Reimplantation of growth plate chondrocyte cultures in central growth plate defects: Part II. Surgical experimentation in rabbits

An original and reliable technique to culture growth plate chondrocytes was developed to obtain an abundant amount of mature and functional chondrocyt es. Growth plates were provided from the epiphysis of 3-week-old rabbits. I solation of the chondrocytes was optimized by the use of trypsin and collag enase. The culture was realized according to the following conditions: seed ing at 20,000 or 30,000/cm(2) on type I collagen substrate and in Ham F-12 medium without a supplementation of glucose or growth factors. After 7 days of culture, the implantation was to be carried out. Different implantation substrates were evaluated in vivo. Agar turned out to be the only substrat e to provide strong and healthy chondrocytes 21 days after the grafting. Th en implantation was tested on large iliac resections in rabbits to check wh ether an enchodral ossification occurred with the culture, Poor results wer e obtained because of an early disappearance of the cultured chondrocytes. In an other experimentation, the culture was implanted into surgically crea ted defects in the growth plate area. In this case, the culture did produce an epiphysiodesis. However, the 6-week postoperative histological examinat ion showed that the implant remained viable, continued to maintain a proteo glycanrich matrix, and began to organize in ordered columns of mature chond rocytes.