Abstract
Osteoarthritis (OA) is a prevalent, degenerative joint disease, with knee OA being particularly common and impactful. This systematic review and meta-analysis aimed to assess the efficacy of eggshell membrane (ESM) supplementation in improving joint functionality and reducing pain in individuals with knee OA. A comprehensive search was conducted across PubMed, Scopus, Web of Science, and Cochrane Database up to July 2024, following PRISMA guidelines. Seven randomized controlled trials (RCTs) met the inclusion criteria, with five included in the meta-analysis. The studies compared ESM to a placebo, evaluating outcomes based on assessment tools such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analogue Scale (VAS), and Knee Injury and Osteoarthritis Outcome Score (KOOS). Results indicated that ESM significantly reduced pain and improved functionality, with notable improvements in total WOMAC score (effect size -0.34; 95% CI: -0.56 to -0.13; p < 0.001) and pain subscale (SMD -0.23; 95% CI: -0.42 to -0.04; p < 0.02). The findings support ESM as a promising adjunctive treatment for knee OA, offering a safe, natural supplement to enhance quality of life. Further high-quality RCTs are needed to confirm these results and explore the long-term effects and mechanisms of ESM.