Results of this Level 1, high quality study were published in the International Journal of Spine Surgery titled: Two-Year Outcomes from a Randomized Controlled Trial of Minimally Invasive Sacroiliac Joint Fusion vs. Non-Surgical Management for Sacroiliac Joint Dysfunction1. 

The study showed that rapid improvements in pain, disability and quality of life for the iFuse group were larger than those seen for the NSM group and were durable to two years. This large, Level 1 RCT adds to the more than 40 peer-reviewed publications on iFuse and further reinforces positive outcomes and product durability demonstrated in previously reported 3 year, 4.5 year and 5 year publications.2-4

148 subjects were enrolled, randomized 2:1 (102 iFuse/46 NSM), and treated at 19 centers in the United States including both private practice and academic institutions.  In the iFuse group, the mean SI joint pain score improved from 82.3 at baseline to 30.1 at 6 months, 28.6 at 12 months and 26.7 at two years, corresponding to improvements from baseline of 52.3, 53.7 and 55.4 points, respectively (all p<.0001, Figure 1). 

Disability, as measured using the Oswestry Disability Index (ODI), decreased from a mean 57.2 at baseline to 29.9, 28.3 and 28.7 at months 6, 12 and 24, representing mean improvements of 27.4, 28.9 and 28.4 points, respectively (p<.0001)

The revision surgery rate was low at 3.4% (3/89) consistent with previously reported long-term results for iFuse2,5 and roughly one-third that for lumbar fusion surgery6.

Two-year results also showed a 29.7% decrease from baseline in the number of study subjects taking opioids (Figure 2) which is consistent with a 28% reduction in opioid use observed in a previously reported prospective multicenter two-year study5.

"These two-year results from the INSITE study illustrate the durability of SI joint fusion with iFuse and further validate previously reported 6- and 12-month results that showed rapid improvement in pain, function and quality of life in this highly debilitated patient population," said Frank Phillips, MD of Rush University Medial Center in Chicago, IL.

 "This positive publication validates the consistency of the earlier publications on iFuse and will hopefully encourage health plans across the U.S. to establish coverage for this effective procedure."

SI-BONE is a leading sacroiliac joint medical device company dedicated to the development of tools and products for patients with low back issues related to certain SI joint disorders.

The company develops, manufactures and markets minimally invasive products for the SI joint. SI-BONE, Inc. received original 510(k) clearance in November 2008 from the Food and Drug Administration (FDA) to market its iFuse Implant System. The CE mark for European commercialization was obtained in November 2010.

The iFuse Implant System is a minimally invasive surgical option that uses titanium implants with a porous surface that acts as an interference surface, designed to help decrease implant motion, and allow for biological fixation to support long term fusion.

iFuse is the only commercially available SI joint fusion device in the United States with published evidence that demonstrates safety, effectiveness and economic benefits, including three large multicenter prospective studies, two of which are randomized controlled trials (RCTs).