90. Decision-making factors leading to fusion vs decompression for one-level degenerative spondylolisthesis: survey results from members of the Lumbar Spine Research Society and Society of Minimally Invasive Spine Surgery

Abstract

<h3>BACKGROUND CONTEXT</h3> Degenerative spondylolisthesis is one of the most common pathologies spine surgeons treat. While a number of potential factors have been identified, there is no current consensus on which variables most impact the decision to fuse vs decompress alone in this population. <h3>PURPOSE</h3> The aim of this study was to identify radiographic and clinical factors leading to the decision to fuse segments for one-level degenerative spondylolisthesis. <h3>STUDY DESIGN/SETTING</h3> We performed a descriptive cross-sectional study utilizing a survey consisting of questions pertaining to decision-making factors leading to fusion or decompression alone in the setting of degenerative spondylolisthesis. <h3>OUTCOME MEASURES</h3> Radiographic parameters included grade of spondylolisthesis, instability, facet orientation >60°, facet diastasis, laterolisthesis or scoliosis, synovial cysts, vacuum disc, vertical disc space, preserved disc height, concomitant herniated nucleus pulposus, and symptomatic foraminal stenosis. Clinical factors included age >70 years, activity level, patient sex, body mass index >35, osteoporosis, primary complaint of low back pain, primary complaint of neurogenic claudication, smoking, and anxiety/depression. <h3>METHODS</h3> A survey was administered to the Lumbar Spine Research Society and Society of Minimally Invasive Spine Surgery. The primary analysis was limited to completed surveys. Baseline characteristics were summarized. Clinical and radiographic parameters were ranked and compared using chi-square, Fisher's exact test, Kruskal-Wallis, or two-sample t-test as appropriate. <h3>RESULTS</h3> A total of 381 (67.9%) surveys were returned completed. Respondents' mean years in practice was 17.8 ± 9.4 years and 296 (77.7%) had undergone a formal spine fellowship. The majority of respondents were from the US (45.9%) followed by Europe (24.1%), and Asia/Pacific (17.1%). The practice setting included academics (32.5%), private practice (31.0%), hospital-employed (17.1%), or a combination (19.4%). The mean number of degenerative spondylolisthesis cases performed was 53.8 ± 46.7 cases per year with 49.9% of the cohort performing these cases utilizing minimally invasive techniques. With regard to fusion vs decompression: 19.9% fuse all cases, 39.1% fuse >75%, 17.8% fuse 50%-75%, and 23.2% fuse <25%. The most common decompressive technique was a partial laminotomy (51.4%), followed by full laminectomy (28.9%). Among respondents, 82.2% instrument all fusion cases. Instability (93.2%), spondylolisthesis grade (59.8%) and laterolisthesis (37.3%) were the most common radiographic factors impacting the decision to fuse. Instability did not fall below the sixth rank with 75% of surgeons ranking it as the most important parameter. The top parameters also included spondylolisthesis grade, laterolisthesis, facet diastasis, and symptomatic foraminal stenosis. With regard to the clinical factors leading to fusion, mechanical low back pain (83.2%), activity level (58.3%) and neurogenic claudication (42.8%) were the top three clinical parameters. When ranked, the top parameters were mechanical low back pain, activity level, neurogenic claudication, bone mineral density and anxiety/depression. <h3>CONCLUSIONS</h3> There is little consensus on the treatment of degenerative spondylolisthesis, with society members showing substantial variation in treatment patterns. The most common radiographic parameters impacting treatment are instability, spondylolisthesis grade, and laterolisthesis while mechanical low back pain, activity level and neurogenic claudication are the most common clinical parameters. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.