open wedge high tibial osteotomy (OWHTO) is a reliable option for the treatment of medial unicompartmental osteoarthritis with varus deformity in relatively young patients., but there is still the risk of nonunion, collapse and loss of correction in the osteotomy space. There are still nonunion, collapse, and osteoarthritis in the osteotomy space. Various bone grafts have been used to fill osteotomy spaces, but there is not yet an ideal bone grafts. This article will present a study of the various bone grafts available at OWHTO in order to make the appropriate selection in each specific clinical situation.