Clinical Efficacy of Intra-articular Mesenchymal Stromal Cells for the Treatment of Knee Osteoarthritis: A Double-Blinded Prospective Randomized Controlled Clinical Trial

Background: Currently, there are limited nonoperative treatment options available for knee osteoarthritis (OA). Cell-based therapies have emerged as promising treatments for knee OA. Autologous stromal vascular fraction (SVF) has been identified as an efficient medium for intra-articular administration of progenitor cells and mesenchymal stem cells derived from adipose tissue. Hypothesis: Patients receiving intra-articular SVF would show significantly greater improvement than patients receiving placebo injections, and this improvement would be dose dependent. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: This was a multisite prospective double-blinded randomized placebo-controlled clinical trial. Adult patients with symptomatic knee OA were eligible. Thirty-nine patients were randomized to high-dose SVF, low-dose SVF, or placebo (1:1:1). SVF was obtained via liposuction, processed to create the cellular implant, and injected during the same clinical visit. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and magnetic resonance images were obtained preoperatively and at 6 and 12 months after injection. The Wilcoxon rank sum nonparametric test was utilized to assess statistical significance, and the Hodges-Lehmann location shift was used to assess superiority. Results: The median percentage change in WOMAC score at 6 months after injection for the high-dose, low-dose, and placebo groups was 83.9%, 51.5%, and 25.0%, respectively. The high- and low-dose groups had statistically significant changes in WOMAC scores when compared with the placebo group (high dose, P = .04; low dose, P = .02). The improvements were dose dependent. The median percentage change in WOMAC score from baseline to 1 year after injection for the high-dose, low-dose, and placebo groups was 89.5%, 68.2%, and 0%, respectively. The high- and low-dose groups displayed a greater percentage change at 12 months when compared with the placebo group (high dose, P = .006; low dose, P = .009). Magnetic resonance image review revealed no changes in cartilage thickness after treatment. No serious adverse events were reported. Conclusion: Intra-articular SVF injections can significantly decrease knee OA symptoms and pain for at least 12 months. The efficacy and safety demonstrated in this placebo-controlled trial support its implementation as a treatment option for symptomatic knee OA. Registration: NCT02726945 (ClinicalTrials.gov identifier)