Intra-articular injections of platelet-rich plasma combined with hyaluronic acid versus platelet-rich plasma alone in the treatment of knee osteoarthritis: a systematic review and meta-analysis

Purpose/aim: This study aimed to evaluate the efficacy and safety of platelet-rich plasma (PRP) combined with hyaluronic acid (HA) compared to PRP alone in treating knee osteoarthritis (OA). Methodology: A systematic review and meta-analysis were conducted according to the 2020 Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. PubMed, Scopus, and Cochrane Library databases were searched for studies comparing PRP + HA to PRP alone in knee OA patients. Data on patient-reported outcomes, adverse events, and study quality were extracted. Results: Nine studies (n = 868 knees) met inclusion criteria. PRP + HA statistically significantly improved The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function, and total scores compared to PRP alone (p < 0.05), though differences were below the minimal clinically important difference (MCID). No significant differences were found in WOMAC pain, stiffness, visual analog scale (VAS) for pain, or Knee Injury and Osteoarthritis Outcome score (KOOS) between groups. Adverse events were more frequent in the PRP group (24.6%) than the PRP + HA group (15.4%), with all events being minor and self-limiting. Conclusion: There were no statistically significant differences between intra-articular PRP combined with HA and PRP alone in terms of WOMAC for pain and stiffness, VAS for pain, and KOOS. However, the combination therapy resulted in statistically significant lower WOMAC scores for physical function and total compared to PRP alone, though the differences were minimal and below the MCID.