Medical Student University of Florida, College of Medicine
Introduction: Interspinous fusion devices (IFD) have been designed for minimally invasive spinal fusion as alternatives to pedicle screw fixation (PSF), the current gold standard procedure. However, the clinical benefits of IFD in lumbar spine fusion procedures are still largely debated. The objective of this study is to systematically review the current literature and compare the clinical efficacy of IFDs to PSF.
Methods: PubMed, Scopus, and Web of Science were queried to identify studies reporting interspinous fusion devices (IFD) use for lumbar spine surgery. We included studies from 2006, the year of FDA approval of the first IFD, to present. Abstract and full-text screening of 1761 initial articles returned by preliminary search yielded 46 studies for inclusion. These included 28 biomechanical and 18 human analyses. Qualitative assessment of the 18 human studies were conducted in accordance with the Newcastle-Ottawa Scale criteria.
Results: Analyses were conducted for IFD vs. PSF human cohorts. In total, 629 IFD (271 male, 52.5 years) and 267 PSF (113 male, 57.5 years) patients were analyzed. Average operative time was 73 minutes for IFD and 122 for PSF. Mean estimated blood loss (EBL) was 128 mL for IFD and 570 for PSF. With respect to patient functional outcomes, average improvement in VAS score was 4.76 for IFD and 4.73 for PSF, while average ODI improvement was 21.8% for IFD and 25.1% for PSF. Rate of arthrodesis was 80.2% for IFD and 81.6% for PSF. Complication rate was 6.1% for IFD and 11.9% for PSF.
Conclusion : Interspinous fusion elements may provide several advantages over PSF in procedures of the lumbar spine - in particular, they appear to be associated with shortened operative times as well as reduced blood loss and complications. More robust analyses, or higher level evidence such as controlled trials, may provide greater insight into the effectiveness of IFD versus PSF.
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