The use of sacroiliac joint (SIJ) injection with anesthetic and corticosteroid may not be efficacious for SIJ pain, according to a study published in Pain Medicine.
This prospective cohort study conducted at a single academic medical center was designed to evaluate the outcomes of SIJ injection with corticosteroid and local anesthetic. A total of 34 participants with a clinical diagnosis of SIJ pain underwent SIJ injections with a 1:1 mixture of 2% lidocaine and triamcinolone 40 mg/mL. Immediately before and after injection, pain provocation physical exam maneuvers were performed and recorded. Outcome measures included scores on the Oswestry Disability Index (ODI) and on the pain numeric rating scale (NRS) at 2 to 4 weeks and 6 months.
In the whole cohort (ie, not stratified by anesthetic block and/or physical exam maneuvers) at 2 to 4 weeks, 58.8%±16.5% of study participants indicated a ≥2 point reduction in NRS score, 32.4%±15.7% of patients had a ≥50% reduction in NRS score, and 38.2%±16.3% of individuals had a reduction ≥30% in ODI score. Similar results were observed at 6 months with 50% and 29.4% of patients indicating a ≥2 point and a ≥50% reduction in NRS score, respectively, and 50% of participants indicating a ≥30% reduction in ODI score. When outcomes were stratified based on preinjection physical exam maneuvers, neither pain, nor disability were found to improve at any of the time points. When stratisfication was based on the presence of an anesthetic response postinjection, a difference was observed for a ≥50% reduction in NRS score, between 2 to 4 weeks.
A significant difference for an improvement ≥50% in NRS score at 2 to 4 weeks and at 6 months, and for a ≥30% improvement in ODI score at 6 months were observed in true positive/true negative group stratification. When patients were stratified as being more likely to have true SIJ pain, an increased injection response was observed, with stratification by true positive/true negative indicating 75%±30% of patients indicated an improvement of ≥2 points in NRS score, 62.5%±33.5% of participants indicating an improvement of ≥50% in NRS score, and 62.5%±33.5% of participants indicating ≥30% improvement, all at 2 to 4 weeks, with similar results at 6 months.
“[I]n patients referred with a clinical diagnosis of [SIJ] pain for injection with corticosteroid and anesthetic, success rates for clinically significant improvement in pain and function are modest. The trend suggesting increased efficacy of injection in patients with true intra-articular SIJ pain (true positives) suggests that more research is needed to identify factors that predict favorable outcomes from injections,” concluded the study investigators.
Schneider BJ, Ehsanian R, Huynh L, Levin J, Zheng P, Kennedy DJ. Pain and functional outcomes after sacroiliac joint injection with anesthetic and corticosteroid at six months, stratified by anesthetic response and physical exam maneuvers [published online May 20, 2019]. Pain Med. doi: 10.1093/pm/pnz111