Umbilical cord-derived mesenchymal stem cell therapy for knee osteoarthritis and cartilage repair: Current evidence and clinical applications

Osteoarthritis is fundamentally a whole-joint disease, and a critical pathological feature is the limited capacity of articular cartilage for self-regeneration, leading to accelerated joint degeneration once breakdown begins. Current therapeutic strategies are primarily palliative, and conventional marrow stimulation procedures such as microfracture often yield suboptimal, short-lived outcomes. Stem cell-based biologic augmentation using mesenchymal stem cells has emerged as a promising approach through direct chondrocyte differentiation, paracrine stimulation, and immunomodulation. Umbilical cord-derived mesenchymal stem cells offer robust proliferative capacity, enhanced biological potency, and lower immunogenicity than adult mesenchymal stem cells, and can be obtained with minimal ethical concerns. Clinical trials of human umbilical cord blood-derived mesenchymal stem cells combined with hyaluronic acid hydrogel (CARTISTEM®) have demonstrated excellent safety, improved patient-reported outcomes, and durable hyaline-like cartilage regeneration. Emerging evidence further suggests that combining high tibial osteotomy with human umbilical cord blood-derived mesenchymal stem cells-based cartilage regeneration for medial compartment osteoarthritis with varus malalignment creates a synergistic biological and mechanical environment that promotes structural cartilage repair. In conclusion, surgically transplanted human umbilical cord blood-derived mesenchymal stem cells show therapeutic potential in arthritic knees, although the role of intra-articular injections and the optimal indications for combined high tibial osteotomy remain to be clarified.