for people ages 21-75 (full criteria)
at La Jolla, California and other locations
study started
estimated completion
Principal Investigator
by Vinko Zlomislic, MD



The purpose of this study is to compare outcomes of subjects undergoing multilevel lumbar fusion (MLF) surgery with and without the iFuse 3-D implants in the "bedrock" trajectory.

Official Title

Sacroiliac Joint Stabilization in Long Fusion to the Pelvis: Randomized Controlled Trial


This is a multicenter randomized controlled, postmarket clinical study to determine the differences between subjects undergoing standard MLF surgery with S2AI fixation in the pelvis vs the additional placement of iFuse 3-D in the bedrock configuration during MLF surgery. Subjects will be monitored for sacroiliac (SI) joint pain and at two years post surgery a CT scan will be taken to assess S2AI screw loosening or any other findings.


Sacroiliac Joint Disruption Scoliosis Lumbar Region Adult Scoliotic Spinal Deformity Sacroiliac joint pain multilevel lumbar surgery si joint pain Scoliosis iFuse 3-D in Bedrock Configuration Multilevel Lumbar Fusion surgery


You can join if…

Open to people ages 21-75

  1. Age 21-75 at time of screening
  2. Patient scheduled for multilevel (>3 levels) spinal fusion surgery with planned fixation to the pelvis using S2AI screws
  3. Patient has signed study-specific informed consent form
  4. Patient has the necessary mental capacity to participate and is physically able to comply with study protocol requirements

You CAN'T join if...

  1. Indication for multilevel spine fusion surgery is any of the following:
  2. Congenital neuromuscular disease
  3. Prior pelvic fixation (i.e., patient already has S2AI or iliac bolts in place, current surgery indicated to revise this hardware)
  4. Grade IV spondylolisthesis
  5. Prior sacroiliac joint fusion/fixation on either side
  6. Presence of spinal cord stimulator
  7. Presence of severe hip pain that could impair functional and quality of life improvement from complex spine surgery
  8. Surgeon plans to use iliac screw for pelvic fixation
  9. Any known sacral or iliac pathology
  10. Any condition or anatomy that makes treatment with the iFuse Implant System infeasible
  11. Known metabolic bone disease
  12. Severe osteoporosis
  13. . Known allergy to titanium or titanium alloys
  14. . Use of medications known to have detrimental effects on bone quality and soft-tissue healing
  15. . Neurologic condition that would interfere with postoperative physical therapy
  16. . Current local or systemic infection that raises the risk of surgery
  17. . Patient currently receiving or seeking short- or long-term worker's compensation and/or currently involved in injury litigation related to the SI joint or low back pain.
  18. . Currently pregnant or planning pregnancy in the next 2 years
  19. . Prisoner or a ward of the state.
  20. . Known or suspected drug or alcohol abuse
  21. . Uncontrolled psychiatric disease that could interfere with study participation
  22. . Fibromyalgia


  • University of California, San Diego accepting new patients
    La Jolla California 92037 United States
  • Scripps Hospital accepting new patients
    La Jolla California 92037 United States

Lead Scientist at UCSD

  • Vinko Zlomislic, MD
    Associate Clinical Professor, Orthopedic Surgery. Authored (or co-authored) 7 research publications.


accepting new patients
Start Date
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