Related Experiment Video
Updated: Nov 11, 2025
A Teleoperated Robotic System-Assisted Percutaneous Transiliac-Transsacral Screw Fixation Technique
Published on: January 6, 2023
Biomechanical analysis of the number of implants for the immediate sacroiliac joint fixation
Roxanne Dubé-Cyr1,2,3,4,5, Carl-Éric Aubin6,7,8, Isabelle Villemure1,2,3
1Department of Mechanical Engineering, Polytechnique Montréal, P.O. Box 6079, Downtown Station, Montreal, QC, H3C 3A7, Canada.
Purpose:
The fusion of the sacroiliac joint (SIJ) is the last treatment option for chronic pain resulting from sacroiliitis. With the various implant systems available, there are different possible surgical strategies in terms of the type and number of implants and trajectories. The aim was to quantify the effect of the number of cylindrical threaded implants on SIJ stabilization.
Methods:
Six cadaveric pelvises were embedded in resin simulating a double-leg stance. Compression loads were applied to the sacral plate. The pelvises were tested non-instrumented and instrumented progressively with up to three cylindrical threaded implants (12-mm diameter, 60-mm length) with a posterior oblique trajectory. Vertical (VD) and angular (AD) displacements of the SIJ were measured locally using high-precision cameras and digital image correlation.
Results:
Compared to the non-instrumented initial state, instrumentation with one implant significantly decreased the VD (- 24% ± 15%, p = 0.028), while the AD decreased on average by - 9% (± 15%; p = 0.345). When compared to the one-implant configuration, adding a second implant further statistically decreased VD (- 10% ± 7%, p = 0.046) and AD (- 19% ± 15, p = 0.046). Adding a third implant did not lead to additional stabilization for VD nor AD (p > 0.5).
Conclusion:
Compared to the non-instrumented initial state, the two-implant configuration reduces both vertical and angular displacements the most, while minimizing the number of implants.
