Intra‐articular injection of culture‐expanded mesenchymal stem cells with or without addition of platelet‐rich plasma is effective in decreasing pain and symptoms in knee osteoarthritis: a controlled, double‐blind clinical trial

Purpose To compare the clinical and laboratory outcomes of intra‐articular injections of culture‐expanded bone‐derived mesenchymal stem cells (MSCs) with or without platelet‐rich plasma (PRP) to intra‐articular corticosteroid injections for the treatment of knee osteoarthritis (OA). Methods Forty‐seven patients with radiographic and symptomatic knee OA were randomized into three groups for intra‐articular injections: autologous bone marrow‐derived culture‐expanded MSCs ( n  = 16); autologous bone marrow‐derived culture‐expanded MSCs + PRP ( n  = 14); and corticosteroid ( n  = 17). The outcomes were assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS) and range of motion (ROM) at baseline, 1, 2, 3, 6, 9 and 12 months and intra‐articular cytokines analysis at baseline, 6 and 12 months postoperatively. Results The three groups showed significant improvement in most KOOS domains and global score at 1st month and all domains and global score at 12‐month follow‐up ( p  < 0.05). At the 1st month, only the MSCs group showed significant differences in KOOS symptoms domain ( p  = 0.003). The MSCs and MSCs + PRP groups showed the highest percentage of improvement in most KOOS domains and global score compared to the corticosteroid group. All three groups showed a significant reduction in intra‐articular levels of human interleukin‐10 cytokine, from baseline to 12 months ( p  < 0.05). Conclusion An intra‐articular injection of bone marrow‐derived culture‐expanded MSCs with or without the addiction of PRP is effective in improving the function and decreasing symptoms caused by knee OA at 12‐month follow‐up. Level of evidence II.