A Comparison of Genicular Nerve Blockade With Corticosteroids Using Either Classical Anatomical Targets vs Revised Targets for Pain and Function in Knee Osteoarthritis: A Double-Blind, Randomized Controlled Trial

Abstract

Objective Compare the effectiveness of genicular nerve blockade (GNB) using classical anatomical targets (CT) versus revised targets (RT) in patients suffering from chronic knee osteoarthritis pain. Design Double-blinded randomized controlled trial. Setting Pain medicine center of a teaching hospital. Methods We randomly assigned 55 patients with chronic knee osteoarthritis pain to receive a GNB (using a fluid mixture of 2 mL: lidocaine 1% + 20 mg triamcinolone) with either classical targets (CT-group, n = 28) or revised targets (RT-group, n = 27). Numeric rating pain scale (NRS), Oxford knee score (OKS), Western Ontario and McMaster Universities osteoarthritis index score (WOMAC), Quantitative analgesic questionnaire (QAQ) and global perceived effects were assessed at baseline, and at 1-hour, 24-hours, 1, 4, and 12 weeks post-intervention. Results The RT-group showed greater reduction in NRS mean score at 1-hour post-intervention (2.4 ± 2.1 vs 0.4 ± 0.9, 95% confidence interval (CI) [.0–.8] vs [1.6–3.2], P < .001). The proportion of patients achieving more than 50% knee pain reduction was higher in the RT-group at each follow up interval, yet these differences were statistically significant only at 1-hour post intervention (82.1% [95% CI = 63.1–93.9] vs 100% [95% CI = 97.2–100] P = .02). Both protocols resulted in significant pain reduction and joint function improvement up to 12 weeks post-intervention. Conclusions The revised technique allowed more pain relief as well as greater proportion of successful responders at 1-hour post intervention. The large volume injected during therapeutic GNB could have compensated the lack of precision of the classical anatomical targets, mitigating differences in outcomes between both techniques.

Predictive factors associated with successful response to utrasound guided genicular radiofrequency ablation

“…Recently, there has been increasing interest in targeting up to 10 additional nerves to improve the efficacy of the procedure. Moreover, several studies have shown that targeting more branches improves the treatment efficacy compared to the three nerve techniques [ 17 , 26 – 28 ]. However, expanding the number of targeted nerves may increase side effects, including motor injury, so safety concerns should always be considered.…”

“…1 ). Depending on physician preference and based on recent anatomical updates, additional nerves including the recurrent fibular nerve (RFN) and the infrapatellar branch of the saphenous nerve (IPBSN) were blocked [ 15 , 17 , 19 ]. The anatomic locations for the additional genicular nerves were identified as follows ( Fig.…”

“…Sensory innervation of the knee is provided by terminal articular branches of the femoral, saphenous, obturator, tibial, and common peroneal nerves; physicians and researchers commonly refer to these nerves as the genicular nerves [ 12 , 13 ]. The superior medial (SM), superior lateral (SL), and inferior medial (IM) genicular nerves are the most used anatomical targets for RF procedures and are described as the ‘three-nerve technique’; depending on the pain location, additional nerves are sometimes targeted for therapy [ 9 , 10 , 14 – 18 ].…”

Short- and mid-term clinical results of ultrasound-guided genicular nerve block in arthroplasty-related chronic postsurgical pain

“…Guler et al (23) showed that ultrasound-guided genicular nerve blockade with a total mixture of 5 ml of 2% lidocaine and 40 mg of triamcinolone, to patients with knee osteoarthritis has sustained improvement in pain, physical function, and physical capacity for up to 12 weeks. Fonkoue et al (24) performed a single session genicular nerve blockade with a mixture of lidocaine and triamcinolone, using scopy-controlled classic and revised target techniques, to patients with chronic knee pain due to osteoarthritis. In both groups, improvement was detected at the 12 th -week control compared to baseline in pain severity assessed by NRS, functionality assessed by WOMAC, and physical and mental health assessed by SF-12 (24).…”

“…Fonkoue et al (24) performed a single session genicular nerve blockade with a mixture of lidocaine and triamcinolone, using scopy-controlled classic and revised target techniques, to patients with chronic knee pain due to osteoarthritis. In both groups, improvement was detected at the 12 th -week control compared to baseline in pain severity assessed by NRS, functionality assessed by WOMAC, and physical and mental health assessed by SF-12 (24). The common point of these studies in patients with knee osteoarthritis is that long-term efficacy was demonstrated with a single-session block with added steroids.…”