Particulate cartilage and platelet-rich plasma treatment for knee chondral defects in sheep

Purpose Articular cartilage is vulnerable to multiple types of damage and it has limited reparative and regenerative capaci-ties due to its absence of vascularity. Although a large number of therapeutic strategies exist to treat chondral defects, they have some limitations, such as fibrocartilage formation. Therefore, the goal of the present study was to evaluate the chondro-genic regenerative properties of an autologous-made matrix of particulated cartilage and platelet-rich plasma (PACI + PRP) implantation for the treatment of full-thickness chondral defects in sheep.Methods A full-thickness 8 mm diameter cartilage defect was created in the weight-bear ing area of the medial femoral condyle in both knees of 16 sheep. The right knees of all animals were treated with particulated autograft cartilage implanta-tion and platelet-rich plasma, while the left knees were injected with Ringer's lactate solution or hyaluronic acid. The sheep were killed 9 or 18 months after surgery. Macroscopic evaluations were performed using three different scoring systems, and histopathological evaluations were performed using a modified scoring system based on different scoring systems.Results The PACI + PRP groups showed statistically significant differences in the percentage of defect repair and chondro-cytes in the newly formed cartilage tissue at 18 months compared to 9 months.Conclusions The results suggest that macroscopic appearance, histological structure and chondrocyte repair were improved when using PACI + PRP treatment for chondral defects, producing an outcome similar to the surrounding healthy cartilage. PACI + PRP is a totally autologous, easy, and unexpensive treatment that can be performed in one-step procedure and is useful as a therapeutic option for knee chondral defects.