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

Abstract

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.

Bloqueo nervioso en Osteoartritis de rodilla: Revisión sistemática

“…Shanahan EM et al, 18 establecieron con su estudio sobre la eficacia del bloqueo genicular guiado por ultrasonido (US) la posibilidad de un tratamiento efectivo para la OA de rodilla, con la capacidad para el manejo del dolor en estos pacientes. El cual se replicó en los estudios que abordaremos a continuación, con diferentes técnicas y métodos.…”

“…Todos fueron pacientes diagnosticados según la escala de Kellgren y Lawrence con grado 2, 3 y 4 de osteoartritis de rodilla con la finalidad de comparar la efectividad del tratamiento para mitigar el dolor y mejorar la funcionalidad de la misma. En un principio Shanahan EM et al 18 y Güler T et al 19 proponen al bloqueo genicular guiado por ultrasonido (US) como una gran opción terapéutica para la osteoartritis de rodilla debido a su efectividad para suprimir el dolor, ya que incluso este último autor compara la técnica de bloqueo con fisioterapia convencional y la supera. Este tratamiento no solo reporta mejora en dolor y funcionamiento a la rodilla, pero para otros problemas articulares, esto lo demuestra Lebleu J et al que evaluó la mejora cuantitativa de la locomoción de toda la extremidad inferior tras someterse a un bloqueo nervioso genicular, donde a parte de mejorar tanto el dolor y funcionamiento de la rodilla, el resultado más significativo fue el aumento de rango de movimiento de cadera, esto nos hace pensar que los problemas con una articulación están biomecánicamente relacionado con los problemas en las otras.…”

Review of Evaluation and Treatment of Knee Pain—Reply

“…However, fluoroscopic or ultrasound-guided RFA is a lowrisk and safe procedure that delivers targeted radiofrequency energy to genicular or intra-articular nerves, thereby disrupting nociceptive signaling and causing partial sensory denervation of the knee joint capsule. 3 A recent systematic review and meta-analysis 4 evaluated different RFA modalities (cooled, pulsed, and conventional) and compared these treatments with other conservative therapies (eg, corticosteroid and hyaluronic acid intra-articular injections, platelet-rich plasma, nonsteroidal anti-inflammatory drugs, exercise). This study reported that RFA was effective at reducing both knee pain and improving function in patients with osteoarthritis.…”

“…2 If expertise is available, these interventions may be useful for patients with debilitating symptoms refractory to conservative treatment, or for patients with contraindications to or a preference for not pursuing knee replacement surgery. In addition to RFA, genicular nerve block 3 and cryoneurolysis, which involve application of low temperatures to peripheral nerves to disrupt pain signals, have also been shown to be superior to placebo and sham, respectively, in randomized trials, although with a short duration of effect of the nerve block (8 weeks). 3 Radiofrequency ablation involves delivering thermal energy to nerves supplying the knee joint, thereby disrupting pain signals.…”

“…In addition to RFA, genicular nerve block 3 and cryoneurolysis, which involve application of low temperatures to peripheral nerves to disrupt pain signals, have also been shown to be superior to placebo and sham, respectively, in randomized trials, although with a short duration of effect of the nerve block (8 weeks). 3 Radiofrequency ablation involves delivering thermal energy to nerves supplying the knee joint, thereby disrupting pain signals. Since the first report of RFA for treatment of knee pain approximately 15 years ago, a number of studies have compared different RFA modalities (cooled, pulsed, or conventional; monopolar or bipolar) with various treatment controls.…”