RESULTS of MORPHOLOGICAL ANALYSIS of ANIMAL HARD TISSUES IN NORMAL AND SIMULATED OSTEOPOROSIS USING A NON-INVASIVE COMPUTED MICROTOMOGRAPHY TECHNIQUE

Abstract

Introduction. X-ray microtomography is a non-destructive method of microstructural analysis, which has a high level of detail and allows the possibility of assessing the internal architecture of organs and tissues using 3D-analysis[1]. The specifics of working with such equipment can be divided into in vivo and in vitro, i.e. working with live laboratory animals (mice, rats, rabbits) under anesthesia or studying organs and tissues separated from the animal [2].

The aim of the work was to study the microstructure of sheep bone tissues in normal and simulated osteoporosis using computed microtomography.

Materials and methods. We performed microCT analysis of different sheep bones in normal and experimental osteoporosis. Bone tissue of the jaw, iliac and femur, and teeth were collected from control and experimental animals. Bone tissue samples were fixed in 10% buffered formalin. X-ray microCT scanner Skyscan 1176 (BrukermicroCT, Belgium) and software Skyscan 1176 control program (10.0.0.0), Nrecon (1.7.4.2), DataViewer (1.5.6.2), CT-analyser (1.18.4.0), CTvox (3.3.0r1403) were used to scan and process materials.

Results. MicroCT examination and 3D-imaging confirmed the elimination of trabeculae in the metaphyseal region of the femur in sheep with experimental osteoporosis from the centre to the periphery; in addition, 3D-analysis showed a 15.1% decrease in bone percentage, a 7.8% decrease in bone mineral density, and an increase in Tb. Sp. (trabecular separation), Tb. Pf. (trabecular pattern factor) and SMI (structure model index) by 30.2%, 20.8% and 23.6%, respectively, and a decrease in Tb.N. (trabecular number) index by 18.6%, indicating calcium washout, decreased trabecular connectivity and a transition from a lamellar to a rod-like architecture. Similar changes were found in the 3D-analysis of the jaw bone tissue. Thus, a decrease of 18.9% in mineral density was found, as well as a significant increase of 11.58 and 2.21 in the indices, particularly Tb. Pf. and SMI. 3D-analysis of iliac microtomography also indicates a simulation of osteoporosis, as evidenced by a significant increase in the main indices characterising the development of this pathology.

Conclusions. The obtained results not only objectively testify to the development of osteoporosis in the experimental animals, but also indicate signs of the adaptation-compensatory reactions of the body, characterized by appearance of large single trabeculae in the metaphysis of the femur as well as by not expressed reduction of bone mineral density and bone tissue area.