Treatment of knee osteochondral defectstwo-layer synthetic to be usedevaluation of the effectiveness of scaffold-experimental study-

Objective: To compare double-layer and single-layer scaffolds produced in a laboratory environment with tissues with cartilage tissue healing by applying it to osteochondral defects created by the microfracture methods, with and without cells. Material and Method: A total of 70 Wester Albino male rats with an average age of 3 months were used in the study. Experimental animals were divided into 5 groups with 14 rats in each group. After creating an osteochondral defect with a diameter of 2 mm and a depth of 1 mm in the right femoral trochlear region in each group, microfracture was performed with a 0.8 mm Kirschner wire. After that, a special scaffold was applied to each group, except the control group. 6 rats from each group were sacrificed in the 4th week to evaluate the early recovery, and in the 8th week to evaluate the mid-term recovery after surgery. By using at least 6 subjects in the study, the power analysis result was 95%. The DNA similarity of the Wester Albino type experimental animals used shown as 99% strengthened the power analysis of our study. The groups were sacrificed by injection of high-dose anesthetic according to the time of sacrification. Materials obtained after removal of the right distal femur bones of the rats were fixed in 10% buffered formalin for 1 week. After fixation, the materials were decalcified in a solution prepared from 50% formic acid and 20% sodium citrate solutions. After decalcification, bone tissue samples were embedded in paraffin blocks and 5-7 μm thick sections cut with a microtome were taken on slides. These sections were stained with Hematoxylin-Eosin and Masson's Tricrom staining method and evaluated according to Modified Mankin and O'Driscol scales. Variables were examined with the Kolmogorov Smirnov test and Histogram, and the Kruskal-Wallis test was used to compare the continuous variables that did not show normal distribution in 3 or more groups. When a significant difference is obtained as a result of the Kruskal-Wallis test, the Mann-Whitney test with Bonferroni correction was used to determine the groups causing the difference.IBM SPSS.23 program was used in all analyzes and p< 0.05 value was accepted as the level of significance. Results: The cellular use of scaffolds showed a positive effect on morphological field changes. When the scaffold layers were compared, a minimal increase in the morphological area score of the double-layered scaffold application was observed compared to the single-layered scaffold, both with and without cells. In the surface regularity, better results were obtained in the double layered cellular scaffold group compared to the control group. The highest scores of adjacent attachment were obtained with the double-layered cell-free scaffold during the acute recovery period. When the acute period results of the cell population are examined; Contrary to expectations, very low values were found in the cellular double and single layered scaffold groups compared to the control group. In cell population assessment, the best results in the acute and mid-term were found in the control group. When the acute period results of cartilage plug quality were examined, the efficiency of the double-layered cell-free scaffold was found to be significantly higher. However, this efficiency was not reflected in the mid-term results. When the state of the matrix is examined in recovery; During the whole recovery period, the closest score to the control group was found in the double-layered cellular scaffold group, and it was found that the double-layered scaffold forms a better matrix than the single-layered scaffold. In all-term results of structural integrity, it was observed that the structural integrity of the double layered cellular scaffold was better in the healed cartilage tissue. It has been observed that the double-layered scaffold is a more effective treatment method in wound filling. The efficiency of the double-layered scaffold in osteochondral attachment was found to be significantly higher. The efficiency of the double-layered scaffold in adjacent attachment was detected in the acute period, and it was observed that this efficiency continued in the mid-term with cell reinforcement. When the cluster distribution is examined, while the double-layer scaffold had a good efficacy in the acute phase results, the effectiveness of medium-term single-layered scaffold has increased significantly. When subchondral bone healing is examined, while double-layered scaffold activity was good in the acute period, single-layered scaffold activity increased significantly in the mid-term. Conclusion: Considering the total score of Mankin scoring; While the double-layered scaffold was found to be more effective in acute recovery, no significant difference was found between the groups in the mid-term results. In the long-term results, the most effective treatment was the microfracture performed control group. Considering the total score of O'Driscol scoring; While the double-layered scaffold was found to be more effective in acute healing, much better results were obtained with the cellular application of this scaffold. These results were also found in the mid-term results. Double-layered scaffold can be considered as an alternative to microfracture treatment. Generally, the closest healing parameters to the microfracture group, which is the control group, were obtained in the cellular double-layered scaffold group. Recovering with the microfracture method in osteochondral cartilage defects is still up to date. Better results can be obtained histologically with various scaffolds produced by cartilage tissue engineering.