Redundant nerve root syndrome (RNRS) is a phenomenon characterized by the presence of elongated, enlarged, tortuous nerve roots in the lumbar subarachnoid space. It is unclear whether RNRS is caused by spinal stenosis or causes these symptoms.This study evaluated the effects of lumbar epidural steroid injection (LESI) on patients with RNRS and assessed factors associated with RNRS. This retrospective observational cohort study was conducted at a single pain clinic of a university hospital.The medical records of 172 outpatients presenting with low back and/or leg pain from July to December 2014 were analyzed. Pain intensity (numeric rating scale [NRS]) and functional status were assessed at baseline and 2, 4, and 12 weeks after the LESI. Patients were considered moderate responders if they showed a 3-point or >30% reduction in baseline NRS, or said “better than 30%,” “a little better,” or “I feel an effect.” Patients were considered substantial responders if they showed a 5-point or >50% reduction in baseline NRS, or said “better than 50%,” “very good,” or “much better.” Generalized estimating equation (GEE) analysis was performed to identify the factors associated with moderate response to LESI. Factors associated with RNRS were also determined by logistic regression analysis.The proportions of both moderate and substantial responders at 2, 4, and 12 weeks were significantly lower in patients with than without RNRS. GEE analysis showed that RNRS were the only factor significantly associated with moderate response to LESI (OR = 0.400; 95% CI, 0.253–0.632; P < .001). The distance from the conus medullaris to the closest level of stenosis was shorter in patients with than without RNRS (P < .001) and was the only independent factor associated with RNRS on multivariate logistic regression analysis (OR = 0.972; P < .001).LESI was less effective in patients with than without RNRS. The only independent factor significantly associated with RNRS was the distance from the conus medullaris to the nearest moderate stenosis.

A previous study showed that transforaminal balloon adhesiolysis via the safe triangle was effective in lumbar spinal stenosis. However, retrodiscal pathology is difficult to treat with this method. Therefore we attempted retrodiscal balloon adhesiolysis via Kambin's triangle. The design of our study is a retrospective analysis. The setting of our study is a tertiary, interventional pain management practice, speciality referral center.The primary indication for this procedure is radicular pain arising from ipsilateral retrodiscal pathology. Medical records were reviewed of patients who received retrodiscal decompression with a transforaminal balloon inflatable catheter between January 1, 2016 and July 31, 2017. The intervention was conducted by 2 well-trained pain specialists. The introducer needle was positioned at Kambin's triangle. Adhesiolysis was performed using a balloon filled with radiocontrast media. After balloon adhesiolysis, an agent containing lidocaine and dexamethasone was injected through the introducer sheath. Numeric rating scale pain scores were obtained 1 and 3 months after the procedure.The mean pre-procedure numeric rating scale score was 7.05 ± 1.40. After 1 and 3 months, the mean scores were 3.91 ± 2.20 and 3.77 ± 2.11, respectively. No patient had significant complications. Also, technical considerations were discussed.Chronic pain due to lumbar central stenosis, especially ipsilateral retrodiscal pathology, can be reduced by retrodiscal balloon adhesiolysis through Kambin's triangle. Although this study is limited by its retrospective design, the results suggest that this procedure is a useful treatment due to its ease of performance and cost-effectiveness.