Genicular Nerve Block for Pain Management in Patients With Knee Osteoarthritis: A Randomized Placebo‐Controlled Trial

Objective This study was undertaken to determine the efficacy of ultrasound‐guided genicular nerve block (GNB) for the management of knee pain in patients with knee osteoarthritis. Methods We performed a 12‐week parallel‐group, placebo‐controlled randomized trial of GNB. Within 2 weeks of randomization, patients with knee osteoarthritis in the active arm received 3 injections of 5.7 mg celestone chronodose (1 ml) and 0.5% bupivacaine (3 ml) to the inferomedial, superomedial, and superolateral genicular nerves; patients with knee osteoarthritis in the placebo arm received injections of normal saline. At baseline and at weeks 2, 4, 8, and 12, patients recorded their pain and disability on a 100‐mm visual analog scale (VAS) (the primary outcome measure), the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), and the Intermittent and Constant Osteoarthritis Pain scale. Statistical significance was set at a 2‐sided Type I error of α = 0.0125 for comparisons at each of the 4 time points. We used a global perceived effect scale to measure patient satisfaction. Results The 59 patients (36 female, 23 male) who completed the trial had a mean ± SD age of 68.2 ± 8.6 years. Patients in the active group reported improvements in pain scores at 2, 4, 8, and 12 weeks with a diminution of the effect over time. VAS scores at baseline and at weeks 2, 4, 8, and 12 in the active group (n = 31) versus placebo group (n = 28) were 6.2 versus 5.3 ( P = 0.294), 2.7 versus 4.7 ( P < 0.001), 3.2 versus 5.1 ( P < 0.001), 3.9 versus 4.9 ( P < 0.001), and 4.6 versus 5.1 ( P = 0.055), respectively. Total WOMAC scores at baseline and at weeks 2, 4, 6, 8, and 12 in the active group versus the placebo group were 54.5 versus 48.1 ( P = 0.177), 32.9 versus 44.4 ( P < 0.001), 33.7 versus 45.8 ( P < 0.001), 39.2 versus 44.8 ( P = 0.001), and 42.65 versus 45.1 ( P = 0.012), respectively. Conclusion GNB offers short‐term pain relief for knee osteoarthritis.