Evaluating the Effect of Electroacupuncture in Knee Osteoarthritis: Protocol for a Multicenter Randomized Controlled Trial.

Background & Objective: Knee osteoarthritis (KOA) is a degenerative disease of the knee joint. Current treatment strategies face considerable limitations. For thousands of years, acupuncture has been used in China to treat KOA due to its unique advantages. However, existing studies often rely excessively on subjective perception for outcome assessment, and the central neural mechanisms by which acupuncture alleviates chronic pain in KOA remain unclear. Our aim is to elucidate the efficacy and central mechanisms of acupuncture for KOA. Methods: In this multicenter, patient- and assessor-blind, superiority, randomized controlled neuroimaging trial, 110 patients with KOA will be randomly assigned in a 1:1 ratio to an electroacupuncture group or a sham electroacupuncture group. Participants are patients with KOA aged between 50 and 75 years who have experienced chronic knee pain for the past three months. Participants will be randomized using a stratified block randomization method, followed by automatic allocation through an electronic system. The trial is scheduled to be conducted from March 2024 to September 2026, and participants will be recruited from the First Affiliated Hospital of Anhui University of Chinese Medicine, Anhui Provincial Hospital, and Bozhou Chinese Medicine Hospital. Treatment will be administered in six sessions over two weeks. Patients will undergo assessments and examinations at baseline and after the completion of treatment. The primary outcome measure is the Clinical Global Impressions scale - Improvement. Secondary outcomes include the Visual Analogue Scale, pressure pain threshold, Knee Injury and Osteoarthritis Outcome Score, Patients' expectancy scale of acupuncture, Self-Rating Anxiety Scale, Self-Rating Depression Scale, functional magnetic resonance imaging (fMRI). A multimodal imaging protocol will be employed for fMRI. Differences in brain functional-structural information and brain network connectivity patterns before and after acupuncture will be comprehensively analyzed. Correlations between neural markers and patients' subjective experiences will be examined. For clinical outcomes, categorical variables will use the chi-square test, and continuous variables will use the Discussion: This multicenter randomized controlled neuroimaging trial integrates validated subjective assessment tools with multimodal fMRI to multidimensionally evaluate the efficacy of acupuncture for KOA. We believe the forthcoming comprehensive results will provide a unified interpretation of the central effects of acupuncture.