Biomechanical analysis of two insertion sites for the fixation of the sacroiliac joint via an oblique lateral approach

Roxanne Dubé-Cyr (1, 2, 3, 4) , Carl-Éric Aubin (1, 2, 3) , Isabelle Villemure (1, 2, 3) , Rohan-Jean Bianco (2, 3) , Yves Godio-Raboutet (3, 4) , Pierre-Jean Arnoux (3, 4)

1 EPM - École Polytechnique de Montréal
2 CHU Sainte Justine [Montréal]
3 International Laboratory on Spine Imaging and Biomechanics (iLab-Spine)
4 LBA UMR T24 - Laboratoire de Biomécanique Appliquée

Background. The sacroiliac joint is an important source of low back pain. In severe cases, sacroiliac joint fusion is used to reduce pain, but revision rates can reach 30%. The lack of initial mechanical stability may lead to pseudarthrosis, thus not alleviating the patient's symptoms. This could be due to the damage induced to the interosseous ligament during implant insertion. Decoupling instrumentation steps (drillingtapping and implant insertion) would allow to verify this hypothesis. Moreover, no biomechanical studies have been published on sacroiliac joint fixation with an oblique lateral approach, while it has important clinical advantages over the lateral approach. Methods. Eight cadaveric human pelves with both ischia embedded were tested in three sequential states: intact, drilled-tapped and instrumented with one cylindrical threaded implant with an oblique lateral trajectory. Specimens were assigned one of two insertion sites (distal point; near the posterior superior iliac spine, and proximal point; anterosuperior to the distal point) and tested in compression and flexionextension. Vertical and angular displacements of the sacroiliac joint were measured locally using digital image correlation methods. Findings. In compression, instrumentation significantly reduced vertical displacements (17% (SD 22%), P=0.04) but no difference was found for angular displacements or flexion-extension loads (P>0.05). Drilling-tapping did not change the stability of the sacroiliac joint (P>0.05); there was no statistical difference between the insertion sites (P>0.05). Interpretations. Insertion of one implant through either the distal or proximal insertion site with an oblique lateral approach significantly reduced vertical displacements of the sacroiliac joint in compression, a predominant load of this joint.

Mots clés: Sacroiliac joint; sacroiliac joint fixation; sacroiliac joint fusion; arthrodesis; biomechanics; minimally invasive surgery

Domaines: Biomécanique [physics.med-ph]; Ingénierie biomédicale

Roxanne Dubé-Cyr, Carl-Éric Aubin, Isabelle Villemure, Rohan-Jean Bianco, Yves Godio-Raboutet, et al.. Biomechanical analysis of two insertion sites for the fixation of the sacroiliac joint via an oblique lateral approach. Clinical Biomechanics, 2020, 74, pp.118-123. ⟨10.1016/j.clinbiomech.2020.02.010⟩. ⟨hal-03226860⟩