Introduction Genicular nerve blocks (GNBs) are an emerging technique that have been used as a part of multimodal analgesia for total knee arthroplasty. The efficacy of intraoperative landmark-based GNBs, a recently introduced technique, has been established. We hypothesized that it would provide non-inferior postoperative analgesia compared with periarticular infiltration (PAI) when combined with continuous adductor canal block.
Methods This study randomized 140 patients undergoing total knee arthroplasty to receive either intraoperative landmark-based GNB (GNB group) or PAI (PAI group), with 139 completing the study. The primary outcomes were the pain scores at rest and during movement at 12 hours postoperatively on an 11-point Numerical Rating Scale; the non-inferiority margin was 1. Pain scores at additional time points, intravenous morphine consumption, time to first rescue analgesia, functional performance and muscle strength tests, and sleep disturbance were also assessed.
Results At 12 hours postoperatively, the PAI and GNB groups had median resting pain scores of 0 (0–2) and 0 (0–2), respectively. The median difference was 0 (95% CI −0.4 to 0.4, p=1), with the 95% CI upper limit below the prespecified non-inferiority margin. The median pain score during movement was 1.5 (0–2.3) and 2 (1–3.1) in the PAI and GNB groups, respectively. The median difference was 0.9 (95% CI 0.3 to 1.6, p=0.004), failing to demonstrate non-inferiority. The GNB group had higher intravenous morphine consumption at 12 hours postoperatively and a shorter time to first rescue analgesia.
Conclusions GNB compared with PAI provides non-inferior resting pain relief. Non-inferiority was not established for pain during movement.
Trial registration number TCTR20220406001 (www.thaiclinicaltrials.org).
- Nerve Block
- Pain, Postoperative
- Lower Extremity
Data availability statement
Data are available on reasonable request.
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Contributors WIK was involved in the planning, conception and design of study, data acquisition, review of the literature, data analysis, data interpretation, and is the author responsible for the overall content as guarantor. WK was involved in the planning, design of the study, review of the literature, data interpretation, and preparation of the manuscript. SN was involved in reviewing the literature, data acquisition, and editing the manuscript. AT was involved in reviewing the literature, data acquisition, and editing the manuscript. CT was involved in reviewing the literature, reviewing the data, and editing the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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