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 capacities 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 chondrogenic 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-bearing area of the medial femoral condyle in both knees of 16 sheep. The right knees of all animals were treated with particulated autograft cartilage implantation 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 chondrocytes 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.