Effect of preoperative symptom duration on outcome in lumbar spinal stenosis: a Canadian Spine Outcomes and Research Network registry study

BACKGROUND CONTEXT: Lumbar degenerative stenosis is one of the most common spine pathologies for which surgical intervention is indicated. There is some evidence that a prolonged duration of neurological compression could lead to a failure of surgery to alleviate symptoms. PURPOSE: Determination of whether longer symptom duration was associated with worse postoperative disability outcomes after decompressive surgery for lumbar degenerative stenosis. STUDY DESIGN/SETTING: The Canadian Spine Outcomes and Research Network (CSORN) prospective database includes pre- and postoperative data from 18 tertiary care hospitals. PATIENT SAMPLE: The CSORN database was queried for all cases of degenerative lumbar stenosis receiving surgical decompression for neurogenic claudication or radiculopathy. Patients with tumor, infection, fracture, or previous surgery were excluded. Patients were divided into groups based on symptom duration (<6 weeks, 6–12 weeks, 3–6 months, 6–12 months, 1–2 years, and >2 years). OUTCOME MEASURES: Change between preoperative and 12-month postoperative Oswestry Disability Index (ODI) was compared between symptom duration groups. Secondary outcomes included SF12 physical component score (PCS), and numeric rating scales for leg and back pain. Outcomes were also assessed at 3 months and 24 months postoperatively. METHODS: Change in ODI, and secondary outcome measures, were compared between different symptom duration groups. Multiple regression analysis was used to identify factors interacting with symptom duration to predict change in ODI. RESULTS: Four hundred and seventy-eight cases of lumbar stenosis with 12-month postoperative data were identified. Longer symptom duration correlated with less improvement in ODI (p<.001). Patients with >1 year of symptoms were less likely to achieve a Minimal Clinically Significant Difference in ODI (54.4% vs. 66.1%; p=.03) and were more likely to experience no improvement or worse disability, postoperatively (22.1% vs. 11.3%; p=.008). Similar results were found at 3- and 24-month timepoints. Smaller postoperative improvements in SF12 PCS and leg pain scales were also correlated with longer symptom duration (p<.05). CONCLUSIONS: Multicenter registry data provides important real-world evidence to guide consent, surgical planning, and health resource management. Longer symptom duration was found to correlate with less improvement in pain and disability after lumbar stenosis surgery suggesting that these patients may benefit from earlier treatment.