SIR 2024
Pain Management/MSK
Zachary McCormick, MD (he/him/his)
Vice Chair of PM&R; Chief of Spine and Musculoskeletal Medicine
University of Utah
Financial relationships: Full list of relationships is listed on the CME information page.
David Provenzano, MD
President
Pain Diagnostics and Intervention Care, LLC
Disclosure information not submitted.
Leo Kapural, MD
Anesthesiology
The Center for Clinical Research
Disclosure information not submitted.
Timothy Deer, MD
Pain Medicine
The Spine and Nerve Center of the Virginias
Disclosure information not submitted.
Francesco Vetri, MD, PhD
Pain Medicine
National Spine & Pain Centers
Disclosure information not submitted.
Lumbar facetogenic back pain has been estimated as high as 45% of all chronic low back pain causes (range 15-45%).1 Radiofrequency ablation of the lumbar medial branches is a commonly performed treatment for this indication.2
The study objective was to compare effectiveness of cooled and standard radiofrequency ablation in the management of chronic lumbar facetogenic back pain.
Materials and Methods:
This prospective, multi-center, randomized study was registered on ClinicalTrials.gov (NCT04803149) on March 17, 2021.
Participants were eligible if they had a positive response from dual medial branch blocks (MBB). Bilateral lumbar medial branch radiofrequency ablation was performed targeting the left and right L3 and L4 medial branches L5 dorsal ramus to treat the L4 – L5 and L5 – S1 facet joints (Fig 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. Endpoints included NRS, SF-36, EQ-5D-5L and the Oswestry Disability Index (ODI).
The primary effectiveness endpoint was defined as the proportion of subjects whose back pain was reduced by > 50% based on Usual NRS (average daily pain over the last 7 days) at 6 months.
A sample size of 75 participants in each group (total of 150) would achieve 80% power. Due to difficulty in finding participants to meet inclusion criteria, 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. The mean NRS at baseline for the CRFA group = 6.9 (+1.22) and at 6 months = 2.7 (+2.88), a 4.2 drop in pain score with 27 participants reporting. The mean NRS at baseline for the SRFA group = 6.8 (+0.83) and at 6 months = 3.4 (+2.29), a 3.4 drop in score, with 34 participants reporting (p = 0.1234 between groups).
Secondary endpoints reported in Table 2 show the mean score and mean change from baseline for secondary endpoints SF-36 (Physical Function Domain), ODI, EQ-5D-5L Index Score and GPE for both cohorts.
Conclusion:
A single treatment of radiofrequency ablation of the lumbar facetogenic joints improves a patient’s pain and function. This stands in contrast to the MINT trials,3 suggesting that appropriately selected patients, combined with widely adopted treatment protocols, result in clinically significant improvements for this patient popular.