Unguided sacroiliac injection: effect on refractory buttock pain in patients with spondyloarthropathies

This study was designed to evaluate the efficacy and safety of unguided sacroiliac injections for refractory sacroiliac pain due to spondyloarthropathies.

An open-label clinical trial lasted 20 weeks for each of 29 patients, with different subtypes of spondyloarthropathies. It was conducted from September 2004 through January 2007. In patients with refractory inflammatory buttock pain (the inclusion criterion), we performed unguided injections of triamcinolone acetonide 40 mg into each sacroiliac joint on an outpatient basis. Assessments by patients and clinicians were recorded at baseline and every 4 weeks until the end of the study.

At week 4, significant decreases were seen in the patients' assessment of pain, morning stiffness, and sleep disturbance and in the clinicians' sacroiliac examination score. Pain reduction, as scored by patient and clinician, was maintained through week 20. No significant improvement was seen on the finger-to-floor or Schober tests. Magnetic resonance imaging (MRI) results showed a significant decrease in inflammatory scores after the sacroiliac injections. The patients' pain score and sleep disturbance were both clearly associated with the MRI inflammation index. The injection was well tolerated by all patients and no serious adverse event was seen.

This technique for sacroiliac injection was effective, and the final results showed a significant improvement in pain, similar to that with imaging-guided interventions. Trained physicians can perform this procedure safely in outpatient settings.