Conventional vs. Cooled RF for Chronic Knee Pain: Interim COGENIUS Trial Findings.

Effectiveness of Conventional and Cooled RF in Treating Chronic Knee Pain: Initial Findings from the COGENIUS Trial: Interim report.

The COGENIUS trial aims to evaluate the cost-effectiveness and efficacy of conventional and cooled RF treatments in patients with therapy-resistant chronic knee pain due to osteoarthritis (OA) and persistent post-surgical pain (PPSP) after a total knee prosthesis.

The COGENIUS trial is a multicenter double-blinded, randomized controlled trial of 2-year follow-up. After an initial run-in period, 200 patients per subgroup will be randomized to receive either conventional RF, cooled RF, or a sham procedure in a 2:2:1 ratio (Fig. 1,2). The analysis includes a comparison of the effectiveness of each RF treatment with the sham procedure and between conventional and cooled RF. The primary outcome is the Western Ontario and McMaster Universities Osteoarthritis Index score at 6 months. Knee pain, functionality, quality of life, emotional health, medication use and cost constitute secondary endpoints.

To date, 822 patients have been screened, of which were 220 eligible for the trial and 164 randomized across 14 centers. Of these, 63 participants belong to the OA subgroup and 101 to the PPSP subgroup. The enrollment began on 7 July 2022, with the trial projected to conclude in March 2028. Most exclusions occurred due to bilateral knee pain (128/822), refusal to participate (85/822), and chronic widespread pain (49/822). Until present 12 of the 220 patients experienced adequate improvement in pain after the run-in period.

This ongoing study aims to delineate the relative effectiveness of cooled and conventional RF treatments compared to a sham procedure in patients with chronic knee pain.