Intra-articularly applied pulsed radiofrequency can reduce chronic knee pain in patients with osteoarthritis

Osteoarthritis (OA) is the most widespread chronic joint disease worldwide. Symptomatic knee OA is observed in approximately 12% of individuals more than 60 years of age. Conservative treatments models may not be effective always, and that some of them have serious adverse effects that prompted the researchers to research different treatment methods. In this study, we investigated short- and mid-term effectiveness of intra-articular pulsed radiofrequency (PRF) applied in patients with chronic knee pain due to OA.

This study was carried out in the pain management center of a university hospital between January 2009 and June 2009. The patient record files of 31 patients who received intra-articular PRF were retrospectively reviewed. The antero-lateral area of the knee, where the intervention would be applied, was anesthetized with 1% lidocaine. An introducer needle was placed intra-articularly. PRF was started as 42°C at 2 Hz for 15 minutes. The pain of the patients was evaluated by 10 cm Visual Analog Scale (VAS). Furthermore, the ages, the gender, the symptom duration of the patients, the side of the knee on which the intervention was applied, and the complications were collected for statistical evaluation.

Although the mean initial VAS scores of the patients were 6.1 ± 0.9 cm, it was found, respectively, to be 3.9 ± 1.9 cm and 4.1 ± 1.9 cm at the first- and sixth-month follow-ups. In general, a decrease of 32.8% in mean in the VAS scores was achieved in the last follow-up; whereas the rate of patients reporting a minimum decrease of 2 points in the VAS scores was 64.5% and the rate of patients reporting a decrease of ≥50% in their pain was calculated as 35.5%.

PRF applied to the knee joint appears to be an effective and safe method.