Repair of knee articular cartilage defects using cryopreserved osteochondral allografts / 中国组织工程研究

ABSTRACT

BACKGROUND: The survival rate of articular chondrocytes is low after traditional cryopreservation,and great differences existed in chondrocytes from surface layer and deep layer,which easily result in graft degeneration and lead to surgery failure.OBJECTIVE: To establish rabbit allograft models of graded frozen articular cartilages with holes made before cryopreservation and to observe the effect of holed cryopreservation on the rabbit articular cartilages.METHODS: Osteochondral plugs taken aseptically from 2 months old rabbits were randomly divided into 3 groups the experimental group,making holes(3 mm× 3 mm)in articular cartilages and graded freezing; non-hole graded freezing group,non-making holes and graded freezing; cryopreservation group non-making holes and rapid freezing.The grafts were thawed and transplanted into the relevant articular cartilage defects of recipient rabbits.The grafts differences were observed by gross observation,histochemistry and immunohistochemistry staining.RESULTS AND CONCLUSION: The gross observation,histochemistry and immunohistochemistry staining of the experimental group were superior to the cryopreservation group.Though there were no significant differences between the non-hole graded freezing group and the experimental group,however,the experimental group enhanced the protective effect on cartilage tissue in the middle layer.The graded cryopreservation of articular cartilage gets an advantage over rapid cryopreservation.And the articular cartilage with holes could be preserved successfully in graded cryopreservation,which assures the survival and function of chondrocytes and slows down degrading process of the articular cartilage tissue after thawed and transplanted.