Platelet-rich plasma versus hyaluronic acid in the treatment of knee osteoarthritis: a meta-analysis

Background This study aimed to evaluate the clinical efficacy of platelet-rich plasma (PRP) injection compared with hyaluronic acid (HA) injection for patients undergoing knee osteoarthritis. Methods We systematically searched electronic databases including PubMed, Embase, Web of Science, and the Cochrane Library on January 23, 2020 to identify relevant studies issued in English languages. The outcomes evaluating the efficacy of knee osteoarthritis (KOA) treatment were Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores (WOMAC pain, function, stiffness, and total scores) at 1, 3, 6, and 12 months; International Knee Documentation Committee (IKDC) scores, Lequesne Index score, Visual Analog Scale (VAS) scores, EQ-VAS scores, and KOOS scores. The pooled data were analyzed by Stata 12.0. Results A total of 20 RCTs were enrolled in the present meta-analysis. The pooled results demonstrated that platelet-rich plasma (PRP) injection reduced pain more effectively than hyaluronic acid (HA) injection at 6-month and 12-month follow-up evaluated by WOMAC pain scores and VAS scores. EQ-VAS in the patients treated with PRP injection was lower than that in patients with HA injection at 12 months. Moreover, the patients with PRP injection had a better function recovery than those with HA injection at 1-month, 3-month, 6-month, and 12-month follow-up, as evaluated by WOMAC function scores. WOMAC total scores showed significant difference at 6-month and 12-month follow-up. The IKDC scores indicated PRP injection was significantly more effective than HA injection at 3 months and 6 months. However, the Lequesne Index scores, KOOS scores, and adverse events did not show any significant difference between groups. Conclusion Intra-articular PRP injection appeared to be more efficacious than HA injection for the treatment of KOA in terms of short-term functional recovery. Moreover, PRP injection was superior to HA injection in terms of long-term pain relief and function improvement. In addition, PRP injection did not increase the risk of adverse events compared to HA injection.