Study Summary

Eleven studies including 1616 patients with knee osteoarthritis (KOA) were included in this systematic review and meta-analysis comparing intra-articular platelet-rich plasma (PRP) vs placebo (saline injection). Pooled outcomes of interest included pain measured by visual analog scale (VAS) and function measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 3, 6, and 12 months. PRP demonstrated statistically significant short-term improvement in pain and function at 3 and 6 months, but no significant benefit was observed at 12 months, with substantial heterogeneity across studies. Overall, PRP showed only weak short-term clinical efficacy, and the long-term clinical relevance remains uncertain.