Ultrasound-guided genicular nerve block provides pain relief up to 12 weeks in patients with knee osteoarthritis (OA), according to study findings published in Arthritis & Rheumatology.
Researchers in Australia conducted a 12-week, parallel-group, randomized, placebo-controlled trial between 2020 and 2021, in which analyzed the efficacy of genicular nerve block for pain management in patients with knee OA.
Patients were assigned to receive 3 ultrasound-guided injections of 5.7 mg celestone chronodose (1 mL) and 0.5% bupivacaine (3 mL) at the inferomedial, superomedial, and superolateral genicular nerves (treatment group) or saline injections (placebo group).
The researchers used the 100-mm visual analog scale (VAS), the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), and the Intermittent and Constant Osteoarthritis Pain Scale to collect patient-reported measurements of pain and disability at baseline and weeks 2, 4, 8, and 12.
A total of 59 patients were included in the study, with 31 in the treatment group and the remaining 28 in the placebo group.
At baseline, patients in the treatment vs placebo group reported higher average pain levels on the VAS scale, although this was not statistically significant (6.2 vs 5.3; P =.294). Patients receiving the genicular nerve block vs those in the placebo scored higher on the total WOMAC index at baseline, although this did not reach statistical significance (54.5 vs 48.1; P =.177).
At weeks 2, 4, 8, and 12, patients who received the genicular nerve block reported significantly reduced pain levels on the VAS scale and decreased disability on the total WOMAC index; however, the researchers observed that these effects diminished over time.
Pain significantly decreased in the treatment group compared with the placebo group (week 2, 2.7 vs 4.7; P <.001; week 4, 3.2 vs 5.1; P <.001; week 8, 3.9 vs 4.9; P <.001; week 12, 4.6 vs 5.1; P =.055).
Compared with baseline measures, disability and pain also decreased more significantly in the treatment group compared with the placebo group (week 2, 32.9 vs 44.4; P <.001; week 4, 33.7 vs 45.8; P <.001; week 8, 89.2 vs 44.9; P =.001; week 12, 42.65 vs 45.1; P =.012).
No complications were reported with both procedures for the duration of the study.
Study limitations included the relatively small sample size, lack of adequate blinding for patient safety, and the loss of patients (n=5) to follow-up.
“This US-guided [genicular nerve block] therapeutic intervention may be safer than the pharmacotherapies currently available,” the study authors said. “Also, a single intervention offered over 3 months may have substantial appeal for some patients compared with regular oral medication.”
This article originally appeared on Rheumatology Advisor
Shanahan EM, Robinson L, Lyne S, et al. Genicular nerve block for pain management in patients with knee osteoarthritis: A randomized placebo-controlled trial. Arthritis Rheumatol. Published online November 11, 2022. doi:10.1002/art.42384