PURPOSE: The aim of this study is to investigate the safety and regenerative potential of a hemicondylar aragonite-based scaffold in the reconstruction of large osteochondral lesions occupying an extensive portion of the medial femoral condyle in a goat model.
METHODS: Eight Saanen goats were treated by the implantation of an aragonite-based scaffold (size: 19x8x8 mm) on a previously prepared hemicondylar osteochondral defect located in the right medial femoral condyle of the knee. Goats were sacrificed after 12 months and the specimens underwent X-ray imaging, macroscopic, micro-CT, histology and immuno-histochemistry evaluations to assess subchondral bone and cartilage regeneration.
RESULTS: In all eight goats, no adverse event or persistent inflammation was observed. The evaluations performed showed integration of the scaffold, which almost completely resorbed at 12 months. In all animals no signs of OA progression were seen. Concurrent regeneration of the osteochondral unit was observed, with trabecular bone tissue replacing the implant and restoring the subchondral layer, and it was also observed the formation of an overlying hyaline cartilage surface, well integrated within the surrounding native tissue.
CONCLUSIONS: The use of the hemicondylar biphasic aragonite-based implant in the treatment of osteochondral defects in the goat model proved to be technically feasible and safe. The scaffold degraded and was replaced by regenerated tissue within the 12-month study period, restoring the osteochondral unit both at the level of the cartilaginous layer and the subchondral bone.