Thermal Nerve Radiofrequency Ablation for the Nonsurgical Treatment of Knee Osteoarthritis

A Systematic Literature Review

Antonia F. Chen, MD, MBA; Kyle Mullen, MPH; Francisco Casambre, MPH; Vidya Visvabharathy, MPH; Gregory A. Brown, MD, PhD


J Am Acad Orthop Surg. 2021;29(9):387-396. 

In This Article

Abstract and Introduction


Background: There are roughly 14 million adults in the United States presenting with symptomatic osteoarthritis (OA) of the knee. Nerve radiofrequency ablation (RFA) is a nonsurgical procedure for the management of knee OA symptoms, and no previous systematic review has been performed comparing geniculate nerve RFA to other nonsurgical treatments.

Questions/Purposes: (1) How does geniculate nerve RFA compare with other nonsurgical modalities for patients with knee OA about pain, function, quality of life, and composite scores? and (2) How does geniculate nerve RFA compare with other nonsurgical modalities for patients with knee OA about adverse events (AEs)?

Methods: A systematic literature review was conducted within PubMed, EMBASE, and Cochrane Central Register of Controlled Trials to identify all studies from 1966 to 2019 evaluating the relative effectiveness of geniculate nerve thermal (heated or cooled) RFA compared with other nonsurgical treatments for knee OA. Two independent abstractors reviewed and analyzed the literature including comparators such as intra-articular (IA) corticosteroids, IA hyaluronic acid, NSAIDs, acetaminophen (paracetamol), and control/sham procedures. Inclusion was based on the following criteria: English language, human subjects, symptomatic knee OA, and patient-reported outcomes.

Results: Five high-quality and two moderate-quality randomized controlled trials (RCTs) met the inclusion criteria for this review. The results showed consistent agreement across all RCTs in favor of geniculate nerve thermal RFA use for nonsurgical treatment of knee OA. One high-quality RCT and one moderate-quality RCT found geniculate nerve RFA to provide statistically significant outcome improvement compared with control or sham procedures regarding pain, function, quality of life, and composite scores. When compared with IA corticosteroids and hyaluronic acid, geniculate nerve RFA also provided notable improvement in pain, function, and composite scores (visual analog scale, Western Ontario, and McMaster Universities Arthritis Index, and Oxford Knee Score). RFA was markedly favored for all pain and composite outcomes (Western Ontario and McMaster Universities Arthritis Index and visual analog scale). The included RCTs did not report any serious AEs related to geniculate nerve RFA.

Discussion: These results demonstrate geniculate nerve thermal RFA to be a superior nonsurgical treatment of knee OA compared with NSAIDs and IA corticosteroid injections. None of the RCTs reported any serious AEs with geniculate nerve thermal RFA, as opposed to known cardiovascular, gastrointestinal, and renal AEs for NSAIDs and accelerated cartilage loss and periprosthetic infection risk for IA corticosteroid injections.

Level of Evidence: Level I


The societal impact of knee osteoarthritis (OA) is notable. The lifetime risk of developing symptomatic knee OA is estimated to be 45%.[1] With changing demographics and an increasing percentage of the United States cohort older than 65 years of age, the burden of knee OA will increase.[2,3] Although a single randomized controlled trial (RCT) demonstrated that total knee arthroplasty (TKA) was more effective than nonsurgical treatment of end-stage knee OA,[4] effective nonsurgical treatments are necessary to manage different subgroups of patients with knee OA including patients who have (1) mild/moderate knee OA, (2) are poor surgical candidates, or (3) decline TKA surgery (approximately 20% of patients are not satisfied with their TKA).[5–7]

The American Academy of Orthopaedic Surgeons (AAOS) Treatment of Osteoarthritis of the Knee, Second Edition evidence-based clinical practice guideline (CPG) recommends (1) self-managed strengthening and/or low-impact aerobic exercise programs (strong evidence), and NSAIDs (strong evidence), and (3) weight loss in patients with a body mass index ≥ 25 kg/m2 (moderate evidence).[8] Intra-articular (IA) hyaluronic acid (HA) injections are not recommended. IA HA did not provide clinically notable pain improvement (strong evidence). The HA recommendation is supported by three independent meta-analyses[9–11] and a network meta-analysis.[12]

The evidence for IA corticosteroid injections was inconclusive in the AAOS CPG. However, a subsequent network meta-analysis[12] shows IA corticosteroids are the most effective treatment of knee OA pain for 4 to 6 weeks, naproxen (an NSAID) is the most effective treatment of knee OA function for 4 to 6 weeks, and naproxen is the most effective treatment of combined knee OA pain and function. Based on the same study, knee corticosteroid injections have not been shown to be effective beyond 6 weeks.

Although adverse events (AEs) and contraindications are considered, the focus for many AAOS CPG recommendations is treatment effectiveness. Of the four knee OA effective treatments discussed above, NSAIDs and IA corticosteroid injections have notable adverse effects and/or contraindications. The FDA issued a "black box" warning on all NSAIDs because of increased cardiovascular risk associated with NSAID use,[13] and a meta-analysis by Varas-Lorenzo et al[14] described the varying levels of individual cardiovascular risks for each NSAID. NSAIDs are also associated with gastrointestinal complications[15] and renal toxicity,[16] whereas IA corticosteroid injections are associated with accelerated OA progression[17,18] and increased risk of periprosthetic joint infection if knee arthroplasty surgery is subsequently performed within 3 to 6 months of the injection.[19,20] A recent AAOS symposium, "Optimizing Clinical Use of Biologics in Orthopaedic Surgery," highlighted the need for additional nonsurgical treatments for knee OA. "The clinical use of biologics such as platelet-rich plasma and cell-based therapies to treat orthopaedic [conditions] has greatly outpaced the evidence. This phenomenon is … in part due to the lack of satisfactory conventional treatment options, …."[21]

Thermal radiofrequency ablation (RFA) is the application of heat to ablate the superior lateral, superior medial, and inferior medial genicular sensory nerve branches around the knee to reduce the pain associated with OA.[22] Multiple RCTs have been conducted on the application of thermal RFA to treat knee OA. However, no systematic review has quantitatively compared geniculate nerve thermal RFA to other effective nonsurgical treatments of knee OA. Thus, the purposes of this study were to (1) determine how geniculate nerve RFA compares with other nonsurgical modalities for patients with knee OA about pain, function, quality of life, and composite scores and (2) evaluate how geniculate nerve RFA compares with other nonsurgical modalities for patients with knee OA about AEs.