressive surgery.

METHODS

A total of 73 patients with middle and lower cervical spine injuries were identified. In 50 patients, pre- and postoperative magnetic resonance (MR) images were obtained, and disc herniation was defined as the presence of an extruded disc that deformed the thecal sac or nerve roots. Traumatic disc herniation was revealed in 16 patients (32%) who underwent a single posterior reduction/fusion procedure in which a cervical pedicle screw system was used. The average follow-up period was 4.25 years (2-6.25 years). In all patients the average kyphotic deformity was 18 degrees, which was corrected to 0.7 degrees lordosis postoperatively. Anterior translation was reduced from 8 to 0.7 mm. The preoperative disc height ratio of 63% (normal 100%) was improved to 104%. Preoperative MR images revealed traumatic disc herniation in all 16 patients; postsurgery, reduction or reversal of disc herniation was observed in all patients. Thecal sac and/or spinal cord compression had disappeared after indirect decompression was achieved using a posterior procedure. No additional decompressive procedures were required to remove residual herniated disc material. Preoperatively, four patients presented with cervical radiculopathy, 10 with myelopathy (eight incomplete and two complete), and two without neurological symptoms. At final follow up, complete recovery was observed in all four patients with radiculopathy and improvement of at least one Frankel grade was shown in six patients (60%) with myelopathy. There were no cases of neurological deterioration immediately after surgery or during the course of the follow-up period. In all patients solid bone union was demonstrated, and there were no implant-related complications.

CONCLUSIONS

Traumatic disc herniation may occur frequently in association with injury of the cervical spine. The incidence of traumatic disc herniation in our series was 32%. The cervical pedicle screw system allowed three-dimensional reduction of the injured cervical segment and reduction or reversal of a disc herniation. After surgery, compression of the thecal sac and/or spinal cord had disappeared. The cervical pedicle screw system provides effective and safe fixation of the cervical spine injury-related traumatic disc herniation, and the surgery can be performed safely in a single posterior-approach procedure without need of additional anterior decompressive interventions.

Emergency magnetic resonance imaging of cervical spinal cord injuries: clinical correlation and prognosis

OBJECTIVE

The goal of this study was to determine the prognostic and clinical value of magnetic resonance imaging (MRI) performed within hours after cervical spinal cord injuries in human patients.

METHODS

Fifty-five patients with acute cervical vertebral column and spinal cord injuries underwent MRI as part of their initial treatment at the University of Michigan Medical Center. All images were obtained within 21 hours after injury (mean, 7.8 h) and were interpreted by an attending neuroradiologist who was blinded to the clinical status of the patients. Neurological function at presentation and in long-term follow-up examinations was compared with MRI characteristics assessed immediately after the injury.

RESULTS

The presence and rostrocaudal length of intra-axial hematoma, the rostrocaudal length of spinal cord edema, the presence of spinal cord compression, and spinal cord compression by extra-axial hematoma were each significantly associated with poor neurological function at presentation and in long-term follow-up examinations. Although the best single predictor of long-term improvement in neurological function was the neurological function at presentation, four MRI characteristics, i.e., the presence of intra-axial hematoma, the extent of spinal cord hematoma, the extent of spinal cord edema, and spinal cord compression by extra-axial hematoma, provided significant additional prognostic information. MRI data demonstrated spinal cord compression for 27 of 55 patients (49%), leading to emergency surgery. Among patients who underwent imaging after restoration of normal vertebral alignment using closed cervical traction, 13 of 26 (50%) underwent emergency surgery for treatment of persistent, MRI-demonstrated, spinal cord compression.

CONCLUSION

Emergency MRI after spinal cord injury provides accurate prognostic information regarding neurological function and aids in the diagnosis and treatment of persistent spinal cord compression after vertebral realignment.

The optimal radiologic method for assessing spinal canal compromise and cord compression in patients with cervical spinal cord injury. Part II: Results of a multicenter study

STUDY DESIGN

A multicenter, retrospective study using computed tomographic and magnetic resonance imaging data to establish quantitative, reliable criteria of canal compromise and cord compression in patients with cervical spinal cord injury.

OBJECTIVES

To develop and validate a radiologic assessment tool of spinal canal compromise and cord compression in cervical spinal cord injury for use in clinical trials.

SUMMARY OF BACKGROUND DATA

There are few quantitative, reliable criteria for radiologic measurement of cervical spinal canal compromise or cord compression after acute spinal cord injury.

METHODS

The study included 71 patients (55 men, 16 women; mean age, 39.7 +/- 18.7 years) with acute cervical spinal cord injury. Causes of spinal cord injury included motor vehicle accidents (n = 36), falls (n = 20), water-related injuries (n = 8), sports (n = 5), assault (n = 1), and farm accidents (n = 1). Canal compromise was measured on computed tomographic scan and T1- and T2-weighted magnetic resonance imaging, and cord compression at the level of maximum injury was measured on T1- and T2-weighted magnetic resonance imaging. All films were assessed by two independent observers.

RESULTS

There was a strong correlation of canal compromise and/or cord compression measurements between axial and midsagittal computed tomography, and between axial and midsagittal T2-weighted magnetic resonance imaging. Spinal canal compromise assessed by computed tomography showed a significant although moderate correlation with spinal cord compression assessed by T1- and T2-weighted magnetic resonance imaging. Virtually all patients with canal compromise of 25% or more on computed tomographic scan had evidence of some degree of cord compression on magnetic resonance imaging, but a large number of patients with less than 25% canal compromise on computed tomographic scan also had evidence on magnetic resonance imaging of cord compression.

CONCLUSIONS

In patients with cervical spinal cord injury, the midsagittal T1- and T2-weighted magnetic resonance imaging provides an objective, quantifiable, and reliable assessment of spinal cord compression that cannot be adequately assessed by computed tomography alone.

The optimal radiologic method for assessing spinal canal compromise and cord compression in patients with cervical spinal cord injury. Part I: An evidence-based analysis of the published literature

STUDY DESIGN

An evidence-based analysis of published radiologic criteria for assessing spinal canal compromise and cord compression in patients with acute cervical spinal cord injury.

OBJECTIVES

This study was conducted to determine whether literature-based guidelines could be established for accurate and objective assessment of spinal canal compromise and spinal cord compression after cervical spinal cord injury.

SUMMARY OF BACKGROUND DATA

Before conducting multicenter trials to determine the efficacy of surgical decompression in cervical spinal cord injury, reliable and objective radiographic criteria to define and quantify spinal cord compression must be established.

METHODS

A computer-based search of the published English, German, and French language literature from 1966 through 1997 was performed using MEDLINE (U.S. National Library of Medicine database) to identify studies in which cervical spinal canal and cord size were radiographically assessed in a quantitative manner. Thirty-seven references were included for critical analysis.

RESULTS

Most studies dealt with degenerative disease, spondylosis, and stenosis; only 13 included patients with acute cervical spinal cord injury. Standard lateral radiographs were the most frequent imaging method used (23 studies). T1- and T2-weighted magnetic resonance imaging were used to assess spinal cord compression in only 7 and 4 studies, respectively. Spinal cord size or compression were not precisely measured in any of the cervical trauma studies. Interobserver or intraobserver reliability of the radiologic measurements was assessed in only 7 (19%) of the 37 studies.

CONCLUSIONS

To date, there are few quantitative, reliable radiologic outcome measures for assessing spinal canal compromise or cord compression in patients with acute cervical spinal cord injury.

Risk of early closed reduction in cervical spine subluxation injuries

OBJECT

The authors retrospectively reviewed 121 patients with traumatic cervical spine injuries to determine the risk of neurological deterioration following early closed reduction.

METHODS

After excluding minor fractures and injuries without subluxation, the medical records and imaging studies (computerized tomography and magnetic resonance [MR] images) of 82 patients with bilateral and unilateral locked facet dislocations, burst fractures, extension injuries, or miscellaneous cervical fractures with subluxation were reviewed. Disc injury was defined on MR imaging as the presence of herniation or disruption: a herniation was described as deforming the thecal sac or nerve roots, and a disruption was defined as a disc with high T2-weighted signal characteristics in a widened disc space. Fifty-eight percent of patients presented with complete or incomplete spinal cord injuries. Thirteen percent of patients presented with a cervical radiculopathy, 22% were intact, and 9% had only transient neurological deficits in the field. Early, rapid closed reduction, using serial plain radiographs or fluoroscopy and Gardner-Wells craniocervical traction, was achieved in 97.6% of patients. In two patients (2.4%) closed reduction failed and they underwent emergency open surgical reduction. The average time to achieve closed reduction was 2.1+/-0.24 hours (standard error of the mean). The incidence of disc herniation and disruption in the 80 patients who underwent postreduction MR imaging was 22% and 24%, respectively. However, the presence of disc herniation or disruption did not affect the degree of neurological recovery, as measured by American Spinal Injury Association motor score and the Frankel scale following early closed reduction. Only one (1.3%) of 80 patients deteriorated, but that occurred more than 6 hours following closed reduction.

CONCLUSIONS

Although disc herniation and disruption can occur following all types of traumatic cervical fracture subluxations, the incidence of neurological deterioration following closed reduction in these patients is rare. The authors recommend early closed reduction in patients presenting with significant motor deficits without prior MR imaging.