Editorial Commentary: Stem Cell Therapy for the Knee: Heterogeneity in Cell Sources, Delivery Methods, and Concomitant Surgery Needs to Be Considered

Mesenchymal stem cells (MSCs) have been investigated for the treatment of knee osteoarthritis because of their unique properties, including self-renewal, multi-linear cellular differentiation, and immunomodulatory capacity. However, the efficacy of MSCs for positive clinical outcomes in the treatment of knee osteoarthritis remains controversial. Because clinical studies in general have high variability, the heterogeneity in the sources of the stem cells used, efficacy of delivery methods, and concomitant surgery should be carefully considered to interpret the benefits of MSC therapy for knee osteoarthritis.