Intra-articular injection of platelet-rich plasma is more effective than hyaluronic acid or steroid injection in the treatment of mild to moderate knee osteoarthritis:a prospective, randomized, triple-parallel clinical trial

Abstract Purpose: To prospectively compare the efficacy and safety of intra-articular injections of platelet-rich plasma (PRP) with hyaluronic acid (HA) and glucocorticosteroid (CS) control groups for knee osteoarthritis (KOA) in a randomized, triple-parallel, single-center clinical trial. Methods: A total of 75 patients were randomly assigned to one of three groups receiving a single injection of either leukocyte-poor platelet-rich plasma (25 knees), hyaluronic acid (25 knees), or glucocorticosteroid (25 knees). The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was collected at baseline and 6, 12, and 26 weeks after treatment. Results: After 6 weeks of PRP administration, a decrease in the mean WOMAC value was observed in all three study groups. Three months after administration, the greatest decrease in the mean WOMAC value was obtained in the PRP group. The results in the HA and CS groups were similar (p = 0.681). In the one-way analysis of variance and post hoc analysis using the HSD Tukey test, a significantly greater improvement was shown by comparing the PRP and CS groups (p = 0.001), and the PRP and HA groups (p = 0.010). After intra-articular injection of CS, the reduction in pain was greatest 6 weeks after administration, and the mean value was the lowest among all groups. During subsequent visits, the value of the pain subscale increased, and after 6 months, it was the highest among the studied groups. Using the Wilcoxon paired test, no PRP effect was found to reduce stiffness at the 6-month follow-up (p = 0.908). Functional improvement was achieved in all groups, i.e., a decrease in the value of this subscale 6 months after administration. The largest decrease was seen in the group that received PRP (p < 0.001) and then in the HA group. The smallest decrease among the investigated methods was shown in the CS group. Conclusions: Intra-articular injections of PRP can provide clinically significant functional improvement for at least 6 months in patients with mild to moderate KOA which is superior to HA or CS injections

The effect of platelet-rich plasma on the intra-articular microenvironment in knee osteoarthritis

Abstract Knee osteoarthritis (KOA) represents a clinical challenge due to poor potential for spontaneous healing of cartilage lesions. Several treatment options are available for KOA, including oral nonsteroidal anti-inflammatory drugs, physical therapy, braces, activity modification, and finally operative treatment. Intra-articular (IA) injections are usually used when the non-operative treatment is not effective, and when the surgery is not yet indicated. More and more studies suggesting that IA injections are as or even more efficient and safe than NSAIDs. Recently, research to improve intra-articular homeostasis has focused on biologic adjuncts, such as platelet-rich plasma (PRP). The catabolic and inflammatory intra-articular processes that exists in knee osteoarthritis (KOA) may be influenced by the administration of PRP and its derivatives. PRP can induce a regenerative response and lead to the improvement of metabolic functions of damaged structures. However, the positive effect on chondrogenesis and proliferation of mesenchymal stem cells (MSC) is still highly controversial. Recommendations from in vitro and animal research often lead to different clinical outcomes because it is difficult to translate non-clinical study outcomes and methodology recommendations to human clinical treatment protocols. In recent years, significant progress has been made in understanding the mechanism of PRP action. In this review, we will discuss mechanisms related to inflammation and chondrogenesis in cartilage repair and regenerative processes after PRP administration in in vitro and animal studies. Furthermore, we review clinical trials of PRP efficiency in changing the OA biomarkers in knee joint