Background We describe our diagnostic sacroiliac joint (SIJ) injection technique under the guidance of three-dimensional cone beam computed tomography (3D-CBCT) fused with real-time fluoroscopy.

Methods A retrospective review of 17 patients (mean age 55.4 (range 40–74) years) who received a total of 23 diagnostic SIJ injections between March 2016 and November 2017 were performed. Pre- and post-procedure pain scores were reviewed from the medical records and then these findings were correlated with which patients were and were not diagnosed with SIJ pain by clinical management. The final diagnosis of SIJ-related pain was made in cases with at least 50% symptomatic improvement following SIJ-specific pain treatments.

Results Some 87% (n=20/23) of injections achieved more than 50% pain relief after the diagnostic SIJ injection. The final diagnosis of the target SIJ-related pain after follow-up and management was found in 90% (n=18/20) of cases. There were two cases with positive tests diagnosed as non-SIJ pain including one with the diagnosis of femuroacetabular impingement and one with pain related to loosening of knee hardware. The sensitivity, specificity, positive predictive value, and negative predicative value of diagnostic SIJ injections were 100%, 60%, 89%, and 100%, respectively, with a 40% false-positive rate. There were no procedure-related complications.

Conclusion 3D-CBCT fused with real-time fluoroscopy for SIJ injection is accurate and safe.