Efficacy of platelet-rich plasma in the treatment of pain syndrome in knee osteoarthritis: a meta-analysis of the studies with a 6-month follow-up

Introduction The scientific literature database contains numerous studies comparing the efficacy of platelet-rich plasma (PRP) and hyaluronic acid (HA) preparations in knee osteoarthritis, but the results are contradictory due to methodological limitations and high heterogeneity of treatment protocols. Purpose To compare the data from scientific studies on the effectiveness of using PRP and medium molecular weight HA preparations in the treatment of patients with knee osteoarthritis. Materials and methods A search of randomized controlled trials was conducted in PubMed, Embase, and the Cochrane Library published in the period 2017–2024 using the following keywords: osteoarthritis, knee joint, intra-articular injections, platelet-rich plasma, hyaluronic acid, WOMAC, and meta-analysis. Studies that examined patients diagnosed with knee osteoarthritis of any severity who received intra-articular injections of PRP or HA and assessed pain using the WOMAC were reviewed. After rigorous selection, four studies with identical treatment protocols were included. Results The meta-analysis included 4 studies involving 333 patients (164 in the PRP group and 169 in the HA group). The mean WOMAC pain score at 6 months after the start of treatment was 4.52 (SD = 1.59) in the PRP group and 4.95 (SD = 2.07) in the HA group. The effect size of Hedges' g was 0.26 (95 % CI: –0.61 to 1.14; p = 0.336). Egger's test did not reveal a statistically significant publication bias (p = 0.06). Discussion Our study revealed no significant differences between the use of PRP and HA, which contradicts several previous meta-analyses. This may be due to the use of more stringent inclusion criteria in our analysis and the evaluation of HA preparations with only medium molecular weight. Conclusion This meta-analysis was aimed to compare the effectiveness of using PRP and medium molecular weight HA in the treatment of patients with knee osteoarthritis and did not reveal statistically significant differences between the groups in severity of pain using the WOMAC system six months after the start of treatment, which indicates comparable effectiveness of these therapy methods.