Retrospective Cohort Study Showing Clinical Equivalence of Microendoscopic Laminotomy to Open Fenestration for Patients with Lumbar Spinal Stenosis

Abstract

Objective Despite the popularity of microendoscopic disectomy, there is currently insufficient studies about microendoscopic laminotomy (MEL) for lumbar spinal stenosis. The purpose of this study was to compare the clinical and radiographic outcomes of MEL and fenestration (laminotomy in open procedure) for lumbar spinal stenosis. Methods This study included 30 patients in the MEL group and 46 patients in the open fenestration group between 2012 and 2016 (follow-up period ≥1 year). The Japanese Orthopedic Association Back Pain Evaluation Questionnaire(JOABPEQ), a visual analog scale(VAS), surgical outcomes, blood test outcomes, and radiographic parameters were studied. Results Mean age was 67 years old in the MEL group and 70 years old in the open fenestration group (p=0.1). There were no significant differences in score change of either domain of JOABPEQ between MEL and fenestration. The 95% confidence intervals of the between-group differences in score change were within clinical important difference (±20 point) in all the domains of JOABPEQ. The MEL group had significantly shorter hospital stays (9 days vs 13 days; p<0.001), smaller increase in C-reactive protein (1.7 mg/dL vs 2.9 mg/dL; p=0.009), and longer operating time (122 min vs 39 min; p<0.001) than the fenestration group. There was no significant difference in hemoglobin level, total protein, albumin, creatine kinase between the groups. The MEL group had one case of dural tear and the fenestration group had two cases(p=1.0). There was no significant differences in complication rate between the groups. There were no significant between-group differences in change of disc height or ROM. Conclusion In the treatment of lumbar spinal stenosis, the clinical effectiveness and safety of MEL was equivalent to that of fenestration, with less invasiveness.

Keywords

• microendoscopic laminotomy
• fenestration
• minimally invasive
• decompression
• facet resection
• outcome