Allogeneic mesenchymal trophic factors (MTF) from human umbilical cord tissue-derived mesenchymal stem cells (UC-MSC) injected into the knee joints of 20 patients (group 1) or injected subcutaneously into 20 patients (group 2) is a safe and useful procedure for inducing joint function improvements in osteoarthritis (OA) patients with grade 2, 3, or 4 radiographic OA severity.