[Value of autologous transplantation of osteo-chondral paste in reconstruction of experimental cartilage defects. Part II. Microscopic analysis of integration with surrounding cartilage, structural integrity and subchondral bone reconstruction in repair tissue].

INTRODUCTION: A limited ability of the cartilage to heal after trauma was the reason to start research on new methods concerning better cartilage reconstruction. The aim of the study was evaluation of repair tissue integration with surrounding cartilage, its structural integrity and subchondral bone reconstruction after osteo-chondral paste transplantation. MATERIAL AND METHODS: Full thickness defect (IV degree--ICRS scale) on distal rabbit femur joint surface was made. Three groups were specified: A--defect with paste graft (cartilage and contiguous bone collected from joint surface, crushed into homogenous paste; B--defect with the paste graft covered with periosteum; C--defect left unfilled. The follow-up periods were established at 4, 8, 12 weeks. Repair tissue was evaluated microscopically according to modified O'Driscoll scale. RESULTS: Newly formed tissue was well integrated with surrounding cartilage in group A (paste graft). That trade of repair tissue in group A was much better than in other groups, especially in late observations. Structural integrity of tissue filling the defect was similar to integrity of normal cartilage in groups A and C, but tissue formed in group C didn't represent a hyaline-like cartilage character. In all the examined groups reconstruction of subchondral bone exhibited similar rate. 12 weeks from the procedure, around 80% of subchondral bone was rebuilt. The obtained results indicate, that osteo-chondral paste autologous transplantation in cartilage defects treatment effects with forming well integrated (structurally and with surrounding cartilage) cartilage tissue, of almost complete subchondral bone rebuilding.