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Background and Aims The study objective was to compare effectiveness of cooled and standard radiofrequency (RF) ablation in the management of lumbar facetogenic back pain at 6- and 12-month timepoints.

Methods This prospective, multi-center, randomized study was registered on ClinicalTrials.gov (NCT04803149). Participants were eligible if they had a positive response from dual medial branch blocks (MBB). Bilateral lumbar medial branch radiofrequency ablation was performed according to figure 1 with either CRFA (17 gauge with a 4mm active tip) or SRFA (20 gauge curved probe with a 10mm active tip). Following treatment, follow-up visits were performed at months 1, 3, 6, 9 and 12. The primary effectiveness endpoint was defined as the proportion of subjects whose back pain was reduced by > 50%. Difficulty with participants meeting our dual medial branch block criteria challenged enrollment early on. Eighteen months into the study, enrollment ended early.

Results 74 participants were treated (37 in each cohort). Usual NRS scores for both cohorts are reported in table 1. At 6 months in the CRFA group, 20 out of 27 (74.1%) were responders and in the SRFA group, 22 out of 34 (64.7%) (p = 0.0069 between groups). Both groups demonstrated a reduction in pain of greater than 2 points on NRS, from baseline to 6 months. Secondary endpoints reported in table 2 show results for secondary endpoints SF-36 (Physical Function Domain), ODI, EQ-5D-5L Index Score and GPE for both cohorts.

Conclusions A single treatment of radiofrequency ablation in appropriately selected patients with lumbar facet pain result in clinically significant improvements.