SI-BONE, Inc. Announces Publication of INSITE, a Prospective Multicenter Randomized Controlled Trial using iFuse Triangular Implants

International Journal of Spine Surgery reports iFuse Implant System® provides superior clinical outcomes compared to non-surgical management in patients with SI joint dysfunction due to degenerative sacroiliitis or SI joint disruptions

Mar 09, 2015, 07:00 ET from SI-BONE, Inc.

SAN JOSE, Calif., March 9, 2015 /PRNewswire/ -- SI-BONE, Inc., a medical device company that pioneered minimally invasive surgical (MIS) fusion for common disorders of the sacroiliac (SI) joint with the iFuse Implant System, announced today that the International Journal of Spine Surgery (IJSS), a peer-reviewed, PubMed-indexed journal and official journal of ISASS (International Society for the Advancement of Spine Surgery), has published results of INSITE (Investigation of Sacroiliac Fusion Treatment), a prospective multicenter randomized controlled trial. 

The publication titled Sacroiliac Joint Fusion Using Triangular Titanium Implants vs. Non-Surgical Management: Six-Month Outcomes from a Prospective Randomized Controlled Trial1, reports six-month results on 148 patients enrolled at 19 centers across the U.S.  The study compares clinical outcomes of patients suffering from SI joint dysfunction due to degenerative sacroiliitis or SI joint disruptions who were randomized to either immediate surgery with the iFuse Implant System or non-surgical management (NSM).  NSM was tailored to each patient's needs by the site investigator and included pain medications, physical therapy following recognized guidelines, SI joint steroid injections and/or SI joint radiofrequency ablation (RFA).  Outcome measures included SI joint pain as measured by visual analog scale (VAS), disability as measured by Oswestry Disability Index (ODI), quality of life as measured by EQ-5D and SF-36, and patient satisfaction. Subjects assigned to NSM were permitted to cross over to surgery after the six-month visit was complete.  The mean duration of SI joint related symptoms prior to study enrollment was 6.2 years.

In the SI joint fusion group, mean SI joint pain improved from 82.3 (0 to 100 scale) at baseline to 29.8 at six months, a 53-point drop.  By contrast, the NSM group showed little improvement with only a 12-point drop from 82.2 to 70.4.  Six-month improvement in pain was 40.5 points greater in the surgery group (p<.0001).   (See Figure 1 below)  Disability scores (ODI) improved by 30 points in the surgery group vs. 4.9 points in NSM patients (difference in means, p<.0001).  (See Figure 2 below)

Quality of life outcomes, as measured by EQ-5D and SF-36, showed statistically significant differences in improvements in the iFuse group compared to NSM for all subdomains.  The study's primary clinical endpoint was overall treatment success defined as patients who achieved clinically significant pain improvement ( ≥ 20 point drop in VAS), no device-related complications, no neurologic worsening, and no re-intervention.  The fusion group saw 81.4% of the patients achieve overall treatment success compared to 23.9% for the NSM group.

"This prospective randomized controlled clinical trial provides Level 1 evidence that patients with chronic SI joint dysfunction due to degenerative sacroiliitis or SI joint disruptions experienced greater improvements in pain, functional disability and quality of life following minimally invasive SI joint fusion compared to subjects who were assigned to non-surgical management," said Peter Whang, MD, FACS, principal investigator of the study.

Jeffrey Dunn, President and CEO of SI-BONE, commented: "there are now nineteen peer-reviewed studies published on MIS SI joint fusion with the iFuse Implant System, including prospective and retrospective studies, multicenter and single center studies, U.S. studies as well as European studies, with follow up ranging from six months to five years.  There are Level 4 studies, Level 3 studies, a Level 2b study and now a Level 1 study, all showing similar positive outcomes.  Now that INSITE is published, the iFuse Implant System is the only SI joint fusion procedure supported by a prospective randomized controlled clinical trial."

Clinical publications have identified the SI joint as a pain generator in 15% to 30% of low back pain patients2-5 and the prevalence of SI joint pain in post-lumbar fusion, so called "failed back surgery" patients, has been shown to be up to 43%.6  Of these patients, some may have degenerative sacroiliitis or SI joint disruptions.  Initial treatment options for patients with SI joint disorders typically involve non-surgical management and, when non-surgical management of the SI joint fails, surgical options such as the iFuse procedure may be considered. 

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 coated with a porous, titanium plasma spray (TPS) that acts as an interference surface, designed to help decrease implant motion, provide immediate fixation and allow for biological fixation to support long term fusion. The iFuse System is intended for sacroiliac joint fusion for conditions including SI joint dysfunction that is a direct result of SI joint disruptions and degenerative sacroiliitis. There are potential risks associated with the iFuse Implant System.  It may not be appropriate for all patients and all patients may not benefit.  For information about the risks, visit:

About SI-BONE, Inc.
SI-BONE, Inc. (San Jose, California) is the 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 has developed, and is manufacturing and marketing, minimally invasive products for patients with certain SI joint disorders.  SI-BONE has an experienced management team with extensive experience in orthopedic and spine medical devices.  SI-BONE and iFuse Implant System are registered trademarks of SI-BONE, Inc. ©2015 SI-BONE, Inc. All Rights Reserved. 9092.030915

1Whang Pa, Cher Db, et al. Sacroiliac Joint Fusion Using Triangular Titanium Implants vs. Non-Surgical Management: Six-Month Outcomes from a Prospective Randomized Controlled Trial. International Journal of Spine Surgery. 2015;9:Article 6

2 Bernard TN, Kirkaldy-Willis WH. Recognizing specific characteristics of nonspecific low back pain. Clinical Orthopedics and Related Research. 1987;217:266–80.

3 Schwarzer AC, Aprill CN, Bogduk N. The Sacroiliac Joint in Chronic Low Back Pain. Spine. 1995;20:31–7.

4 Maigne JY, Aivaliklis A, Pfefer F. Results of Sacroiliac Joint Double Block and Value of Sacroiliac Pain Provocation Tests in 54 Patients with Low Back Pain. Spine. 1996;21:1889–92.

5 Sembrano JNc, Polly DW.c How Often is Low Back Pain Not Coming From The Back? Spine. 2009;34:E27–32. 

6 DePalma Mc, Ketchum JM, Saullo TR. Etiology of Chronic Low Back Pain Patients Having Undergone Lumbar Fusion. Pain Medicine. 2011;12:732-9.

a Paid Consultant of and investigator in a clinical research study sponsored by SI-BONE, Inc.
b Employee of SI-BONE, Inc.
c Investigator in a clinical research study sponsored by SI-BONE, but has no financial interest in the company.

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