Prospective, Multicenter, Randomized, Crossover Clinical Trial Comparing the Safety and Effectiveness of Cooled Radiofrequency Ablation With Corticosteroid Injection in the Management of Knee Pain From Osteoarthritis

Abstract

Background and objectives: Osteoarthritis (OA) of the knee affects the aging population and has an associated influence on the health care system. Rigorous studies evaluating radiofrequency ablation for OA-related knee pain are lacking. This study compared long-term clinical safety and effectiveness of cooled radiofrequency ablation (CRFA) with intra-articular steroid (IAS) injection in managing OA-related knee pain.

Methods: This is a prospective, multicenter, randomized trial with 151 subjects with chronic (≥6 months) knee pain that was unresponsive to conservative modalities. Knee pain (Numeric Rating Scale [NRS]), Oxford Knee Score, overall treatment effect (Global Perceived Effect), analgesic drug use, and adverse events were compared between CRFA and IAS cohorts at 1, 3, and 6 months after intervention.

Results: There were no differences in demographics between study groups. At 6 months, the CRFA group had more favorable outcomes in NRS: pain reduction 50% or greater: 74.1% versus 16.2%, P < 0.0001 (25.9% and 83.8% of these study cohorts, respectively, were nonresponders). Mean NRS score reduction was 4.9 ± 2.4 versus 1.3 ± 2.2, P < 0.0001; mean Oxford Knee Score was 35.7 ± 8.8 vs 22.4 ± 8.5, P < 0.0001; mean improved Global Perceived Effect was 91.4% vs 23.9%, P < 0.0001; and mean change in nonopioid medication use was CRFA > IAS (P = 0.02). There were no procedure-related serious adverse events.

Conclusions: This study demonstrates that CRFA is an effective long-term therapeutic option for managing pain and improving physical function and quality of life for patients with painful knee OA when compared with IAS injection.

Clinical trial registration: ClinicalTrials.gov (NCT02343003).

FIGURE 1

A, True anteroposterior image of distal femur with CRF probes (3; at arrows) in place and (B) true lateral image of proximal tibia with probes (3; at arrows) in place.

FIGURE 2

Disposition of study volunteers and study timeline, including follow-up time points for data collection. *Reasons for screen failures: 6 patients failed the diagnostic block entry criterion, 15 presented with grade 1 OA, 3 had evidence of a structural abnormality other than OA that affected their gait, function, and/or pain, 8 withdrew consent during the screening period because of a non-AE reason, 7 failed the OKS requirement, 25 were excluded for multiple reasons, and the remaining 18 patients violated other unique inclusion/exclusion criteria.

FIGURE 3

Numeric Rating Scale—mean usual knee pain. Mean CRFA and IAS study group NRS scores are indicated by bars, and SDs are expressed as whiskers. *P < 0.05 and **P < 0.0001 (Wilcoxon rank sum test) versus IAS means at same time points.

FIGURE 4

Numeric Rating Scale—changes in usual knee pain at 6 months. Changes in CRFA (A) and IAS (B) study group NRS scores from baseline at 6 months are indicated by the horizontal black bars. The treatment “responder” qualification required an NRS score decrease from baseline of 50% or greater.