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.

Background Genicular nerve blockade is a possible treatment for patients with knee osteoarthritis. Pain relief and improvement in functioning is expected. This procedure could be of major interest for patients in low-income countries where total knee arthroplasty is not available for the population. This study aims at assessing the immediate benefits on pain, gait, and stairs kinematics after a genicular nerve blockade in patients suffering from knee osteoarthritis in Cameroun. Methods A prospective study was carried out on 26 subjects in Cameroun. A genicular nerve blockade was performed on 14 women with painful knee osteoarthritis grade 2–4. Lower limb joint angles were recorded with inertial sensors before and 1 h after injection. Patient-reported outcomes of pain and perceived difficulty were collected, as well as 10 m and 6 min walking tests. A reliability analysis of inertial sensors was performed on a sample of 12 healthy subjects by calculating the intraclass correlation coefficient and the standard error of measurement. Results Pain and perceived difficulty decreased significantly (p < 0.001). Cadence increased significantly in stairs climbing (upstairs: + 7.7 steps/min; downstairs: + 7.6 steps/min). There was an improvement for hip sagittal range of motion during gait (+ 9.3°) and pelvis transverse range of motion in walking upstairs (− 3.3°). Angular speed range of the knee in the sagittal plane and of the hip in the frontal plane increased significantly in stairs descent (+ 53.7°/s, + 94.5°/s). Conclusions This study quantified improvement of gait and stair climbing immediately after a genicular nerve blockade in patients suffering from knee OA in Cameroon. This is the first study objectifying this effect, through wearable sensors. Trial registration Pan African Clinical Trial Registry, PACTR202004822698484. Registered 28 March 2020 - Retrospectively registered.