Berezhnoy E. Structure, growth and formation of the long bones under effect of hydroxyapatite and demineralized bone matrix implants.

The dissertation is dedicated to studying morphogenesis of the skeletal bones in adult rats after implantation of the hydroxyapatite ceramics, demineralized bone matrix and their 2:1 combination into the proximal part of the tibia diaphysis. Using modern morphological research methods we proved that 2:1 combination of hydroxyapatite and demineralized bone matrix implants with ceramic particles smaller than 63 µm leads to marked bone growth rate retardation, narrowing of the proximal epiphyseal cartilages mainly within the osteogenesis zone, narrowing of both external and internal bone lamellae of the cortical bone, widening of osteon canal diameter. Alongside with this, within implantation area, we observed acceleration of resorbtion of the ceramic particles in presence of the demineralized bone matrix and induction of nucleation and formation of new elementary cells of the bone hydroxyapatite. We also described dynamic changes of microhardness of the cancellous bone in the proximal epiphysis of the tibia under combined effect of the hydroxyapatite and demineralized bone matrix implants implanted into the proximal part of tibia diaphysis.