Histological Comparison of Nanocomposite Multilayer Biomimetic Scaffold, A Chondral Scaffold, and Microfracture Technique to Repair Experimental Osteochondral Defects in Rats.

OBJECTIVE: We used biomimetic scaffolds, chondral scaffolds, and microfractures to repair experimentally created osteochondral defects in rat knees and then compared the results of each method. MATERIALS AND METHODS: We used a total of 56 female Wistar albino rats. The rats were grouped into 4 groups, with 14 rats each: biomimetic scaffold, chondral scaffold, microfracture, and control groups. Cylindrical full-thickness osteochondral defects 2.5 mm in diameter and 2 mm in depth were drilled into the right knees with the rats under general anesthesia. The knees of all rats were operated again after 4 weeks. Biomimetic and chondral scaffolds were classified into two groups. Microfractures 0.5 mm in diameter and 0.8 mm in depth were created in the rats of the microfracture group. The control group received no treatment. All the rats were observed for 6 weeks and then sacrificed, with samples subjected to macroscopic and histopathological examinations. RESULTS: The macroscopic and histopathological results in the biomimetic scaffold group differed significantly from those of the other treatment groups (p<0.05). When we compared the 3 treatment groups, the results of the chondral scaffold group were better than those of the microfracture group. The results of the microfracture group were somewhat better than those of the control group, but the result was not statistically significant (p>0.05). CONCLUSIONS: Nanocomposite multilayer biomimetic scaffolds were better than chondral scaffolds and microfractures when used to treat osteochondral defects.

The Effects of Corticosteroid Injection in the Healthy and Damaged Achilles Tendon Model: Histopathological and Biomechanical Experimental Study in Rats.

OBJECTIVE: To show the effects of corticosteroids on inflammatory reactions in the injured Achilles tendon in rats. MATERIAL AND METHOD: Thirty-two adult Wistar Albino rats were used in the study. The rats were divided into 4 groups. In the first group (Intact Saline), saline solution was injected to the intact Achilles tendon. In the second group (Intact Corticosteroid), corticosteroid was injected to the intact tendon. In the third group (Injured Saline), saline solution was injected to the injured Achilles tendon. In the fourth group (Injured Corticosteroid), corticosteroid was injected to the injured tendon. All groups were sacrificed on day 30 and Achilles tendons were taken and prepared for histological and biomechanical evaluation. RESULTS: According to the biomechanical test; mean load-to-failure of the Intact Saline group was significantly lower than the Intact Corticosteroid (p=0.016), Injured Saline (p=0.001) and Injured Corticosteroid) (p=0.012) groups. According to the histopathological evaluation, tenocyte mean of the Intact Saline group was statistically lower than the Injured Saline and Injured Corticosteroid groups. Tenocyte mean of the Intact Corticosteroid group was statistically significantly lower than the Injured Saline and Injured Corticosteroid groups. The ground substance mean of the Intact Saline group was significantly lower than the Injured Saline and Injured Corticosteroid groups. The ground substance mean of the Intact Corticosteroid group was significantly lower than the Injured Saline and Injured Corticosteroid groups. There was no statistically significant difference between the groups in terms of calcification. CONCLUSION: It has been found that there is biomechanical and histopathological significant benefit of intra-tendon corticosteroid administration in the experimentally generated Achilles tendon injury model.