Background There has been a surge in interest in radiofrequency ablation (RFA) of the genicular nerves over the past decade, with wide variability in selection, technique and outcomes. The aim of this study is to determine factors associated with treatment outcome.
Methods We retrospectively evaluated the effect of 23 demographic, clinical and technical variables on outcomes in 265 patients who underwent genicular nerve RFA for knee pain at 2 civilian and 1 military hospital. A primary outcome was designated as a > 30% decrease in average knee pain score lasting at least 3 months without cointerventions.
Results The overall rate of a positive response was 61.1% (95% CI 55.2% to 67.0%). In univariable analysis, larger electrode size (p=0.01), repeated lesions (p=0.02), having>80% pain relief during the prognostic block (p=0.02), not being on opioids (p=0.04), having no coexisting psychiatric condition (p=0.02), having a lower baseline pain score (p=0.01) and having >3 nerves targeted (p=0.02) were associated with a positive outcome. In multivariate logistic analysis, being obese (OR 3.68, 95% CI 1.66 to 8.19, p=0.001), not using opioids (OR 0.35, 95% CI 0.16 to 0.77, p=0.009), not being depressed (OR 0.29, 95% CI 0.10 to 0.82, p=0.02), use of cooled RFA (OR 3.88, 95% CI 1.63 to 9.23, p=0.002) and performing multiple lesions at each neural target (OR 15.88, 95% CI 4.24 to 59.50, p<0.001) were associated with positive outcome.
Conclusions We identified multiple clinical and technical factors associated with treatment outcome, which should be considered when selecting patients for RFA treatment and in the design of clinical trials.
- treatment outcome
- diagnostic techniques and procedures
- chronic pain
- pain management
- nerve block
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Contributors All of the authors have contributed to the planning, conducting and reporting of the work described in the article.
Funding Funded in part by a grant from MIRROR, Uniformed Services University of the Health Sciences, US Dept. of Defense, and grant # HU00011920011.
Competing interests SPC has served as a consultant for Avanos (Alpharetta, GA) in the past 2 years.
Patient consent for publication Not required.
Ethics approval Permission to conduct this study was granted by the Institutional Review Boards of Johns Hopkins and Penn State-Hershey Medical Center, the Board of Directors at the Pain Management Institute, Bethesda, MD and Washington, DC, and the Walter Reed Dept. of Investigation.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available on reasonable request. Deidentified participant data.
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