RecruitingPhase 3Biological interventionPhase 3 Pivotal Trial Comparing CARTISTEM® and Surgical Comparator for Knee Cartilage Lesions and OsteoarthritisTo establish the efficacy and safety of CARTISTEM®, a combination product composed of allogeneic human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) formulated with a cross-linked sodium hyaluronate (HA) hydrogel, CARTISTEM® compared to the surgical comparator of debridement in Subjects with knee cartilage lesions and osteoarthritis. This trial is intended to provide evidence of the superiority of CARTISTEM® to reduce knee pain and improve knee function compared to debridement for Subjects with knee cartilage lesions and osteoarthritis at 2-years post-treatment. Additionally, this trial is intended to intended to explore whether CARTISTEM® may have disease-modifying effects on osteoarthritis progression through the use of semi-quantitative MRI assessment.