Background and aims Pulsed radiofrequency (PRF) treatment is a minimally invasive procedure highly used in pain units. Several studies show that pulsed radiofrequency applied to chronic knee pain seems to be effective. In this study, we investigated effectiveness of transcutaneous PRF applied in patients with chronic knee pain due to knee arthrosis. A magnetic field is created between two shields, one active and other dispersive, on the pain zone.

Methods Local committee authorizes observational anonymous retrospective study without Ethics Committee approval. We reviewed files of 44 patients who received knee transcutaneous PRF for chronic knee arthrosis between January 2014 and December 2018 at chronic pain unit in Zamora Hospital, Spain. We evaluate by Visual Analogic Scale (VAS) the patient and physician global impression about pain relief. Furthermore, gender was also collected for statistic evaluation. The technique was started as 60 V for 10 minutes.

Results 72,7% of the patients were female. The mean initial VAS scores of the patients were 8 in activity and 4 in rest. 1 month after the treatment, it was found to be 7 and 2, respectively, not being significant. 40,9% presented ‘no changes’ in pain. 50,1% improved as shown in the previous data (from 8 to 7 and from 4 to 2). Same impression by the physician. No one got worse.

Conclusions Patients VAS showed a slight improvement after the treatment. The majority refers to be like before the treatment. Differences between gender were not found.