SI-BONE: Three New Studies on iFuse

SI-BONE, Inc. is on a publishing roll, with two prospective randomized clinical trials appearing in print, as well as a systematic review of 18 MIS (minimally invasive surgery) SI (sacroiliac) joint fusion studies.

The first clinical trial—the INSITE (Investigation of Sacroiliac Fusion Treatment)—was published in Neurosurgery and involved 19 institutions. The study, which included 148 patients, examined minimally invasive SI joint fusion as compared to non-surgical management of chronic SI joint dysfunction.

At 12 months, clinically important improvements in SI joint pain on the Visual Analog Scale (VAS) were seen in 81.6% of SI joint fusion subjects, but in only 12.5% of those who had nonoperative treatment. Patients in the surgical group experienced sustained pain relief at 12 months; those who crossed over to iFuse treatment did nearly as well as those originally assigned to iFuse surgery.

David Polly, M.D., is professor and chief of spine surgery at the University of Minnesota, and lead author on the INSITE study. Asked about the most interesting portion of the research, he told OTW, “A high quality data set that really answers the question. It was also interesting to see that 10% did respond to non-surgical management after having failed it for at least 6 months—now we have to figure out how to identify that subgroup. Hopefully, surgeons will pay attention to the differential diagnosis of low back and buttock pain and not just presume it is spine or the hip.”

Regarding future work that should be undertaken, Dr. Polly noted, “Figuring out the psychological distress aspect for responders vs. non responders to the surgical treatment.”

The second clinical trial—SIFI (Sacroiliac Joint Fusion with iFuse Implant System)—was published in Global Spine Journal and involved 26 facilities and 172 participants. The results showed that mean SI joint pain improved from 79.8 at baseline to 30.0 and 30.4 at six and 12 months, respectively. Mean Oswestry Disability Index improved from 55.2 at baseline to 32.5 and 31.4 at six and 12 months, respectively.

The third study, a systematic review and meta-analysis, was published in International Journal of Spine Surgery. The researchers reviewed the clinical outcomes of patients who underwent MIS SI joint fusion using a lateral transarticular approach. They found that this approach meant minimal blood loss: 36.9 cc (10-70 cc range), a brief operating time: 59 minutes (27-28 minute range), and a shorter length of stay: 1.7 days (0-7 day range).

Daniel Cher, M.D. is vice president of clinical affairs at SI-BONE, and was involved in all three studies. He told OTW, “It was great to see the enthusiasm and excitement from spine surgeons to be able to participate in a surgery vs. non-surgery trial. These types of studies are challenging and very rare these days and of course, the results were really excellent to say the least.”

“Hopefully, this research will encourage the use of the iFuse Implant System to perform SI joint fusions in appropriately diagnosed patients with SI joint dysfunction who have failed to respond to non-surgical treatments. Going forward we need long-term follow-up.”