Posterolateral Fusion Versus Interbody Fusion for Degenerative Spondylolisthesis: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic literature review and meta-analysis.

OBJECTIVE: This study is a meta-analysis assessing the clinical outcomes of degenerative lumbar spondylolisthesis treated with either a posterolateral fusion (PLF) or interbody fusion (IBF) SUMMARY OF BACKGROUND DATA.: Degenerative spondylolisthesis remains one of the most common reasons for which lumbar fusion is performed in the United States. Both PLF and IBF have been advanced as adequate surgical techniques that result in successful fusion and improved clinical outcomes.

METHODS: A systematic review of PubMed, Cochrane, and Embase was performed. The pooled results were performed by calculating the effect size based on the Hedges g standardized difference in means or odds ratio. Studies were weighted by the inverse of the variance. Heterogeneity was assessed using the Q statistic and I. Sensitivity analysis was performed through single elimination of studies. Publication bias was assessed by funnel plot assessment and the Egger-Harbord test.

RESULTS: The systematic review resulted in 865 articles. After two-reviewer assessment, five articles were found to match all of the inclusion criteria and were included in the meta-analysis. The combined effect size was found to be in favor of PLF for length of stay (P = 0.002); however, there were no differences in fusion rate, operative time, Estimated blood loss, Oswestry Disability Index, Short Form 36, Visual Analog Scale, or complication rate between PLF and IBF. All of the variables demonstrated relative homogeneity, with I < 25. The sensitivity analysis validated the results of the model and there was no publication bias detected.

CONCLUSION: Patients with degenerative spondylolisthesis can be effectively managed with either a PLF or IBF with no significant differences in clinical outcomes or fusion rate between the two groups. Length of stay was the only variable that was found to be in favor of either group, with the PLF group demonstrating a shortened hospitalization.

LEVEL OF EVIDENCE: 3.