LAUSR

Abstract Lumbar spinal stenosis is a common degenerative disorder that is characterized by pain and neurogenic claudication. Previous studies have evaluated the effects of an epidural steroid injection (ESI) on spinal stenosis, based on changes to the spinal canal diameter. This study aimed to examine the impact of the ESI on pain scores and walking distance in patients with lumbar central spinal stenosis, stratified based on disease severity, which was graded according to the degree of cauda equina separation. We reviewed the medical records of patients who received the ESI for lumbar spinal central canal stenosis. A total of 128 patients were divided into moderate and severe groups, based on the degree of cauda equina separation. Relative to baseline values, 2 weeks after the ESI, the moderate group showed a significant decrease in the numeric rating scale (NRS) scores and an increase in walking distance. Meanwhile, the severe group showed a significant decrease in the NRS scores and no significant change in walking distance. The moderate group had lower NRS scores and a longer walking distance than did the severe group 2 weeks after the ESI. The proportion of patients with improved levels of satisfaction was higher in the moderate group than in the severe group. Lumbar interlaminar ESI may reduce pain scores and increase walking distance in patients with moderate lumbar spinal central canal stenosis. Patients with moderate spinal stenosis achieved better outcomes than did patients with severe stenosis.