Chornyi V. Experimental and clinical substantiation of the use of carbon composite material for osteosynthesis

The thesis was performed on the basis of the Zaporizhzhia Regional Clinical Hospital and the Zaporizhia State Medical and Pharmaceutical University during 2020-2024. Treatment of fractures, despite the significant progress of modern technologies, has a number of unresolved or debatable issues related to consolidation violations and not always satisfactory functional results of treatment. Osteosynthesis is a separate item on the list of problematic issues of fracture treatment. There are a variety of fixation methods, each with advantages, disadvantages, and specific uses. In addition, there remains, and cannot be eliminated, the contradiction between the mechanical parameters of bone tissue and the rigidity of the metal fixator, which is several times higher than bone. Attempts to improve the results of osteosynthesis and make it more reliable led to the use of new materials for connecting bone fragments. The purpose of this work was to improve the results of treatment of patients with fractures of the proximal part of the humerus by experimentally and clinically substantiating the use of a bone plate made of carbon composite material, based on an experimental and clinical study. The thesis is based on the results of own experimental research and analys of the results of observations of operative treatment, clinical and instrumental methods of examining patients. For the first time, in an experiment on laboratory animals (rats) based on histo-morphological indicators, new data on the effect of carbon composite material on bone and soft tissues were obtained, and the possibility of its use for osteosynthesis was proven. A new non-x-ray contrast-enhanced bone plate made of carbon composite material was developed for osteosynthesis of fractures of the proximal part of the humerus with angular stability of screws. As a result of a direct experiment, the sufficient stiffness of the blocked screws in the developed plate was determined, which is 660 mPa, which exceeds the stress in the cancellous bone (150 mPa) by 4.4 times, which is sufficient for stable osteosynthesis, and the modeling of the stiffness of osteosynthesis using the finite element method showed that stresses in the "bone-implant" system made of carbon composite material are much smaller than the limits of strength of it and bone tissue. A comparative analysis of the results proved that the function of the upper limb was restored more quickly during osteosynthesis with a plate made of carbon material. The use of a bone plate made of non-X-ray contrast carbon composite made it possible to reduce the time of surgical intervention by 11.6% due to the convenient performance of radiological control during surgical intervention. The results of the work made it possible to establish the feasibility of using the plate for osseous osteosynthesis of the proximal part of the humerus and its further implementation in clinical practice.