INFLUENCE OF MESENCHYMAL STEM CELLS AND FIBRIN RICH PLASMA MEMBRANE TO REPAIR OSTEOCHONDRAL DEFECTS IN THE RABBIT KNEE

Background Bone marrow-derived mesenchymal stromal cells (BMMSC) can be expanded ex vivo, they have the ability to regenerate cartilage for accelerated knee recovery as already demonstrated in several studies. This study evaluated the influence BMMSC and fibrin-rich plasma membrane (FRPM) to repair osteochondral defects in the rabbit knee. Methods We evaluated 51 New Zealand male and female rabbits of average weight 4 kg and seven months. The animals were randomly separated into five groups: Group 0 (immediate control): 7 animals submitted to removal of cartilaginous flap until exposure of the subchondral bone of femoral trochlea, by abrasion sulcoplasty of 0.3 (width) x 0,9 (length) cm; Group A (control 60 days): 11 animals submitted to the same procedure as Group 0; Group B (stem cells): 11 animals submitted to the same Group 0 procedure and 5 × 106 BMMSC transplantation at the lesion site; Group C (fibrin-rich plasma membrane): 11 animals submitted to the same procedure of Group 0 and application of MPRF on the lesion and Group D (BMMSC + FRPM): 11 animals submitted to the same procedure of Group 0 and transplantation of 5 × 106 of BMMSC at the site of injury, covered with FRPM. Group 0 animals were submitted to euthanasia shortly after removal of the cartilaginous flap, while the animals of Groups A, B, C and D were submitted to euthanasia after 60 days of cartilage flap removal and established therapy in Groups B, C and D. Results It evaluated by morphometry and histological analysis, if there was a decrease in lesion length and an increase in the density of chondrocytes and chondroblasts in the regenerated tissue and adjacent tissue. In the present study, it was observed that the association of the treatments was superior to the isolated treatments regarding the reduction of the iatrogenic lesion. In all groups the chondrocyte density of both regenerated tissue and adjacent tissue was greater than the density observed in Group 0, whereas the chondroblasts density in all groups was lower than the density observed in Group 0. Even without statistical difference, the association of BMMSC and FRPM presented a more uniform histological evaluation. Conclusion The association of BMMSC and FRPM was more efficient in decreasing the iatrogenic injury than the natural repair and their isolated administration.