Changes in Calculated Indices of Biochemical Indicators of Blood Serum of Rats of Different Age after Filling the Defect in the Metaphysis of the Femur Bone with Allogeneous Bone Implants

The purpose of the study was to analyze estimated biochemical parameters of mineralization in the blood serum of laboratory rats, to evaluate the course of metabolic processes in bone tissue after filling the defect in the metaphysis of the femur with allogeneic bone implants. Materials and methods. The work uses a model of creating a transcortical defect in the femur metaphysis of a critical size in white rats. Indicators of mineralization of bone tissue in the blood serum of white rats were studied: the content of total protein, calcium, alkaline and acid phosphatase activity, the ratio of alkaline to acid phosphatase activity, as well as the degree of mineralization, were calculated. Based on the results of a biochemical study of the blood serum of 3- and 12-month-old experimental rats with a critical size defect in the metaphysis of the femur with filling of the defect with bone alloimplants and without filling, it was determined that the introduction of alloimplants into the defect zone of the femoral metaphysis led to an acceleration of the course of mineralization of bone tissue in experimental rats of both age groups. Results and discussion. The introduction of alloimplants into the defect zone of the femoral metaphysis led to an acceleration of bone tissue mineralization in experimental rats of both age groups. Thus, on the 28th day when alloimplants were introduced, the ratio of alkaline and acid phosphatase activity in 3-month-old rats was by 1.26 times higher than the corresponding indicator in experimental animals without defect filling (p=0.008), as well as by 1.34 times – the level indicator on the 14th day. Both in the conditions of using alloimplants to fill the defect, and in the case of an unfilled defect for both age groups, the maximum manifestation of markers of bone tissue formation was recorded on the 28th day of the experiment, and the values of this maximum were higher in the group of animals with alloimplants. If in the case of an unfilled defect on the 90th day there was a sharp decrease in the analyzed indicators, which indicates the actual cessation of the mineralization process, then under the conditions of using alloimplants the decrease was less pronounced, which is a sign of the continuation of these processes. In 3-month-old animals with an unfilled defect, the stages of mineralization processes passed faster and these processes were more developed at the same time. The ratio between the activity of alkaline phosphatase and acid phosphatase in blood serum has proven to be a more informative and sensitive indicator than the degree of mineralization. Conclusion. Treatment of experimental rats with a critical size defect in the metaphysis of the femur with alloimplants leads to the detection of biochemical signs of activation of regenerative processes in them, but this activation quickly decreases in intensity, is insufficient and requires additional strengthening due to certain external influences