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

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.