Effectiveness of Platelet-Rich Plasma in Knee Osteoarthritis: A Systematic Review and Meta-Analysis.

INTRODUCTION: Knee osteoarthritis (OA) causes chronic pain and disability, with limited benefit from conventional treatments. Platelet-rich plasma (PRP) has been proposed as a biologic therapy with potential tissue-repair properties; however, its clinical efficacy remains uncertain. OBJECTIVE: To assess the effectiveness of intra-articular PRP injections in reducing pain and improving function in patients with knee OA. METHODOLOGY: This systematic review and meta-analysis included randomized controlled trials comparing intra-articular PRP with placebo or no treatment. Pain outcomes were measured using the Visual Analog Scale (VAS), while functional outcomes were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) or Knee injury and Osteoarthritis Outcome Score (KOOS). RESULTS: PRP significantly reduced pain and improved function compared with placebo across short-, mid-, and long-term follow-up. The magnitude of benefit varied but remained clinically relevant. CONCLUSION: PRP provides significant improvements in pain relief and functional outcomes compared with placebo or no treatment in patients with knee OA, supporting its potential as a therapeutic option. Standardized protocols and larger RCTs are warranted to further confirm its clinical effectiveness.