Fig. 1

hUCB-MSC implantation in arthroscopy descripted. A: Medial compartment osteoarthritis in a 61-year-old woman; B: Multiple holes, 4 mm in diameter and 4 mm in depth, drilled using a drill bit; C: Human umbilical cord blood–derived mesenchymal stem cells mixed with hyaluronic acid hydrogel and implanted into the cartilage lesion. hUCB-MSC, allogenic human umbilical cord blood-derived mesenchymal stem cell