Lack of cartilage vascularization is the reason of its low regenerative potential. The aim of this part of the study was microscopic evaluation of repair tissue thickness and its integration with surrounding cartilage, after autologous chondrocyte transplantation.
Material and methods: Repair of partial thickness cartilage defect (ICRS III(o) grade) on distal femur joint surface was evaluated (25 adolescent rabbits). Procedures were performed in two groups: I--autologous chondrocyte transplantation under periosteal flap, II--periosteal graft. Chondrocytes were isolated from the cartilage specimens by enzymatic digestion and cultured in vitro. The follow-up periods were established at 4, 8, 12 weeks. Repair tissue was evaluated microscopically according to modified O'Driscoll scale.
Results: In group I, 8 weeks after the procedure most of defects were filled with the newly formed tissue almost completely. Regenerate thickness after 4 and 12 weeks usually exceeded 1/2 of surrounding cartilage. In group II, 8 weeks after the procedure regenerate thickness amounted to at least 1/2 of surrounding cartilage, but 4- and 12-week observation revealed the decreased repair tissue thickness. In group I, 4 weeks after the procedure regenerative tissue was well integrated with surrounding cartilage, and this trait still gradually increased with time. In group II, there was partial integration or no integration of repair tissue with surrounding cartilage.
Conclusion: Obtained results indicate, that tissue formed after autologous chondrocyte transplantation with use of periosteal flap was better in its thickness and integration with surrounding cartilage, as compared to tissue formed after use of periosteum alone. Autologous chondrocyte transplantation can not guarantee complete filling of the cartilage defect with the graft tissue and full integration with surrounding cartilage, without three-dimensional scaffold application.