Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters

BACKGROUND CONTEXT The success of surgical interventions for lumbar spinal stenosis can vary significantly depending on various factors, one of which is the duration of symptoms. Literature does not provide a clear indication of when lumbar decompression surgery become less effective in the setting of acute versus chronic symptoms from nerve root compression. PURPOSE The main objective of this study was to assess whether the duration of symptoms has an effect on clinical outcomes, especially resolution of radicular symptoms due to pathology compressing the lumbar nerve roots in patients undergoing lumbar decompression-only procedures. STUDY DESIGN/SETTING Retrospective cohort series. PATIENT SAMPLE We performed a retrospective cohort analysis of patients who underwent a primary lumbar laminectomy, discectomy or a combination of the two between 2009 and 2015 by one of two senior orthopedic spine surgeons. Patients were excluded from analysis if they had any previous lumbar surgery were under 18years of age at the time of surgery or had postoperative follow-up less than 3 months. Patients were divided into two groups: those with lumbar radicular symptoms for less than one year prior to surgery, and those who experienced symptoms for one year or greater before undergoing surgery. OUTCOME MEASURES Patient reported outcomes were obtained in the form of Oswestry Disability Index scores, Visual Analog Scales (VAS) scores for the back and leg, 12-Item Short Form Mental and Physical Survey (SF-12) scores, and the Veterans Rand 12-Item Health Mental and Physical Survey (VR-12) scores. Patients were also surveyed about their expectations and satisfactions following surgery. METHODS Baseline patient characteristics were compared using chi-squared analysis and independent sample t-tests for categorical and continuous data, respectively. Bivariate and multivariate regressions were subsequently used to compare clinical outcomes between procedure groups. Multivariate analyses controlled for differences in baseline patient characteristics. RESULTS Overall, 210 consecutive patients who fulfilled our inclusion criteria were assessed. Average follow-up was 24.14 months (range 3–78 months). There were 108 patients that experienced radicular symptoms for less than one year, while 102 patients experienced radicular symptoms for one year or more. Patients who experienced radicular symptoms for less than one year had a significantly higher rate of a herniated nucleus pulposus present (75.9% vs. 49.0%; p 1 year 7.9%; p=.904). Patients presented with high levels of satisfaction (pain 1 year 82.4%; OR1.06, p=.904) and expressed that the surgery met or exceeded their expectations (pain 1 year 96.1%; OR1.06, p=.904). CONCLUSIONS Overall, patients present with similar clinical outcome scores, despite the differences in the duration of their lumbar radicular symptoms prior to surgery. At approximately 2years following lumbar decompression-only surgery, all patients, despite their symptom chronicity, appear to show similar improvement in their clinical outcome scores. Re-operation rates were low and similar between the two groups of patients. Most patients report being satisfied with their outcome and with their expectations being met or exceeded to similar degrees. Given the various options available for nonoperative management of lumbar spinal stenosis and/or a lumbar herniated nucleus pulposus, the extended effort of these conservative treatments or delay of operative intervention do not appear to negatively impact the eventual outcome of surgery. Patients report significant improvement in their symptoms, based on clinical outcome surveys, regardless of their symptom chronicity.