Finite element modelling of biologic system in orthopedic trauma

Surgical treatment of the proximal femur fractures is a challenge due to the lack of a unified treatment strategy. Among these, of particular importance is the analysis of the processes occurring in bone tissue during the healing of fractures under dynamic conditions, especially the analysis of mechanical stresses. The finite element method is an effective method of mathematical modelling of complex objects and a description of the stress-strain states of these objects. With the aim of improving the results of fracture treatment of the proximal femur and pelvic bones, a mathematical simulation was performed using the finite element method on the intertrochanteric fracture of the femur fixed by a dynamic hip screw and a pelvic fracture fixed by submersible osteosynthesis under various conditions. The calculation parameters are based on the literature data and the optimal accuracy of the ratio specified and the calculation time of the "bone-implant" software system. The models were constructed by taking into account the various properties of cortical and spongy bone as well as the implant. A virtual weight of 80 kg was applied to the models. The estimation of the displacement of the bone-implant system was done along with the prediction of stresses according to the von Mises yield criterion. Thus, the results of mathematical modelling with the use of finite element method allows prediction of the movement of bone fragments in the broken skeleton segment and to choose the correct method of osteosynthesis of the fragments and to evaluate its consequences. The application of methods of mathematical modelling expands the possibilities of scientific and personified approach to surgical treatment of diseases of the musculoskeletal system.