Summary of prospective studies on the effectiveness of the cooled radiofrequency treatment in patients with chronic knee pain

Author, year Study design Patient Groups Outcome measures Results Complications Comments
McCormick et al., 2017 [51] Cross-sectional study Knee OA and 50% or greater pain relief following GN blocks CRFA (n = 33, 52 discrete knees) NRS, MQSIII, and PGIC

35% resulted in a 50% or greater reduction in NRS scores, reductions of 3.4 or more points in MQSIII scores, and "very much improved/improved" PGIC scores.

19% resulted in complete pain relief at a minimum of six months of follow-up.

No serious adverse events
Davis et al., 2018 [15] Multicenter, cross-over, RCT Chronic knee pain (OA)

CRFA (n = 76)

IAS (n = 75)

NRS, OKS, GPE, and analgesic drug use at 1, 3, and 6 mo The CRFA group had more favorable outcomes in NRS at 6 mo: pain reduction, 50% or greater (74.1% vs. 16.2%); mean NRS score reduction, 4.9 ± 2.4 vs. 1.3 ± 2.2; mean OKS, 35.7 ± 8.8 vs. 22.4 ± 8.5; mean improved GPE, 91.4% vs. 23.9%; mean changes in nonopioid medication use, CRFA > IAS. No serious adverse events
Davis et al., 2019 [55] Multicenter, cross-over, RCT Chronic knee pain (OA)

CRFA (n = 58)

IAS (n = 4)

XO (IAS → CRFA, n = 58)

NRS, OKS, GPE, and analgesic drug use at 12 mo At 12 mo, 65% of the original CRFA group had pain reduction ≥ 50%, and the mean overall drop was 4.3 points on NRS. In addition, 75% reported' improved' effects. The cross-over group demonstrated improvements in pain and functional capacity. No serious adverse events related to CRFA The XO group was a group that performed CRFA in the IAS group in the previous study.
Walega et al., 2019 [54] Randomized sham-controlled trial Postoperative pain after TKA

CRFA (n = 35)

Sham (n = 32)

Opioid consumption, MQSIII, WOMAC, HADS, SF-12, and McGill Pain Questionnaire score No difference in opioid consumption, postoperative analgesia side effects, and MQSIII for 48 hr, no difference in physical functioning for 2 d, and no difference in any outcome measure at 1, 3, or 6 mo. No adverse events Cooled RFA of the superior lateral, superior medial, and inferomedial genicular nerves when performed 2–6 wk prior to elective TKA
Chen et al., 2020 [56] Multicenter RCT Chronic knee pain (OA)

CRFA (n = 88)

HA (n = 87)

NRS, WOMAC, GPE, EQ-5D-5L, and safety at 1, 3, and 6 mo Successful responders (≥ 50% reduction in NRS) (CRFA vs. HA): 71% vs. 38%. Mean NRS reduction at 6 mo: 4.1 ± 2.2 vs. 2.5 ± 2.5. Mean WOMAC improvement at 6 mo: 48.2 vs. 22.6. GPE improvement at 6 mo: 72% vs. 40%. CRFA vs. HA: 19% vs. 14%
Vallejo et al., 2023 [62] Double-blind RCT Chronic knee pain (OA)

CRFA (n = 49)

MRFA (n = 47)

VAS, WOMAC, OKS, 5-point Likert scale, and adverse events during 52 wk (1, 4, 12, 24, 52) Effective for 52 wk in both groups. CRFA seemed to be better sustained beyond 24 wk than MRFA (no significant difference at any time point). Moderate worsening of knee pain 1 in the CRFA group and 2 in the MRFA group
Vanneste et al., 2023 [63] Multicenter double-blind, noninferiority, and pilot RCT Knee OA, PPSP after TKA

RFA (n = 24)

CRFA (n = 25)

Responder at 3 mo, knee pain, functionality, QOL, emotional health, and adverse effect at 6 mo

Successful responders: 17% vs. 33% (no significant difference).

Inconclusive for noninferiority.

Subcutaneous hematoma (3), infrapatellar hypoesthesia (1), and transient increase in pain (2) in the CRFA group. Transient increase in pain (5) in the RFA group.

Insufficient sample size (pilot trial)

Low statistical power

CRFA: cooled radiofrequency ablation, EQ-5D-5L: EuroQol-5 Dimensions-5 Level, GN: genicular nerve, GPE: Global Perceived Effect, HA: hyaluronic acid, HADS: Hospital Anxiety and Depression Inventory scores, IAS: intra-articular steroid, MRFA: monopolar radiofrequency ablation, MQSIII: medication quantification scale III, NRS: numeric rating scale, OA: osteoarthritis, OKS: Oxford Knee Score, PGIC: patient global impression of change, PPSP: persistent postsurgical pain, QOL: quality of life, RCT: randomized clinical trial, RFA: radiofrequency ablation, SF-12: 12-Item Short Form Health Survey, TKA: total knee arthroplasty, VAS: visual analog scale, WOMAC: Western Ontario McMaster Universities Osteoarthritis index.

Korean J Pain 2024;37:13~25
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