Dynamic change of dural sac cross-sectional area in axial loaded magnetic resonance imaging correlates with the severity of clinical symptoms in patients with lumbar spinal canal stenosis

Correlation Between Clinical Improvement and Dural Sac Cross-Sectional Area Expansion in Biportal Endoscopic Lumbar Decompression

STUDY DESIGN

Retrospective study.

OBJECTIVE

To correlate the changes in the dural area on MRI and clinical outcome after unilateral biportal endoscopic (UBE) decompression.

SUMMARY OF BACKGROUND DATA

Clinical outcomes after UBE decompression have been published for up to 2 years for patients with isolated spinal stenosis at 1 level. Serial dural expansion after UBE decompression has not been published as well as correlation to clinical outcomes.

METHOD

We retrospectively reviewed the clinical and radiologic outcomes of 86 patients who underwent UBE decompression for spinal stenosis. Preoperative and postoperative visual analog score (VAS) and Oswestry Disability Index (ODI) were analyzed, and MRI was used for radiologic evaluation before surgery, 3 days after surgery, and 2 years after surgery. The correlation of dural spinal area CSA (preoperative-final) and difference of clinical outcome (preoperative-final) were analyzed.

RESULT

None of the 86 patients had permanent neurological complications. Back VAS, leg VAS, and ODI showed improvement in symptoms postoperatively and 2 years postoperatively. The postoperative CSA of the dural sac on MRI was statistically significantly increased after surgery at all time points. VAS leg was moderately correlated with change in CSA, while ODI and VAS back were weakly correlated. Correlations were all statistically significant.

CONCLUSION

UBE decompression showed good clinical outcomes similar to previous studies, and the CSA of ​​the dural sac on MRI significantly increased in the late postoperative phase compared with the early postoperative phase. This technique is viable option to achieve radiographic dural expansion and improvement in clinical outcomes in degenerative lumbar spinal stenosis. However, there is at best only a moderate correlation with change in CSA and clinical outcomes.

Effects of axial loading and positions on lumbar spinal stenosis: an MRI study using a new axial loading device

OBJECTIVE

A new axial loading device was used to investigate the effects of axial loading and positions on lumbar structure and lumbar spinal stenosis.

METHODS

A total of 40 patients sequentially underwent 4 examinations: (1) the psoas-relaxed position MRI, (2) the extended position MRI, (3) the psoas-relaxed position axial loading MRI, (4) the extended position axial loading MRI. The dural sac cross-sectional area, sagittal vertebral canal diameter, disc height and ligamentum flavum thickness of L3-4, L4-5, L5-S1 and lumbar lordosis angle were measured and compared. A new device with pneumatic shoulder-hip compression mode was used for axial loading.

RESULTS

In the absence of axial loading, there was a significant reduction in dural sac cross-sectional area with extension only seen at the L3-4 (p = 0.033) relative to the dural sac area in the psoas-relaxed position. However, with axial loading, there was a significant reduction in dural sac cross-sectional area at all levels in both psoas-relaxed (L3-4, p = 0.041; L5-S1, p = 0.005; L4-5, p = 0.002) and extension (p < 0.001) positions. The sagittal vertebral canal diameter and disc height were significantly reduced at all lumbar levels with axial loading and extension (p < 0.001); however, in psoas-relaxed position, the sagittal vertebral canal diameter was only reduced with axial loading at L3-4 (p = 0.018) and L4-5 (p = 0.011), and the disc height was reduced with axial-loading at all levels (L3-4, p = 0.027; L5-S1, p = 0.001; L4-5, p < 0.001). The ligamentum flavum thickness and lumbar lordosis in extension position had a statistically significant increase compared to psoas-relaxed position with or without axial loading (p < 0.001).

CONCLUSION

Both axial loading and extension of lumbar may exacerbate lumbar spinal stenosis. Axial loading in extension position could maximally aggravate lumbar spinal stenosis, but may cause some patients intolerable. For those patients, axial loading MRI in psoas-relaxed position may be a good choice.

Influence of radiological factors, psychosocial factors, and central sensitization-related symptoms on clinical symptoms in patients with lumbar spinal canal stenosis

BACKGROUND

No study to date has concurrently evaluated the impact of radiological factors, psychosocial factors, and central sensitization (CS) related symptoms in a single lumbar spinal canal stenosis (LSS) patient cohort.

OBJECTIVE

To investigate the associations between these factors and clinical symptoms in LSS patients.

METHODS

We recruited 154 patients with LSS scheduled for surgery. Patient-reported outcome measures and imaging evaluation including clinical symptoms, psychosocial factors, CS-related symptoms, and radiological classifications. Spearman's rank correlation coefficient and multiple regression analyses were employed.

RESULTS

Spearman's correlation revealed CS-related symptoms positively correlated with low back pain (r= 0.25, p< 0.01), leg pain (r= 0.26, p< 0.01), and disability (r= 0.32, p< 0.01). Pain catastrophizing positively correlated with leg pain (r= 0.23, p< 0.01) and disability (r= 0.36, p< 0.01). Regression analysis showed that pain catastrophizing was associated with disability (β= 0.24, 95%CI = 0.03-0.18), and CS-related symptoms with low back pain (β= 0.28, 95%CI = 0.01-0.09). Radiological classifications were not associated with clinical symptoms.

CONCLUSION

Our findings suggest that psychosocial factors and CS-related symptoms, rather than radiological factors, seem to contribute to clinical symptoms in patients with LSS.

Comparison of the Tubular Approach and Uniportal Interlaminar Full-Endoscopic Approach in the Treatment of Lumbar Spinal Stenosis: Our 3-Year Results

BACKGROUND

To report the long-term results of patients with lumbar spinal stenosis (LSS), for whom we applied the tubular and endoscopic approaches and previously published the short-term results.

METHODS

A multicenter, prospective, randomized, double-blind study was carried out to evaluate 2 groups of patients with LSS who underwent microsurgery via a tubular retractor with a unilateral approach (T group) and bilateral spinal decompression using uniportal interlaminar endoscopic approaches (E group). Dural sac cross-sectional and spinal canal cross-sectional areas were measured with the patients' preoperative and postoperative magnetic resonance images. The visual analog scale, Oswestry Disability Index, and Japanese Orthopedic Association scores in the preoperative period and the first, second, and third years after surgery were evaluated.

RESULTS

Twenty patients met the inclusion criteria for the research (T group; n = 10, E group; n = 10). The groups' visual analog scale (respectively; P = 0.315, P = 0.529, and P = 0.853), Oswestry Disability Index (respectively; P = 0.529, P = 0.739, and P = 0.912), and Japanese Orthopedic Association (respectively; P = 0.436, P =0.853, and P = 0.684) scores from the first, second, and third postoperative years were quite good compared with the preoperative period, but there was no statistically significant difference. A significant difference was found in the E group, with less blood loss (P < 0.001).

CONCLUSIONS

The long-term results of the patients with LSS treated with tubular and endoscopic approaches were similar and very good. Bilateral decompression with minimally invasive spinal surgery methods can be completed with less tissue damage, complications, and blood loss with the unilateral approach.

Diagnostic value of a new axial loading MRI device in patients with suspected lumbar spinal stenosis

OBJECTIVES

This study was carried out to investigate a new device for axial loading MRI (alMRI) in the diagnosis of lumbar spinal stenosis (LSS).

METHODS

A total of 87 patients with suspected LSS sequentially underwent conventional MRI and alMRI using a new device with pneumatic shoulder-hip compression mode. Four quantitative parameters of dural sac cross-sectional area (DSCA), sagittal vertebral canal diameter (SVCD), disc height (DH), and ligamentum flavum thickness (LFT) at L3-4, L4-5, and L5-S1 in both examinations were measured and compared. Eight qualitative indicators were compared as valuable diagnostic information. Image quality, examinee comfort, test-retest repeatability, and observer reliability were also assessed.

RESULTS

Using the new device, all 87 patients successfully completed alMRI with no statistically significant differences in image quality and examinee comfort from conventional MRI. Statistically significant changes were observed in DSCA, SVCD, DH, and LFT after loading (p < 0.01). SVCD, DH, LFT, and DSCA changes were all positively correlated (r = 0.80, 0.72, 0.37, p < 0.01). Eight qualitative indicators increased from 501 to 669 after axial loading, for a total increase of 168 (33.5%). Nineteen patients (21.8%, 19/87) developed absolute stenosis after axial loading and 10 of them (11.5%, 10/87) also had a significant reduction in DSCA (> 15 mm²). The test-retest repeatability and observer reliability were good to excellent.

CONCLUSION

The new device is stable for performing alMRI and can exacerbate the severity of spinal stenosis, providing more valuable information for diagnosing LSS and reducing missed diagnoses.

KEY POINTS

• The new axial loading MRI (alMRI) device could detect a higher frequency of patients with lumbar spinal stenosis (LSS). • The new device with pneumatic shoulder-hip compression mode was used to investigate its applicability in alMRI and diagnostic value for LSS. • The new device is stable for performing alMRI and can provide more valuable information for diagnosing LSS.

Japanese Orthopaedic Association (JOA) clinical practice guidelines on the management of lumbar spinal stenosis, 2021 - Secondary publication

BACKGROUND

The Japanese Orthopaedic Association (JOA) guideline for the management of lumbar spinal stenosis (LSS) was first published in 2011. Since then, the medical care system for LSS has changed and many new articles regarding the epidemiology and diagnostics of LSS, conservative treatments such as new pharmacotherapy and physical therapy, and surgical treatments including minimally invasive surgery have been published. In addition, various issues need to be examined, such as verification of patient-reported outcome measures, and the economic effect of revised medical management of patients with lumbar spinal disorders. Accordingly, in 2019 the JOA clinical guidelines committee decided to update the guideline and consequently established a formulation committee. The purpose of this study was to describe the formulation we implemented for the revision of the guideline, incorporating the recent advances of evidence-based medicine.

METHODS

The JOA LSS guideline formulation committee revised the previous guideline based on the method for preparing clinical guidelines in Japan proposed by the Medical Information Network Distribution Service in 2017. Background and clinical questions were determined followed by a literature search related to each question. Appropriate articles based on keywords were selected from all the searched literature. Using prepared structured abstracts, systematic reviews and meta-analyses were performed. The strength of evidence and recommendations for each clinical question was decided by the committee members.

RESULTS

Eight background and 15 clinical questions were determined. Answers and explanations were described for the background questions. For each clinical question, the strength of evidence and the recommendation were both decided, and an explanation was provided.

CONCLUSIONS

The 2021 clinical practice guideline for the management of LSS was completed according to the latest evidence-based medicine. We expect that this guideline will be useful for all medical providers as an index in daily medical care, as well as for patients with LSS.

Indirect Effects on Adjacent Segments After Minimally Invasive Transforaminal Lumbar Interbody Fusion

OBJECTIVE

To compare radiographic parameters at adjacent segments before and after minimally invasive transforaminal lumbar interbody fusion and assess relationships of radiographic changes between adjacent segments and fused level.

METHODS

Study participants included 44 patients who underwent minimally invasive transforaminal lumbar interbody fusion at L4-5 level. Radiographic parameters at adjacent segments (L3-4 and L5-S1) and clinical parameters were reviewed.

RESULTS

Postoperative dural sac area significantly increased in upper (mean change 8.05 mm2, P < 0.001) and lower (14.08 mm2, P < 0.001) adjacent segments. Significant increases in SAPD were seen in upper (0.85 mm, P < 0.001) and lower (0.66 mm, P < 0.001) adjacent segments. Ligamentum flavum thickness significantly decreased in lower adjacent segments (-0.37 mm, P = 0.006). For every 1-mm increase in fused level disc height, lower SAPD increased 0.22 mm (P = 0.04), and lower segmental angle increased 0.91° (P = 0.04). For every 1° increase in fused level segmental angle, lower dural sac area increased 1.25 mm2 (P = 0.03), and lower SAPD increased 0.12 mm (P = 0.003). The 6- and 12-month postoperative visual analog scale back and leg scores significantly decreased compared with preoperatively (back: mean change -5.98 and -6.05, P < 0.001; leg: -6.86 and -6.89, P < 0.001).

CONCLUSIONS

Performing minimally invasive transforaminal lumbar interbody fusion at the symptomatic index level does not worsen canal dimension of asymptomatic adjacent segments during short-term follow-up. It might be possible to improve canal dimension at adjacent segments by changing disc height or lordosis at the fused level via adjusting size and position of the interbody cage.

MRI grading of spinal stenosis is not associated with the severity of low back pain in patients with lumbar spinal stenosis

Background

Although lumbar spinal stenosis (LSS) often coexists with other degenerative conditions, few studies have fully assessed possible contributing factors for low back pain (LBP) in patients with LSS. The purpose of this study was to identify factors associated with the severity of LBP in patients with LSS.

Methods

The patients with neurogenic claudication caused by LSS, which was confirmed by magnetic resonance imaging (MRI) were included in this cross-sectional study. Data included ratings of LBP, buttock and leg pain, and numbness on a numerical rating scale (NRS), 36-item Short-Form Survey (SF-36) scores, muscle mass measured by bioelectrical impedance analysis, and radiographic measurements including lumbopelvic alignment and slippage. The severity of LSS, endplate defects, Modic endplate changes, intervertebral disc degeneration, and facet joint osteoarthritis were evaluated on MRI. Spearman correlation and multivariate linear regression analyses were used to examine the factors associated with the severity of LBP (NRS score).

Results

A total of 293 patients (135 male and 158 female, average age 72.6 years) were analyzed. LBP was moderately correlated with buttock and leg pain, and buttock and leg numbness. Significant but weak correlations were observed between LBP and body mass index, appendicular and trunk muscle mass, all domains of SF-36, pelvic tilt, total number of endplate defects and Modic endplate changes, and summary score of disc degeneration grading, but not severity or number of spinal stenoses. In the multivariate regression analysis, age, female sex, trunk muscle mass, diabetes, NRS buttock and leg pain, NRS buttock and leg numbness, SF-36 vitality, pelvic tilt, and total number of endplate defects were associated with the severity of LBP.

Conclusions

Trunk muscle mass, lumbopelvic alignment, and endplate defects, but not severity of stenosis are partly associated with severity of LBP, but buttock and leg pain and buttock and leg numbness have strongest relationships with LBP in patients with LSS.

Is radiographic lumbar spinal stenosis associated with the quality of life?: The Wakayama Spine Study

Objectives

This prospective study aimed to determine the association between radiographic lumbar spinal stenosis (LSS) and the quality of life (QOL) in the general Japanese population.

Methods

The severity of radiographic LSS was qualitatively graded on axial magnetic resonance images as follows: no stenosis, mild stenosis with ≤1/3 narrowing, moderate stenosis with a narrowing between 1/3 and 2/3, and severe stenosis with > 2/3 narrowing. Patients less than 40 years of age and those who had undergone previous lumbar spine surgery were excluded from the study. The Oswestry Disability Index (ODI), which includes 10 sections, was used to assess the QOL. One-way analysis of variance was performed to determine the statistical relationship between radiographic LSS and ODI. Further, logistic regression analysis adjusted for gender, age, and body mass index was performed to detect the relationship.

Results

Complete data were available for 907 patients (300 men and 607 women; mean age, 67.3±12.4 years). The prevalence of severe, moderate, and non-mild/non-radiographic were 30%, 48%, and 22%, respectively. In addition, the mean values of ODI in each group were 12.9%, 13.1%, and 11.7%, respectively, and there was no statistically significant difference between the three groups in logistic analysis (P = 0.55). In addition, no significant differences in any section of the ODI were observed among the groups. However, severe radiographic LSS was associated with low back pain in the "severe" group as determined by logistic analysis adjusted for gender, age, and body mass index (odds ratio: 1.53, confidence interval: 1.13–2.07) compared with the non-severe group.

Conclusion

In this general population study, severe radiographic LSS was associated with low back pain (LBP), but did not affect ODI.

Walking Biomechanics and Spine Loading in Patients With Symptomatic Lumbar Spinal Stenosis

Symptomatic lumbar spinal stenosis is a leading cause of pain and mobility limitation in older adults. It is clinically believed that patients with lumbar spinal stenosis adopt a flexed trunk posture or bend forward and alter their gait pattern to improve tolerance for walking. However, a biomechanical assessment of spine posture and motion during walking is broadly lacking in these patients. The purpose of this study was to evaluate lumbar spine and pelvic sagittal angles and lumbar spine compressive loads in standing and walking and to determine the effect of pain and neurogenic claudication symptoms in patients with symptomatic lumbar spinal stenosis. Seven participants with symptomatic lumbar spinal stenosis, aged 44–82, underwent a 3D opto-electronic motion analysis during standing and walking trials in asymptomatic and symptomatic states. Passive reflective marker clusters (four markers each) were attached to participants at T1, L1, and S2 levels of the spine, with additional reflective markers at other spinal levels, as well as the head, pelvis, and extremities. Whole-body motion data was collected during standing and walking trials in asymptomatic and symptomatic states. The results showed that the spine was slightly flexed during walking, but this was not affected by symptoms. Pelvic tilt was not different when symptoms were present, but suggests a possible effect of more forward tilt in both standing (p = 0.052) and walking (p = 0.075). Lumbar spine loading during symptomatic walking was increased by an average of 7% over asymptomatic walking (p = 0.001). Our results did not show increased spine flexion (adopting a trunk-flexed posture) and only indicate a trend for a small forward shift of the pelvis during both symptomatic walking and standing. This suggests that provocation of symptoms in these patients does not markedly affect their normal gait kinematics. The finding of increased spine loading with provocation of symptoms supports our hypothesis that spine loading plays a role in limiting walking function in patients with lumbar spinal stenosis, but additional work is needed to understand the biomechanical cause of this increase.

Use of machine learning to select texture features in investigating the effects of axial loading on T2-maps from magnetic resonance imaging of the lumbar discs

BACKGROUND

Recent advances in texture analysis and machine learning offer new opportunities to improve the application of imaging to intervertebral disc biomechanics. This study employed texture analysis and machine learning on MRIs to investigate the lumbar disc's response to loading.

METHODS

Thirty-five volunteers (30 (SD 11) yrs.) with and without chronic back pain spent 20 min lying in a relaxed unloaded supine position, followed by 20 min loaded in compression, and then 20 min with traction applied. T₂-weighted MR images were acquired during the last 5 min of each loading condition. Custom image analysis software was used to segment discs from adjacent tissues semi-automatically and segment each disc into the nucleus, anterior and posterior annulus automatically. A grey-level, co-occurrence matrix with one to four pixels offset in four directions (0°, 45°, 90° and 135°) was then constructed (320 feature/tissue). The Random Forest Algorithm was used to select the most promising classifiers. Linear mixed-effect models and Cohen's d compared loading conditions.

FINDINGS

All statistically significant differences (p < 0.001) were observed in the nucleus and posterior annulus in the 135° offset direction at the L4-5 level between lumbar compression and traction. Correlation (P_2-Offset, P_4-Offset) and information measure of correlation 1 (P_3-Offset, P_4-Offset) detected significant changes in the nucleus. Statistically significant changes were also observed for homogeneity (P_2-Offset, P_3-Offset), contrast (P_2-Offset), and difference variance (P_4-Offset) of the posterior annulus.

INTERPRETATION

MRI textural features may have the potential of identifying the disc's response to loading, particularly in the nucleus and posterior annulus, which appear most sensitive to loading.

LEVEL OF EVIDENCE

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Single-segment central lumbar spinal stenosis: Correlation with lumbar X-ray measurements

BACKGROUND

Lumbar X-rays are usually preferred in patients with lower back pain, but lumbar spinal stenosis (LSS) cannot be directly observed on lumbar X-ray films.

OBJECTIVE

The purpose of this study is to explore the correlation between the degree of single-segment central LSS and lumbar X-ray measurements.

METHODS

The data of 60 male patients aged 39-78 years with single-segment central LSS were analyzed. Linear correlation analysis was used to determine the correlation between the single-segment central LSS and the various measurement parameters. Multiple linear regression analysis was used to analyze the factors affecting single-segment central LSS.

RESULTS

There were significant differences in S1/S0, E, B, L1-5Cobb, and M among the three groups (p< 0.05). S1/S0 was positively correlated with E, B, L1-5Cobb, and M (p< 0.05), but was not correlated with D (p= 0.66). After multiple linear regression analysis, B, L1-5Cobb, and M were independently associated with S1/S0.

CONCLUSIONS

The B, L1-5Cobb, and M parameters were independently associated with single-stage central LSS, and would likely be of particular value in evaluating the degree of single-segment central LSS; B, L1-5Cobb, and M served as independent predictors of the degree of LSS. These findings will guide clinicians' decision-making in the future.

Dynamic morphometric changes in degenerative lumbar spondylolisthesis: A pilot study of upright magnetic resonance imaging

The objectives of this study were to (a) develop a standing MRI imaging protocol, tolerable to symptomatic patients with degenerative spondylolisthesis (DLS), and (b) to evaluate the morphometric changes observed in DLS patients in both supine and standing postures. Patients with single level, Meyerding grade 1 DLS undergoing surgery at a single institution between November 2015 to May 2017 were consented. Patients were imaged in the supine and standing positions in a 0.5 T vertically open MRI scanner (MROpen, Paramed, Genoa, Italy) with sagittal and axial T2 images. The morphometric parameters measured were: cross-sectional area of the thecal sac (CSA), lateral recess height, disc height, degree of anterolisthesis, disc angle, lumbar lordosis, the presence of facet effusion and restabilization signs. Measures from both postures were compared using paired T-test. Associations of posture with the magnitude of change in the various measurements was determined using Pearson correlation or paired T-test when appropriate. All fourteen patients (mean age 64.4 years) included tolerated standing for the time required for image acquisition. All measurements with the exception of lumbar lordosis and disk height showed a statistically significant difference between the postures (p < 0.05). In the standing position, CSA and lateral recess height were reduced by 28% and 50%, respectively. There was no relationship between the change in CSA of the thecal sac and any measures. Standing images acquired in an upright MRI scanner demonstrated postural changes associated with Meyerding grade 1 DLS and images acquisition was tolerated in all patients.

Predictability of the effects of epidural injection in lumbar spinal stenosis by assessment of lumbar MRI scans

BACKGROUND

Numerous classification systems have been proposed to interpret lumbar MRI scans. The clinical impact of the measured parameters remains unclear. To evaluate the clinical significance of imaging results in patients with multisegmental degenerative pathologies, treating specialists can perform image-guided local injections to target defined areas such as the epidural space.

OBJECTIVE

The aim of this retrospective study was to evaluate the correlation between lumbar spinal stenosis measurements obtained by MRI and improvement obtained through local epidural injection.

METHODS

In this retrospective study various measurement and classification systems for lumbar spinal stenosis were applied to MRI scans of 100 patients with this pathological condition. The reported effect of epidural bupivacaine/triamcinolone injections at the site was recorded in these patients and a comparative analysis performed.

RESULTS

MRI features assessed in this study did not show any relevant correlation with reported pain relief after epidural injection in patients with chronic lumbar stenosis, with the exception of posterior disc height with a weak Kendall's tau of -0.187 (p= 0.009).

CONCLUSIONS

Although MRI is crucial for evaluating lumbar spinal stenosis, it cannot replace but is rather complementary to a good patient history and clinical examination or the results of local diagnostic injections.

Weight-Bearing Magnetic Resonance Imaging as a Diagnostic Tool That Generates Biomechanical Changes in Spine Anatomy

Weight-bearing magnetic resonance imaging (MRI) is a unique modality in diagnostic imaging that allows for the assessment of spinal pathology in ways considered previously inaccessible or insufficient with the conventional MRI technique. Due to limitations in positioning within the MRI machine itself, difficulties would be posed in determining the underlying cause of a patient’s pain or neurological symptoms, as the traditional supine position utilized can, in many cases, alleviate the severity of presented symptoms. Weight-bearing MRI addresses this concern by allowing a clinician to position a patient (to a certain degree) into flexion, extension, rotation, or side-bending with an axial load that can mimic physiologic conditions in order to replicate the conditions the patient experiences in order to give clinicians a clearer understanding of the anatomical relationship of the spine and surrounding tissues that may lead to a particular presentation of symptoms. These findings can then guide treatment approaches that are better tailored to a patient’s needs in order to initiate treatment earlier and shorten the duration of treatment necessary for patient benefit. The goal of this review is to describe and differentiate weight-bearing MRI from conventional MRI as well as examine the advantages and disadvantages of either imaging modality. This will include assessing cost-effectiveness and improvements in clinical outcomes. Further, the advancements of weight-bearing MRI will be discussed, including potentially unique clinical applications in development.

Associations between psychological factors and daily step count in patients with lumbar spinal stenosis

Background: Body mass index, pain, female sex, and age have been reported as predictors of physical activity in patients with lumbar spinal stenosis (LSS). However, no reports have examined the psychological factors associated with physical activity in people with LSS.Purpose: To use psychological assessments to identify the factors associated with physical activity measured as daily step count in people with LSS.Methods: Seventy-one patients who received outpatient physical therapy were included. All patients completed the following scales at baseline: Zurich Claudication Questionnaire; self-paced walking test (SPWT); numerical rating scale of low back pain, leg pain, and leg numbness; Hospital Anxiety and Depression Scale (HADS); Pain Catastrophizing Scale; Pain Anxiety Symptoms Scale (PASS-20); and Tampa Scale for Kinesiophobia. Physical activity was measured using a pedometer as the average number of daily steps.Results: Daily step count was significantly associated with age, number of stenoses, severity of stenosis at L3-L4, walking distance on the SPWT, PASS-20 total score, cognitive anxiety, escape/avoidance, fear, and HADS depression score (p < .05). Multiple regression analysis showed that age, severity of stenosis at L3-L4, walking distance on the SPWT, and PASS-20 fear predicted daily step count (r² = 0.414).Conclusion: Older age, fewer stenoses, less severe stenosis at L3-L4, lower walking capacity, higher anxiety, and fear-avoidance beliefs about pain and depression are more closely associated with lower daily step count than are back and leg pain. Assessment and treatment of psychological factors might help to increase physical activity in patients with LSS.

Correlation Between Dural Sac Size in Dynamic Magnetic Resonance Imaging and Clinical Symptoms in Patients with Lumbar Spinal Stenosis

OBJECTIVE

To assess the dynamic change of the dural sac size in patients with lumbar spinal stenosis (LSS) from supine to standing position and their correlation with clinical symptoms.

METHODS

A total of 110 patients with LSS were prospectively enrolled to undergo both supine (0°) and standing (78°) magnetic resonance imaging (MRI). Dural sac cross-sectional area (DCSA) and dural sac anteroposterior diameter (DAPD) at the most constricted spinal level in supine and standing MRI were measured and compared. Clinical symptoms were assessed by duration of disease, claudication distance, visual analog scale (VAS) score of leg pain, and Chinese Oswestry Disability Index score of low back pain. The correlation between the parameters and clinical symptoms was analyzed by Pearson correlation coefficient (r).

RESULTS

Mean minimum DCSA and DAPD in the standing position were significantly smaller (both P < 0.01) than in the supine position. DCSA and DAPD in standing MRI and their changes had better correlation with the intermittent claudication distance and VAS score of leg pain than in the supine position. A more than 15 mm² reduction of DSCA was observed in patients with shorter claudication distance and more severe VAS score of leg pain (both P < 0.01).

CONCLUSIONS

Dural sac size on MRI was reduced significantly from supine to standing position. Standing MRI and the changes of DCSA significantly correlated with claudication distance and VAS score of leg pain in patients with LSS. Therefore, standing MRI provides more radiologic information correlating with clinical symptoms in patients with LSS than supine MRI.

Axial loading during MRI reveals insufficient effect of percutaneous interspinous implants (Aperius™ PerCLID™) on spinal canal area

PURPOSE

To evaluate the effect on the spinal canal at the treated and adjacent level(s), in patients treated for lumbar spinal stenosis (LSS) with percutaneous interspinous process device (IPD) Aperius™ or open decompressive surgery (ODS), using axial loading of the spine during MRI (alMRI).

MATERIALS

Nineteen LSS patients (mean age 67 years, range 49-78) treated with IPDs in 29 spine levels and 13 LSS patients (mean age 63 years, range 46-76) operated with ODS in 22 spine levels were examined with alMRI pre- and 3 months postoperatively. Radiological effects were evaluated by measuring the dural sac cross-sectional area (DSCSA) and by morphological grading of nerve root affection.

RESULTS

For the IPD group, no DSCSA increase was observed at the operated level (p = 0.42); however, a decrease was observed in adjacent levels (p = 0.05). No effect was seen regarding morphological grading (operated level: p = 0.71/adjacent level: p = 0.94). For the ODS group, beneficial effects were seen for the operated level, both regarding DSCSA (p < 0.001) and for morphological grading (p < 0.0001). No changes were seen for adjacent levels (DSCSA; p = 0.47/morphological grading: p = 0.95). Postoperatively, a significant difference between the groups existed at the operated level regarding both evaluated parameters (p < 0.003).

CONCLUSIONS

With the spine imaged in an axial loaded position, no significant radiological effects of an IPD could be detected postoperatively at the treated level, while increased DSCSA was displayed for the ODS group. In addition, reduced DSCSA in adjacent levels was detected for the IPD group. Thus, the beneficial effects of IPD implants on the spinal canal must be questioned. These slides can be retrieved under Electronic Supplementary Material.

Effect of active TENS versus de-tuned TENS on walking capacity in patients with lumbar spinal stenosis: a randomized controlled trial

Background context

Lumbar spinal stenosis (LSS) leads to diminished blood flow to the spinal nerves causing neurogenic claudication and impaired walking ability. Animal studies have demonstrated increased blood flow to the spinal nerves and spinal cord with superficial para-spinal electrical stimulation of the skin.

Purpose

The aim of this study was to assess the effectiveness of active para-spinal transcutaneous electrical nerve stimulation (TENS) compared to de-tuned TENS applied while walking, on improving walking ability in LSS.

Study design

This was a two-arm double-blinded (participant and assessor) randomized controlled trial.

Patient sample

We recruited 104 participants 50 years of age or older with neurogenic claudication, imaging confirmed LSS and limited walking ability.

Outcome measures

The primary measure was walking distance measured by the self-paced walking test (SPWT) and the primary outcome was the difference in proportions among participants in both groups who achieved at least a 30% improvement in walking distance from baseline using relative risk with 95% confidence intervals.

Methods

The active TENS group (n = 49) received para-spinal TENS from L3-S1 at a frequency of 65-100 Hz modulated over 3-s intervals with a pulse width of 100-200 usec, and turned on 2 min before the start and maintained during the SPWT. The de-tuned TENS group (n = 51) received similarly applied TENS for 30 s followed by ramping down to zero stimulus and turned off before the start and during the SPWT.Study funded by The Arthritis Society ($365,000 CAN) and salary support for Carlo Ammendolia funded by the Canadian Chiropractic Research Foundation ($500,000 CAN over 5 years).

Results

From August 2014 to January 2016 a total of 640 potential participants were screened for eligibility; 106 were eligible and 104 were randomly allocated to active TENS or de-tuned TENS. Both groups showed significant improvement in walking distance but there was no significant difference between groups. The mean difference between active and de-tuned TENS groups was 46.9 m; 95% CI (- 118.4 to 212.1); P = 0.57. A total of 71% (35/49) of active TENS and 74% (38/51) of de-tuned TENS participants achieved at least 30% improvement in walking distance; relative risk (RR), 0.96; 95% CI, (0.7 to 1.2) P = 0.77.

Conclusions

Active TENS applied while walking is no better than de-tuned TENS for improving walking ability in patients with degenerative LSS and therefore should not be a recommended treatment in clinical practice.

Registration

ClinicalTrials.gov ID: NCT02592642. Registration October 30, 2015.

Diagnostic Importance of Axial Loaded Magnetic Resonance Imaging in Patients with Suspected Lumbar Spinal Canal Stenosis

OBJECTIVE AND BACKGROUND

To study the efficacy of lumbar (AL) magnetic resonance imaging (MRI) in patients with suspected lumbar spinal stenosis (LSS), with and without AL compression. Supine MRI is used in the assessment of patients with LSS. However, MRI findings may poorly correlate with neurologic findings because of the morphologic changes of the lumbar spinal canal between upright standing and supine positions. In patients without significant stenosis in routine lumbar MRI, by applying AL, MRI can show significant LSS.

METHODS

This study included 103 consecutive patients (188 disc levels) who presented with neurogenic claudication with and without low back pain. AL was performed using a nonmagnetic compression device for 5 minutes. T1- and T2-weighted axial and sagittal sequences were obtained during AL applied to the spine. The dural sac cross-sectional area (DSCA) appeared to be narrow at each disc level of L4-5 to L5-S1 in all patients and was measured using T2-weighted images in routine supine and AL images.

RESULTS

The groups included patients with a reduction in the DSCA (>15 mm²) according to patient age and DSCA in routine spine MRI. The mean DSCA of the disc levels without and with AL were 138 mm² and 123 mm², with a mean difference of 15 mm² at L4-5, 134 mm² and 125 mm² and a mean difference of 9 mm² at L5-S1, respectively.

CONCLUSIONS

The use of AL MRI in patients with clinically suspected LSS could reduce the risk of misdiagnosis of stenosis, leading to inappropriate treatment.

CORRELATION BETWEEN LUMBAR SPINAL STENOSIS BASED ON MORPHOLOGY OF THE DURAL SAC AND THE QUALITY OF LIFE

ABSTRACT Objective: To evaluate the possible existence of a significant correlation between quality of life and severity classification of lumbar stenosis based on dural sac morphology in outpatients. Methods: Forty patients with a diagnosis of lumbar stenosis followed at a university hospital were submitted to magnetic resonance imaging (MRI) and quality of life questionnaires: Oswestry Disability Index (ODI), SF-36, Swiss Spinal Stenosis Questionnaire (SSS) and EQ-5D. They were classified as type A, B, C or D based on MRI. For the statistical analysis, the Spearman correlation was used. Results: Seventeen female patients and 23 male patients with mean age of 56.5 years constituted the sample. ODI had a mean dysfunction of 44.9%, the PCS score averaged 29.9, the MCS score was 41.3. The general symptoms of SSS presented a mean of 3.2 and the EQ-5D presented an average of 0.491. The patients with the highest severity in the classification were not necessarily those who presented worse scores in the quality of life questionnaires. Conclusion: The classification of severity of the lumbar spinal stenosis based on dural sac morphology does not correlate with the applied quality of life questionnaires. Level of Evidence III; Cross-sectional observational study.

Effect of a prototype lumbar spinal stenosis belt versus a lumbar support on walking capacity in lumbar spinal stenosis: a randomized controlled trial

BACKGROUND CONTEXT

Lumbar spinal stenosis (LSS) can impair blood flow to the spinal nerves giving rise to neurogenic claudication and limited walking ability. Reducing lumbar lordosis can increases the volume of the spinal canal and reduce neuroischemia. We developed a prototype LSS belt aimed at reducing lumbar lordosis while walking.

PURPOSE

The aim of this study was to assess the short-term effectiveness of a prototype LSS belt compared to a lumbar support in improving walking ability in patients with degenerative LSS.

STUDY DESIGN

This was a two-arm, double-blinded (participant and assessor) randomized controlled trial.

PATIENT SAMPLE

We recruited 104 participants aged 50 years or older with neurogenic claudication, imaging confirmed degenerative LSS, and limited walking ability.

OUTCOME MEASURES

The primary measure was walking distance measured by the self-paced walking test (SPWT) and the primary outcome was the difference in proportions among participants in both groups who achieved at least a 30% improvement in walking distance from baseline using relative risk with 95% confidence intervals.

METHODS

Within 1 week of a baseline SPWT, participants randomized to the prototype LSS belt group (n=52) and those randomized to the lumbar support group (n=52) performed a SPWT that was conducted by a blinded assessor. The Arthritis Society funded this study ($365,000 CAN) with salary support for principal investigator funded by the Canadian Chiropractic Research Foundation ($500,000 CAN for 5 years).

RESULTS

Both groups showed significant improvement in walking distance, but there was no significant difference between groups. The mean group difference in walking distance was -74 m (95% CI: -282.8 to 134.8, p=.49). In total, 62% of participants wearing the prototype LSS belt and 82% of participants wearing the lumbar support achieved at least 30% improvement in walking distance (relative risk, 0.7; 95% CI: 0.5-1.3, p=.43).

CONCLUSIONS

A prototype LSS belt demonstrated significant improvement in walking ability in degenerative LSS but was no better than a lumbar support.

An increase in the degree of olisthesis during axial loading reduces the dural sac size and worsens clinical symptoms in patients with degenerative spondylolisthesis

BACKGROUND CONTEXT

Previous studies have shown that axial loading during magnetic resonance imaging (MRI) significantly reduces the size of the dural sac compared with conventional MRI in patients with degenerative lumbar disease. In our previous study, axial-loaded MRI showed a significantly larger degree of olisthesis than conventional MRI in patients with degenerative spondylolisthesis (DS). Furthermore, the degree of olisthesis on axial-loaded MRI correlated more strongly with that observed on X-ray in the upright position. However, no study has investigated whether or not the increase in the degree of olisthesis during axial loading correlates with the reduction in the dural sac size and affects the severity of clinical symptoms in patients with DS.

PURPOSE

The objective of this study was to determine whether or not the increase in the degree of olisthesis correlates with the reduction of the dural sac cross-sectional area (DCSA) detected on axial-loaded MRI and worsens the severity of clinical symptoms in patients with DS.

STUDY DESIGN/SETTING

This is an imaging cohort study.

PATIENT SAMPLE

A total of 41 consecutive patients with DS were prospectively evaluated in this study.

OUTCOME MEASURES

The outcome measures include the degree of olisthesis, the DCSA, the Pearson correlation coefficient, and the severity of clinical symptoms.

MATERIALS AND METHODS

The differences in the degree of olisthesis and the DCSA between conventional and axial-loaded MRIs were determined. The Pearson correlation coefficient of the increase in the degree of olisthesis with the reduction in the DCSA during axial loading was calculated. The reduction in the DCSA and the severity of clinical symptoms in patients exhibiting a ≥2-mm increase in the degree of olisthesis were compared with those in patients exhibiting a <2-mm increase.

RESULTS

The increase in the degree of olisthesis was significantly correlated with the reduction in the DCSA during axial loading (Pearson correlation coefficient=0.63, p<.001). The reduction in the DCSA during axial loading in patients with a ≥2-mm increase in the degree of olisthesis (26±3 mm²) was significantly greater than in those with a <2-mm increase (13±2 mm²) (p<.01). Clinical symptoms such as walking distance and activity of daily living evaluated using the Japanese Orthopaedic Association score were significantly worse in patients with a ≥2-mm increase in the degree of olisthesis (117±19 m and 6.7±0.5 points, respectively) than in those with a <2-mm increase (236±36 m and 8.4±0.4 points, respectively) (p<.05).

CONCLUSIONS

The present study demonstrated that the increase in the degree of olisthesis was significantly correlated with the reduction in the dural sac size detected on axial-loaded MRI and worsened the severity of clinical symptoms in patients with DS. These results suggest that axial-loaded MRI may be a useful imaging study for detecting dynamic changes in the degree of olisthesis during axial loading to the lumbar spine related to the narrowing of the spinal canal and the severity of clinical symptoms in the assessment of patients with DS.

Myelography in the Assessment of Degenerative Lumbar Scoliosis and Its Influence on Surgical Management

Objective

Myelography has been shown to highlight foraminal and lateral recess stenosis more readily than computed tomography (CT) or magnetic resonance imaging (MRI). It also has the advantage of providing dynamic assessment of stenosis in the loaded spine. The advent of weight-bearing MRI may go some way towards improving assessment of the loaded spine and is less invasive, however availability remains limited. This study evaluates the potential role of myelography and its impact upon surgical decision making.

Methods

Of 270 patients undergoing myelography during 2006–2009, a period representing peak utilisation of this imaging modality in our unit, we identified 21 patients with degenerative scoliosis who fulfilled our inclusion criteria. An operative plan was formulated by our senior author based initially on interpretation of an MRI scan. Subsequent myelogram and CT myelogram investigations were scrutinised, with any additional abnormalities noted and whether these impacted upon the operative plan.

Results

From our 21 patients, 18 (85.7%) had myelographic findings not identified on MRI. Of note, in 4 patients, supine CT myelography yielded additional information when compared to supine MRI in the same patients. The management of 7 patients (33%) changed as a result of myelographic investigation. There were no complications of myelography of the total 270 analysed.

Conclusion

MRI scan alone understates the degree of central and lateral recess stenosis. In addition to the additional stenosis displayed by dynamic myelography in the loaded spine, we have also shown that static myelography and CT myelography are also invaluable tools with regards to surgical planning in these patients.

Indications for prophylactic lumbar decompression at the L3/4 level in patients with L4/5 responsible lumbar spinal canal stenosis

Introduction

Lumbar spinal canal stenosis (LSS) is a very common disease. When the responsible level is considered to be L4/5 despite the appearance of double-level (L3/4 and L4/5) stenosis on magnetic resonance imaging (MRI), it is difficult for spinal surgeons to decide whether prophylactic decompression should be performed at the L3/4 level. The purpose of this study was to investigate the relationship between the dural sac cross-sectional area (DCSA) at the L3/4 level and clinical symptoms in patients with double-level stenosis.

Methods

Thirty-five patients with double-level stenosis were registered in this study. All patients underwent decompression surgery at the L4/5 responsible level. The severity of patients' symptoms was evaluated by the Japanese Orthopaedic Association (JOA) score and its rate of recovery. A measurement program on MRI was used to determine the DCSA.

Results

The clinical course of LSS according to the JOA score recovery rate at the final follow-up revealed that the good group (≥50%) included 27 patients, and the poor group (<50%) included 8 patients. In the good group, the mean DCSA at the L3/4 level was 72.3 ± 32.1 mm² preoperatively and 71.3 ± 29.0 mm² at the final follow-up. In contrast, in the poor group, the mean DCSA at the L3/4 level was 49.1 ± 23.8 mm² preoperatively and 40.6 ± 14.1 mm² at the final follow-up. Significant differences were observed in the preoperative and final follow-up DCSAs at the L3/4 level between two groups.

Conclusions

Considering the present results, prophylactic decompression surgery at the L3/4 level should be performed for patients with double-level stenosis and DCSA <50 mm² at the L3/4 level.

Tumor Occupation in the Spinal Canal and Clinical Symptoms of Cauda Equina Schwannoma: An Analysis of 22 Cases

STUDY DESIGN

Retrospective, radiological study.

PURPOSE

To determine the relationship between clinical symptoms and the extent of tumor occupation of the spinal canal by cauda equina schwannoma.

OVERVIEW OF LITERATURE

Little is known about the relationship between the size of tumors of the cauda equina and the manifestation of clinical symptoms. We analyzed this relationship by estimating the percentage of tumor occupation (PTO) in the spinal canal in cauda equina schwannomas and by correlating this parameter with the presence and severity of clinical symptoms.

METHODS

Twenty-two patients (9 men and 13 women; age, 19-79 years; mean age, 55.3 years) who were radiologically diagnosed with schwannomas of the cauda equina between April 2004 and July 2014 were retrospectively analyzed. PTO was measured in axial and sagittal magnetic resonance imaging slices in which the cross-sectional area of the tumor was the largest. Data regarding clinical symptoms and results of physical examinations were collected from patient medical records. PTO differences between symptom-positive and -negative groups were analyzed for each variable.

RESULTS

In the 4 cases in which tumor presence was not related to clinical symptoms, PTO was 5%-10% (mean, 9%) in axial slices and 23%-31% (mean, 30%) in sagittal slices. In the 18 cases in which symptoms were associated with the tumor, PTO was 11%-86% (mean, 50%) in axial slices and 43%-88% (mean, 71%) in sagittal slices. PTO in axial slices was significantly higher in the presence of Déjèrine symptoms and/or muscle weakness, a positive straight leg raise test, and a positive Kemp sign.

CONCLUSIONS

PTO >20% in axial slices and >40% in sagittal slices can be an indication of symptomatic cauda equina schwannoma.

Effect of TENS Versus Placebo on Walking Capacity in Patients With Lumbar Spinal Stenosis: A Protocol for a Randomized Controlled Trial

Background

Lumbar spinal stenosis (LSS) is a growing health problem and a leading cause of disability and loss of independence in older adults. It is usually caused by age-related degenerative narrowing of the spinal canals leading to compression and ischemia of the spinal nerves and symptoms of neurogenic claudication. Limited walking ability is the dominant functional impairment caused by LSS. Animal studies suggest increased blood flow to the spinal nerves and spinal cord with superficial paraspinal electrical stimulation. The purpose of this study is to assess the effectiveness of paraspinal transcutaneous electrical nerve stimulation (TENS) applied while walking on walking ability in patients with LSS.

Methods/Design

We propose to conduct a 2-arm double-blinded (participant and assessor) randomized controlled trial. We will recruit individuals who have limited walking ability due to degenerative LSS from hospital specialists, community physicians, and chiropractors located in the city of Toronto, Canada. Eligible consenting participants will be randomly assigned to either paraspinal TENS or placebo paraspinal TENS applied while walking. The primary outcome will be walking distance measured during a single self-paced walking test. We will calculate the differences in proportions among participants in both groups who achieve at least a 30% improvement in walking distance from baseline using Pearson χ² test with 95% confidence intervals.

Discussion

Effective nonoperative interventions for LSS are unknown. Interventions that can improve blood flow to the spinal nerves while walking may increase walking ability in this population. Transcutaneous electrical nerve stimulation is a low-cost intervention that may have the potential to achieve this objective. To our knowledge, this study will be the first clinical trial to assess the effects of TENS on walking ability of patients with LSS.

Trial Registration

ClinicalTrials.gov ID: NCT02592642

Upright magnetic resonance imaging of the lumbar spine: Back pain and radiculopathy

BACKGROUND

Lumbar back pain and radiculopathy are common diagnoses. Unfortunately, conventional magnetic resonance imaging (MRI) findings and clinical symptoms do not necessarily correlate in the lumbar spine. With upright imaging, disc pathologies or foraminal stenosis may become more salient, leading to improvements in diagnosis.

MATERIALS AND METHODS

Seventeen adults (10 asymptomatic and 7 symptomatic volunteers) provided their informed consent and participated in the study. A 0.6T upright MRI scan was performed on each adult in the seated position. Parameters were obtained from the L2/3 level to the L5/S1 level including those pertaining to the foramen [cross-sectional area (CSA), height, mid-disc width, width, thickness of ligamentum flavum], disc (bulge, height, width), vertebral body (height and width), and alignment (lordosis angle, wedge angle, lumbosacral angle). Each parameter was compared based on the spinal level and volunteer group using two-factor analysis of variance (ANOVA). Bonferroni post hoc analysis was used to assess the differences between individual spinal levels.

RESULTS

Mid-disc width accounted for 56% of maximum foramen width in symptomatic volunteers and over 63% in asymptomatic volunteers. Disc bulge was 48% greater in symptomatic volunteers compared to asymptomatic volunteers. CSA was generally smaller in symptomatic volunteers compared to asymptomatic volunteers, particularly at the L4-L5 and L5-S1 spinal levels. Thickness of ligamentum flavum (TLF) generally increased from the cranial to caudal spinal levels where the L4-L5 and L5-S1 spinal levels were significantly thicker than the L1-L2 spinal level.

CONCLUSIONS

The data implied that upright MRI could be a useful diagnostic option, as it can delineate pertinent differences between symptomatic volunteers and asymptomatic volunteers, especially with respect to foraminal geometry.

Degenerative disease of the lumbar spine

In the last 25 years, scientific research has brought about drastic changes in the concept of low back pain and its management. Most imaging findings, including degenerative changes, reflect anatomic peculiarities or the normal aging process and turn out to be clinically irrelevant; imaging tests have proven useful only when systemic disease is suspected or when surgery is indicated for persistent spinal cord or nerve root compression. The radiologic report should indicate the key points of nerve compression, bypassing inconsequential findings. Many treatments have proven inefficacious, and some have proven counterproductive, but they continue to be prescribed because patients want them and there are financial incentives for doing them. Following the guidelines that have proven effective for clinical management improves clinical outcomes, reduces iatrogenic complications, and decreases unjustified and wasteful healthcare expenditures.

Increased Facet Fluid Predicts Dynamic Changes in the Dural Sac Size on Axial-Loaded MRI in Patients with Lumbar Spinal Canal Stenosis

BACKGROUND AND PURPOSE

Axial-loaded MR imaging, which simulates the spinal canal in a standing position, demonstrates reductions of the dural sac cross-sectional area in patients with lumbar spinal canal stenosis. However, there has been no useful conventional MR imaging finding for predicting a reduction in the dural sac cross-sectional area on axial-loaded MR imaging. Previous studies have shown that increased facet fluid is associated with the spinal instability detected during positional changes. The purpose of this study was to analyze the correlations between facet fluid and dynamic changes in the dural sac cross-sectional area on axial-loaded MR imaging.

MATERIALS AND METHODS

In 93 patients with lumbar spinal canal stenosis, the dural sac cross-sectional area was measured by using axial images of conventional and axial-loaded MR imaging. Changes in the dural sac cross-sectional area induced by axial loading were calculated. The correlation between the facet fluid width measured on conventional MR imaging and the change in dural sac cross-sectional area was analyzed. The change in the dural sac cross-sectional area was compared between the intervertebral levels with and without the facet fluid width that was over the cutoff value determined in this study.

RESULTS

The dural sac cross-sectional area was significantly smaller on axial-loaded MR imaging than on conventional MR imaging. The facet fluid width significantly correlated with the change in the dural sac cross-sectional area (r = 0.73, P < .001). The change in the dural sac cross-sectional area at the intervertebral level with the facet fluid width over the cutoff value was significantly greater than that at the other level.

CONCLUSIONS

The increased facet fluid on conventional MR imaging is highly predictive of the dynamic reduction of dural sac cross-sectional area detected on axial-loaded MR imaging in the clinical assessment of lumbar spinal canal stenosis.

Lumbar Spinal Canal Stenosis Classification Criteria: A New Tool

Study Design

Case-control study.

Purpose

To design a new tool for classifying lumbar spinal canal stenosis (CLSCS).

Overview of Literature

Grading of patients with lumbar spinal canal stenosis (LSCS) is controversial.

Methods

The Oswestry disability index (ODI) and the neurogenic claudication outcome score (NCOS) were recorded. Four parameters, which indicate the severity of LSCS disease, including Hufschmidt-grade, grading of magnetic resonance imaging, self-paced walking test, and stenosis ratio (SR) were employed. For the SR, quartile analysis was applied for classifying LSCS and the Hufschmidt-grade was modified into a 4-grade score. An initial score was assigned to each metric based on the severity of LSCS. Using the inverse-variance weighting method, the relative weights of these domains and their categories were determined. The score for all of the cases was obtained based on their weight by summing up the points of the four variables. Quartile analysis was used and a CLSCS score was proposed. Finally, intra- and interobserver reliability, and validity were assessed.

Results

A total of 357 patients were studied. The final CLSCS score for each case ranged from 4 to 16.5. Based on the quartile analysis, using the new criteria set, the CLSCS score was divided into four categories: CLSCS<7 (grade 0); 7≤CLSCS<10 (grade 1); 10≤CLSCS<13 (grade 2); and 13≤CLSCS≤16.5 (grade 3). The kappa values of for the CLSCS score indicated a perfect agreement. The CLSCS was correlated with the ODI and NCOS. All patients with grade 3 CLSCS were observed in the surgical group.

Conclusions

The CLSCS score can be helpful for classifying LSCS patients and in the decision-making process.

Changes in lumbar spondylolisthesis on axial-loaded MRI: do they reproduce the positional changes in the degree of olisthesis observed on X-ray images in the standing position?

BACKGROUND CONTEXT

Axial-loaded magnetic resonance imaging (MRI) can partially simulate the lumbar spine in patients in a standing position and potentially provides additional imaging findings that cannot be obtained with conventional MRI in the clinical assessment of patients with degenerative lumbar disease. Previous studies have shown that axial-loaded MRI demonstrates a significant reduction in the size of the dural sac compared with conventional MRI. However, there has been no study to compare the degree of olisthesis among conventional MRI, axial-loaded MRI, and upright X-ray imaging in patients with degenerative spondylolisthesis (DS).

PURPOSE

The purpose of the study is to determine whether axial-loaded MRI can demonstrate similar positional changes in lumbar olisthesis as those detected on upright lateral X-ray in patients with DS.

STUDY DESIGN

This is an imaging cohort study.

PATIENT SAMPLE

A total of 43 consecutive patients with DS exhibiting olisthesis of 3 mm or more on X-ray images in the standing position were prospectively evaluated in this study.

OUTCOME MEASURES

The degree of olisthesis, intraclass correlation coefficient (ICC), and percentage of patients exhibiting olisthesis of 3 mm or more on MRI.

METHODS

The degree of olisthesis was measured on conventional MRI, axial-loaded MRI, and lateral X-ray imaging performed in the upright position. The degree of olisthesis was compared among the three imaging techniques. The ICC values for the measurements of olisthesis between X-ray studies and conventional and axial-loaded MRI were calculated and compared. The percentage of patients exhibiting olisthesis of 3 mm or more was compared between conventional MRI and axial-loaded MRI.

RESULTS

The degree of olisthesis on axial-loaded MRI (5.9±2.5 mm) was significantly greater than that observed on conventional MRI (4.4±2.4 mm) (p<.05) although the degrees on conventional and axial-loaded MRI were significantly smaller than that on upright X-ray images (7.1±2.8 mm) (p<.05). The ICC between axial-loaded MRI and X-ray imaging (0.75, 95% confidence interval: 0.58-0.85) was considerably greater than that observed between conventional MRI and X-ray imaging (0.40, 95% confidence interval: 0.11-0.62). The percentage of patients exhibiting olisthesis of 3 mm or more was significantly higher on axial-loaded MRI (91%) than on conventional MRI (63%) (p<.01).

CONCLUSIONS

Axial-loaded MRI demonstrates a significantly larger degree of olisthesis than conventional MRI. In addition, the degree of olisthesis on axial-loaded MRI was found to be more strongly correlated with that observed on X-ray studies in the upright position. Furthermore, the use of axial-loaded MRI significantly reduced the misdiagnosis of olisthesis of 3 mm or more that was detected on X-ray imaging. These results suggest that axial-loaded MRI may be superior to identify the olisthesis of the lumbar spine and show the degrees of olisthesis correlated to those detected on upright X-ray imaging. Further studies should be needed to clarify the actual value of these findings on axial-loaded MRI and provide the evidence to support its clinical significance in the assessment of patients with DS.

Postoperative expansion of dural sac cross-sectional area after unilateral laminotomy for bilateral decompression: correlation with clinical symptoms

OBJECTIVE

Dural sac cross-sectional area (DSCSA) is a way to measure the degree of central spinal canal compression. The objective was to investigate the correlation between the expansion ratio of DSCSA after unilateral laminotomy for bilateral decompression (ULBD) and the clinical results for lumbar spinal stenosis.

METHODS

We retrospectively reviewed the clinical data and radiographs of 103 patients who underwent ULBD for symptomatic spinal stenosis in one year. We compared preoperative and postoperative clinical data and DSCSA and evaluated the correlation between clinical and radiographic measurements.

RESULTS

There was a significant increase of DSCSA after ULBD (p=0.000) and mean expansion ratio of DSCSA was 203.7±147.2%(range -32.9-826.1%). Clinical outcomes, measured by VAS and ODI were improved significantly not only in early postoperative period, but also in the last follow-up. However, there were no statistically significant correlations between the preoperative DSCSA and clinical symptoms, Perioperative expansion ratio of DSCSA and clinical parameters were also not correlated to the improvement of clinical symptoms significantly in both early postoperative phase and last follow-up.

CONCLUSION

Our result indicates that the DSCSA itself has a definite limitation to be correlated to the clinical symptoms, and thus meticulous correlation between the clinical presentation and MRI imaging is essential in determination of surgical treatment.

Clinical outcomes for neurogenic claudication using a multimodal program for lumbar spinal stenosis: a retrospective study

OBJECTIVE

The purpose of this preliminary study was to assess the effectiveness of a 6-week, nonsurgical, multimodal program that addresses the multifaceted aspects of neurogenic claudication.

METHODS

In this retrospective study, 2 researchers independently extracted data from the medical records from January 2010 to April 2013 of consecutive eligible patients who had completed the 6-week Boot Camp Program. The program consisted of manual therapy twice per week (eg, soft tissue and neural mobilization, chiropractic spinal manipulation, lumbar flexion-distraction, and muscle stretching), structured home-based exercises, and instruction of self-management strategies. A paired t test was used to compare differences in outcomes from baseline to 6-week follow-up. Outcomes included self-reported pain, disability, walking ability, and treatment satisfaction.

RESULTS

A total of 49 patients were enrolled, with a mean age of 70 years. The mean difference in the Oswestry Disability Index was 15.2 (95% confidence interval [CI], 11.39-18.92), and that for the functional and symptoms scales of the Swiss Spinal Stenosis Questionnaire was 0.41 (95% CI, 0.26-0.56) and 0.74 (95% CI, 0.55-0.93), respectively. Numeric pain scores for both leg and back showed statistically significant improvements. Improvements in all outcomes were clinically important.

CONCLUSIONS

This study showed preliminary evidence for improved outcomes in patients with neurogenic claudication participating in a 6-week nonsurgical multimodal Boot Camp Program.

Visually assessed severity of lumbar spinal canal stenosis is paradoxically associated with leg pain and objective walking ability

Background

Lumbar spinal stenosis (LSS) is the common term used to describe patients with symptoms related to the anatomical reduction of the lumbar spinal canal size. However, some subjects may have a markedly narrowed canal without any symptoms. This raises the question of what is the actual role of central canal stenosis in symptomatic patients. The purpose of this study was to compare radiological evaluations of LSS, both visually and quantitatively, with the clinical findings of patients with LSS.

Methods

Eighty patients [mean age 63 (11) years, 44% male], with symptoms severe enough to indicate LSS surgery, were included in this prospective single-center study. Lumbar magnetic resonance imaging was performed and one experienced neuroradiologist classified patients into three groups: 0 = normal or mild stenosis, 1 = moderate stenosis, and 2 = severe stenosis. In addition, the same observer measured the minimal dural sac area level by level from the inferior aspect of L1 to the inferior aspect of S1. The association between radiological and clinical findings were tested with Oswestry Disability Index, overall visual analog pain scale, specific low back pain, specific leg pain, Beck Depression Inventory, and walking distance on treadmill exercise test.

Results

In the visual classification of the central spinal canal, leg pain was significantly higher and walking distance achieved was shorter among patients with moderate central stenosis than in patients with severe central stenosis (7.33 (2.29) vs 5.80 (2.72); P = 0.008 and 421 (431) m vs 646 (436) m; P = 0.021, respectively). Patients with severe stenosis at only one level also achieved shorter walking distance than patients with severe stenosis of at least two levels. No correlation between visually or quantitatively assessed stenosis and other clinical findings was found.

Conclusions

There is no straightforward association between the stenosis of dural sac and patient symptoms or functional capacity. These findings indicated that dural sac stenosis is not the single key element in the pathophysiology of LSS.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-348) contains supplementary material, which is available to authorized users.

Preoperative MRI findings predict two-year postoperative clinical outcome in lumbar spinal stenosis

PURPOSE

To study the predictive value of preoperative magnetic resonance imaging (MRI) findings for the two-year postoperative clinical outcome in lumbar spinal stenosis (LSS).

METHODS

84 patients (mean age 63±11 years, male 43%) with symptoms severe enough to indicate LSS surgery were included in this prospective observational single-center study. Preoperative MRI of the lumbar spine was performed with a 1.5-T unit. The imaging protocol conformed to the requirements of the American College of Radiology for the performance of MRI of the adult spine. Visual and quantitative assessment of MRI was performed by one experienced neuroradiologist. At the two-year postoperative follow-up, functional ability was assessed with the Oswestry Disability Index (ODI 0-100%) and treadmill test (0-1000 m), pain symptoms with the overall Visual Analogue Scale (VAS 0-100 mm), and specific low back pain (LBP) and specific leg pain (LP) separately with a numeric rating scale from 0-10 (NRS-11). Satisfaction with the surgical outcome was also assessed.

RESULTS

Preoperative severe central stenosis predicted postoperatively lower LP, LBP, and VAS when compared in patients with moderate central stenosis (p<0.05). Moreover, severe stenosis predicted higher postoperative satisfaction (p = 0.029). Preoperative scoliosis predicted an impaired outcome in the ODI (p = 0.031) and lowered the walking distance in the treadmill test (p = 0.001). The preoperative finding of only one stenotic level in visual assessment predicted less postoperative LBP when compared with patients having 2 or more stenotic levels (p = 0.026). No significant differences were detected between quantitative measurements and the patient outcome.

CONCLUSIONS

Routine preoperative lumbar spine MRI can predict the patient outcome in a two-year follow up in patients with LSS surgery. Severe central stenosis and one-level central stenosis are predictors of good outcome. Preoperative finding of scoliosis may indicate worse functional ability.

Correlation of lateral stenosis in MRI with symptoms, walking capacity and EMG findings in patients with surgically confirmed lateral lumbar spinal canal stenosis

BACKGROUND

To evaluate the clinical significance of lateral lumbar spinal canal stenosis (LLSCS), found by magnetic resonance imaging (MRI), through correlating the imaging findings with patient symptoms, walking capacity and electromyography (EMG) measurements.

METHOD

102 patients with symptoms of LSS referred for operative treatment were studied in this uncontrolled study. Of these patients, subjects with distinct only lateral LSS were included. Accordingly, 140 roots in 14 patients (mean age 58, range 48-76 years, male 43%) were evaluated. In MR images the entrance and mid zones of the lateral lumbar nerve root canal were graded as normal, narrowed but not compressed, or compressed. In quantitative analysis, the minimal widths of the lateral recess and mid zone area were measured. Clinical symptoms were recorded with the Oswestry Disability Index (ODI), overall Visual Analogue Scale (VAS), specific low back pain (LBP; NRS-11), specific leg pain (LP NRS-11), Beck Depression Inventory (BDI) and walking distance in the treadmill test. Lumbar paraspinal (L2- L5) and lower limb (L3 - S1) needle EMG studies were performed. The findings were classified root by root as 1 = normal, 2 = abnormal. The associations between radiological, EMG and clinical findings were tested with each other.

RESULTS

EMG findings were normal in 92 roots and abnormal in 48 roots. All of the patients had at least one abnormal nerve root finding. Severity of the mid zone stenosis in MRI correlated with abnormal EMG findings (p = 0.015). Patients with abnormal EMG had also higher scores in the VAS (41.9 ± 25.7 vs 31.5 ± 18.1; p = 0.018), NRS leg pain (7.5 ± 1.5 vs 6.3 ± 2.1; p = 0.000) and BDI (9.8 ± 3.8 vs 8.0 ± 3.9; p = 0.014). However, no statistically significant correlations between MRI findings and clinical symptoms or walking capacity were found.

CONCLUSIONS

Among persons previously selected for surgery, lateral stenosis seen on MRI correlates with EMG, and thus may be a clinically significant finding. Our EMG findings were also associated with patient symptoms. However, no relationships between the MRI findings and symptoms or walking capacity were found, suggesting their multifactorial etiology.

Clinical validity of the nerve root sedimentation sign in patients with suspected lumbar spinal stenosis

BACKGROUND CONTEXT

The nerve root sedimentation sign in transverse magnetic resonance imaging has been shown to discriminate well between selected patients with and without lumbar spinal stenosis (LSS), but the performance of this new test, when used in a broader patient population, is not yet known.

PURPOSE

To evaluate the clinical performance of the nerve root sedimentation sign in detecting central LSS above L5 and to determine its potential significance for treatment decisions.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

One hundred eighteen consecutive patients with suspected LSS (52% women, median age 62 years) with a median follow-up of 24 months.

OUTCOME MEASURES

Oswestry disability index (ODI) and back and leg pain relief.

METHODS

We performed a clinical test validation study to assess the clinical performance of the sign by measuring its association with health outcomes. Subjects were patients referred to our orthopedic spine unit from 2004 to 2007 before the sign had been described. Based on clinical and radiological diagnostics, patients had been treated with decompression surgery or nonsurgical treatment. Changes in the ODI and pain from baseline to 24-month follow-up were compared between sedimentation sign positives and negatives in both treatment groups.

RESULTS

Sixty-nine patients underwent surgery. Average baseline ODI in the surgical group was 54.7%, and the sign was positive in 39 patients (mean ODI improvement 29.0 points) and negative in 30 (ODI improvement 28.4), with no statistically significant difference in ODI and pain improvement between groups. In the 49 patients of the nonsurgical group, mean baseline ODI was 42.4%; the sign was positive in 18 (ODI improvement 0.6) and negative in 31 (ODI improvement 17.7). A positive sign was associated with a smaller ODI and back pain improvement than negative signs (both p<.01 on t test).

CONCLUSIONS

In patients commonly treated with decompression surgery, the sedimentation sign does not appear to predict surgical outcome. In nonsurgically treated patients, a positive sign is associated with more limited improvement. In these cases, surgery might be effective, but this needs investigation in prospective randomized trials (Australian New Zealand Clinical Trial Registry, number ACTRN12610000567022).

An investigation of the value of tridimensional kinematic analysis in functional diagnosis of lumbar spinal stenosis

Diagnosis of lumbar spinal stenosis (LSS) is based on clinical examination and imaging. The aim of this study was to evaluate the influence of 3D gait analysis as a tool in the differential diagnosis of LSS. Fourteen patients participated in the study that consisted of three phases: (1) capture six gait cycles after rest, (2) walk on a treadmill for a maximum of 20 min, (3) capture six gait cycles after effort. From these data, the kinematic variables were compared with the perception of pain and the cross sectional area of the spinal canal as measured by magnetic resonance. Most of correlations were weak and showed that the most significant results are reported by the Gait Deviation Index (GDI). The Gait Deviation Index demonstrated moderate negative correlation with the perception of pain after effort was made by both limbs. This means that there is a significant decrease in the overall function of the lower limbs according to the increase in pain symptoms. This situation may be reflected in decreased cadence and speed beyond the times of single support for the left limb, and the balance of the right limb, as part of a strategy to protect against pain and imbalance. We found no correlation between gait and pain in the cross-sectional area of the spinal canal. Therefore, we believe that there is no advantage for the patient to make a 3-D gait analysis because the analysis does not add relevant information to clinical diagnosis.

What interventions improve walking ability in neurogenic claudication with lumbar spinal stenosis? A systematic review

PURPOSE

To investigate what interventions can improve walking ability in neurogenic claudication with lumbar spinal stenosis.

METHODS

We searched CENTRAL, Medline, EMBASE, CINAHL and ICL databases up to June 2012. Only randomized controlled trials published in English and measuring walking ability were included. Data extraction, risk of bias assessment, and quality of the evidence evaluation were performed using methods of the Cochrane Back Review Group.

RESULTS

We accepted 18 studies with 1,220 participants. There is very low quality evidence that calcitonin is no better than placebo or paracetamol regardless of mode of administration. There is low quality evidence that prostaglandins, and very low quality evidence that gabapentin or methylcobalamin, improves walking distance. There is low and very low quality evidence that physical therapy was no better in improving walking ability compared to no treatment, oral diclofenac plus home exercises, or combined manual therapy and exercise. There is very low quality evidence that epidural injections improve walking distance up to 2 weeks compared to placebo. There is low- and very low-quality evidence that various direct decompression surgical techniques show similar significant improvements in walking ability. There is low quality evidence that direct decompression is no better than non-operative treatment in improving walking ability. There is very low quality evidence that indirect decompression improves walking ability compared to non-operative treatment.

CONCLUSIONS

Current evidence for surgical and non-surgical treatment to improve walking ability is of low and very low quality and thus prohibits recommendations to guide clinical practice.

Improved magnetic resonance myelography of the lumbar spine using image fusion and volumetry

Object

The goal of this study was to investigate the usefulness and diagnostic potential of an improved MR myelography approach using a dedicated, heavily T2-weighted, 3D MRI sequence in combination with image fusion. A further aim was to compare dural areas and volumes of normal and pathological altered lumbar spine levels, and accuracy in the assessment of the stenoses, with those obtained by postmyelographic CT.

Methods

Fifty patients underwent myelography, postmyelographic CT, and the improved MR myelography approach using a dedicated, heavily T2-weighted, 3D MRI sequence and image fusion. Dural cross-sectional areas and volumes for normal lumbar levels and levels with stenosis were calculated for postmyelographic CT and MR myelography data. The significant differences and Pearson correlations between dural cross-sectional areas and volumes from L1–2 to L5–S1 of postmyelographic CT and MR myelography were analyzed. The 99% CIs for normal and stenotic levels in patients with claudication distances less than 100 meters were calculated.

Results

For both dural areas and volumes in normal lumbar levels, the authors found no significant differences and strong correlations between postmyelographic CT and MR myelography. For the lower lumbar levels (L4–5 and L5–S1) they found significantly larger dural areas on MR myelography compared with postmyelographic CT, but not for the upper levels (L2–3 and L3–4). Dural volume analysis revealed significantly larger volumes for MR myelography at all 4 lumbar levels with stenoses in the cohort (L2–3 to L5–S1). Complete separation with no overlap was found between the 99% CIs for normal levels and stenotic levels.

Conclusions

Differences in dural areas and volumes in this study may have been caused by the fact that in the case of a severely compressed thecal sac, the viscosity of the intrathecally applied contrast agent is too high in the framework of myelography. The gravitationally dependent component is thus too low to achieve sufficient fluid contrast. An optimized MR myelography approach—a dedicated 3D MR myelography sequence with high spatial resolution in combination with image fusion—is required to achieve a more reliable diagnosis of lumbar spine stenoses, especially with severe compression, compared with postmyelographic CT. This MR myelography approach may be helpful in preventing overestimation of lumbar spine stenoses. The upper limits of 99% CIs for stenotic levels can be interpreted as an indication for surgical treatment. However, further studies that include postoperative outcomes are required.

Does the presence of the nerve root sedimentation sign on MRI correlate with the operative level in patients undergoing posterior lumbar decompression for lumbar stenosis?

BACKGROUND CONTEXT

Recent research describes the use of a nerve root sedimentation sign to diagnose lumbar spinal stenosis (LSS). The lack of sedimentation of the nerve roots (positive sedimentation sign) to the dorsal part of the dural sac is the characteristic feature of this new radiological parameter.

PURPOSE

To demonstrate how the nerve root sedimentation sign compares with other more traditional radiological parameters in patients who have been operated for LSS.

STUDY DESIGN/SETTING

A retrospective chart and image review.

PATIENT SAMPLE

Preoperative magnetic resonance images (MRIs) were reviewed from 71 consecutive operative patients who presented with LSS and received spinal decompression surgery from 2006 to 2010.

OUTCOME MEASURES

Preoperative T2-weighted MRIs were reviewed for each patient.

METHODS

One hundred thirty-four vertebral levels from L1 to L5 were measured for: sedimentation sign, cross-sectional area (CSA) and anterior/posterior (A/P) diameter of the dural sac, thickness of the ligamentum flavum, and Fujiwara grade of facet hypertrophy. Radiological measurements were made using Surgimap 1.1.2.169 software (Nemaris, Inc., New York, NY, USA). Statistical analyses were performed using the SPSS 17.0 statistical software (SPSS Inc., Chicago, IL, USA). Significance was demonstrated using unpaired t tests and chi-squared tests. Study funding was departmental. There were no study-specific conflicts of interest-associated biases.

RESULTS

A positive sedimentation sign was determined in 120 operated levels (89.5%), whereas 14 levels (10.5%) had no sign (negative sedimentation sign). The mean CSA and A/P diameter were 140.62 mm(2) (standard deviation [SD]=53) and 11.76 mm (SD=3), respectively, for the no-sign group; the mean CSA and A/P diameter were 81.87 mm(2) (SD=35) and 8.76 mm (SD=2.2), respectively, for the sedimentation sign group (p<.001). We found that 60% of levels with Fujiwara Grade A facet hypertrophy did not have a sedimentation sign, whereas 86.3% of levels with Grade B, 93.2% of levels with Grade C, and 100.0% of levels with Grade D did have a sedimentation sign (p<.001).

CONCLUSIONS

The sedimentation sign is a new measurement tool that can enable physicians to objectively assess and quantify spinal stenosis. The sign is most often present in patients who have clinically significant lumbar stenosis and require surgery.