Study Summary

This meta-analysis included 21 randomized controlled trials evaluating intra-articular platelet-rich plasma (PRP) compared with placebo or corticosteroid injections for knee osteoarthritis (KOA). Across studies, PRP demonstrated superior improvements in pain and functional outcomes compared with placebo and corticosteroids. Improvements were observed in visual analogue scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores when compared with placebo, as well as in the VAS, WOMAC, and Knee Injury and Osteoarthritis Outcome Score (KOOS) scores when compared with corticosteroids. Leukocyte-rich PRP showed greater improvements in pain outcomes versus leukocyte-poor PRP at 6 months. Treatment effects were generally sustained up to 12 months, after which deterioration was reported in some long-term analyses. No major safety concerns were identified.