Cooled Radiofrequency Ablation Compared with a Single Injection of Hyaluronic Acid for Chronic Knee Pain: A Multicenter, Randomized Clinical Trial Demonstrating Greater Efficacy and Equivalent Safety for Cooled Radiofrequency Ablation.

BACKGROUND

Knee osteoarthritis is a painful and sometimes debilitating disease that often affects patients for years. Current treatments include short-lasting and often repetitive nonsurgical options, followed by surgical intervention for appropriate candidates. Cooled radiofrequency ablation (CRFA) is a minimally invasive procedure for the treatment of pain related to knee osteoarthritis. This trial compared the efficacy and safety of CRFA with those of a single hyaluronic acid (HA) injection.

METHODS

Two hundred and sixty subjects with knee osteoarthritis pain that was inadequately responsive to prior nonoperative modalities were screened for enrollment in this multicenter, randomized trial. One hundred and eighty-two subjects who met the inclusion criteria underwent diagnostic block injections and those with a minimum of 50% pain relief were randomized to receive either CRFA on 4 genicular nerves or a single HA injection. One hundred and seventy-five subjects were treated (88 with CRFA and 87 with HA). Evaluations for pain (Numeric Rating Scale [NRS]), function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), quality of life (Global Perceived Effect [GPE] score and EuroQol-5 Dimensions-5 Level [EQ-5D-5L] questionnaire), and safety were performed at 1, 3, and 6 months after treatment.

RESULTS

Demographic characteristics did not differ significantly between the 2 study groups. A total of 158 subjects (76 in the CRFA group and 82 in the HA group) completed the 6-month post-treatment follow-up. In the CRFA group, 71% of the subjects had ≥50% reduction in the NRS pain score (primary end point) compared with 38% in the HA group (p < 0.0001). At 6 months, the mean NRS score reduction was 4.1 ± 2.2 for the CRFA group compared with 2.5 ± 2.5 for the HA group (p < 0.0001). The mean WOMAC score improvement at 6 months from baseline was 48.2% in the CRFA group and 22.6% in the HA group (p < 0.0001). At 6 months, 72% of the subjects in the CRFA group reported improvement in the GPE score compared with 40% in the HA group (p < 0.0001).

CONCLUSIONS

CRFA-treated subjects demonstrated a significant improvement in pain relief and overall function compared with subjects treated with a single injection of HA. No serious adverse events related to either procedure were noted, and the overall adverse-event profiles were similar.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.