Cooled Radiofrequency Ablation Shown Superior to Hyaluronic Acid for Chronic Knee Pain
Cooled radiofrequency ablation (CRFA) is a minimally invasive procedure for the treatment of pain due to knee osteoarthritis. In a multicenter trial of 260 patients with knee osteoarthritis, the authors compared the efficacy and safety of CRFA to a single hyaluronic acid (HA) injection.
The study enrolled 182 participants who met the inclusion criteria and underwent diagnostic block injections. Those with a minimum of 50% pain relief were randomized to receive either CRFA on 4 genicular nerves or a single HA injection.
Of the enrolled participants, 175 subjects were treated (88 with CRFA and 87 with HA). Patients were evaluated for pain using the Numeric Rating Scale (NRS). They were evaluated for function using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Participants were evaluated for quality of life using the Global Perceived Effect (GPE) score and EuroQol-5 Dimensions-5 Level (EQ-5D-5L) questionnaire. They were also evaluated for safety.
Studies were performed at 1, 3, and 6 months after treatment.
A total of 158 subjects (76 in the CRFA group and 82 in the HA group) completed the 6-month posttreatment 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).
The researchers concluded that CRFA-treated subjects demonstrated significant improvement in pain relief and overall function over single injection of HA. No serious adverse events were noted. Level of evidence was therapeutic level I. (See Chen AF, Khalouf F, Zora K, et al. 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. J Bone Joint Surg Am. 2020;102(17):1501-1510. doi:10.2106/JBJS.19.00935.)
C-CIESI and Dexamethasone Both Effective for Refractory Unilateral Radicular Pain
In a prospective, randomized, comparative trial of 120 patients (55.6% females, 52.3 +/- 12.5 years of age, body mass index 28.2 +/- 6.5 kg/m2), the authors considered the primary outcome of the proportion of participants with 50% Numeric Rating Scale pain score reduction from baseline "dominant pain" (the greater of arm vs neck) at 1 month postinjection.
Secondary outcomes included: 30% Neck Disability Index (NDI-5) reduction and Patient Global Impression of Change (PGIC) response indicating "much improved" or "very much improved."
Participants who experienced 50% pain reduction at 1, 3, and 6 months were 68.5% [95% confidence interval (CI), 54.9%-79.5%], 59.3% (95% CI, 45.7%-71.6%), and 60.8% (95% CI, 46.7%-73.2%), respectively, in the triamcinolone group (group 1), compared with 49.1% (95% CI, 36.4%-62.0%), 46.4% (95% CI, 33.8%-59.6%), and 51.9% (95% CI, 38.4%-65.2%), in the dexamethasone group (group 2).
The between-group difference at 1 month was significant (P = 0.038). The proportions of participants who experienced a 30% NDI-5 score improvement were 64.0% (95% CI, 49.8%-76.1%) and 54.9% (95% CI, 41.1%-68.0%) in the 2 groups (P = 0.352). Participants reported similar PGIC improvement in both groups: At 6 months, 53.2% (95% CI, 38.9%-67.1%) and 54.5% (95% CI, 39.7%-68.7%) in both groups reported being "much improved" or "very much improved," respectively (P = 0.897).
The authors concluded that methods with triamcinolone and with dexamethasone are effective in reducing pain and disability associated with refractory unilateral cervical radiculopathy in a substantial proportion of participants for at least 6 months. (See McCormick ZL, Conger A, Sperry BP, et al. A randomized comparative trial of targeted steroid injection via epidural catheter vs standard transforaminal epidural injection for the treatment of unilateral cervical radicular pain: six-month results [published online ahead of print August 14, 2020]. Pain Med. doi:10.1093/pm/pnaa242.)