Two-Year Trial Demonstrates Long-Term Durability of iFuse

SI-BONE Inc., a medical device company that pioneered the use of the iFuse Implant System (“iFuse”), a patented triangular-shaped minimally invasive surgical (MIS) device indicated for fusion for certain disorders of the sacroiliac (SI) joint, announced the publication of two-year results from INSITE (Investigation of Sacroiliac Fusion Treatment – NCT01681004) a landmark prospective, multicenter, randomized controlled trial (RCT) of MIS SI joint fusion with iFuse compared to non-surgical management (NSM).  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 iFuse^2,5 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.”
 
References
¹Polly DW, Swofford J, Whang PG, Frank CJ, Glaser JA, Limoni RP, Cher DJ, Wine KD, Sembrano JN, and the INSITE Study Group. Two-Year Outcomes from a Randomized Controlled Trial of Minimally Invasive Sacroiliac Joint Fusion vs. Non-Surgical Management for Sacroiliac Joint Dysfunction. Int J Spine Surg. 2016;10:Article 28. doi: 10.14444/3028.
²Sachs D, Kovalsky D, Redmond A, Limoni R, Meyer SC, Harvey C, Kondrashov D. Durable Intermediate- to Long-term Outcomes after Minimally Invasive Transiliac Sacroiliac Joint Fusion using Triangular Titanium Implants. Med Devices (Auckl). 2016;9:213-22. doi: 10.2147/MDER.S109267.
³Vanaclocha-Vanaclocha V, Verdú-López F, Sánchez-Pardo M, Gozalbes-Esterelles L, Herrera JM, Rivera-Paz M, Martínez-Gómez D. Minimally Invasive Sacroiliac Joint Arthrodesis: Experience in a Prospective Series with 24 Patients. J Spine. 2014;3:185. doi: 10.4172/2165-7939.1000185.
⁴Rudolf L, Capobianco R. Five-Year Clinical and Radiographic Outcomes After Minimally Invasive Sacroiliac Joint Fusion Using Triangular Implants. Open Orthop J. 2014;8:375–83. doi: 10.2174/1874325001408010375.
⁵Duhon BS, Bitan F, Lockstadt H, Kovalsky DA, Cher DJ, Hillen T, on behalf of the SIFI Study Group. Triangular Titanium Implants for Minimally Invasive Sacroiliac Joint Fusion: 2-year Follow-up from a Prospective Multicenter Trial. Int J Spine Surg. 2016;10:Article 13. doi: 10.14444/3013.
⁶Martin BI, Mirza SK, Comstock BA, Gray DT, Kreuter W, Deyo RA. Reoperation rates following lumbar spine surgery and the influence of spinal fusion procedures. Spine. 2007;32(3):382-7. doi: 10.1097/01.brs.0000254104.55716.46.