Association between Redundant Nerve Root and Clinical Outcome after Fusion for Lumbar Spinal Stenosis

Objective: This study aimed to determine the association between redundant nerve root and clinical outcome after fusion for lumbar spinal stenosis by comparing outcomes in patients with or without redundant nerve root.Methods: A total of 163 patients who underwent spinal fusion surgery between January 1, 2014, and December 31, 2018, were enrolled. Patients were divided into two groups: with a redundant nerve root (R group) and without a redundant nerve root (N group). The clinical outcome of the two groups was compared using VAS and claudication distance.Results: A total of 46 patients had a redundant nerve root, while the remaining 117 did not. Symptom duration was significantly different between the two groups (R=41.0±25.0, N=24.1±12.2, p<0.001). Changes in the VAS score for lower extremity pain between the two groups at 1 year after surgery showed that patients without a redundant nerve root had significantly better outcomes than those with a redundant nerve root (R: 4.2±1.3 vs. N: 5.5±1.4; p<0.001). Conclusion: Redundant nerve root on MRI is associated with clinical outcome after fusion for lumbar spinal stenosis. Patients with a redundant nerve root had poor outcomes after fusion surgery for lumbar spinal stenosis than those without a redundant nerve root.