The Percentage of Postoperative Slip Reduction in Single Level Low-Grade Lumbar Spondylolisthesis Impact on Clinical, Radiologic Outcome and Complication

Abstract

Introduction: Reduction of spondylolisthesis is intended to restore the original morphology of the spinal canal, foramina, and alignment, potentially leading to neural decompression and reduced shear forces on the spine. However, the optimal extent of reduction during surgical management remains debated due to concerns about complications, particularly neurological deficits. This study aimed to evaluate the correlation between the postoperative slip reduction (Total or partial reduction) in 1 level spondylolisthesis and clinical outcomes, radiologic outcomes, and complications.
Methods: We conducted a retrospective analysis of 98 patients who underwent single-level transforaminal lumbar interbody fusion or posterior lumbar interbody fusion with or without polyetheretherketone (TLIF/PLIF ± PEEK) with intraoperative reduction in low-grade spondylolisthesis at the Neurological institute of Thailand between 2015 and 2020. Patients were divided into a total reduction group (n = 64) and a partial reduction group (n = 34). Both groups were followed for over 24 months, and outcomes were compared.
Results: Surgical complications were similar across both groups, with no statistically significant differences (p > 0.05) in postoperative motor deficits, adjacent segment disease, pseudarthrosis, intraoperative blood loss, length of hospital stay, infection rates, or dural tears. The only significant difference noted was in operative time, which was longer in the partial reduction group. Postoperative spinal MRI findings showed no significant differences in disc or facet degeneration between the groups.
However, there was a trend toward reduced pseudarthrosis and adjacent segment disease, as well as slower degeneration of facet joints and discs in the total reduction group, although these findings did not reach statistical significance, likely due to insufficient follow-up duration.
Conclusion: Total reduction does not lead to better outcomes than partial reduction. However, it also does not increase the rate of complications. Total reduction of spondylolisthesis potentially improves fusion rates, reduces adjacent segment disease, slows facet and disc degeneration, although this difference was not statistically significant.