Clinical Data

iMIA 2-year Results (Dengler - JBJS Am 2019)

Randomized Trial of Sacroiliac Joint Arthrodesis Compared with Conservative Management for Chronic Low Back Pain Attributed to the Sacroiliac Joint

Dengler J, Kools D, Pflugmacher R, Gasbarrini A, Prestamburgo D, Gaetani P, Cher D, Van Eeckhoven E, Annertz M, Sturesson B
J Bone Joint Surg Am. 2019;101(5):400-411. [Epub 2019 Mar 6].
PMID: 30845034. DOI:10.2106/JBJS.18.00022


Background: Sacroiliac joint pain is increasingly recognized as a cause of low back pain. We compared the safety and effectiveness of minimally invasive sacroiliac joint arthrodesis using triangular titanium implants and conservative management in patients with chronic sacroiliac joint pain.

Methods: This study was a prospective, multicenter randomized controlled trial of adults with chronic sacroiliac joint pain assigned to either conservative management or sacroiliac joint arthrodesis with triangular titanium implants. The study end points included self-rated low back pain (visual analog scale [VAS]), back dysfunction (Oswestry Disability Index [ODI]), and quality of life. Ninety percent of subjects in both groups completed the study.

Results: Between June 6, 2013, and May 15, 2015, 103 subjects were randomly assigned to conservative management (n = 51) or sacroiliac joint arthrodesis (n = 52). At 2 years, the mean low back pain improved by 45 points (95% confidence interval [CI], 37 to 54 points) after sacroiliac joint arthrodesis and 11 points (95% CI, 2 to 20 points) after conservative management, with amean difference between groups of 34 points (p < 0.0001). Themean ODI improved by 26 points (95% CI, 21 to 32 points) after sacroiliac joint arthrodesis and 8 points (95% CI, 2 to 14 points) after conservative management, with a mean difference between groups of 18 points (p < 0.0001). Parallel improvements were seen in quality of life. In the sacroiliac joint arthrodesis group, the prevalence of opioid use decreased from 56% at baseline to 33% at 2 years (p = 0.009), and no significant change was observed in the conservative management group (47.1% at baseline and 45.7% at 2 years). Subjects in the conservative management group, after crossover to the surgical procedure, showed improvements in allmeasures similar to those originally assigned to sacroiliac joint arthrodesis. In the first 6 months, the frequency of adverse events did not differ between groups (p = 0.664). By month 24, we observed 39 severe adverse events after sacroiliac joint arthrodesis, including 2 cases of sacroiliac joint pain, 1 case of a postoperative gluteal hematoma, and 1 case of postoperative nerve impingement. The analysis of computed tomographic (CT) imaging at 12 months after sacroiliac joint arthrodesis showed radiolucencies adjacent to 8 implants (4.0% of all implants).

Conclusions: For patients with chronic sacroiliac joint pain due to joint degeneration or disruption, minimally invasive sacroiliac joint arthrodesis with triangular titanium implants was safe and more effective throughout 2 years in improving pain, disability, and quality of life compared with conservative management

Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Author Information

  • Dengler J - Department of Neurosurgery, Charité-Universitaetsmedizin Berlin, Berlin, Germany; Brandenburg Medical School Theodor Fontane, Campus Bad Saarow, Bad Saarow, Germany; Department of Neurosurgery, Helios Clinic, Bad Saarow, Germany.
  • Kools D - Department of Neurosurgery, Onze-Lieve-Vrouw Hospital Aalst, Aalst, Belgium.
  • Pflugmacher R - Department of Orthopedics and Traumatology, University Hospital Bonn, Bonn, Germany.
  • Gasbarrini A - Instituto Ortopedico Rizzoli di Bologna, Bologna, Italy.
  • Prestamburgo D - Department of Orthopedics and Traumatology, ASST Ovest Milanese-Ospedale di Legnano, Legnano, Italy.
  • Gaetani P - Department of Neurosurgery, Policlinico S. Matteo, Pavia, Italy.
  • Cher D - SI-BONE, Inc., Santa Clara, California.
  • Van Eeckhoven - Eeckhoven bvba, Kontich, Belgium.
  • Annertz M - Department of Radiology, Skåne University Hospital, Lund, Sweden.
  • Sturesson B - Department of Orthopedics, Aleris, Ängelholm Hospital, Ängelholm, Sweden.

Disclosure: The study was funded by SI-BONE (Santa Clara, California), the manufacturer of the iFuse Implant System used in the study. One author of this study (D.C.) is an employee at SI-BONE. Four authors (D.K., R.P., E.V.E., and B.S.) are consultants to SI-BONE. The study sponsors participated in study design, data collection, data analysis, data interpretation, and writing of the report. One author of this study (J.D.) had full access to all study data and had final responsibility for the decision to submit for publication. Study data are available through the Yale University Open Data Access (YODA) data-sharing program. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article. (

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