冷冻保存同种异体软骨移植修复膝关节软骨缺损

背景:采用传统方法冻存后,关节软骨细胞存活率低,且软骨表层与深层的软骨细胞存活率差别较大,移植物易发生退行性变,导致手术失败.目的:经打孔梯度降温冻存膝关节软骨后并行异体移植,观察打孔梯度降温冻存对兔关节软骨的影响.方法:自2月龄新西兰白兔膝关节股骨膑面取骨软骨移植物,随机分为3组:实验组在软骨面以3 mm×3 mm矩阵打孔,梯度降温冷冻保存.以非打孔经梯度降温冷冻保存组、非打孔超低温冷冻保存组为对照.复温后移植到成年新西兰白兔相应膝关节缺损部位,观察各组移植物大体形态学、组织化学、免疫组织化学染色效果的差别.结果与结论:实验组、非打孔经梯度降温冷冻保存组大体形态学、组织化学、免疫组织化学染色效果均明显优于非打孔超低温冷冻保存组.实验组与非打孔经梯度降温冷冻保存组效果差别不明显,但实验组明显加强了对中间层软骨组织的保护程度.提示关节软骨的梯度降温冷冻保存效果优于快速降温冷冻保存;关节软骨打孔冷冻保存对深层细胞有一定的保护作用,提高了软骨细胞存活率,延缓了移植软骨组织的退变过程.

Repair of knee articular cartilage defects using cryopreserved osteochondral allografts

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.