Prospective, non-inferiority, multicenter, randomized, single-blind clinical trial comparing cooled radiofrequency ablation to standard radiofrequency ablation to manage chronic facetogenic lumbar back pain

Reg Anesth Pain Med. 2026 Mar 13:rapm-2025-107299. doi: 10.1136/rapm-2025-107299. Online ahead of print.

ABSTRACT

BACKGROUND: Low back pain is a leading cause of disability. Up to 45% of lumbar spine pain may be facetogenic. Both standard radiofrequency ablation (SRFA) and cooled radiofrequency ablation (CRFA) have been deployed to treat facetogenic pain.

METHODS: Patients with lumbar facetogenic back pain, identified by two positive medial branch blocks (MBBs), were randomized to treatment with CRFA or SRFA. The primary endpoint was the proportion of subjects whose back pain decreased by ≥50% on the Numeric Rating Scale (NRS (usual): patient's level of pain over the past 7 days) at 6 months, with subjects followed through 12 months. Secondary endpoints included changes in SF-36 (36-Item Short Form Health Survey) Physical Functioning (PF), Oswestry Disability Index (ODI), Global Perceived Effect scale (GPE), and EQ-5D-5L index (EuroQol's Health-Related Quality of Life Score using 5 levels over 5 dimensions).Enrollment (target 188) ended early after 18 months due to funding reallocation and strict Medicare criterion requiring ≥80% pain relief from dual MBBs.

RESULTS: 74 patients (37 CRFA, 37 SRFA) were randomized, treated, and included in the intention-to-treat analysis. 61 patients (27 CRFA, 34 SRFA) completed the 6-month primary endpoint visit. Both CRFA and SRFA provided robust, statistically significant and clinically relevant reductions in NRS pain scores from baseline at every time point (p≤0.0001). CRFA met the predefined non-inferiority criterion relative to SRFA (p=0.0069), with a high proportion of both groups achieving ≥50% pain relief at the primary endpoint-74.1% with CRFA and 64.7% with SRFA. Although CRFA showed numerically greater reductions in NRS pain scores from baseline (-4.3 vs -3.4), both treatments exceeded the minimal clinically important difference threshold. No statistically significant differences in NRS scores were observed between groups at any time point, likely due to the premature termination of the study (only 52% enrolled). Both groups also showed significant and comparable improvements in NRS, EQ-5D-5L, ODI, SF-36 (PF), and GPE at 6 and 12 months.

CONCLUSION: Despite the smaller than intended sample size, due to early termination by the sponsor, this study demonstrated that with appropriate patient selection and proper procedural technique, both CRFA and SRFA can relieve chronic facetogenic low back pain, improve disability, function, and quality of life for 6-12 months.

TRIAL REGISTRATION NUMBER: NCT04803149.

PMID:41825940 | DOI:10.1136/rapm-2025-107299