Elsevier

World Neurosurgery

Volume 96, December 2016, Pages 165-170
World Neurosurgery

Original Article
Comparison of Surgeon Rating of Severity of Stenosis Using Magnetic Resonance Imaging, Dural Cross-Sectional Area, and Functional Outcome Scores

https://doi.org/10.1016/j.wneu.2016.08.093Get rights and content

Objective

To determine the relationship between the severity of stenosis graded using both surgeons' visual assessment of spinal stenosis as well as measurement of dural cross-sectional area on magnetic resonance imaging (MRI), with the patient's disability.

Methods

Seven fellowship-trained spine surgeons reviewed MRI studies retrospectively of 30 symptomatic consecutive patients with lumbar stenosis and graded stenosis in the central canal, the lateral recess, and the foramen at T12-L1 to L5-S1 as none, mild, moderate, or severe. Dural cross-sectional area was measured at each level from T12-L1 to L5-S1. All patients completed the questionnaires for Oswestry Disability Index (ODI), Short Form 36 (SF-36), and recorded Visual Analog Scale scores for leg and back pain, and symptom severity scale of the Zurich claudication questionnaire.

Results

There was positive correlation between the right leg pain Visual Analog Scale score and the mean surgeon grades for central and lateral recess stenosis at L4-L5 and lateral recess stenosis at L5-S1. Except for a positive correlation between role physical score and surgeon grade for lateral recess stenosis at L5-S1, we found no correlation between the surgeons' grading of stenosis at any level with the ODI or SF-36. We found no correlation between the dural cross-sectional area with the ODI or SF-36. We did not find any correlation between the Zurich symptom severity scale and surgeons' grading of stenosis at any level.

Conclusions

Although surgeons rely on visual assessment of the severity of stenosis while making surgical decisions, we found that objective and subjective imaging parameters to grade severity of stenosis did not consistently indicate the patient's disability level.

Introduction

Magnetic resonance imaging (MRI) is the usual modality used to diagnose lumbar spinal stenosis, but a lack of universally accepted diagnostic criterion or grading systems for lumbar spinal stenosis remains. Schizas et al.1 described a 7-grade classification system based on morphology of the dural sac seen on T2-weighted axial MRI images. A dural cross-sectional area less than 70 mm2 has been previously suggested to represent critical stenosis2 and has been used in multiple studies. In a surgical clinic, such morphometric measurements are unlikely to be used to diagnose and grade spinal stenosis. Surgeons usually rely on visual assessment of axial MRI images to ascertain the degree of stenosis. Despite the central role played by MRI in surgical decision making, there is a paucity of data to indicate a correlation between the severity of stenosis found on MRIs and clinical disability. Many asymptomatic patients have spinal stenosis on MRI.3

Multiple studies4, 5, 6, 7 have failed to establish a correlation between any morphometric grading of stenosis on MRI and clinical disability. None has assessed a correlation between surgeons' visual grading of spinal stenosis on MRI and clinical disability in patients who are evaluated for surgery. This is a critical issue because an operating surgeon's visual assessment of stenosis on MRI has a direct impact on surgical decision making.

Our aim was to assess the relationship of the surgeon's visual grading of spinal stenosis and dural cross-sectional area measurement on MRI, with the patient's disability level using the Oswestry Disability Index (ODI), Visual Analog Scale (VAS), Short Form 36 (SF-36), and symptom severity scale of the Zurich claudication questionnaire.

Section snippets

Methods

After institutional review board approval, 30 patients who consecutively presented to our academic tertiary-care referral center with symptoms of lumbar spinal stenosis were consented and prospectively enrolled in the study between July 2009 and March 2010. Patients showed a variety of symptoms of lumbar spinal stenosis, including back pain, neurogenic claudication, and leg pain. The symptoms had not been relieved after conservative management for more than 6 weeks. Nonoperative measures that

Results

Sixteen women and 14 men enrolled, with ages ranging between 43 and 86 years (mean, 62.8 years). The mean ODI was 44. We did not find any correlation between the patient's age and ODI score, and VAS scores for back pain or leg pain. We found no correlation between surgeons' grading of stenosis at any level with ODI scores. We found no significant correlation between dural cross-sectional area at any levels and ODI. Table 1 lists overall minimum dural cross-sectional area as well as mean dural

Discussion

Lumbar spinal stenosis associated with neurogenic claudication and clinical disability is the most common indication for spinal surgery.12, 13 Although this is a common diagnosis, there remains a lack of reliable diagnostic criterion and clinical consensus regarding surgical indications. MRI is the choice imaging modality to diagnose lumbar spinal stenosis. A myelogram with computed tomographic myelography can provide a more functional assessment in lumbar spinal stenosis, but surgeons and

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    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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