Repair of large articular high-load-bearing osteochondral defects in canine hip joint using tissue-engineered osteochondral constructs / 中华骨科杂志

ABSTRACT

Objective To investigate the effects of the novel scaffold on repairing large,high-loadbearing osteochondral defects of femoral head in a canine model.Methods The biphasic scaffolds were fabricated using cartilage extracellular matrix (ECM)-derived scaffold (cartilage layer) and acellular bone matrix (bone layer) by phase separation technique.Articular high-load-bearing osteochondral defects with a diameter of 11-mm and the depth of 10-mm were created in femoral heads.The defects were treated with constructs of a biphasic scaffold seeded with chondrogenically induced bone marrow-derived mesenehymal stem cells (BMSCs).The outcomes were evaluated for gross morphology,histological,biomechanical and micro-CT analysis at the third and sixth month after implantation.Results The gross and X-ray results showed femoral head slightly collapsed at the third month and severely collapse at the sixth month.Histological analysis showed cartilage defects were repaired with fibrous tissue or fibrocartilage with severe osteoarthritis and the varied degrees of the collapse of femoral heads were presented.Micro-CT showed that the values of bone volume fraction in defect area were always lower than those of the normal area in the femoral heads.Biomechanical analysis showed rigidity of the subchondral bone in defect area was significantly lower than that in normal area in the femoral heads at the sixth month.Conclusion The ECM-derived,integrated biphasic scaffold seeded with chondrogenically induced BMSCs could not successfully repair the large high-load-bearing osteochondral defects of the femoral head.