Clinical selection and functional outcomes in symptomatic adult lumbar scoliosis: A systematic review of operative and nonoperative pathways

Objective: To characterize clinical and biomechanical features associated with selection of operative or nonoperative management and to describe short term and long term functional response, treatment switching, and harms in symptomatic adult lumbar scoliosis. The review is descriptive and does not estimate comparative treatment superiority. Methods: Reporting was guided by PRISMA 2020. PubMed/MEDLINE and the first 30 relevance ranked Google Scholar records were searched on 24 October 2026. Eligibility was restricted to peer reviewed, open access, English language clinical reports published from 2011 onward that addressed treatment selection or functional outcomes in adults with symptomatic lumbar or thoracolumbar scoliosis. Case reports, case series, reviews, technical reports, editorials, and reports linked to an erratum or correction were excluded from the primary synthesis. Risk of bias was appraised qualitatively using RoB 2, ROBINS I, and Newcastle Ottawa frameworks; numerical totals were not available. Screening and extraction were completed by one reviewer, and the source record did not preserve itemized title and abstract exclusion reasons. Results: Four reports from two independent cohorts were retained. Three reports described the ASLS multicenter cohort and one described de novo degenerative lumbar scoliosis at extended follow up. In ASLS, five year within pathway mean change was 0.13 ODI points and minus 0.02 SRS 22 points in the nonoperative group. Operative subgroup mean change ranged from minus 16.3 to minus 8.21 ODI points and from plus 0.63 to plus 0.29 SRS 22 points according to the occurrence of related serious adverse events. Forty two of 135 initially nonoperative participants, or 31 percent, changed to surgery during up to eight years. Fifty five of 179 operative participants had at least one revision by five years. In the separate ten year cohort, final ODI was available for 29 of 88 participants and did not differ significantly by treatment pathway. The retained reports did not provide harmonized longitudinal spinopelvic changes. Conclusion: Treatment selection in adult lumbar scoliosis is most consistently associated with functional burden, pain, and symptomatic stenosis, while alignment measures support assessment and planning rather than stand alone indications. Nonoperative care can maintain function for some patients and can include structured rehabilitation, although pathway specific response varies and crossover is common in a selected surgical candidate cohort. Operative reconstruction can produce sustained functional improvement for patients who choose it, with a substantial serious adverse event and revision burden. The evidence supports individualized shared decision making and does not establish a causal threshold for choosing either pathway.