By Nancy Shaw
Radiofrequency therapy, including thermal, pulsed, and cooled methods, provides significant improvement in osteoarthritic and chronic knee pain for up to 3 months, according to a study presented here at the 2020 Annual Meeting of the American Academy of Pain Medicine (AAPM).
“Radiofrequency therapy significantly reduces osteoarthritic knee pain for at least up to 3 months when compared with controls,” reported Thomas Cheriyan, MD, South Nassau Communities Hospital, Oceanside, New York.
Patients with osteoarthritic knee pain often continue to experience pain despite conservative treatments such as nonsteroidal anti-inflammatory drugs or intra-articular injections of hyaluronic acid and corticosteroids. Radiofrequency therapy has gained interest as a minimally invasive alternative to arthroscopic surgery or total knee arthroplasty, with more rapid recovery and minimal adverse events.
For the current study, the researchers analysed data from 5 randomised controlled trials involving radiofrequency therapy, including thermal ablation of the genicular nerve, pulsed and cooled techniques for the treatment of osteoarthritic knee pain.
The studies included a total of 236 patients, with 119 treated with radiofrequency therapy and 117 in control groups. The studies, which had a low-medium risk of bias, had an average of 47 patients each (35-73).
Overall, the pain scores in the radiofrequency therapy groups were significantly lower compared with controls at 1 week (2 studies; n = 73; standardised mean difference [SMD], -1.51; P = .01), 1 month (5 studies; n = 236; SMD, -0.94; P = .0004), and 3 months (4 studies; n = 196; SMD, -0.66; P = .01).
Only one of the studies evaluated pain at 6 months, and those findings were not included. No complications or safety issues were reported in any of the studies.
“Randomised controlled trials investigating longer term benefits [of radiofrequency therapy in knee osteoarthritis] are required,” the authors noted.
Adding to the data on radiofrequency ablation therapy for chronic knee pain was another study presented at the meeting, in which Neil Shah, MD, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, reported on real-world outcomes of 68 patients who underwent genicular radiofrequency ablation at their centre between April 2016 and August 2019.
Those results showed that at an average of a 3-month follow-up 75% of patients reported pain to be “slightly better” or “definitely better.” While baseline pain scores averaged 6.49 among 57 patients, the mean follow-up pain score was 5.96 (P = .074).
“At follow-up, responders had significantly improved pain intensity, physical function, depression and sleep,” the authors reported. “Future work should aim to further elucidate factor predictive of genicular radiofrequency ablation, which will help identify patients who would most likely benefit from this intervention.”