Posterolateral Fusion and Transforaminal Lumbar Interbody Fusion Provide Similar Degrees of Lordosis Restoration in Correction of Low-grade Lumbar Spondylolisthesis

Introduction: Hypolordosis in the setting of low-grade degenerative lumbar spondylolisthesis (Meyerding Grades I and II) can contribute to sagittal imbalance, which increases the risk of adjacent segment degeneration and compounds neurologic and functional deterioration over time. Interbody cages are often placed in concert with posterolateral fusion constructs to better restore lordosis, but a paucity of literature exists to directly quantify whether this practice more effectively restores lordosis compared to posterolateral fusion alone.

Methods: Using a prospectively maintained institutional database, consecutive patients who had no prior history of lumbar spine surgery and underwent one- or two-level posterolateral fusion alone (PLF) or transforaminal lumbar interbody fusion (TLIF), for correction of low-grade lumbar spondylolisthesis were identified. Using standing XR, lumbar lordosis (LL) and segmental lordosis (SL) were calculated preoperatively and postoperatively, and the relationship between interbody placement and changes in LL and SL were analyzed with inferential statistics

Results: 101 consecutive patients who met eligibility criteria were included in the analysis. were included in the analysis. 57 patients underwent TLIF, 44 patients underwent PLF, and these groups did not significantly differ by BMI or medical comorbidities. Interbody placement was not significantly associated with increased LL or SL postoperatively (Chi-squared test, p = 0.65 and p > 0.99, respectively), nor was it associated with the magnitude of LL or SL change (Mann Whitney U-Test, p = 0.31 and p = 0.89, respectively).

Conclusion : TLIF and PLF provide comparable degrees of SL and LL improvement in patients with low-grade spondylolisthesis.