Meta-Analysis of Clinical Outcomes of Lumbar Fusion Surgical Interventions for Degenerative Spondylolisthesis

Introduction: Surgical interventions for degenerative spondylolisthesis are varied with comparable claims of success. Fusion based technique is one of the most commonly used surgical interventions in treating this condition. The aim of this meta-analysis is to compare the effectiveness of the Lumbar Interbody Fusion techniques (specifically Posterolateral Interbody approach—PLIF) versus Posterolateral Instrumented Fusion (PLF). The clinical outcomes investigated were: back pain, leg pain, function, Oswestery Disability Index (ODI), Disability Rating Index (DRI), fusion and revision rates if reported. Methods: Combinations of keywords and MeSH terms, where appropriate, were used to search for studies in Medline via Ovid, Embase, Cochrane Library, and Google scholar. The initial search was conducted on 10 August 2016 and updated on 13 June 2017. Eligibility criteria for the studies to be selected for this meta-analysis were: Randomised Controlled Trials (RCTs), cohort and consecutive cases studies that compared at PLIF versus PLF surgical interventions at the lumbar region. Heterogeneity indicators and Forest plot were computed using RevMan 5. Results: Out of the initial hits of 3021, 5 articles were selected as relevant and assessed for risk of bias and then data was extracted and tabulated. These 5 studies reported data from (900 patients’ records, follow up ranges from 6 months to 5 years) undergone one of 2 interventions (PLIF or PLF). The overall effect for ODI and leg pain showed no advantage of any intervention over the other while there was a greater odd ratio of fusion if the operation applied PLIF techniques (Overall Z = 2.86, p = 0.004). Conclusions: There is a need for more high quality clinical trials to compare these two interventions. However, available data indicate that there are comparable results in the main clinical outcomes between PLIF and PLF. PLIF has superior fusion rate which does not seem to affect post-operative pain ratings.