Histomorphological assessment of the germanium-doped calcium phosphate ceramics on reparative osteogenesis in rabbits with systemic osteoporosis

Abstract

Bone fractures are mostly urgent in nature, complex in pathogenetic, diagnostic and therapeutic aspects, and reparative osteogenesis is multimodal and depends on the balanced and reciprocal interaction of many factors. The results of histological studies for osteoreplacement of bone defects in rabbits with systemic osteoporosis are presented. The purpose of the work is histomorphological evaluation of bone regenerates after osteoreplacement with germanium-doped hydroxyapatite ceramics in rabbits with secondary osteoporosis. Experimental osteoporosis in rabbits (n=18) was induced by administration of 0.4% dexamethasone solution. In animals of the experimental group, bone defects were replaced with granules of hydroxyapatite ceramics doped with germanium, and in animals of the control group, they healed under a blood clot. Histological sections were made on a rotary microtome with a thickness of 5 to 10 μm and stained with Weigert's iron hematoxylin and 1% alcohol-based eosin solution (manufactured by Diapath, Italy). On the 60th day of reparative osteogenesis in the animals of the experimental group, the site of the bone defect was flled with compact bone tissue with minor remnants of spongy bone tissue. Slightly expanded Haversian canals were noted. In the control group, the defect site was flled with coarse and spongy bone tissue. Bone beams of various thicknesses with a small number of osteoblasts and single walled osteocytes were visualized. A signifcant number of osteocyte lacunae were empty due to the process of osteocyte lysis. Haversian canals are signifcantly dilated with a small number of vessels. Also, lacunae of bone tissue resorption and acellular areas were observed on histological specimens. Histomorphological assessment of bone regenerates confrms the realization of osteoconductive, osteointegrative and osteoinductive properties of calcium-phosphate ceramics doped with germanium in conditions of osteoporotic fractures of tubular bones. Keywords: systemic osteoporosis, bone fractures, cancellous and compact bone tissue, histological sections, histomorphological changes, rabbits.