Cooled radiofrequency ablation may be a treatment option for knee OA in the Singaporean population.A small pilot study from Singapore demonstrates the feasibility of cooled radiofrequency ablation (CRFA) for the management of knee osteoarthritis (OA).
“CRFA and hyaluronic acid (HA) injection have demonstrated efficacy, but CRFA is less well studied in Asian populations … In this study, both interventions were safe and efficacious for knee OA,” the investigators said.
At 6 months, responder rates for CRFA and HA were 28.6 percent and 40 percent, respectively. These participants achieved a ≥50 percent reduction in Visual Analogue Scale (VAS) score for knee pain. However, between-group difference was not significant (p=1). [Singapore Med J 2026;doi:10.4103/singaporemedj.SMJ-2025-210]
This differs from studies showing better results with CRFA than HA and intra‑articular corticosteroids. [J Bone Joint Surg Am 2020;102:1501‑1510; Reg Anesth Pain Med 2018;43:84‑91] “However, given the small sample size and baseline differences, the outcomes are descriptive and do not imply equivalence,” the researchers noted.
VAS score significantly decreased from baseline in the pooled analysis (1 month: β, –2.17; p=0.011), as did WOMAC* pain score (1 month: −4.58; p<0.001; 3 months: −2.83; p=0.017). The WOMAC total score improved at 1 month (β, −14.25; p=0.013).
Other notable improvements are the KOOS** pain scores (1 month: 19.44; p<0.001; 6 months: 11.83; p=0.038), which exceed the MCID*** for surgical patients (7.6). [Knee 2024;46:1-7]
Global Perceived Effect (GPE) also improved in both CRFA and HA groups, with peak improvements 1 month after the procedure (5.29 and 6.20, respectively). “The average GPE for both groups … was consistently above 4, reflecting a trend towards improvement, with stronger effects in the HA group, albeit not statistically significant,” the researchers noted.
Adverse events
Adverse event (AE) rate in the immediate and early follow‑up period (2 weeks) was higher in the CRFA than the HA group (28.6 percent vs 0 percent), but there were no significant differences at any timepoint (p>0.05 for all).
In the HA group, one participant developed transient fever, but this resolved after a day. In the CRFA group, one participant developed an irregular heartbeat. This was considered a serious AE, but it was not procedure‑related.
There were similar rates of delayed AEs (6 months) in the CRFA and HA groups (57.1 percent and 60 percent). These included knee pain that did not improve or return to baseline, potentially due to underlying disease progression.
“AEs were generally minor and self‑limiting. Intergroup differences were not statistically significant,” the researchers said.
Other Tx modalities needed
“Nonoperative management with activity modification, weight management, physiotherapy, and analgesia remains the cornerstone of treatment for knee OA,” the researchers said.
However, chronic opioid prescription and associated misuse have become a significant public health issue, while adjunctive treatments (eg, intra‑articular corticosteroid, platelet‑rich plasma injections) offer only modest benefit. [Drugs Aging 2019;36:129‑143; Am J Sports Med 2015;43:1575‑1582; Ther Adv Chronic Dis 2019;10:2040622319825567]
“There remains a need to identify safe and effective nonoperative modalities with sustained outcomes for managing knee OA,” they said.
Twelve participants underwent genicular nerve block for patient selection and were randomized 1:1 to receive either CRFA or HA. CRFA recipients underwent image‑guided genicular nerve ablation, while those on HA received a single 6 mL injection to the affected knee.
Given the small sample size, the results were preliminary and hypothesis-generating, the researchers noted. “[Nonetheless,] this study contributes valuable data to our understanding of CRFA as a treatment for knee OA in the Singaporean population.”
They called for larger studies comparing CRFA with other interventions for knee OA in the Singapore population to better assess their relative effectiveness.