Аналіз напружено-деформованого стану моделей вертлюгових переломів стегнової кістки типу 5 за Евансом після ендопротезування

Aim of research: to develop the mathematical model of trochanteric fractures of a femur by Evans’ classification and to use it for studying main directions of loading the proximal femur section at endoprosthesis with the additional fixation of fragments by needles.Materials and methods of research. For solving the set task, we developed the mathematical models of a femur with trochanteric fractures of different types by Evans’ classification. We modeled trochanteric fractures of a femoral bone of 5 type by Evans, using the standard endoprosthesis, fixing separate fragments and model endoprosthesis of the offered construction.Results. The loading results were obtained. At using the endoprosthesis, the zone of maximal loads covers its neck and is 97,6 МPа on its upper surface and 118,4 МPа – on the low one. The least loaded zone is the little trochanter area, where the load value is only 1,0 МPа, and adjacent zones, where tensions don’t exceed the value 10,0 МPа. The diaphyseal part of a femur is characterized with the tension values at the level from 21,1 to 23,8 МPа. At using the model system, the most tension level (88,2 МPа) is observed in the upper part of the neck. Tensions in other control points are distributed evenly and don’t exceed the value 25,4 МPа by absolute values in the femoral diaphase and 17,3 МPа in the fracture zone.Conclusions. At modeling variants of endoprosthesis of the proximal section of a femur with trochanteric fractures of 5 type by Evans’ classification, it was determined, that the model system at all fracture types allows to lower a tension in practically all control points of bone elements of the models essentially. Elements of metal constructions demonstrate zones of higher tensions, where they are rather higher than in the model with the endoprosthesis at the expanse of the essentially less hardness in the node of connecting the carrying pivot with the intramedullary oneУ статті проведено аналіз за допомогою розроблених кінцеве елементних моделей перелому вертелюгової ділянки 5 типу за класифікацією Еванса зон напруження при використанні запатентованого авторами модульного фіксатора-протеза та стандартного ендопротеза кульшового суглоба з головкою подвійної рухомості. Виявлено значне зниження навантаження в кісткових елементах при використанні модульного фіксатора-протеза у порівнянні зі стандартною конструкціє

Analysis of the Stress-deformed Condition of Models of Trochanteric Fractures of Femoral Bone of 5 Type by Evans After Endoprosthesis

Aim of research: to develop the mathematical model of trochanteric fractures of a femur by Evans' classification and to use it for studying main directions of loading the proximal femur section at endoprosthesis with the additional fixation of fragments by needles.Materials and methods of research. For solving the set task, we developed the mathematical models of a femur with trochanteric fractures of different types by Evans' classification. We modeled trochanteric fractures of a femoral bone of 5 type by Evans, using the standard endoprosthesis, fixing separate fragments and model endoprosthesis of the offered construction.Results. The loading results were obtained. At using the endoprosthesis, the zone of maximal loads covers its neck and is 97,6 МPа on its upper surface and 118,4 МPа – on the low one. The least loaded zone is the little trochanter area, where the load value is only 1,0 МPа, and adjacent zones, where tensions don't exceed the value 10,0 МPа. The diaphyseal part of a femur is characterized with the tension values at the level from 21,1 to 23,8 МPа. At using the model system, the most tension level (88,2 МPа) is observed in the upper part of the neck. Tensions in other control points are distributed evenly and don't exceed the value 25,4 МPа by absolute values in the femoral diaphase and 17,3 МPа in the fracture zone.Conclusions. At modeling variants of endoprosthesis of the proximal section of a femur with trochanteric fractures of 5 type by Evans' classification, it was determined, that the model system at all fracture types allows to lower a tension in practically all control points of bone elements of the models essentially. Elements of metal constructions demonstrate zones of higher tensions, where they are rather higher than in the model with the endoprosthesis at the expanse of the essentially less hardness in the node of connecting the carrying pivot with the intramedullary on