RESUMEN
BACKGROUND: The sacroiliac joint is one of the most common sources of low back pain; however, it is difficult to place the needle accurately inside the joint space without image guidance. Improvement of ultrasound technology may lead to a high success rate for intra-articular drug deposition. OBJECTIVE: Assessment of the success rate of ultrasound-guided intra-articular sacroiliac joint injection. DESIGN: Prospective observational study. METHODOLOGY: Ultrasound-guided injections were performed on 34 patients suffering from sacroiliitis. After injection of the drug solution and withdrawal of the needle, an anteroposterior fluoroscopy image was obtained and recorded for the injected joint to detect whether it was predominantly intra-articular or peri-articular. Clinical outcome using a numeric pain rating scale as well as limitation of physical functioning measured by the Oswestry Disability Index (ODI) were determined. RESULTS: Thirty-three injections (84.6%) were intra-articular, while 6 injections (15.4%) were peri-articular, as confirmed by fluoroscopy, with no statistical difference regarding clinical outcome between them. The baseline mean pain score decreased from 7.21 to 1.92 1 month after injection, and the mean ODI scores improved from 61.41% to 17.13%. Intervention was well tolerated, and 91.2% of patients were satisfied or mostly satisfied. CONCLUSION: Ultrasonography provides a high success rate of intra-articular sacroiliac joint injection as confirmed by fluoroscopy. No significant difference in clinical outcome between intra-articular and peri-articular injection was found.