Bipolar radiofrequency ablation of the superomedial (SM), superolateral (SL) and inferomedial (IM) genicular nerves for chronic osteoarthritis knee pain: a randomized double-blind placebo-controlled trial with 12-month follow-up

Abstract

BackgroundVariability in anatomy in the knees supports the use of aggressive lesioning techniques such as bipolar-radiofrequency ablation (RFA) to treat knee osteoarthritis (KOA). There are no randomized controlled trials evaluating the efficacy of bipolar-RFA.MethodsSixty-four patients with KOA who experienced >50% pain relief from prognostic superomedial, superolateral and inferomedial genicular nerve blocks were randomly assigned to receive either genicular nerve local anesthetic and steroid injections with sham-RFA or local anesthetic and steroid plus bipolar-RFA. Participants and outcome adjudicators were blinded to allocation. The primary outcome was Visual Analog Scale pain score 12 months postprocedure. Secondary outcome measures included Western Ontario and McMaster Universities Arthritis (WOMAC) and Patient Global Improvement-Indexes (PGI-I).ResultsBoth groups experienced significant reductions in pain, with no significant differences observed at 12 months (reduction from 5.7±1.9 to 3.2±2.6 in the RFA-group vs from 5.0±1.4 to 2.6±2.4 in the control-group (p=0.40)) or any other time point. No significant changes were observed between groups for WOMAC and PGI-I at the primary endpoint, with only the control group experiencing a significant improvement in function at 12-month follow-up (mean reduction from 91.2±38.2 to 67.1±51.9 in the RFA-group (p=0.06) vs from 95.8±41.1 to 60.6±42.8 in the control group (p=0.001); p=0.85 between groups).ConclusionOur failure to find efficacy for genicular nerve RFA, coupled with evidence showing that a plenitude of nerves supply the knee joint and preliminary studies indicating superiority of lesioning strategies targeting more than three nerves, suggest controlled trials using more aggressive lesioning strategies are warranted.Trial registration numberTCTR20170130003.

Is radiofrequency ablation effective in treating patients with chronic knee osteoarthritis? A meta-analysis of randomized controlled trials

“…After removing duplicates and irrelevant papers, we evaluated 201 published reports to determine their eligibility for full-text evaluation. Ultimately, 9 RCT articles 7 , 10 – 12 , 19 – 23 (714 participants) were considered appropriate for inclusion in this meta-analysis (Table 1 ). Most of the study subjects included in the research were over the age of 60.…”

“…Specifically, the study did not analyze the long-term and short-term effects of RFA. In clinical practice, some clinicians rely on the results of diagnostic genicular nerve blocks to determine whether to perform RFA on patients 10 – 12 . However, this aspect was not addressed in the previous meta-analysis.…”

Diagnosis and Treatment of Post-Radiofrequency Synovial Knee Fistula: Case Report

“…However, since its first description, newer studies have highlighted the variability of genicular nerves, 2 leading to exploring some options, such as bipolar and cooled radiofrequency. 3,4 Here we present a rare case of synovial knee fistula after cooled radiofrequency and its management; to the best of our knowledge, this is the first case reported in the literature. Written informed consent was obtained from the patient for the publication of this case report.…”

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.…”

“…Besides the obvious limitation of targeting only a tiny portion of the nociceptive input to the knee joint complex, there are several other limitations to consider. The study by Malaithong et al was not a true placebo-controlled study as the authors used prelesioning lidocaine to reduce procedure-related pain, enhance lesion size and facilitate blinding, and administered steroids postablation to possibly reduce neuritis 19. The placebo group received the same genicular nerve blocks with steroids, which uncontrolled studies suggest may result in long-term benefit in some patients, possibly by washing out inflammatory cytokines, the antiinflammatory effects of local and systemically absorbed steroids, and breaking the cycle of pain (ie, unwinding ‘wind-up’), among other reasons 8 15–17.…”