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Background: Radiofrequency ablation (RFA) is a validated treatment option for the treatment of chronic pain in patients with lumbar spondylosis. Lesion size has been suggested to correlate with good clinical outcomes. This has created an abundance of scientific interest in the development of products with larger lesion characteristics. Needle characteristics, energy transfer, and heat rate are known to modify lesion size. Here, we demonstrate that common intraoperative solutions, such as lidocaine, iodine, and gadolinium-based products, can also affect lesion shape., Objectives: To determine whether lidocaine and contrast agents modify lesion characteristics during the performance of monopolar RFA., Study Design: Controlled, ex vivo study using clinically relevant conditions and pre-injections., Setting: Academic institution in a procedural setting., Methods: RFA lesion size was compared among six cohorts: 1) lidocaine 1%, 2) lidocaine 2%, 3) iohexol 180, 4) iohexol 240, 5) gadodiamide, and 6) control (no fluid control). Radiofrequency (RF) current was applied for 90 seconds at 80°C via 20-gauge 100-mm standard RFA needles with 10-mm active tips in orgranic chicken breasts without preservative at room temperature (21°C). Twelve lesions were performed for each medication cohort. The length, width, and depth of each lesion were measured. The statistical significance between each medication group and the control group was evaluated by t test., Results: The mean lesion surface area of monopolar RFA without any pre-injection used was 80.8 mm2. The mean surface area of the monopolar RF lesion with a pre-injection of 0.2 mL of 2% lidocaine was 114 mm2, and the mean surface area of the monopolar RF lesion with a pre-injection of 0.2 mL of iohexol 240 was 130.6 mm2. The statistical analysis demonstrated that the control group had significantly smaller lesion sizes than did the groups in which lidocaine 2% and iohexol 240 were used (P<0.01). There were no statistically significant differences among the groups in which lidocaine 1%, iohexol 180, and gadodiamide were used. A notable difference was a 20% longer lesion with iohexol 240 compared with the control group and a 20% wider lesion with lidocaine 2% compared with the control group., Limitations: In vivo anatomy within a human was not used in this study, nor were the chicken breasts heated to physiological temperature. Randomization of pieces of chicken breast did not occur, and thus intrinsic differences among the chicken breast pieces could play a confounding role., Conclusions: Lidocaine 2% and iohexol 240, when used as pre-injections in RFAs, were found to be associated with statistically significant increases in lesion surface area. However, RFAs with lidocaine 1%, iohexol 180, or gadodiamide were not found to produce a statistically significant difference in lesion size compared with monopolar RFA without the use of injectate., (© The Author(s) 2022. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose of Review: Radiofrequency ablation (RFA) has become an increasingly widespread treatment tool for various chronic pain syndromes within the last two decades with the majority of publications on the topic coming after 2006. Not only are clinicians using RFA to treat more peripheral nerve pain syndromes but the technology itself is evolving quickly to the point that it is nearly impossible to stay abreast on the complexity of such a diversely utilized instrument. This review summarizes studies that focus on the use of RFA for peripheral nerve neurotomy and anatomical studies regarding RFA published between 2015 and 2020., Recent Findings: Topics in this review include anatomical regions or nerves of the body published since 2015. Significant findings are summarized in each section. Peripheral nerve RFA is rapidly changing. Many studies have been performed over the last 5 years showing the usefulness of RFA., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: To assess long‐term outcomes of cooled radiofrequency ablation (CRFA) of genicular nerves for chronic knee pain due to osteoarthritis (OA). Methods: A prospective, observational extension of a randomized, controlled trial was conducted on adults randomized to CRFA. Subjects were part of a 12‐month clinical trial comparing CRFA of genicular nerves to a single hyaluronic injection for treatment of chronic OA knee pain, who then agreed to visits at 18‐ and 24‐months post CRFA and had not undergone another knee procedure since. The subjects were evaluated for pain using the Numeric Rating Scale (NRS) function using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), subjective benefit using the Global Perceived Effect (GPE) scale, quality of life using the EuroQol‐5‐Dimensions‐5 Level (EQ‐5D‐5L) questionnaire, and safety. Results: Of 57 subjects eligible, 36 enrolled; 32 completed the 18‐month visit with a mean NRS score of 2.4 and 22 (69%) reporting ≥50% reduction in pain from baseline (primary endpoint); 27 completed the 24‐month visit, with a mean NRS of 3.4 and 17 (63%) reporting ≥50% pain relief. Functional and quality of life improvements persisted similarly, with mean changes from baseline of 53.5% and 34.9% in WOMAC total scores, and 24.8% and 10.7% in EQ‐5D‐5L Index scores, at 18‐ and 24‐months, respectively. There were no identified safety concerns in this patient cohort. Conclusion: In this subset of subjects, CRFA of genicular nerves provided durable pain relief, improved function, and improved quality of life extending to 24 months post procedure, with no significant safety concerns. [ABSTRACT FROM AUTHOR]

Background: Knee osteoarthritis is a painful and sometimes debilitating disease that often affects patients for years. Current treatments include short-lasting and often repetitive nonsurgical options, followed by surgical intervention for appropriate candidates. Cooled radiofrequency ablation (CRFA) is a minimally invasive procedure for the treatment of pain related to knee osteoarthritis. This trial compared the efficacy and safety of CRFA with those of a single hyaluronic acid (HA) injection.Methods: Two hundred and sixty subjects with knee osteoarthritis pain that was inadequately responsive to prior nonoperative modalities were screened for enrollment in this multicenter, randomized trial. One hundred and eighty-two subjects who met the inclusion criteria underwent diagnostic block injections and those with a minimum of 50% pain relief were randomized to receive either CRFA on 4 genicular nerves or a single HA injection. One hundred and seventy-five subjects were treated (88 with CRFA and 87 with HA). Evaluations for pain (Numeric Rating Scale [NRS]), function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), quality of life (Global Perceived Effect [GPE] score and EuroQol-5 Dimensions-5 Level [EQ-5D-5L] questionnaire), and safety were performed at 1, 3, and 6 months after treatment.Results: Demographic characteristics did not differ significantly between the 2 study groups. A total of 158 subjects (76 in the CRFA group and 82 in the HA group) completed the 6-month post-treatment follow-up. In the CRFA group, 71% of the subjects had ≥50% reduction in the NRS pain score (primary end point) compared with 38% in the HA group (p < 0.0001). At 6 months, the mean NRS score reduction was 4.1 ± 2.2 for the CRFA group compared with 2.5 ± 2.5 for the HA group (p < 0.0001). The mean WOMAC score improvement at 6 months from baseline was 48.2% in the CRFA group and 22.6% in the HA group (p < 0.0001). At 6 months, 72% of the subjects in the CRFA group reported improvement in the GPE score compared with 40% in the HA group (p < 0.0001).Conclusions: CRFA-treated subjects demonstrated a significant improvement in pain relief and overall function compared with subjects treated with a single injection of HA. No serious adverse events related to either procedure were noted, and the overall adverse-event profiles were similar.Level Of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Safe and effective non-surgical treatments are an important part of the knee osteoarthritis (OA) treatment algorithm. Cooled radiofrequency ablation (CRFA) and hyaluronic acid (HA) injections are two commonly used modalities to manage symptoms associated with knee OA.Methods: A prospective 1:1 randomized study was conducted in 177 patients comparing CRFA to HA injection with follow-ups at 1, 3, 6 and 12 months. HA subjects with unsatisfactory outcomes at 6-months were allowed to crossover and receive CRFA. Knee pain (numeric rating scale = NRS), WOMAC Index (pain, stiffness and physical function), overall quality of life (global perceived effect = GPE, EQ-5D-5 L), and adverse events were measured.Results: At 12-months, 65.2% of subjects in the CRFA cohort reported ≥50% pain relief from baseline. Mean NRS pain score was 2.8 ± 2.4 at 12 months (baseline 6.9 ± 0.8). Subjects in the CRFA cohort saw a 46.2% improvement in total WOMAC score at the 12-month timepoint. 64.5% of subjects in the crossover cohort reported ≥50% pain relief from baseline, with a mean NRS pain score of 3.0 ± 2.4 at 12 months (baseline 7.0 ± 1.0). After receiving CRFA, subjects in the crossover cohort had a 27.5% improvement in total WOMAC score. All subjects receiving CRFA reported significant improvement in quality of life. There were no serious adverse events related to either procedure and overall adverse event profiles were similar.Conclusion: A majority of subjects treated with CRFA demonstrated sustained knee pain relief for at least 12-months. Additionally, CRFA provided significant pain relief for HA subjects who crossed over 6 months after treatment.Trial Registration: This trial was registered on ClinicalTrials.gov, NCT03381248. Registered 27 December 2017. [ABSTRACT FROM AUTHOR]

The objective was to determine the effectiveness of fluoroscopically guided genicular nerve radiofrequency ablation for painful knee osteoarthritis. Primary outcome measure was improvement in pain after 6 mos. Secondary outcomes included the Oxford Knee Score and Western Ontario and McMaster Universities Osteoarthritis Index. Two reviewers independently assessed publications before October 10, 2020. The Cochrane Risk of Bias Tool and Grades of Recommendation, Assessment, Development, and Evaluation system were used. One hundred ninety-nine publications were screened, and nine were included. Six-month success rates for 50% or greater pain relief after radiofrequency ablation ranged from 49% to 74%. When compared with intra-articular steroid injection, the probability of success was 4.5 times higher for radiofrequency ablation (relative risk = 4.58 [95% confidence interval = 2.61–8.04]). When radiofrequency ablation was compared with hyaluronic acid injection, the probability of treatment success was 1.8 times higher (relative risk = 1.88, 95% confidence interval = 1.38–2.57). The group mean Oxford Knee Score and Western Ontario and McMaster Universities Osteoarthritis Index scores improved in participants receiving genicular radiofrequency ablation compared with intra-articular steroid injection and hyaluronic acid injection. According to Grades of Recommendation, Assessment, Development, and Evaluation, there is moderate-quality evidence that fluoroscopically guided genicular radiofrequency ablation is effective for reducing pain associated with knee osteoarthritis at minimum of 6 mos. Further research is likely to have an important impact on the current understanding of the long-term effectiveness of this treatment. [ABSTRACT FROM AUTHOR]