Meaningful effectiveness of platelet-rich plasma in treating patients with osteoarthritis of the knee: Meta-analysis and review

Background: Osteoarthritis (OA) of the knee is a significant cause of disability. The current conservative treatment options include physiotherapy, analgesia, intra-articular injection of platelet-rich plasma (PRP), hyaluronic acid, or corticosteroids. Regarding PRP, some meta-analyses studies have been reported. However, these studies focused on the effectiveness of intra-articular PRP when compared to other controls, and none thoroughly investigated the anchored-based effectiveness concerning the minimal clinically important difference (MCID). Objective: We, therefore, conducted this work to address this apparent knowledge gap and to provide objective data that could be used by decision-makers. Methods: Electronic databases were searched to identify relevant publications. We included controlled trials that evaluated the efficacy of PRP for the treatment of OA of the knee. All included studies must have had a minimum follow-up of 24 weeks as well as pre- and post-injection Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores. Results: A total of 12 studies, involving 405 patients, were included in this analysis. The primary endpoint of this study was to compare the treatment effect measured by WOMAC scores improvement to MCID. For WOMAC score analyses, the mean difference (MD) between baseline and 6-month scores was utilized. The pooled data established significant functional improvement as demonstrated by MD of 25.5 ± 3.3 (95% confidence interval: 19.1–31.9, P