Bodnya O. Clinical and biomechanical justification of minimally invasive osteosynthesis in the treatment of posterior foot bone fractures and their consequences

The dissertation is devoted to the problem of improving the outcomes of treatment of posterior foot bone fractures and is based on the results of the examination of 461 victims, of which 189 patients were treated conservatively, minimally invasive osteosynthesis was performed according to the developed methods in 250 patients and subastragalar arthrodesis was used in 22 cases for the consequences of the calcaneal bone fractures. A comparative analysis of the functional results of treatment with different methods was carried out in two clinical groups of patients who had contraindications for open reposition and internal fixation according to AO / ASIF. A retrospective evaluation of the treatment materials in the comparison group revealed the factors and their influence on the adverse outcomes. Based on the obtained data, a minimally invasive treatment strategy was developed and the technique of minimally invasive osteosynthesis was improved. In the experiment, a biomechanical substantiation of the possibility of using transosseous osteosynthesis in intra-articular fractures of the calcaneal and neck of the talus bones is given. Based on the mathematical calculation, a comparative analysis of the rigidity of fixation in various structures for osteosynthesis of the bones forming the subastragalar joint is carried out. The analysis of the obtained data showed that the stability of the external fixation of the damaged bones of the posterior part of the foot is no less effective to the epibone and intraosseous fixators. When performing surgical interventions in patients with the consequences of fractures of the calcaneus, a modified technique of corrective subastragalar arthrodesis was used. Innovative technologies are proposed in the form of an axial load limiter and a computer program that allows determining the optimal width of the wedge base during osteotomy of the calcaneus body and improving the quality of eliminating deformation in the sagittal plane. The comparative analysis showed that the positive results of treatment in the study group were 81.6 % of cases, in the comparison group – 30.16 %. It was found that unfavorable treatment outcomes are caused by errors and developed complications, mainly (69.47 %) with conservative treatment.