P.132 Is a positive nerve root sedimentation sign associated with better outcomes after lumbar laminectomy?

Background: The nerve root sedimentation sign (SedSign) has been correlated with clinically significant lumbar spinal stenosis (LSS), and promoted as a possible prognostic indicator. However, diagnostic methods were not clearly defined in prior reports. In this study, the clinically validated Saskatchewan Spine Pathway enabled diagnosis of neurogenic claudication due to LSS. The objective was to compare the outcome of lumbar laminectomy for neurogenic claudication with respect to SedSign. Methods: This was a retrospective analysis of prospectively-collected data in patients with neurogenic claudication who underwent lumbar laminectomy. Outcome measures included Oswestry Disability Index, Visual Analogue Scale (VAS) for back and leg pain, and EuroQol 5-Dimension questionnaire. Results: Laminectomy was performed in 106 patients, and 60 were SedSign positive. Outcomes did not differ with respect to SedSign for all outcome measures, in non-instrumented and instrumented cohorts. Improvement in walking distance was associated with dural cross-sectional area of stenosis (p=0.02). VAS back and leg improvements were associated with back dominant (p=0.038) and leg dominant (p=0.0036) pain. Conclusions: This is the largest analysis of SedSign with respect to operative outcomes, and the only study with validated criteria for defining neurogenic claudication. Although other radiological and clinical factors are associated with improvements, SedSign did not correlate with laminectomy outcome.