Comparison of cooled versus conventional radiofrequency treatment of the genicular nerves for chronic knee pain: a multicenter non-inferiority randomized pilot trial (COCOGEN trial)

Abstract

BackgroundRadiofrequency (RF) treatment of the genicular nerves has the potential to reduce chronic knee pain due to osteoarthritis or persistent postsurgical pain, however, a direct comparison between the two main modalities used, conventional and cooled, is lacking.MethodsThis double blind, non-inferiority, pilot, randomized controlled trial compared the effects of cooled and conventional RF in chronic knee pain patients suffering from osteoarthritis or persistent postsurgical pain after total knee arthroplasty. Patients were randomized following a 1:1 rate. The primary outcome was the proportion of patients with ≥50% pain reduction at 3 months postintervention. Other outcomes were knee pain, functionality, quality of life, emotional health, and adverse events up to 6 months postintervention. Conventional RF treatment was tested for non-inferiority to cooled in reducing knee pain at 3 months follow-up.ResultsForty-nine of 70 patients were included, of which 47 completed a 3-month follow-up. The primary outcome was achieved in 4 of 23 patients treated with conventional RF (17%) vs in 8 of 24 with cooled (33%) (p=0,21). Results from the non-inferiority comparison were inconclusive in relation to the non-inferiority margin. There was no statistically significant difference between secondary outcomes. There were no serious adverse events.ConclusionsBoth conventional and cooled RF treatment reduced pain in the osteoarthritis and persistent postsurgical pain population. This pilot study did not demonstrate statistically significant differences in the proportion of patients experiencing ≥50% pain reduction between techniques. The non-inferiority analysis was inconclusive. These results warrant further research.Trial registration numberNCT03865849.

Comparison of conventional and cooled radiofrequency treatment of the genicular nerves versus sham procedure for patients with chronic knee pain: protocol for a multicentre, double-blind, randomised controlled trial (COGENIUS)

“…The study will follow the Standard Protocol Items Recommendations for Interventional Trials and the Consolidated Standards of Reporting Trials 32 33. Design of the COGENIUS trial was preceded by a pilot trial, the COCOGEN study, comparing cooled to conventional RF in the OA and PPSP population 29…”

“…Furthermore, retrospective and pilot studies indicate a possible larger effectivity of cooled RF compared with conventional RF on knee pain. However, these have not been directly compared in powered prospective studies in both the OA and PPSP population 29 30. Comparison of RF to a sham procedure is only tested in the relative small study of Choi et al 31.…”

Cooled radiofrequency ablation of genicular nerves for knee osteoarthritis

“…Several prospective and retrospective studies have compared CRFA with conventional RFA [ 58 , 59 , 61 – 63 ]. Most of these studies have concluded that the clinical effectiveness of CRFA is comparable to [ 58 , 62 , 63 ] or better than that of conventional RFA [ 59 ]. Although all prospective studies published in 2023 found no statistically significant difference between CRFA and conventional RFA [ 62 , 63 ], a pilot study by Vanneste et al [ 63 ] with a small sample size revealed a notably higher responder rate (50% or greater effect) in the CRFA group than in the conventional RFA group at the 6 month follow-up.…”

“…Most of these studies have concluded that the clinical effectiveness of CRFA is comparable to [ 58 , 62 , 63 ] or better than that of conventional RFA [ 59 ]. Although all prospective studies published in 2023 found no statistically significant difference between CRFA and conventional RFA [ 62 , 63 ], a pilot study by Vanneste et al [ 63 ] with a small sample size revealed a notably higher responder rate (50% or greater effect) in the CRFA group than in the conventional RFA group at the 6 month follow-up. In addition, a retrospective study by Kapural et al [ 61 ] reported that the duration of pain score reduction by more than 50% was 2.6 months for conventional RFA and 11.1 months for CRFA, indicating a significant difference ( P < 0.001) in favor of CRFA.…”

Emperor’s nakedness exposed: unmasking fairytales for genicular nerve radiofrequency ablation in knee osteoarthritis

“…In the past 2 issues of RAPM are two randomized trials reporting poor outcomes for RFA using the three-nerve technique described by Choi et al 2. The first is a ‘placebo’-controlled trial from Thailand19 using bipolar RFA that failed to demonstrate any additional benefit compared with genicular nerve local anesthetic and steroid injections along with sham lesioning in 64 patients who responded with at least 50% pain relief to 1 mL prognostic blocks with lidocaine, while the second was a non-inferiority study from the Netherlands that showed poor outcomes with both conventional (17% success rate) and cooled RFA (33%) performed at the same traditional 3-nerve target sites 20. The Dutch study did not screen patients with prognostic blocks, which makes sense based on the lack of diagnostic utility and studies demonstrating an extremely high positive rate and poor positive and negative predictive values using 50% cut-off thresholds 9 13.…”