Background: Patients suffering from osteoarthritis of the knee and patients post total knee arthroplasty
often develop refractory, disabling chronic knee pain. Radiofrequency ablation, including conventional,
pulsed, and cooled, has recently become more accepted as an interventional technique to manage
chronic knee pain in patients who have failed conservative treatment or who are not suitable candidates
for surgical treatment.
Objective: This systematic review aimed to analyze published studies on radiofrequency ablation to
provide an overview of the current knowledge regarding variations in procedures, nerve targets, adverse
events, and temporal extent of clinical benefit.
Study Design: A systematic review of published studies investigating conventional, pulsed, or cooled
radiofrequency ablation in the setting of chronic knee pain.
Methods: Medline, Google Scholar, and the Cochrane Central Register of Controlled Trials (CENTRAL)
databases were reviewed for studies on radiofrequency ablation for patients with chronic knee pain
through July 29, 2016. From the studies, the procedural details, outcomes after treatment, follow-up
points, and complications were compiled and analyzed in this literature review. Included studies were
analyzed for clinical relevance and strength of evidence was graded using either the NHLBI Quality
assessment of controlled intervention studies or the NHLBI quality assessment for before-after (pre-post)
studies with no control group.
Results: Seventeen total publications were identified in the search, including articles investigating
conventional, pulsed, or cooled radiofrequency ablation. These studies primarily targeted either the
genicular nerves or used an intraarticular approach. Of the studies, 5 were small-sized randomized
controlled trials, although one involved diathermy radiofrequency ablation. There were 8 retrospective
or prospective case series and 4 case reports. Utilizing the strength of evidence grading, there is a low
level of certainty to suggest a superior benefit between targeting the genicular nerve, an intraarticular
approach, or targeting the larger nerves such as femoral and tibial nerves. Utilizing the strength of
evidence grading, there is a low level of certainty in supporting the superiority of any specific RFA
procedure modality. The majority of the studies report positive patient outcomes, but the inconsistent
procedural methodology, inconsistent patient assessment measures, and small study sizes limit the
applicability of any specific study to clinical practice.
Limitations: While the wide search strategy included a variety of articles, broad conclusions and
pooled data could not be obtained based on the studies analyzed.
Conclusions: Overall, the studies showed promising results for the treatment of severe chronic
knee pain by radiofrequency ablation at up to one year with minimal complications. Numerous
studies, however, yielded concerns about procedural protocols, study quality, and patient follow-up.
Radiofrequency ablation can offer substantial clinical and functional benefit to patients with chronic
knee pain due to osteoarthritis or post total knee arthroplasty.
Key words: Radiofrequency ablation, knee osteoarthritis, knee pain, genicular nerve, total knee
arthroplasty (TKA), cooled radiofrequency ablation, pulsed radiofrequency ablation
2 - Efficacy of ultrasound-guided radiofrequency ablation for genicular nerve in patients with chronic knee pain after total knee arthroplasty
