Treatment of rabbit growth plate injuries with an autologous tissue-engineered composite. An experimental study

Tissue engineering has become a promising way of treating growth plate injuries. In this study, we attempted investigating the role of the autologous tissue-engineered composite in the treatment of rabbit growth plate injuries. Growth plate chondrocytes from iliac crest epiphyseal cartilage of immature New Zealand rabbits were obtained by dissection and sequential digestion with 0.2% collagenase (type II). After proliferating in monolayer culture in vitro for 3 weeks, the cells were harvested and seeded onto the demineralized bone matrix (DBM) scaffold to construct the composite. The autologous tissue-engineered composites were finally implanted into the proximal right tibia defects of the growth plate created in 12 rabbits (group A underwent the operation after obtaining chondrocytes 3 weeks beforehand), another 12 rabbits were implanted with only the DBM scaffold (group B), and the defects in group C (12 rabbits) were not implanted. The left tibias of all animals were left undone as the normal control. Two weeks after the operation, severe shortness and angulation deformity of the right tibia evaluated by X-ray were gradually observed in groups B and C. However, there were no obvious changes in group A and there were significant differences between group A and groups B and C (p < 0.05) at the 4-, 8-, and 16-weeks time points. 16 weeks after operation, histological examination revealed that the defects of the right tibias in group A had restored to almost the normal columnar structure of the growth plate. The results demonstrate that tissue-engineered composite established by combination of autologous growth plate chondrocytes and DBM can prevent the formation of a bone bridge and restore the growth of damaged growth plate.