Full-thickness osteochondral defects experimental model of rats, multilayer composite nano biomimetic scaffold, scaffold and microfracture chondral comparison of methods

Background and Aim: The treatment of osteochondral defects is the most difficult problem of the orthopedics because the ability of self-treatment of articular cartilage is very low. The common aim of all treatments is to provide the formation of hyaline cartilage which resembles a healthy cartilage in terms of biological and morphological aspects. To repair osteochondral lesions, various treatment options have been developed. These treatment options involve bone marrow situmulation techniques (abrasion, debridement, drilling and microfracture), cell-based therapies (autologous chondrocyte transplantation, bone marrow stem cells), defect filling techniques (osteochondral autograft or allograft transfer), tissue engineering products (scaffold and matrix) and pharmacological agents. The microfracture method is proved to be effective in the treatment of full thickness cartilage defects. After drilling subchondral bone, biological response and blood clot are formed. This blood clot which is formed of pluripotent mesenchymal stem cells arisen from bone marrow forms the fibrous cartilage tissue. Another treatment method of the osteochondral defects is the matrix supported treatment methods that provides the cells and growth factors to be stucked in the defected area. To apply this treatment, there are some scaffold materials. Nano composite multilayer biomimetic scaffold (Maioregen, Fin-Ceramica Faenza S.p.A., Faenza?Italy) is a tissue engineering product produced for this purpose. This scaffold has a 3D composition. It is designed to treat cartilage and osteochondral defects with its type 1 collagen and hydroxyapatite composition. Another synthetic scaffold is chondral scaffold (ACS, Swissbiomed Orthopaedics AG, Zürich, Switzerland) which is formed of polyglycolic acid (PGA). Autologous serum and PGA scaffold are put together and implanted to full thickness osteochondral defect. In this experiment, it is aimed to compare the methods of biomimetic scaffold, chondral scaffold and microfracture in the treatment of ostochondral defects which are created deliberately in the knees of the rats. Materials and Methods: In this experiment, total 46 female Wistar albino rats are used. The distribution of the groups were as follows; 12 rats for biomimetic scaffold method, 10 rats for chondral scaffold method, 10 rats for microfracture method and 14 rats as the control group. Cylindrical full thickness osteochondral defects were 2,5 mm in diameter and 2 mm in depth created with drill on the right knees of the rats. The knees of all the rats were operated again after 4 weeks. Biomimetic scaffold method is applied to the 12 rats in the first group. Chondral scaffold method is applied after microfracture process to the 10 rats in the second group. 0,5 mm in diameter and 0,8 mm in depth was applied to the 10 rats in the third group. No treatment was applied to the 14 rats in the control group. All the rats were observed for 6 weeks and at the end of the sixth week, all the rats were sacrificed and the obtained preparates were taken for macroscopic and histopathologic examination. Results: The macroscopic and histopathologic results of the biomimetic scaffold method treatment group were compared to the chondral scaffold method, microfracture treatment group and control group and it is observed that there is a statistically significent difference between them (p<0.05). When we compare other three treatment groups, we concluded that the results of the chondral scaffold group is superior to the result of the microfracture group, the result of the microfracture group is superior to the result of the control group quantitatively; ? but there isn?t not statistically difference between these groups (p>0.05). Conclusion: The results of nano composite multilayer biomimetic scaffold in the treatment of osteochondral lesions were better than the results of chondral scaffold and microfracture treatments. Key Words: Osteochondral defect, biomimetic scaffold, chondral scaffold, microfracture, rat