None of the methods of osteosynthesis provides the consolidation of bone fragments which have lost contact with soft tissues. It makes extremely difficult treating of this type fractures. Bone defect between the fragments and absence of a primary biological matrix complicates revascularization, causes long-term life of the connective tissue and cells of cartilaginous phenotype in the fracture zone. It is leads to a long-term consolidation of the fracture. Composites of hydroxyapatite and calcium phosphates are considered as bioactive and therefore the most promising for bone defects replacing. The aim of this investigation was clinical, radiological and hematological evaluation using of silicon-doped ceramics for fragmented bone fractures in dogs. For study was chosen dogs with accidental fragmented fractures of tubular bones which treated by extracortical osteosynthesis method. Animal was divided into two groups. A bone defects were filled with ceramics (GTlKg-3) for experimental animal group (n = 7), while no filling of bone defects in control animal group(n = 7) was performed. Protocol of anesthesia included medetomidine, butorphanol tartrate and epidural anesthesia with 2 % lidocaine solution. Animals of the control group began to lean on the injured limb from the 12–15th day after surgery, while the animal of research group from the 8-9th day. Complete limb repair in dogs of the control group occurred on the 38–42th day, but such period for experimental group animals was shorter – 25–27th day after the osteosynthesis. X-ray investigation (60th day) of experimental group dogs showed new formed bone tissue with osteosclerotic zones without a periosteal reaction, bone tissue, with a normal view of the epiphyseal areas and the bone marrow cavity. This is evidence of localized reparative osteogenesis (within bone trauma only), and completed fracture consolidation. At the same time in cases of the control group we found lower X-ray density of new bone, periosteum was thickened with excessive proliferation of the endosteum, especially below the site of bone injury. Thus, in case the absence of hydroxyapatite matrix in bone defects there were compensatory increasing proliferation of periosteum and endoosteum. Fragmented fractures of tubular bones in dogs have occurred by erythrocytopenia, that quickly disappear due to the reparative osteogenesis in dog of experimental group. These animals have had leukocytosis increasing due to the first three days after osteosynthesis as a reaction to the implantation of a calcium-phosphorus composite material. Dogs of control group have had second wave of leukocytosis increasing on forty-second day associated with elongated remodeling process. Areparative osteogenesis can be accelerated in 1.5 times in case of replacement of bone defects with silicon doped hydroxyapatite ceramics. It is possibility realized thru moderate reduction of active phase of inflammation and acceleration of proliferative phase, mainly from endosteum side with early mineralization of bone regenerate. The dynamics of hematology parameters is a typical for the tubular bone consolidation that indicates about moderate inflammation and demonstrate biological tolerance of silicon-doped hydroxyapatite ceramics.

Among the entire public of fractures of long bones, more complications of reparative osteogenesis occur fragmental fractures. Their significant defects, which arise as a result of the removal of non-viable fragments, cause disturbances in local hemodynamics and microcirculation and loss of osteoconduction in the area of injury, lead to a loss of the reparative potential of bone tissue in the defect zone, and the methods of osteosynthesis do not provide restoration of osteoconduction and do not have osteointegration properties. For osteosis, a number of composite materials have been proposed, among which ceramics based on calcium phosphates are considered the most promising, which is confirmed by previous clinical, radiological and histomorphological studies. The aim of the study is to determine the dynamics of the blood levels of TGF-β and interleukins IL-1β and IL-10 for osteosis replacement of splinter bone fractures in dogs with calcium phosphate ceramics doped with silicon. Material and research methods: a control (n = 7) and research group (n = 7) dogs with accidental splinter fractures of long bones were formed. In both groups, extracortical osteosynthesis was performed with a support plate from an unalloyed titanium alloy. In the control group, bone defects were left to heal under a blood clot, and in the experimental group they were replaced with ceramics (GTlKg-3). Blood samples were taken after trauma no later than on the 48th day, and on the third, twelfth, twenty-first, forty-second and 60th days after surgical treatment. The enzyme immunoassay was used to determine the serum levels of interleukins IL-1β and IL-10 and transforming growth factor (TGF-β) тhat for a bureta reaction is a bit of a home-made bottle. The study results showed an anti-inflammatory cytokine profile with physiological norms in dogs. In case of bone injury, it becomes pro-inflammatory in nature, triggers the process of osteoresorption in the fracture area. At the same time, during reparative osteogenesis after extracortical osteosynthesis for splinter fractures, proinflammatory cytokinemia acquires a permanent character with a peak on the forty-second day, and this implies inhibition of metaplasia of cartilaginous regenerate into bone, that is, it slows down the consolidation of the fracture. However, in the case of osteosis with ceramics, the level of pro-inflammatory cytokinemia is significantly lower and continues during the first 12 days with a peak on the third day, during the inflammatory-resorptive stage. However, the key in understanding the effectiveness of osteosis was the dynamics of TGF-β, which showed its biphasic hyperreactivity in control animals, while in experimental animals, its balanced production was noted. Conclusion. Osteosis replacement of bone defects in long tubular bones in dogs with hydroxyapatite with β-tricalcium phosphate ceramics doped with silicon is accompanied by moderate cytokinemia in accordance with the course of the inflammatory-resorptive stage and the phase of remodeling with a peak of induction of transforming growth factor during the period of active osteogenesis forty-second course of reparative osteogenesis.