Cooled radiofrequency ablation provides extended clinical utility in the management of chronic sacroiliac joint pain: 12-month follow-up results from the observational phase of a randomized, multicenter, comparative-effectiveness crossover study.

Abstract

Introduction: Sacroiliac joint (SIJ) pain comprises up to 30% of cases of mechanical low back pain (LBP), the leading cause of disability worldwide. Despite sacral lateral branch cooled radiofrequency ablation (CRFA) showing efficacy in clinical trials, there is a lack of comparative-effectiveness long-term follow-up.

Methods: In this randomized, multicenter, comparative-effectiveness study, 210 patients with injection-confirmed SIJ pain who responded to prognostic lateral branch blocks were randomly assigned to receive CRFA of the L5 dorsal ramus and S1-S3/4 lateral branches or standard medical management (SMM) consisting of pharmacotherapy, physical therapy, injections, and integrative therapies. Patients were followed up at 1, 3, 6, 9, and 12 months, with participants reporting unsatisfactory SMM outcomes being allowed to crossover (XO) and receive CRFA at 3 months. The primary outcome measure was the mean change in average LBP score on a 0-10 Numeric Rating Scale (NRS), with secondary outcomes including measures of quality of life (QoL) and function. A responder was defined as a participant who experienced a ≥30% or ≥2-point decrease in average daily NRS pain score coupled with a score ≥5 out of 7 (moderately better) on the Patient Global Impression of Change scale.

Results: At 12 months, the mean NRS pain score declined from a baseline of 6.4±1.4 to 3.5±2.6, with 57.4% (35/61) of participants in the randomized CRFA cohort experiencing a ≥2-point or 30% decrease in average LBP from baseline. In the crossover cohort, 35/63 (55.6%) subjects had the same experience 12 months following the XO procedure; in the XO group, the mean LBP decreased from 6.1±1.5 to 3.4±2.5. Patients also experienced clinically meaningful improvements in QoL via EuroQoL-5D-5L at 12 months (mean change of +0.22±0.27 in the originally-treated CRFA group and +0.21±0.33 in the XO group). Oswestry Disability Index (ODI) scores also improved by 12.4%±14.7 (CRFA) and 13.7%±17.1 (XO) from baseline at study-end. No serious adverse events related to the CRFA procedure were reported.

Conclusion: CRFA in patients with SIJ pain provided clinically significant and sustained improvements for 12 months following a single CRFA treatment, regardless of previous SMM treatment.

Trial registration number: NCT03601949.