Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P61. Clinical outcomes of microendoscopic decompression for lumbar canal stenosis: a comparison between patients with and without degenerative lumbar scoliosis

Abstract

BACKGROUND CONTEXT The operative management of degenerative lumbar scoliosis includes decompression or decompression with fusion. However, there is currently no consensus on the criteria for the role of adjunctive fusion. We have performed microendoscopic decompression in patients with the chief complaint of radicular and/or cauda equina symptoms due to degenerative lumbar scoliosis. Although the surgical procedure almost improved leg symptoms, it seemed that the patients had severe low back pain postoperatively as compared with patients without degenerative lumbar scoliosis. PURPOSE To compare the clinical outcomes of microendoscopic decompression for lumbar canal stenosis between patients with and without degenerative lumbar scoliosis. METHODS A total of 75 patients with lumbar canal stenosis between March 2006 and December 2014 were included in this study. The patients who had disc herniation and foraminal stenosis were excluded. The patients were treated with microendoscopic decompression and followed more than two years after the surgery. Of those, 34 were males and 41 were females. The mean age at the time of the surgery was 73.1years (range, 61–86 year). The mean follow-up period was 48.1 months (range, 24–102 months). Twenty-seven patients had degenerative lumbar scoliosis with coronal curvature of more than 10° measured by Cobb's method (DLS group). The other 48 patients had neither degenerative lumbar scoliosis nor degenerative lumbar spondylolisthesis (nonDLS group). Clinical outcomes were assessed using the Japanese Orthopedic Association (JOA) score and Short-Form 36 (SF-36) preoperatively and at the final follow-up. Recovery rate of the JOA score was calculated as (postoperative score − preoperative score)/(29 − preoperative score)×100%. The visual analogue scale (VAS) for low back pain was also measured at the final follow-up. RESULTS In the DLS group, the JOA score significantly improved from 13.7 preoperatively to 23.4 postoperatively. Also in the nonDLS group, the preoperative JOA score of 15.7 significantly improved to 25.0 postoperatively. Recovery rate in the DLS and nonDLS group were 62.5% and 69.0%, respectively. There were no significant differences in preoperative and postoperative JOA scores between the two groups. At the final follow-up, VAS for low back pain in the DLS group (45.4 mm) was significantly higher than that in the nonDLS group (25.4 mm). As for the preoperative SF-36 score, there were no significant differences in all 8 subscales between the two groups. In the DLS group, a significant improvement was observed only in bodily pain scores after surgery. In the nonDLS group, all subscales except general health perception significantly improved after surgery. All postoperative subscales except social role function and mental health in the DLS group were significantly lower than in the nonDLS group. CONCLUSIONS This study showed that the patients with lumbar degenerative scoliosis had higher VAS for low back pain and lower QOL scores after microendoscopic decompression as compared with the patients without lumbar degenerative scoliosis. We might consider other surgical options in patients with lumbar canal stenosis due to degenerative lumbar scoliosis.