Effect of Sagittal Imbalance on Functional Disability in Patients with Degenerative Spondylolisthesis

BACKGROUND: Sagittal imbalance often causes pain and disability in patients with degenerative spondylolisthesis (DS). This occurs due to the slipping of one vertebra over another as a result of degenerative changes in the disc and facet joints. In this study, we aimed to assess the impact of sagittal imbalance on functional disability in these patients. METHODS: This was a single-center cross-sectional study conducted among 50 patients with DS, aged over 45 years, over a period of 1 year. The participants underwent standing lateral radiographs of the spine, with their knees maximally extended and their arms raised horizontally forward over a support. Two radiographic films were stitched at baseline via Digital Radiography Operating Console software. Spine-specific functional assessment scoring was performed via the Oswestry Disability Index (ODI). Statistical analysis was performed via IBM SPSS, Windows version 25.0. RESULTS: Our study had a female preponderance, commonly involving the L4-L5 level. Fifty-eight percent of patients were found to have severe functional disability. A significant association was noted between sagittal vertical axis (SVA) and severity. Both Meyerding Grade I and II were significantly associated with pelvic incidence (PI) and functional disability according to ODI. The pelvic tilt and SVA were the two most significant variables at the end of the backward elimination analysis. CONCLUSIONS: Sagittal imbalance in DS necessitates the evaluation of spinopelvic parameters. PI, pelvic tilt, and the SVA are important associated factors of functional disability in patients with DS.