Experimental modeling of deforming osteoarthrosis of the knee in small rodents

Abstract

The results of experimental work on modeling deforming osteoarthrosis of the knee joint in small rodents are presented. The pathogenetic basis of this process is a violation of the blood supply and the distribution of physiological load in the joint. Variants of rigid and non-rigid limb immobilization systems are proposed. The results of morphofunctional assessment are given, indicating a violation of the anatomical and histological structure of the metaphysis, pineal gland and metaepiphysis of the femur and tibia. The leading role in the development of deforming osteoarthritis of the knee belongs to the violation of the physiological distribution of the dynamic load on the joint, and the most vulnerable to the progression of this process are subchondral structures. Violation of regional blood circulation of the lower limb of the animal was achieved by crossing the femoral artery. Limb immobilization was carried out for 4 weeks. The results were evaluated by the severity of changes in the morphological structure of the operated joints and radiographic examination. The high mitotic activity of cellular elements, revealed as a result of histological examination in all groups of animals, indicates the rapid formation of vascular collaterals in rats. It was noted that with non-rigid immobilization of the joint with a plaster cast, the cartilaginous tissue of the articular surface becomes thinner, while the subchondral structures change slightly. With severe immobilization of the joint in the external fixation apparatus, significant changes are revealed precisely in the structure of subchondral structures. In animals subjected to a two-week rehabilitation period after dismantling the external fixation apparatus, a further progression of the pathological process was noted. Thus, with severe immobilization of the limb in the experiment, it was possible to obtain a stable joint deformation corresponding to the 3rd clinical and radiological stage of osteoarthritis.