Lumbar Lordosis and Segmental Lordosis Restoration Do Not Influence Patient-reported Outcomes After Fusion for Low-grade Lumbar Spondylolisthesis Correction

Introduction: In patients with degenerative lumbar spondylolisthesis, loss of lumbar lordosis and associated sagittal imbalance is thought to predispose patients to degeneration at adjacent segments, neurologic impairment, and functional limitation. As such, one of the goals of surgical correction of spondylolisthesis is lumbar lordosis improvement. Despite this emphasis, there is little evidence-based guidance regarding whether improved lordosis is associated with favorable functional outcomes after correction of low grade spondylolisthesis (Meyerding Grades I and II).

Methods: Using a prospectively-maintained institutional database who had no prior history of lumbar spine surgery and underwent one- or two-level fusion for correction of low-grade lumbar spondylolisthesis. Using standing XR, lumbar lordosis (LL) and segmental lordosis (SL) were calculated preoperatively and postoperatively. Patient-reported outcome measures (PROMs) were recorded at preoperative, 6 month postoperative, and 12 month postoperative timepoints, and longitudinal relationships between SL and LL restoration and PROMs were calculated using repeated measures linear mixed effects models.

Results: 105 patients who met eligibility criteria were included in the analysis. 62 patients experienced increased LL with fusion and 43 did not, while 48 patients experienced increased SL with fusion and 57 did not. Patients with and without LL and SL restoration demonstrated comparable levels of improvement in VAS-Back and Leg scores at 6 month and 12 month timepoints, and improvements in ODI and PROMIS-29 physical function at 6 months postop. However, LL and SL restoration did not confer any significant additional improvement in these measures.

Conclusion : Postoperative LL and SL restoration does not confer additional functional benefits for patients who undergo fusion for correction of low grade degenerative spondylolisthesis.