25 patients with varus deformity undergoing medial opening wedge high tibial osteotomy of the knee were randomized to determine the efficacy of platelet-rich plasma (PRP) combined with a biological graft of bone marrow aspirate compared to an autologous iliac graft. Participants were allocated to receive either the biological graft, or the gold-standard autologous iliac bone graft, and were followed-up for 24 weeks postoperatively. Kaplan-Meier estimates indicated that bone healing took longer in those who received the PRP graft, but the difference between groups was not significant. By the end of the 24-week study period, consolidation was observed in 10 of the 11 patients who received the biological graft compared to all patients who were treated with the iliac bone graft.