Evolving Trends in the use of Sacroiliac Fusion from 2015 to 2020

Study Design. Retrospective cohort analysis. Objective. To assess the evolution of patients undergoing sacroiliac (SI) fusion with minimally invasive surgery (MIS) relative to open approaches. Summary of Background Data. The SI joint can be a contributor to lumbopelvic symptoms. The MIS approach to SI fusion has been shown to have fewer complications compared to the open approach. Recent trends and evolved patient populations have not been well characterized. Methods. Data was abstracted from the large, national, multi-insurance, administrative 2015-2020 M151 PearlDiver database. The incidence, trends, and patient characteristics of MIS, as well as open, SI fusions for adult patients with degenerative indications were determined. Univariable and multivariable analysis were then performed to compare the MIS relative to open populations. The primary outcome was to assess the trends of MIS and open approaches for SI fusions. Results. In total, 11,217 SI fusions were identified (of which 81.7% were MIS) with a clear increase in numbers over the years from 2015 (n=1,318, 62.3% of which were MIS) to 2020 (n=3,214 86.6% of which were MIS). Independent predictors of MIS (as opposed to open) SI fusion included: older age (odds ratio [OR] 1.09 per decade increase), higher Elixhauser Comorbidity Index (ECI, OR 1.04 per two-point increase), and geographic region (relative to South, Northeast OR 1.20 and West OR 1.64). As might be expected, 90-day adverse events were lower for MIS than open cases (OR 0.73). Conclusion. The presented data quantify the increasing incidence of SI fusions over the years, with the increase being driven by MIS cases. This was largely related to an expanded population (those who are older and with greater comorbidity), fitting the definition of disruptive technology with lesser adverse events than open procedures. Nonetheless, geographic variation highlights differential adoption of this technology.