Minimally Invasive Lumbar Spinal Fusion Is More Effective Than Open Fusion: A Meta-Analysis

PURPOSE: To evaluate the efficacy of minimally invasive spinal fusion in comparison to open fusion for adult lumbar spondylolisthesis or spondylosis. MATERIALS AND METHODS: The present study was conducted as a meta-analysis of all estimates from studies that were selected after comprehensive literature search by two independent reviewers. RESULTS: Of 745 articles, nine prospective cohort studies were identifed. The quality of evidence was downgraded because of study design, inconsistency, imprecision, and publication bias. Greater Oswestry Disability Index score improvement [weighted mean difference (WMD), 3.2; 95% confdence interval (CI), 1.5 to 5.0; p=0.0003] and a lower infection rate (odds ratio, 0.3; 95% CI, 0.1 to 0.9; p=0.02) were observed in the minimally invasive group (low-quality evidence). The minimally invasive group had less blood loss (WMD, 269.5 mL; 95% CI, 246.2 to 292.9 mL; p<0.0001), a shorter hospital stay (WMD, 1.3 days; 95% CI, 1.1 to 1.5 days, p<0.0001), and longer operation time (WMD, 21.0 minutes; 95% CI, 15.9 to 26.2 minutes; p<0.0001) and radiation exposure time(WMD, 25.4 seconds; 95% CI, 22.0 to 28.8 seconds, p<0.0001) than the open group (low-quality evidence). There were no significant differences in pain improvement, fusion rate, complications, or subsequent surgeries between the two treatment groups (low-quality evidence). CONCLUSION: Although present findings are limited by insufficient evidence and there is a lack of adequately powered high-quality randomized controlled trials to address this gap in evidence, our results support that minimally invasive lumbar fusion is more effective than open fusion for adult spondylolisthesis and other spondylosis in terms of functional improvement, reducing infection rate, and decreasing blood loss and hospital stay.