Evaluation of the radiographic picture in the area of a bone defect filled with osteoplastic material based on hydroxyapatite

Reparative regeneration of bone tissue occurs by activating complex biological processes. In some cases, there is a need to stimulate these processes using biomaterials. One of the suitable biomaterials that has a stimulating effect on osteogenesis is hydroxypatite doped with silicate ions (silicate-substituted hydroxyapatite). Analogues of this biomaterial are used to replace bone tissue in clinical practice and show relatively high efficiency of use, which makes it possible to improve the structure by introducing various components into it. Thus, the osteoplastic material we proposed is being studied for the efficiency of use and evaluation of stimulation of reparative regeneration. Preclinical study was conducted on the basis of the Institute of Biomedical and Biological Sciences of the Omsk State Agrarian University named after P.A. Stolypin. In vivo studies were conducted using granules of silicate-substituted hydroxyapatite in a ratio of 50/50 to wollastonite with a diameter of 0.5 mm. The objects of the study were laboratory rabbits with models of bone defects performed in the form of an induced fracture of the proximal third of the tibia diaphysis with subsequent fixation by transosseous introduction of pins. Groups of animals were formed: experimental with the introduction of silicate-substituted hydroxyapatite granules into the defect cavity and control without defect replenishment. To assess the course of reparative regeneration and osteogenesis, an X-ray examination was performed on the 7th and 21st days, and an assessment of the clinical condition of the animals was carried out for 30 days. According to the X-ray images obtained on the 7th day, the following changes were revealed: the experimental group of animals showed signs of new bone tissue formation, as well as full contact of the defect cavity with the studied osteoplastic material, while in animals from the control group, clearly defined edges of the defect zone are visualized without signs of bone regenerate formation. Repeated X-ray examination on the 21st day showed pronounced signs of bone callus formation in the experimental group, while in the control group the regeneration process was slower, the formation of bone regenerate was less pronounced, and initial signs of fibrocartilaginous bone callus formation were noted. The data obtained during the study suggest that silicate-substituted hydroxyapatite has a stimulating effect on reparative regeneration and requires further study.