Complications of Lumbar Spinal Stenosis Surgery and Their Effects on Outcome: A National FinSpine Registry Study.

STUDY DESIGN: Retrospective observational study with prospectively collected data based on three national registries. OBJECTIVE: To investigate complications of lumbar spinal stenosis (LSS) surgery in Finland, clinically linked to complications, and their effects on functional outcomes, patient satisfaction, and risk of reoperation. SUMMARY OF BACKGROUND DATA: LSS surgeries continue to increase. Complication rates in previous studies vary greatly due to methodological differences, data quality, and the definition of complications. METHODS: Patients with a primary diagnosis of LSS identified from the Finnish Spine Register (FinSpine) were included in this study. Complications within 30 days of index operation were identified from FinSpine, the Finnish Care Register for Health Care (HILMO), and the Register of Primary Health Care Visits (AvoHILMO). The effect of complications on functional outcome was assessed using the Oswestry Disability Index (ODI) and by measuring patient satisfaction. Various factors including ASA grade and fusion surgery were analyzed as potential factors clinically linked to complications. The risk of reoperation at 1 year after the index operation was also assessed. RESULTS: The overall complication rate in LSS surgery was 16.8% (7.8% intraoperative, 4.6% in-hospital, and 4.4% later). The most common complications by group were dural tear, urinary retention, and wound infection. Older age, higher ASA grade, longer operative time, multilevel decompression, and fusion surgery increased complication risk. At 1-year follow-up, mean ODI was 28.1 and 24.3 with and without complications. Patients with complications of any type had significantly higher risk of reoperation 13.9% than patients without complications, which was further elevated by specific complications, spinal hematoma at 57.8% and wound infection 53.8%. CONCLUSION: By combining three national registries, a comprehensive overview of LSS surgery complications was obtained. Older age, higher ASA grade and multilevel decompression were identified as factors clinically linked to complications. Patients with and without complications achieved acceptable amelioration of disability. Complications increased the risk for reoperation within 1 month after index operation, and the risk remained higher up to 1 year than without complications. LEVEL OF EVIDENCE: Level III.