Does restoration of focal lumbar lordosis for single level degenerative spondylolisthesis result in better patient-reported clinical outcomes? A systematic literature review.

It is controversial whether the surgical restoration of sagittal balance and spinopelvic angulation in a single level lumbar degenerative spondylolisthesis results in clinical improvements. The purpose of this study to systematically review the available literature to determine whether the surgical correction of malalignment in lumbar degenerative spondylolisthesis correlates with improvements in patient-reported clinical outcomes. Literature searches were performed via Ovid Medline, Embase, CENTRAL and Web of Science using search terms "lumbar," "degenerative/spondylolisthesis" and "surgery/surgical/surgeries/fusion". This resulted in 844 articles and after reviewing the abstracts and full-texts, 13 articles were included for summary and final analysis. There were two Level II articles, four Level III articles and five Level IV articles. Most commonly used patient-reported outcome measures (PROMs) were Oswestery disability index (ODI) and visual analogue scale (VAS). Four articles were included for the final statistical analysis. There was no statistically significant difference between the patient groups who achieved successful surgical correction of malalignment and those who did not for either ODI (mean difference -0.94, CI -8.89-7.00) or VAS (mean difference 1.57, CI -3.16-6.30). Two studies assessed the efficacy of manual reduction of lumbar degenerative spondylolisthesis and their clinical outcomes after the operation, and there was no statistically significant improvement. Overall, the restoration of focal lumbar lordosis and restoration of sagittal balance for single-level lumbar degenerative spondylolisthesis does not seem to yield clinical improvements but well-powered studies on this specific topic is lacking in the current literature. Future well-powered studies are needed for a more definitive conclusion.