Purpose: Fluoroscopy-guided sacroiliac joint (SIJ) injections are
technically difficult to perform because of the complex anatomy with
helicoidal conformation of the joint. Our study describes the procedure
of CT-guided SIJ injection, its feasibility and its rate of success.
Methods and materials: Retrospective study included 46 consecutive
patients. The procedure was performed by 3 MSK radiologists and
consisted in a puncture with a posterior approach in the inferior articular
part of SIJ, then in an injection of iodinated contrast agent (1ml) with CT
control of SIJ space opacification and finally in an injection of slowacting
corticosteroid. The SIJ approach was noticed as correct if there
was an inferior articular puncture and if the needle was in the articular
space, and as impossible if there was ankylosis or osteophytosis. The
study was divided in two successive periods: period 1 (4 first months)
and period 2 (12 last months).
Results: SIJ opacification was successful in 57% (26/46). We observed
a learning curve: opacification was succeeded in 66% (23/35) and there
was incorrect approach in 9% (3/35) during period 2 versus respectively
27% (3/11) and 45% (5/11) during period 1. Causes of failure were
incorrect approach in 40% (6/20 too low, 2/20 too high), impossible
approach in 30% (6/20) and unexplained in 30% (6/20). Mean duration
of procedure was about 28 minutes. No complication occurred.
Conclusion: CT guided SIJ injection is safe and successful in 66%
after a training period. The success depends on SIJ correct approach
and also on anatomical lesions.