Публикации - Наталья Кононович
Статьи: 4
Статья научная
Diaphyseal defects of canine tibia bones were replaced with bioactive cylindrical mesh implants made of Ti–6Al–4V titanium alloy. Bone−implant units were cut with a precision cutter using abrasive cutting discs (thickness, 0.76 mm; rotational speed, 2000 rpm; feed rate, 12 mm/min for sample 1 and 5 mm/min for samples 2–4). Tissues were found to suffer thermal damage at a disc feed rate of 12 mm/min; 72.6% of tissues in the projection of the defect cavity were found to be unsuitable for histological examination. At a feed rate of 5 mm/min, thermal damage or significant mechanical damage to the tissues was not observed. Thus, at the stage of preparation of samples of titanium–containing bone−implant units for the assessment of osseointegration, the degree of tissue preservation, under otherwise identical conditions, depends on the cutting tool feed rate. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
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Статья научная
A lot of research was conducted on the use of various biomaterials in orthopedic surgery. Our study investigated the effects of nanostructured calcium–phosphate coating on metallic implants introduced into the bone marrow canal. Stainless steel or titanium 2-mm wires (groups 1 and 2, respectively), and hydroxyapatite-coated stainless steel or titanium wires of the same diameter (groups 3 and 4, respectively) were introduced into the tibial bone marrow canal of 20 dogs (each group = 5 dogs). Hydroxyapatite coating was deposited on the wires with the method of microarc oxidation. Light microscopy to study histological diaphyseal transverse sections, scanning electron microscopy to study the bone marrow area around the implant and an X-ray electron probe analyzer to study the content of calcium and phosphorus were used to investigate bioactivity and osteointegration after a four weeks period. Osteointegration was also assessed by measuring wires’ pull-off strength with a sensor dynamometer. Bone formation was observed round the wires in the bone marrow canal in all the groups. Its intensity depended upon the features of wire surfaces and implant materials. Maximum percentage volume of trabecular bone was present in the bone marrow canals of group 4 dogs that corresponded to a mean of 27.1 ± 0.14%, while it was only 6.7% in group 1. The coating in groups 3 and 4 provided better bioactivity and osteointegration. Hydroxyapatite-coated titanium wires showed the highest degree of bone formation around them and greater pull-off strength. Nanostructured hydroxyapatite coating of metallic wires induces an expressed bone formation and provides osteointegration. Hydroxyapatite-coated wires could be used along with external fixation for bone repair enhancement in diaphyseal fractures, management of osteogenesis imperfecta and correction of bone deformities in phosphate diabetes.
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Статья научная
We studied osteogenesis and morphofunctional features of the anterior tibial muscle using 3-mm high-frequency automated lengthening with the Ilizarov apparatus alone and in combination with intramedullary nailing. Material and Methods. Tibia was lengthened with a round-the-clock automated distractor at a 3-mm daily rate for 10 days in 16 mongrel dogs. In group 1 (n = 8), a 1.8-mm intramedullary titanium wire coated with hydroxyapatite was introduced into the tibial canal followed by Ilizarov frame mounting and transverse osteotomy of the diaphysis. Distraction mode was 0.025 mm x 120 increments a day. In group 2 (n = 8), distraction mode was the same but nailing was not used. Bone formation and the anterior tibial muscle were studied at two time points: (1) upon distraction completion; (2) three months after the apparatus removal. Bone formation was studied radiographically. Muscle preparations were examined histologically and stereomicroscopically. Results. There was a threefold reduction in the distraction time in both groups. Consolidation took 13.83±4.02 days in group 1 and 33.7±2.4 days in group 2. Muscle macropreparations of the experimental limb in group 1 at study time points did not show significant differences from intact tissues. Muscle histostructure in both groups was characterized by activation of angiogenesis and myohistogenesis, but the volumetric density of microvessels in the lengthening phase was three times higher in group 1. Conclusion. Combined technology significantly reduces the total lengthening procedure and does not compromise limb functions. Intramedullary HA-coated wires promote faster bone formation. The muscle was able to exhibit structural adaptation and plasticity of a restitution type.
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Статья научная
In this work, the bioavailability of calcium and phosphate from the surface of rods with calcium phosphate coatings applied using different techniques was studied. It was shown that the amounts of released osteotropic elements depend on the coating technique. The differences in the bioavailability of calcium and phosphate should be taken into account in compiling the indications for use of implants coated using different application techniques. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
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