Spinal Canal Dimensions Research Articles

The Short Term Results of Selective Nerve Root Block in Spinal Stenosis by Contrast Pattern

.Conclusions: There was a short term effect of selective nerve root block (sNRB) in patients with spinal stenosis regardless of their contrast pattern, type I group showing a stronger correlation. In regards to spinal canal dimension, patients with larger spinal canal sizes not only showed a significant decrease in VAS score after selective nerve root block (sNRB) but also showed differences depending on the contrast pattern. On the contrary, there was no significant difference in VAS score before and after selective nerve root block (sNRB) in patients with small spinal canal sizes, and there was also no difference in the outcome depending on the contrast pattern in patients with small spinal canal sizes. Therefore, when performing selective root nerve block (sNRB), the operator should remember to manipulate the angle and position of the spinal needle when injecting the appropriate drug after confirming that the contrast material reached the spinal canal. The operator should also consider surgical management when performing selective nerve root block (sNRB) in patients with severe central spinal stenosis.

Long-term Outcomes of 2 Cervical Laminoplasty Methods

Two major current methods are midline splitting laminoplasty (MSL) and unilateral single-door laminoplasty (USDL). Few studies have compared the 2 techniques. We retrospectively analyzed the outcomes of 100 consecutive myelopathy patients who underwent decompressive laminoplasty between January 2004 and June 2008. The mean follow-up duration was 48.2 months. The mean Japanese Orthopedic Association scores changed from 6.9 to 11.9 in the MSL group and from 6.2 to 12.4 in the USDL group, resulting in mean calculated recovery rates of 55.5% and 63.0%, respectively (P = 0.14). Mean cervical lordosis declined from 12.0 to 10.2 degrees in the MSL group and from 10.3 to 8.5 degrees in the USDL group (P = 0.24). Mean cervical range of motion declined from 27.8 to 25.6 degrees in the MSL group, and from 23.4 to 16.0 degrees in the USDL group (P = 0.38). Bony spinal canal dimension increased from 201.2 to 280.8 mm in the MSL group and from 204.3 to 331.7 mm in the USDL group (P < 0.001). In the USDL group, 6 patients experienced postoperative neck pain, 7 experienced C5 palsy, and 2 experienced cerebrospinal fluid leakage. No such complications occurred in the MSL group (P ≥ 0.05 for both complications). MSL and USDL patients had similar long-term clinical and radiologic outcomes, except that bony canal expansion was greater in the latter. We believe that removal of the ligamentum flavum and drilling of the internal bony edge were factors in the favorable clinical outcomes and low rate of complications in the MSL group.

Morphologic Variation in Lumbar Spinal Canal Dimensions by Gender, Race and Age

Accurate data regarding anatomic dimensions of the lumbar spinal canal are relevant for establishing diagnostic criteria for stenosis and assessing surgical outcomes. Previous studies utilized advanced imaging techniques such as CT and MRI to provide population-based data. However, we believe that direct measurements of a large cadaveric collection provide valuable normative data.

Kinematic effects of a pedicle-lengthening osteotomy for the treatment of lumbar spinal stenosis

Lumbar spinal stenosis (LSS) may lead to disabling neurogenic symptoms and has traditionally been treated using open laminectomy. A new technique for correcting LSS involves lengthening the lumbar pedicles through bilateral percutaneous pedicle osteotomies. In this paper, the authors' goal was to evaluate the changes in spinal canal dimensions and kinematic behavior after pedicle-lengthening osteotomies. The kinematic behavior of 8 cadaveric lumbar segments was evaluated intact and after bilateral pedicle-lengthening osteotomies at the L-4, L-5, and L-4 and L-5 levels. Testing was conducted with and without a compressive preload using a custom kinematic apparatus that allowed for 3D tracking of each vertebra during flexion-extension, right-left bending, and right-left rotation. A validated finite element (FE) spine model was used to measure the changes in the cross-sectional area of the spinal canal and neural foramen after 2-, 3-, and 4.5-mm simulated pedicle-lengthening osteotomy procedures. The overall and segmental kinematics were not significantly altered after the pedicle-lengthening osteotomy procedure at the L-4 and/or L-5 pedicles. The kinematic signatures of the intact and lengthened states were similar for all motion pairs. The FE spine model yielded kinematics predictions within or close to the 95% confidence interval for the cadaveric data. The FE spine demonstrated substantial, pedicle length-dependent enlargement of the cross-sectional areas of the spinal canal and neural foramen after simulated pedicle lengthening. Bilateral pedicle-lengthening osteotomies produced substantial increases in the cross-sectional areas of the spinal canal and neural foramen without significantly altering normal spinal kinematics. This technique deserves further study as a less invasive treatment option for LSS.

Ethnic differences in pedicle and bony spinal canal dimensions calculated from computed tomography of the cervical spine: a review of the English-language literature

The aims of this study were to review published data on pedicle dimensions and bony spinal canal diameters calculated from CT examinations of the cervical spine through the English-language literature and analyze these data for ethnic disparities and similarities. The authors reviewed the literature on "pedicle" and "spinal canal" by conducting a bibliographic search using PubMed, Ovid MEDLINE, and Science Direct from January 1985 to December 2010. After evaluating all of the selected abstracts, we ultimately selected 19 studies involving living subjects: 12 studies on pedicle dimensions and 7 on spinal canal diameters. The four parameters, pedicle width (PW), pedicle transverse angle (PTA), anterior-posterior diameter of the spinal canal (APD), and transverse diameter of the spinal canal (TD), were analyzed at the relevant levels from C3 to C7. In addition, the values for pedicle dimensions and spinal canal diameters in the European/American populations were compared using the data from Asian populations as a baseline. The smallest mean PW was found at C4 in the male (5.1 mm) and female populations (4.1 mm); the largest mean PW was found at C7 in both male (7.7 mm) and female populations (7 mm). The PW in males was greater than in females at the majority of levels. The smallest mean PTA was found at C7 in both male (33.4°) and female populations (33°); the largest mean PTA was found at C4 in both male (53.2°) and female populations (52.1°). The overall PW, PTA, APD, and TD ratio of European/American to Asian populations was 91.4-98.8, 99.6-106.2, 110.7-122, and 100-108.3 %, respectively. Although our cervical spine CT data were suggestive of possible ethnic differences in spinal canal morphology, our analysis failed to identify significant ethnic disparity in pedicle dimensions despite potential differences in physique between populations.

Expansive Open-door Laminoplasty With Titanium Miniplate Versus Sutures

Expansive laminoplasty is an effective treatment for cervical myelopathy. Since the design of classic open-door laminoplasty with the use of suture, the procedure has been modified to reduce complications such as restenosis, axial symptoms, and segmental motor paralysis. Expansive open-door laminoplasty with the use of titanium miniplate is becoming popular. It is effective in expanding spinal canal dimensions with good clinical efficacy. However, a lack of studies exist comparing titanium miniplate fixation with classical suture fixation.We performed a retrospective study of 54 patients with cervical myelopathy. Twenty-nine patients (4 women and 25 men) receiving expansive open-door laminoplasty by titanium miniplate fixation were classified as the modified group, and 25 patients (5 women and 20 men) fixed with suture served as the control group. Clinical and radiologic outcomes were assessed. No significant differences were observed in Japanese Orthopaedic Association scores and the recovery rate of C5 palsy. The incidence of axial symptoms in the modified group was significantly lower than that in control group. Radiologic examination showed that postoperative C2-C7 lordosis and range of motion of the cervical spine in the modified group were preserved. No significant differences were observed in mean anteroposterior diameter and open angle in the 2 groups. Both surgical protocols were effective in preventing reclosure of open laminae. Furthermore, the modified laminoplasty was superior in reducing the incidence of axial symptoms and loss of cervical lordosis and range of motion.

Tapering of the Cervical Spinal Canal in Patients with Chiari I Malformations

Upper cervical spinal canal dimension may have a role in abnormal CSF dynamics in patients with Chiari I malformation. We attempted to measure spinal canal tapering from anteroposterior spinal canal dimensions in patients with Chiari I. Twenty-one patients with Chiari I malformation, including 12 with syringomyelia and 7 patients with IS were identified from a local registry. Age- and sex-matched control subjects with cervical spine MR imaging findings reported as normal were selected from the PACS. The anteroposterior diameter of the spinal canal was measured at C1-C7 on T2-weighted sagittal MR images. The taper ratio of the spinal canal was calculated with the regression line. Goodness of fit was calculated as R(2). Differences between patients with Chiari I and other patients were tested for significance with Kruskal-Wallis tests and multivariate analysis. Taper ratios averaged -0.6 ± 0.3 mm/level in the patients with Chiari and syrinx, -0.4 ± 0.2 mm/level (mean ± 1 SD) in the patients with Chiari without syrinx, and -0.3 ± 0.5 mm/level in the patients with IS; control groups had average taper ratios of -0.3 ± 0.2 mm/level. Mean R(2) equaled 0.43. Taper ratios in patients with Chiari and syringomyelia differed significantly from those in the control group (P = .003). Taper ratios in the patients with Chiari without syrinx and in patients with IS did not differ significantly from their matched control groups (P = .60 and 0.76, respectively). Patients with Chiari I and a syrinx have steeper tapering of the upper cervical spinal canal than matched controls.

Obesity and Hyperostosis of the Spinal Ligaments: A Comprehensive CT Analysis of the Entire Spine in a Random Trauma Population

occurs in adults, it may predispose the KFS patient to a lower threshold for neurologic deficit. PURPOSE: To compare the clinical and the radiographical characteristics between KFS and the controls. STUDY DESIGN/SETTING: Retrospective 1:2 case: control study. PATIENT SAMPLE: 22 KFS and 44 control patients. OUTCOME MEASURES: Independent t-test. METHODS:We performed an independent 1: 2 case:control retrospective radiographic and chart review of a consecutive series of adult KFS patients (O18 years old) who underwent surgical intervention by a single surgeon between 1996-2007. The control group consisted of a consecutive group of non-KFS surgical patients operated by the same surgeon. Patients were matched in 1:2 case: control manner according to gender and BMI category (malnourished (!18.5); normal weight (18.5-25); overweight (25-30); obese (O30)). Their charts were reviewed and the clinical characteristics were compared. Axial T2-weighted MRI was used to measure the antero-posterior and medio-lateral axial spinal cord and spinal canal of the operative levels. Spinal cord and canal area were then calculated using the equation of an ellipse: Area (ellipse)5pi x (antero-posterior dimension) x (medio-lateral dimension), a previously validated technique. If there were multiple levels in a patient, the average area of the levels was used for comparison. RESULTS: A total of 22 KFS and 44 control patients were identified. The most common congenital fusion level was C2-3 followed by C3-4. 27% patients hadO1 congenital fusion level. In the KFS population, the surgical level was as follows: 1-level cephalad to the congenital fusion (17%), 1-level caudal to the congenital fusion (66%), in between 2 congenitally-fused areas (17%). The KFS group had a tendency of more myeloradiculopathy, and the control group had a tendency towards more radiculopathy. However, both tendencies were not significantly different. MRIs of 10 KFS and 22 control group were available. There was no difference in the area of both spinal cord and canal at the operative levels. CONCLUSIONS: Contrary to the finding in previous reports on pediatric patients, there were no differences between KFS and well-matched control group in terms of age of onset, presentation, revision rate, complication rates, surgical outcomes, and cross sectional spinal cord and canal dimensions at the operative level. This either suggests that previous reports may have erred or that KFS patients undergo a relative enlargement of the spinal cord as they grow. FDA DEVICE/DRUG STATUS: This abstract does not discuss or include any applicable devices or drugs.

Establishment of Parameters for Congenital Stenosis of the Lumbar Spine

No studies till date have been done to anatomically determine the actual dimensions of spinal canal to define a criteria for congenital lumbar spinal stenosis. A number of studies with various radiographic means of evaluation have been conducted for defining spinal stenosis.

Distraction of facets with intraarticular spacers as treatment for lumbar canal stenosis: report on a preliminary experience with 21 cases

The authors report their experience in treating 21 patients by using a novel form of treatment of lumbar degenerative disease that leads to canal stenosis. The surgery involved distraction of the facets using specially designed Goel intraarticular spacers and was aimed at arthrodesis of the spinal segment in a distracted position. The operation is based on the premise that subtle and longstanding facet instability, joint space reduction, and subsequent facet override had a profound and primary influence in the pathogenesis of degenerative lumbar canal stenosis. The surgical technique and the rationale for treatment are discussed. Between April 2006 and January 2011, 21 cases of lumbar degenerative disease resulting in characteristic lumbar canal stenosis were treated in the authors' department with the proposed technique. The patients were prospectively analyzed. There were 15 men and 6 women who ranged in age from 48 to 71 years (mean 58 years). Nine patients underwent 1-level and 12 patients underwent 2-level treatment. Surgery involved wide opening of the articular joint, denuding of the articular capsule/endplate cartilage, distraction of the facets, and forced impaction of Goel intraarticular spacers. Bone graft pieces obtained by sectioning the spinous processes were placed within and over the joint and in the midline over the adequately prepared host area of laminae. The Oswestry Disability Index and visual analog scale were used to clinically assess the patients before and after surgery and at follow-up. The alterations in the physical architecture of spinal canal and intervertebral foramen dimensions were evaluated before and after placement of the intrafacet implant and after at least 6 months of follow-up. All patients had varying degrees of relief from symptoms of local back pain and radiculopathy. Impaction of spacers within the facet joints resulted in an increase in the spinal canal and intervertebral root canal dimensions (mean 2.33 mm), reduction of buckling of the ligamentum flavum, and reduction of the extent of bulge of the disc into the spinal canal. The procedure resulted in firm stabilization and fixation of the spinal segment and provided a ground for arthrodesis. No patient worsened neurologically after treatment. During the follow-up period, all patients had evidence of segmental bone fusion. No patient underwent reexploration or further surgery of the lumbar spine. Impaction of the spacers within the articular cavity after facet distraction resulted in reversal of several effects of spine degeneration that had caused spinal and root canal stenosis. The safe, firm, and secure stabilization at the fulcrum of lumbar spinal movements provided a ground for segmental spinal arthrodesis. The immediate postoperative and lasting recovery from symptoms suggests the validity of the procedure.

New approach for graded compression spinal cord injuries in Rhesus macaque: method feasibility and preliminary observations

Current models of spinal cord injury (SCI) have been ineffective for translational research. Primate blunt SCI, which more closely resembles human injury, could be a promising model to fill this gap. Graded compression SCI was produced by inflating at T9 an epidural balloon as a function of spinal canal dimensions in a non-uniform group of monkeys. Sham injury and cord compression by canal invasion of 50-75% produced minimal morpho-functional alterations, if at all. Canal invasion of 90-100% resulted in proportional functional deficits. Unexpectedly, these animals showed spontaneous gradual recovery over a 12-week period achieving quadruped walking, although with persistent absence of foot grasping reflex. Histopathology revealed predominance of central cord damage that correlated with functional status. Our preliminary results suggest that this model could potentially be a useful addition to translational work, but requires further validation by including animals with permanent injuries and expansion of replicates.

The Effect of Cerebrospinal Fluid Thickness on Traumatic Spinal Cord Deformation

A spinal cord injury may lead to loss of motor and sensory function and even death. The biomechanics of the injury process have been found to be important to the neurological damage pattern, and some studies have found a protective effect of the cerebrospinal fluid (CSF). However, the effect of the CSF thickness on the cord deformation and, hence, the resulting injury has not been previously investigated. In this study, the effects of natural variability (in bovine) as well as the difference between bovine and human spinal canal dimensions on spinal cord deformation were studied using a previously validated computational model. Owing to the pronounced effect that the CSF thickness was found to have on the biomechanics of the cord deformation, it can be concluded that results from animal models may be affected by the disparities in the CSF layer thickness as well as by any difference in the biological responses they may have compared with those of humans.

The development of a clinical decision making algorithm for detection of osteoporotic vertebral compression fracture or wedge deformity

The clinical diagnosis of an osteoporotic vertebral compression fracture (OVCF) is challenging and requires detailed assessment using comprehensive imaging methods. Further complicating matter is that the clinical sequelae associated with OVCF typically involves asymptomatic findings and variable pain patterns. The purpose of this study was to identify clinical characteristics and assessment findings that were associated with a diagnosis of OVCF. The study evaluated routine clinical findings in over 1400 subjects seen at an adult spine surgery clinic for thoracolumbar spine-related conditions within the years 2005–2009. All patients underwent a standardized clinical examination that included a self-report, observational, physical examination and imaging assessment. The diagnosis of OVCF was made after assessment of radiographic findings in sagittal alignment, vertebral body compression, and spinal canal dimensions. Data from the patient history and observational findings were then statistically analyzed and compared between those patients with a diagnosis of OVCF and those with an alternative diagnosis. Based on the results, a diagnostic support tool was created to predict the likelihood of OVCF. The most diagnostic combination included a cluster of: (1) age > 52 years; (2) no presence of leg pain; (3) body mass index ≤ 22; (4) does not exercise regularly; and (5) female gender. A finding of two of five positive tests or less demonstrated high sensitivity of 0.95 (95% CI 5 0.83–0.99) and low negative likelihood ratio of 0.16 (95% CI = 0.04–0.51), providing moderate value to rule out OVCF. Four of five yielded a positive likelihood ratio (LR+) of 9.6 (95% CI = 3.7–14.9) providing moderate value in ruling in the diagnosis of OVCF. Further validation is necessary prospectively to determine the value of these findings on a disparate sample of patients in other unique environments.

Facet distraction spacers for treatment of degenerative disease of the spine: Rationale and an alternative hypothesis of spinal degeneration

Facet distraction spacers for treatment of degenerative disease of the spine: Rationale and an alternative hypothesis of spinal degeneration

Advanced imaging of the cervical spine and spinal cord in 22q11.2 deletion syndrome: Age-matched, double-cohort, controlled study

The 22q11.2 deletion syndrome is a common genetic syndrome with a wide spectrum of abnormalities. We have previously described multiple anomalies of the upper cervical spine in this disorder. The objective of this study was to use advanced imaging to further define the morphology of the cervical spine and spinal cord in the 22q11.2 deletion syndrome, with a comparison to age-matched controls. A total of 32 patients with a 22q11.2 deletion underwent advanced imaging (computed tomography/magnetic resonance imaging; CT/MRI) of the cervical spine. In 27 patients, space available for the cord (SAC); the sagittal diameter of the vertebral body, spinal canal, cerebrospinal fluid (CSF), and spinal cord; and the cross sectional area of the spinal canal, CSF, and spinal cord were measured at each cervical level and compared to 29 age-matched controls. Statistical analysis was performed and potential implications were hypothesized. In 22q11.2 patients, advanced imaging identified 40 pathologies not evident on plain radiographs with potential mechanical and/or neurological implications. These patients also had significantly smaller values (P </= 0.05) of the following parameters at one or more cervical levels, relative to age-matched controls: width of the vertebral body, spinal canal, CSF, and spinal cord; area of the spinal canal, CSF, and spinal cord. Neurologic symptoms were observed in 4/32 patients, with one patient requiring surgical intervention. Advanced imaging of the cervical spine can detect findings not evident on plain radiographs in the 22q11.2 deletion syndrome. CT and/or MRI may be indicated when there is a high index of suspicion for clinical instability or neurologic compromise in order to rule out dynamic encroachment or impending neurologic sequelae. Spinal canal and spinal cord dimensions are reduced in these patients relative to controls with currently unknown clinical significance.

Analysis and Measurement of the Lumbar Spinal Canal Dimension using Magnetic Resonance Imaging

2 , respectively. The correlation coefficient was high at 0.913 for the L3/4 and L4 interpedicular transverse plane. The correlation coefficient for L4/5 and L5 was 0.905, and the correlation coefficient for L5/S1 and S1 was 0.845. Conclusion: The lumbar spinal canal dimension measured at the intervertebral disc level in a population of normal Korean subjects is expected to be useful as reference data. The transpedicular plane perpendicular to the spinal canal can give information for estimating the spinal canal dimension at the disc level.

Correlation of Spinal Canal Dimensions to Efficacy of Epidural Steroid Injection in Spinal Stenosis

Journal of Spinal Disorders & Techniques 20(7):p 546-547, October 2007. | DOI: 10.1097/BSD.0b013e31813ffbff

Correlation of Spinal Canal Dimensions to Efficacy of Epidural Steroid Injection in Spinal Stenosis

To determine a critical canal dimension in patients with spinal stenosis that predicts response to epidural steroid injections (ESI). Lumbar spinal stenosis patients with a computed tomography scan before ESI were identified through ICD-9/CPT codes. Using a digital caliper, canal dimensions on axial cuts of each lumbar intervertebral level were recorded: the transverse canal diameter in line with the facets including the soft tissues, TC; the transverse osseous canal diameter, OS; and the mid-sagittal anteroposterior diameter, MS. Minimum and maximum measurements were determined. Patients who improved after ESI and those that required a decompression after ESI were differentiated. Eighty-four patients were included in the study. Fifty required surgical decompression after ESI and 34 patients improved after ESI. There were no statistically significant differences in the demographics between the 2 groups. Mean minimum dimensions in the surgical group were 9.47 mm (TC), 16.53 mm (OS), and 12.40 mm (MS); and 9.75 mm (TC), 16.65 mm (OS), and 12.39 mm (MS) in the nonsurgical group. Mean ratio between the maximum and minimum dimensions in the surgical group was 1.76 (TC), 1.35 (OS), and 1.57 (MS); and 1.86 (TC), 1.47 (OS), and 1.63 (MS) in the nonsurgical group. There was no statistically significant difference in the minimum measurement in any dimension between the surgical and the nonsurgical group. There was also no statistically significant difference in the ratio between the minimum and maximum measurement in any dimension between the surgical and the nonsurgical group. Spinal canal dimension is not predictive of success or failure of ESI in patients with spinal stenosis.

5:03152. Two-Year Clinical and Positional MRI Results of X Stop Interspinous Device – A Preliminary Report

BACKGROUND CONTEXT: In vitro and in vivo studies of the X Stop device have shown increase in foraminal and lumbar spinal canal dimensions with reduction in the segmental range of movement at the surgical level. Previous clinical studies of X Stop have shown an improvement in symptoms and function of 75% and 45% at 1 year and 2 years respectively.

Poster 103: Magnetic Resonance Imaging of the Lumbar Spine in Asymptomatic Older Adults

Objective: To determine the range of magnetic resonance imaging (MRI) findings and normal spinal canal dimensions in asymptomatic older subjects. Design: Cross-sectional study. Setting: Community volunteers. Participants: Asymptomatic subjects greater than 55 years old. Intervention: Lumbar spine MRI studies were done. Main Outcome Measures: 2 radiologists, blinded to the subjects’ history, independently read lumbar MRI scans for the presence of abnormalities. A radiologist also measured spinal canal dimensions.