[Value of osteo-chondral paste autologous transplantation in experimental cartilage defects reconstruction. Part III--Microscopic analysis of reconstructed cartilage thickness and surface regularity].

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 thickness and surface regularity after osteochondral paste transplantation. MATERIAL AND METHODS: Full thickness defect (IV(o)--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 trait 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 osteochondral 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.