Platelet-rich plasma plus hyaluronic acid vs platelet-rich plasma intra-articular injections for knee osteoarthritis: A systematic review and meta-analysis

BACKGROUND: Knee osteoarthritis (KOA) is a common condition characterized by pain, stiffness, and reduced function, significantly impacting quality of life. OBJECTIVES: This study aimed to evaluate the combined use of platelet-rich plasma (PRP) and hyaluronic acid (HA) compared to PRP alone in treating KOA. The hypothesis was that PRP + HA would provide superior outcomes in pain relief and functional improvement due to their complementary biological effects. MATERIAL AND METHODS: A systematic review and meta-analysis were conducted according to PRISMA guidelines. The analysis included 11 trials with a total of 892 participants. The studies compared the efficacy of PRP + HA compared to PRP alone. Key outcomes evaluated were changes in the visual analogue scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Inter-national Knee Documentation Committee (IKDC) scores at 1, 3, 6, 12, and 24 months post-treatment. RESULTS: At baseline, no significant differences in VAS scores were observed between the 2 groups (5.82 ±2.71 for PRP + HA vs 5.66 ±2.96 for PRP). By the 6-month follow-up, PRP + HA showed a more substantial reduction in VAS scores (-2.83 ±1.60 vs -2.56 ±1.66; standardized mean difference (SMD) = -1.08, 95% confidence interval (95% CI): -2.22 to 0.05; p < 0.001), with the largest improvement seen at 24 months (-2.7 ±0.2 for PRP + HA vs 0.4 ±0.23 for PRP; SMD = -14.10, 95% CI: -17.41 to -10.79; p < 0.001). WOMAC scores at 12 months also favored the PRP + HA group (-25.26 ±15.24 vs -19.6 ±14.20; SMD = -0.95; p = 0.01). IKDC scores showed no significant differences between groups. CONCLUSION: The combination of PRP and HA provides superior pain relief and functional improvement compared to PRP alone, particularly at 6 and 24 months. These findings support the inclusion of PRP + HA in KOA treatment protocols and warrant further investigation into its long-term benefits.