28 knees from 15 patients with knee osteoarthritis were randomized to receive an implantation of umbilical cord mesenchymal cell (UC-MSCs) implantation alongside hyaluronic acid injections and somatotropin injections, UC-MSC implantation with hyaluronic acid (HA) injection, or hyaluronic acid injection only. Outcomes of interest included the International Knee Documentation Committee (IKDC) score, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analog Scale (VAS), and MRI T2 mapping of knee cartilage. Follow up was performed up to 12 months post-implantation. Results revealed significant differences among the three groups in IKDC score at 12 months. The US-MSC+somatotropin group displayed a significant medial T2 improvement in knee cartilage after 12 months, and overall achieved the highest level of improvement.