Healing of osteochondral defects in canine knee with avocado/soybean unsaponifiables: a morphometric comparative analysis

Abstract

Objectives: This study aims to determine the effects of avocado/soybean unsaponifiables (ASU) on healing in a canine osteochondral defect model. Materials and methods: Fourteen dogs were included in the study and randomly divided into two groups. Two osteochondral defects were produced in the lateral aspect of the trochlear groove of the knee joint. The treatment group (group 1; n=7) was given 300 mg ASU capsules every three days whereas the control group (group 2; n=7) was given a normal diet. Animals were then allowed to ambulate normally until euthanasia at 15 weeks. The knees were dissected and the trochlear grooves with defects were removed for pathological examination. The amount of regenerated tissue was determined quantitatively using image analysis and the tissue content was evaluated semi-quantitatively using Safranin-O and Masson trichrome histochemical stains. Transforming growth factor beta (TGF-beta) increase was evaluated semi-quantitatively with immunohistochemical staining methods. Results: Morphometric analysis revealed a significantly more immature repair tissue in group 1 (p<0.002). Both collagen and chondral tissue content of the regenerated tissue were significantly increased in group 1 (p<0.002). Compared to that in group 2, cartilage tissue in group 1 showed a much more marked immunostaining reaction of TGF-beta. Conclusion: Avocado/soybean unsaponifiables treatment stimulates the healing of the osteochondral defects in canine knee possibly by increasing TGF-beta in the tissues.