Area Of Dural Sac Research Articles

P47. Acute postoperative epidural hematomas in minimally invasive lumbar fusions: A prospective comparative cohort study

<h3>BACKGROUND CONTEXT</h3> The incidence of postoperative spinal epidural hematomas (SEH) in open lumbar decompression/fusions has been reported to be up to 89%. However, the incidence of asymptomatic SEH and the radiographic parameters predicting symptomatic SEH in minimally invasive transforaminal lumbar interbody fusions (MiTLIF) has not been established. <h3>PURPOSE</h3> To determine the incidence of asymptomatic epidural compression/SEH and the radiologic parameters which predict compression/SEH becoming symptomatic. <h3>STUDY DESIGN/SETTING</h3> Prospective comparative cohort study performed at a community hospital. <h3>PATIENT SAMPLE</h3> Forty-two consecutive patients undergoing MiTLIFs at a single institution from 2017-2018. Exclusions were >3 operative levels, revision spinal fusion, perioperative intake of Aspirin/Plavix/NSAID, abnormal clotting profile or hardware malpositioning. <h3>OUTCOME MEASURES</h3> Our primary outcome was the incidence of epidural compression/SEH and the associated radiographic parameters. <h3>METHODS</h3> The onset of pain and neurological deficits was evaluated daily. MRI was performed. <h3>RESULTS</h3> Thirty patients were enrolled in the asymptomatic group and 12 in the symptomatic group. Eight (26.67%) asymptomatic patients had postoperative thecal sac compression. Symptomatic patients had a significantly higher BMI compared to asymptomatic patients (34.6 ± 7.4 vs 28.2 ± 5.4, p=.010). Four of the asymptomatic patients had SEH (13.3%, 95%CI: 3.8–30.7). Comparing symptomatic vs asymptomatic compression, there were significant differences for the CR (0.57 ± 0.20 vs 1.08 ± 0.53, <b>Δ</b> 95%CI: -.84 - -.19, p<.001), the dural sac area at MC (0.62 ± 0.28 vs 1.3 ± 1.0, <b>Δ</b> 95%CI: -1.2 - -0.1, p=0.003). The CR of symptomatic SEH was not significantly different from asymptomatic SEH. (0.57 ± 0.20 vs 0.70 ± 0.15, <b>Δ</b> 95%CI: -0.37 - 0.09, p=.17). The length of MC of symptomatic SEH was significantly smaller when compared to asymptomatic SEH (2.3 ± 1.1 vs 5.3 ± 2.9, <b>Δ</b> 95%CI: -5.1 - -1.0, p=.030). <h3>CONCLUSIONS</h3> The incidence of early postoperative spinal epidural hematomas in asymptomatic patients following MiTLIF was lower than previously described for open lumbar surgeries. The CR can be used in evaluating the likelihood of a compression becoming symptomatic. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Relationship between the cross-sectional area of the lumbar dural sac and lower urinary tract symptoms: A population-based cross-sectional study

This study aimed to investigate the relationship between the cross-sectional area of the dural sac (DCSA) and lower urinary tract symptoms (LUTS). This study included 270 Japanese participants from a community health check-up in 2016. Overactive bladder (OAB) was diagnosed during the assessment of LUTS. The smallest DCSA of each participant was defined as the minimum DCSA (mDCSA). The cutoff size of the mDCSA in OAB was evaluated using receiver operating characteristic analysis. Multiple logistic regression analyses were performed to identify the independent risk factors for OAB, and a scoring system was developed for estimating these. The prevalence of OAB was 11.1%. Age and low back pain visual analogue scale (LBP VAS) scores were significantly higher, and the mean mDCSA was significantly lower in participants with OAB than in those without. The cutoff size of mDCSA in OAB was 69 mm2. There were significant correlations between OAB and age, LBP VAS score, and mDCSA<70 mm2. Lumbar spinal stenosis (LSS) should be considered a cause of LUTS when mDCSA is <69 mm2. Assessing the mDCSA with age and LBP VAS score was more valuable in detecting LUTS in LSS than the mDCSA alone.

High-resolution, three-dimensional magnetic resonance imaging axial load dynamic study improves diagnostics of the lumbar spine in clinical practice.

BACKGROUNDThe response to axial physiological pressure due to load transfer to the lumbar spine structures is among the various back pain mechanisms. Understanding the spine adaptation to cumulative compressive forces can influence the choice of personalized treatment strategies. AIMTo analyze the impact of axial load on the spinal canal’s size, intervertebral foramina, ligamenta flava and lumbosacral alignment.METHODSWe assessed 90 patients using three-dimensional isotropic magnetic resonance imaging acquisition in a supine position with or without applying an axial compression load. Anatomical structures were measured in the lumbosacral region from L1 to S1 in lying and axially-loaded magnetic resonance images. A paired t test at α = 0.05 was used to calculate the observed differences. RESULTSAfter axial loading, the dural sac area decreased significantly, by 5.2% on average (4.1%, 6.2%, P < 0.001). The intervertebral foramina decreased by 3.4% (2.7%, 4.1%, P < 0.001), except for L5-S1. Ligamenta flava increased by 3.8% (2.5%, 5.2%, P < 0.001), and the lumbosacral angle increased. CONCLUSIONAxial load exacerbates the narrowing of the spinal canal and intervertebral foramina from L1-L2 to L4-L5. Cumulative compressive forces thicken ligamenta flava and exaggerate lumbar lordosis.

Spinal cord compression in relation to clinical symptoms in patients with spinal meningiomas

ObjectiveSpinal meningiomas are common primary tumors of the spinal canal and the resulting spinal cord compression (SCC) is intrinsically related to symptoms and outcome, but literature concerning this association is limited. We aimed to present data on both degree of SCC and tumor occupancy percentage in relation to neurological symptoms and outcome. MethodsPatients ≥ 18 years with a histological diagnosis of spinal canal meningioma treated between 2000 and 2017 were retrospectively evaluated for symptoms and neurological outcome in relation to SCC (i.e. compression of spinal cord at maximal tumor compression compared to maximum area above/below compression) and tumor occupancy percentage (percentage of dural sac area occupied by tumor at maximal tumor compression). Area segmentation of spinal cord, tumor and dural sac (as marker of spinal canal) was performed manually on magnetic resonance imaging (MRI) scans. The neurological deficit was assessed pre- and postoperatively according to the McCormick score. A logistic regression was made with a training set to identify the cut-off level for motor deficit. ResultsThe cohort included 111 patients with a mean age of 62.5 years and 77.5% were female. The dominating symptoms preoperatively were sensory disturbance (91.0%), motor deficit (80.2%) and gait disturbance (67.6%). Postoperatively 53.2% of patients, also in some of those with severe deficit and high tumor occupancy, improved their neurological deficit and 43.2% were unchanged. Patients with intradural meningioma and assessable MRI scans were included to evaluate SCC (n = 83). The mean extent of SCC was 50.6%. Exploration of tumor occupancy percentage identified a cut-off at 65% tumor occupancy to best discriminate between patients with or without motor deficit. ConclusionPatients with an intradural tumor occupancy percentage of > 65% are more likely to have a preoperative symptom and deficit, validating previous findings. Therefore, we suggest that even in asymptomatic, otherwise fit, patients with tumor occupancy approaching 65% should be considered for surgery since there is a high risk of developing deficit with even minimal growth. Concerning recovery, patients with tumor both high tumor occupancy and significantly impaired function tended to improve their functional level postoperatively.

Radiological evaluation of spinal canal, dural sac, epidural fat and superior articular process in diagnosis of lumbar spinal stenosis

Aim: The aim of our study; to investigate the location of hypertrophy in the epidural adipose tissue in the lumbar spinal stenosis clinic, to compare the area measurements of the spinal canal and dural sac in patients with a preliminary diagnosis of lumbar spinal stenosis or radiculopathy, and to determine the place of the superior articular process area measurement in the diagnosis of spinal stenosis.&#x0D; Material and Method: 180 patients aged 50-69 years who underwent Lumbar Magnetic Resonance Imaging were divided into two groups according to the prediagnosis of lumbar spinal stenosis or radiculopathy and retrospectively analyzed. Spinal canal, dural sac, epidural fat, and superior articular process areas were measured. Statistical relationships of the findings were investigated.&#x0D; Results: There was no difference between the stenosis groups of these patients in terms of age and gender (respectively p=0.078; p=0.564). There is a significant difference in terms of the spinal canal, dural sac, superior articular process, and epidural fat widths between spinal stenosis and radiculopathy (p

P40. Indirect effect on adjacent segment after minimally invasive transforaminal lumbar interbody fusion

<h3>BACKGROUND CONTEXT</h3> MIS-TLIF is an alternative treatment for degenerative spine disease, which aims to decompress and stabilize the most stenotic level correlating with clinical symptoms, while sparing the less severe adjacent segments. According to previous studies, interbody fusion was reported to not only affect the fused level, but also the adjacent segments. These effects might cause changes in canal dimensions at the adjacent segments, leading to unsatisfactory postoperative symptoms. <h3>PURPOSE</h3> The goal of this study was to compare the dural sac area and other canal dimension parameters on MRI at the adjacent segments before and after minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF), including the change in segmental and regional parameters measured on plain radiograph. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study King Chulalongkorn Memorial Hospital. <h3>PATIENT SAMPLE</h3> Patients who underwent MIS-TLIF at L4/5 level in King Chulalongkorn Memorial Hospital The indications for surgery were spinal canal stenosis, herniated nucleus pulposus, and spondylolisthesis grade 1-2. <h3>OUTCOME MEASURES</h3> MR image parameters: dural sac area (DSA), sagittal spinal AP diameter (SAPD), ligamentum flavum area (LFA), ligamentum flavum thickness (LFT), foraminal area (FA), foraminal height (FH), at the adjacent segments of fused level. Standing lateral plain radiograph: disc height (DH), segmental angle (SA) of adjacent segments and fused level lumbar lordosis (LL) <h3>METHODS</h3> Forty-four patients who underwent MIS-TLIF at L4/5 level were examined. The indications for surgery were spinal canal stenosis, herniated nucleus pulposus, and spondylolisthesis grade 1-2. We reviewed their standing plain radiograph and MR image parameters, including dural sac area (DSA), sagittal spinal AP diameter (SAPD), ligamentum flavum area (LFA), ligamentum flavum thickness (LFT), foraminal area (FA), foraminal height (FH), disc height (DH), segmental angle (SA), and lumbar lordosis (LL) at the adjacent segments of fused level. Disc height and segmental angle at fused level was also reviewed. All parameters were compared before, and 3 months postoperatively. <h3>RESULTS</h3> The mean (SD) pre- and postoperative DSA at upper adjacent segment was 125.12 (35.72) and 133.17 (35.07) mm2, while pre- and postoperative DSA at lower adjacent segment was 103.58 (44.32) and 117.66 (46.34) mm2 respectively. The postoperative DSA significantly increased in the upper (mean change 8.05 (95%CI 4.44-11.66) mm2, P <0.001) and lower (14.08 (95%CI 9.47 – 18.69) mm2; P <0.001) adjacent segments. Eleven (25%) and 22 (25%) patients had preoperative upper adjacent segment areas <100 mm2 and ≥100 mm2respectively. The mean change in DSA was greater in patients with preoperative DSA <100 mm2 versus ≥100 mm2, but the difference was more pronounced in the upper versus the lower adjacent segment (4.3 (95%CI -4 to 12.7) mm2; P = 0.30 versus 1.1 (95%CI -8.3 to 10.4); P = 0.82, respectively). Significant increases in SAPD were also seen in both upper (0.85 (95%CI 0.45 to 1.25 mm; P <0.001) and lower (0.66 (95%CI 0.34 to 0.97) mm; P<0.001) adjacent segments. LFT significantly decreased in the lower adjacent segment (-0.37 (95%CI -0.62 to -0.11) mm; P=0.006); a small but non-significant decrease was also observed in the upper adjacent segment (-0.1 (95%CI -0.37 to 0.17) mm; P=0.47). No other significant changes in other canal dimensions were noted. <h3>CONCLUSIONS</h3> Adjacent segment DSA increased significantly after MIS-TLIF. In addition, other parameters representing canal dimension (SAPD, LFT) also significantly changed after the operation. Further studies are needed to assess the relationship between these changes and postoperative clinical outcomes. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Influence of Lumbar Spinal Canal Dimensions on Neurological Claudication Symptomatology - A Case Control Study

Lumbar spinal stenosis (LSS) is abnormal narrowing of spinal canal of lumbar vertebrae causing compression of neural tissue which leads to a neurologic deficit. LSS is diagnosed based on clinical symptoms of patient and it is confirmed using MRI (Magnetic Resonance Imaging). The aim of the study is to determine the association between MRI lumbar spinal canal and foraminal dimensions in on neurological claudication symptomology. A total of 89 patients (45 males ,44 females, age range: 20-60 years) referred for MRI Lumbar spine were included in this prospective study. Patients were categorized into symptomatic (49 cases) and asymptomatic (40 controls) based on Edinburgh claudication questionnaire (ECQ). The Antero-posterior diameter of dural sac, Transverse diameter of dural sac, Cross sectional area of dural sac, Cross sectional area of lateral recess, Lateral recess depth, Angle of lateral recess, Ligamentous interfacet distance was measured from L3 to S1 on Axial T2 weighted MRI images. The strength of association between MRI measurements and clinical symptoms were assessed using logistic regression analysis and Cramer’s V test. The Phi coefficient value for the lumbar spinal canal, foraminal dimensions with neurogenic claudication symptomology based on ECQ was 0.108 &amp; 0.207 respectively, which showed weak positive correlation. Our study concludes that MRI measurements of lumbar spinal canal and foraminal dimensions denoting LSS were found to show weak positive correlation with clinical symptoms assessed based on Edinburgh claudication questionnaire.

A new classification for spinal epidural hematoma following microendoscopic decompressive laminotomy: A prospective clinical and magnetic resonance imaging study of 245 patients.

The aim of this study was to develop a new radiological classification system for postoperative spinal epidural hematoma (SEH) using magnetic resonance imaging (MRI) and to determine the correlation of this classification system with clinical and radiological outcomes. This prospective study included a total of 245 consecutive patients (126 females, 119 males; mean age=72 years; age range=39-91 years) with single level spinal stenosis who were treated by microendoscopic decompressive laminotomy (MEDL). MRI was performed for all patients 24 hours postoperatively and at 12 months. SHEs were categorized into four grades using our new MRI-based classification system based on the measurement of dural sac area: Grade A, small hematoma with a round shape; grade B, small hematoma that show no round shape; grade C, moderate hematoma; grade D: severe hematoma. Patients were then divided into four groups according to their hematoma grades, Group A, 107 patients with grade A hematomas; group B, 47 with grade B; group C, 67 with grade C; group D, 24 with grade D. Also, patients who had neurological deterioration or who pain resistant to medical treatment were treated surgically, and those were assigned to group H+(14 patients). The study, therefore, contained five groups. Clinical evaluation was done using Japanese Orthopaedic Association (JOA) score preoperatively and at 12 months postoperatively. No significant difference existed among groups in the preoperative median measurement of the dural sac area, which were 0.90 cm2 in group A, 0.80 cm2 in group B, 0.70 cm2 in group C, 1.1 cm2 in group D, and 0.80 cm2 in group H+ (p=0.076). At the postoperative 12-month measurement, no significant difference was noted among groups A (2.05 cm2), B (1.80 cm2 ), and H+ (1.90cm2) (A vs B: p=0.891, A vs H+: p=0.089, B vs H +: p=0.933). The measurements were greater in groups A and B than in groups C and D (p<0.05). Also, larger dural sac areas were determined in group H+ (1.90cm2) compared to Groups C (1.80 cm2) and D (1.60 cm2) but the difference reached no statistical significance (p=0.078). In preoperative JOA scores, there were no significant differences among groups (p>0.05). At 12-month JOA scores, no significant difference was observed between groups A and B (p=0.061) and between groups C and D (p=0.511). The scores were higher in groups A and B than in groups C and D (p<0.05). It seems that the narrower the preoperative dural sac area, the better the clinical symptoms of the patients with SEHs based on our new MRI-based classification system. This classification may be useful to predict the clinical status of these patients at one-year follow-up. Level IV, Diagnostic study.

Axial-Loaded MRI Using a SpineMAC Device to Show Narrowing of Dural Sac and Disc Height in Lumbar Spinal Stenosis

Background: A lumbosacral spinal compression device has been developed by the authors (SpineMAC) to simulate normal weight-bearing by axial-loading of the lumbar spine while the patient is in the supine position. Objective: To investigate the effect of axial loading using a SpineMAC device, on lumbar spine, spinal canal, and spine curvature, in subjects with suspected spinal stenosis. Materials and Methods: The present study was prospective cross-sectional study. Forty-five (21 males and 24 females) consecutive Thai adults underwent unloaded and axial-loaded supine magnetic resonance imaging (MRI) examinations of the lumbosacral spine. Radiographic parameters included cross-sectional area of disc (DA), cross-sectional area of dural sac (DCSA), disc height (DH), anterior to posterior distance of disc (DAP), L1-L3-L5 angle (LA), and lumbar lordosis (LL). Results: During the axial-loaded MRIs, the pathologic features of the lumbar spinal stenosis such as the disc bulging, nerve root compression, narrowing of the spinal canal, and the spinal neural foramina, were frequently observed in L4-L5 and L5-S1. Radiographic parameters differences of more than 5% between unloaded and axial-loaded supine MRIs were observed in DCSA and DH. Narrowing of the dural sac due to axial compression was observed at the L4-L5 level (8.1%), while loss of DH was found at both the L5-S1 (-7.9%) and the L4-L5 (-6.8%) levels. Axial compression only slightly affected the DA and DAP of the intervertebral discs with a difference of 5% or less. Furthermore, it rarely changed the spine curvature (LL and LA) of the subjects, with a difference of 2% or less. LL decreased during axial loading and may not correlate with the findings during normal standing position. Although the authors found greater DA and DAP values in male (p&lt;0.001) and obese (p&lt;0.05) subjects, changes of radiographic parameters with axial loading were otherwise not correlated with sex, age, or body mass index. Conclusion: An axial-loaded MRI, using a SpineMAC device, may be superior to conventional MRI when evaluating narrowing of the dural sac and disc height of patients. Keywords: Lumbar lordosis, Spinal stenosis, Axial loading, Weight bearing, Disc herniation, Low back pain

Multiple Axial Spine Indices Estimation via Dense Enhancing Network With Cross-Space Distance-Preserving Regularization.

Automatic estimation of axial spine indices is clinically desired for various spine computer aided procedures, such as disease diagnosis, therapeutic evaluation, pathophysiological understanding, risk assessment, and biomechanical modeling. Currently, the spine indices are manually measured by physicians, which is time-consuming and laborious. Even worse, the tedious manual procedure might result in inaccurate measurement. To deal with this problem, in this paper, we aim at developing an automatic method to estimate multiple indices from axial spine images. Inspired by the success of deep learning for regression problems and the densely connected network for image classification, we propose a dense enhancing network (DE-Net) which uses the dense enhancing blocks (DEBs) as its main body, where a feature enhancing layer is added to each of the bypass in a dense block. The DEB is designed to enhance discriminative feature embedding from the intervertebral disc and the dural sac areas. In addition, the cross-space distance-preserving regularization (CSDPR), which enforces consistent inter-sample distances between the output and the label spaces, is proposed to regularize the loss function of the DE-Net. To train and validate the proposed method, we collected 895 axial spine MRI images from 143 subjects and manually measured the indices as the ground truth. The results show that all deep learning models obtain very small prediction errors, and the proposed DE-Net with CSDPR acquires the smallest error among all methods, indicating that our method has great potential for spine computer aided procedures.

Comparable increases in dural sac area after three different posterior decompression techniques for lumbar spinal stenosis: radiological results from a randomized controlled trial in the NORDSTEN study

PurposeTo investigate changes in dural sac area after three different posterior decompression techniques in patients undergoing surgery for lumbar spinal stenosis.Summary of background dataDecompression of the nerve roots is the main surgical treatment for lumbar spinal stenosis. The aim of this study was to radiologically investigate three commonly used posterior decompression techniques.MethodsThe present study reports data from one of two multicenter randomized trials included in the NORDSTEN study. In the present trial, involving 437 patients undergoing surgery, we report radiological results after three different midline retaining posterior decompression techniques: unilateral laminotomy with crossover (UL) (n = 146), bilateral laminotomy (BL) (n = 142) and spinous process osteotomy (SPO) (n = 149). MRI was performed before and three months after surgery. The increase in dural sac area and Schizas grade at the most stenotic level was evaluated. Three different predefined surgical indicators of substantial decompression were used: (1) postoperative dural sac area of > 100 mm2, (2) increase in the dural sac area of at least 50% and (3) postoperative Schizas grade A or B.ResultsNo differences between the three surgical groups were found in the mean increase in dural sac area. Mean values were 66.0 (SD 41.5) mm2 in the UL-group, 71.9 (SD 37.1) mm2 in the BL-group and 68.1 (SD 41.0) mm2 in the SPO-group (p = 0.49). No differences in the three predefined surgical outcomes between the three groups were found.ConclusionFor patients with lumbar spinal stenosis, the three different surgical techniques provided the same increase in dural sac area.Clinical trial registrationThe study is registered at ClinicalTrials.gov reference on November 22th 2013 under the identifier NCT02007083.

Radiologic Efficacy and Patient Satisfaction after Minimally Invasive Unilateral Laminotomy and Bilateral Decompression in Patients with Lumbar Spinal Stenosis: A Retrospective Analysis.

Lumbar spinal stenosis (LSS) is the most common spinal disease in older adults. Although surgical modalities are recommended in patients who are unresponsive to conservative treatment, the most appropriate minimally invasive surgical procedure for patients with LSS remains controversial. Moreover, few previous studies have focused on patient-centered outcomes with radiologic correlation. In the present study, we aimed to investigate radiologic efficacy and patient satisfaction following bilateral decompression via unilateral laminotomy. We performed a retrospective analysis of radiologic efficacy and patient satisfaction in a series of surgical patients treated at our institution. We classified patients into two groups based on the primary pathology (i.e., central or lateral recess stenosis). Medical records were analyzed retrospectively for radiologic outcomes and clinical parameters including pain and changes in quality of life. Data related to outcomes were collected at 2 weeks, 3 months, and 12 months after surgery in the outpatient clinic. Among the 122 patients enrolled in this study, 51 had central spinal stenosis; 71 had lateral recess stenosis. Radiologically, we observed significant improvements in the anteroposterior diameter and cross-sectional area of the dural sac (central stenosis) and the lateral width of the central canal and depth of the lateral recess (lateral recess stenosis). Two weeks and 12 months after the surgical procedure, we observed significant improvements in the extent of symptoms, patient satisfaction, and quality of life (including physical function). Our findings suggest that bilateral decompression via a unilateral approach shows improved radiologic outcomes, varying based on the type of stenosis. Furthermore, patient satisfaction significantly improved regardless of the type of disease.

MRI evaluation of dural sac enlargement by interspinous process spacers in patients with lumbar spinal stenosis: Does it play a role in the long term?

BackgroundTo investigate dural sac enlargements and spinal alignments in patients who underwent indirect decompression with interspinous spacers. MethodsThe subjects were 20 patients who underwent indirect decompression using an interspinous spacer (X-STOP) without laminectomy. Of these 20 patients, 1 patient underwent implant removal surgery 1 month after X-STOP surgery and two patients dropped out. Ultimately, 17 patients were included in this study. MRI and X-ray images were investigated before surgery, 1 week after surgery, 3 months after surgery, and 2 years after surgery. ResultsOn MRI, the mean cross-sectional areas of the dural sac were 52.7 mm2 before surgery, 73.2 mm2 1 week after surgery, 62.4 mm2 3 months after surgery, and 58.3 mm2 2 years after surgery. There was a significant 37% increase at 1 week postoperatively compared with that before surgery, but there were no significant differences between 3 months postoperatively and 2 years postoperatively. The disc angle in an extension posture was significantly decreased at 1 week after surgery compared with that before surgery, but there were no significant differences between before surgery, 3 months after surgery, and 2 years after surgery. ConclusionsThe interspinous process spacer increased the dural sac area by 37% 1 week after surgery, but the enlargement was not maintained at 3 months or 2 years after surgery. The use of interspinous process spacers produced an enlargement of the dural sac by limiting extension of the stenotic level only. However, its effect diminished 2 years after surgery.

Validity of MRI Measurements in Lumbar Spinal Canal Stenosis

Background:Lumbar spinal canal stenosis results from compression of spinal cord and/or nerves at any level of lumbar vertebra. The relationship between clinical features of the patients and the degree of stenosis is not clear and there is no accepted “gold standard” for the diagnosis of lumbar stenosis. Objective:To evaluate the relationship between the degree of radiologically confirmed stenosis and the severity of Oswestry disability Index and to assess the most valid parameter for the diagnosis of the lumbar stenosis. Methods;A cross-sectional study conducted on randomly selected patients with lumbar stenosis at Magnetic Resonance Image Unit of Al-Imamein Al-Kadhimein Medical City in Baghdad from May to September 2018. All patients filled Oswestry disability Index questionnaire and underwent examination using 1.5 Tesla magnetic resonance unit (Avanto, SIEMENS). Results:A total of 41 patients were included (51.46±12.62) years of age. The measurements of spinal canal including the cross-sectional area of dural sac at intervertebral levels, stenosis ratio, and depth of lateral recesses are found to be correlated significantly with the level of disability assessed by Oswestry disability Index. At all levels, neither the cross-sectional area of the lateral recesses nor Ligamentous interfacet distance correlated significantly to the level of disability. Conclusion:Magnetic resonance image measurements of spinal canal correlated to the level of disability. Stenosis ratio and cross-sectional area of dural sac at intervertebral disc were more sensitive measurements for lumbar stenosis than other parameters. Keywords: Oswestry disability Index, Spinal stenosis, magnetic resonance image Citation: Al-Jaberi HKH, Shakir BK, Hjazeen AA. Validity of MRI measurements in lumbar spinal canal stenosis. Iraqi JMS. 2019; 17(2): 126-134. doi: 10.22578/IJMS.17.2.6

Spinal subarachnoid space tapering in patients with syringomyelia.

Cervical spine tapering affects cerebrospinal fluid dynamics. Cervical spine taper ratios derived from anteroposterior diameters reportedly differ between patients with syringomyelia and controls. We attempted to verify the differences in diameter and to show differences in cross-sectional area between syringomyelia and controls. Cervical spine magnetic resonance images in syringomyelia patients (idiopathic or Chiari I related) and control patients were examined. In each subject, the anteroposterior diameter of the spinal canal was measured at each cervical level, and C1-C4, C4-C7, and C1-C7 taper ratios were calculated. Differences in taper ratio between groups were tested for statistical significance with the t-test. Cross-sectional areas of the spinal canal were measured at each cervical spinal level, and tapering was calculated. Eighteen patients with idiopathic syringomyelia, 28 with Chiari I, and 29 controls were studied. Chiari and syringomyelia patients had significantly steeper diameter-based taper ratios than controls. The dural sac areas tapered proportionally with the diameter-based taper ratio in all groups. Cervical spine anteroposterior diameter tapering and dural sac cross-sectional areas tapering differ between syringomyelia patients and controls.

Pathological changes of cervical spinal canal in cervical spondylotic myelopathy: A retrospective study on 39 cases

Objective: To evaluate and compare the cervical spinal canal (CSC) morphology among healthy people, cervical spondylosis myelopathy (CSM), and latent cervical spondylosis (LCS, people with cervical spine degeneration on medical imaging but without clinic symptoms). Patients and Methods: We reviewed MRI data describing cervical spinal morphology in healthy persons, LSC patients and CSM patients. All cases underwent cervical MRI. In transverse image, anteroposterior diameter (A–P diameter), area of cervical spinal canal (CSC) and area of cervical spinal cord were measured. In sagittal image, A–P diameter was measured. Dural sac area = the area of CSC in the transverse position – the area of cervical spinal cord in transverse position. Results: There’re 8 cases in the healthy group, 18 cases in the group of LCS, and 13 cases in CSM group. Generally, the measured indicators at two ends of CSC (C2/3 and C7) are larger than those at C3–C6. A–P diameters on axial and sagittal position show a decrease trend from healthy group to LCS group and to CSM group. CSC area and dural sac area on axial position of CSM group are significantly lower than those in healthy group and LCS group. Almost all measured indicators of CSM group are significantly lower than healthy group and LCS group. Every two measured indicators in each group are significantly corelated. Conclusions: The results suggested that CSC size of CSM was smaller than that of LCS, and A–P diameter <11 mm, CSC area <170mm2 and dural sac area <90 mm2 were more advisable to indicate cervical spinal canal stenosis in Chinese people.

Lumbar epidural lipomatosis is associated with visceral fat and metabolic disorders.

Lumbar spinal epidural lipomatosis (LEL) is a condition characterized by excessive deposition of epidural fat in the spinal canal. Metabolic abnormalities may be associated with LEL, but few validated reports exist. Thus, we investigated the association between LEL and metabolic disorders in this study. A total of 218 patients who had neurological symptoms due to neural compression in the lumbar spinal canal were examined by magnetic resonance imaging (MRI), abdominal computed tomography (CT) scans and blood tests. We evaluated the epidural fat, dural sac and spinal canal areas using MRI, and the visceral fat and subcutaneous fat areas using abdominal CT. We compared the patients' demographics and the radiological parameters between the LEL and non-LEL patients. There were 58 LEL patients and 160 non-LEL patients. The LEL group included more men than women. In the MRI measurement, the dural sac area was similar between the LEL and non-LEL patients; however, the epidural fat/spinal canal ratio was much greater in the LEL group. In the LEL patients, factors associated with metabolic disorders, such as visceral fat area, uric acid (UA) and insulin levels, were significantly greater, compared to the non-LEL patients. In the logistic regression analysis, UA and visceral fat area were the independent explanatory factors in the pathogenesis of LEL. LEL patients had significantly more visceral fat and increased levels of insulin, UA and ferritin, which are closely related with metabolic disorders. This study indicates that the increased epidural fat in the spinal canal seen in the LEL patients is associated with metabolic syndrome. These slides can be retrieved under Electronic Supplementary material.

Dural sac area is a more sensitive parameter for evaluating lumbar spinal stenosis than spinal canal area: A retrospective study.

Narrowing of the dural sac cross-sectional area (DSCSA) and spinal canal cross-sectional area (SCCSA) have been considered major causes of lumbar central canal spinal stenosis (LCCSS). DSCSA and SCCSA were previously correlated with subjective walking distance before claudication occurs, aging, and disc degeneration. DSCSA and SCCSA have been ideal morphological parameters for evaluating LCCSS. However, the comparative value of these parameters is unknown and no studies have evaluated the clinical optimal cut-off values of DSCSA and SCCSA. This study assessed which parameter is more sensitive.Both DSCSA and SCCSA samples were collected from 135 patients with LCCSS, and from 130 control subjects who underwent lumbar magnetic resonance imaging (MRI) as part of a medical examination. Axial T2-weighted MRI scans were acquired at the level of facet joint from each subject. DSCSA and SCCSA were measured at the L4-L5 intervertebral level on MRI using a picture archiving and communications system.The average DSCSA value was 151.67 ± 53.59 mm2 in the control group and 80.04 ± 35.36 mm2 in the LCCSS group. The corresponding average SCCSA values were 199.95 ± 60.96 and 119.17 ± 49.41 mm2. LCCSS patients had significantly lower DSCSA and SCCSA (both P < .001). Regarding the validity of both DSCSA and SCCSA as predictors of LCCSS, Receiver operating characteristic curve analysis revealed an optimal cut-off value for DSCSA of 111.09 mm2, with 80.0% sensitivity, 80.8% specificity, and an area under the curve (AUC) of 0.87 (95% confidence interval, 0.83–0.92). The best cut off-point of SCCSA was 147.12 mm2, with 74.8% sensitivity, 78.5% specificity, and AUC of 0.85 (95% confidence interval, 0.81–0.89).DSCSA and SCCSA were both significantly associated with LCCSS, with DSCSA being a more sensitive measurement parameter. Thus, to evaluate LCCSS patients, pain specialists should more carefully investigate the DSCSA than SCCSA.

Study-protocol for a randomized controlled trial comparing clinical and radiological results after three different posterior decompression techniques for lumbar spinal stenosis: the Spinal Stenosis Trial (SST) (part of the NORDSTEN Study)

BackgroundThere are several posterior decompression techniques for lumbar spinal stenosis (LSS). There is a trend towards performing less invasive surgical procedures, but no multicentre randomized controlled trials have evaluated the relative efficacy of these techniques at short and long-term.Method/designA multicentre randomized controlled trial [the Spinal Stenosis Trial (SST) (part of the NORDSTEN study)] including 465 patients aged 18–80 years with neurogenic claudication or radiating pain and MRI findings indicating lumbar spinal stenosis without spondylolisthesis is performed to compare three posterior decompression techniques: unilateral laminotomy with crossover, bilateral laminotomy and spinous process osteotomy. The primary outcome is change in Oswestry Disability Index (ODI 2 years postoperatively). Secondary outcomes are change in EQ-5D, Zurich Claudication Questionnaire, and Numeric Rating Scale for leg-pain and back-pain. Also recorded were Global Perceived Effect score, complications, length of hospital stay, reoperation rate 2 years postoperatively, difference in recurrence of symptoms or postoperative instability, and MRI change in the dural sac area. Further, a 5 and 10 years follow-up is planned with the same outcome measures.DiscussionNewer and less invasive techniques are increasingly favoured in surgery for LSS. This trial will compare the clinical and radiological results of three different techniques, and may contribute to better clinical decision making in the surgical treatment of LSS.Trial registrationClinicalTrials.gov reference: NCT02007083 (November 22, 2013).

Low Back Pain in Patients with Lumbar Spinal Stenosis-Hemodynamic and electrophysiological study of the lumbar multifidus muscles.

Introduction Several studies have demonstrated improvement in low back pain (LBP) after decompression surgery for lower extremity symptoms in lumbar spinal stenosis (LSS); however, the influence of neuropathic disorders on LBP is uncertain. Aim of this study is to identify the features of motion-induced and walking-induced LBP in patients with LSS and to assess whether neuropathic LBP develops. Methods In total, 234 patients with LSS including L4/5 lesion were asked to identify their LBP. Subjects were classified into three groups: walking-induced LBP that aggravated during walking (W group), motion-induced LBP that aggravated during sitting up (M group), and no LBP (N group). Cross-sectional areas of the dural sac, lumbar multifidus, and the erector spinae were measured. Intramuscular oxygenation was evaluated with near-infrared spectrophotometer. Surface electromyography (EMG) and mechanomyography (MMG) were performed on the lumbar multifidus. Morphological, hemodynamic, and electrophysiological differences in the onset of LBP were evaluated. Results The prevalence of W, M, and control groups was 31.2%, 32.1%, 36.8%, respectively. Concordance between the laterality of LBP and leg symptoms including pain and numbness was 86.3% in the W group and 47.0% in the M group. Dural sac area was lower in the W group than in the M and control groups. In the hemodynamic evaluation, the oxygenated hemoglobin level was significantly lower in the W group than in the M and N groups. In electrophysiological evaluation of lumbar multifidus, the mean power frequency in EMG was significantly higher in the W group than in the N group. Amplitude in MMG was significantly lower in the W group than in the N group. Conclusions Neurologic disturbance in patients with LSS may be attributed to “neuropathic LBP.” Neuropathic multifidus disorder plays a role in walking-induced LBP.