Biomechanical analysis of bone healing at one and double-plates fixation of femoral bone fractures

Along with the development of technology, mainly motorization and active lifestyle of a contemporary person, we can observe a substantial increase of a variety of injuries of organs responsible for locomotion. In the light of medical knowledge, in the cases of healing bone fractures it is essential to reduce the fracture and maintain it in such a position as to restore the functions of the injured body part until synostosis occurs. The most beneficial method is to obtain a stable fixation of the fractured bone, which enables the patient to undergo therapeutic rehabilitation as soon as possible. In the majority of clinical cases, difficulties are observed in long bone stabilisation with the use of widely applied osteosynthesis methods. Excessive obesity, ankylosis, infected nonunion of fragments with bone defect, mental diseases and the need to avoid the bone fractions rotation constitute an example complex of factors making it impossible to apply an ordinary plate, an intermarrow rod, or an external stabiliser in order to obtain stable fixation. The main direction of the research carried out in the work were the unsolved issues of the biomechanics of the bone–Polfix type plate stabiliser system functioning in a multi-plane system. The work includes an analysis of the influence of different plate fixation parameters on the state of the fixation’s tensions and displacements with the use of a parametric numerical model as well as experiments on a physical model with the aim to establish the actual biomechanical characteristics. In order to facilitate physicians in the process of diagnosing, highly advanced computer systems are becoming more and more popular. CAE (Computer Aided Engineering) programmes are often used, allowing to analyse the model’s operating with the load force imposed on it. An example of such a programme is ANSYS using the Finite Element Method (FEM). Some of the advantages of this type of research are its low costs and the possibility of carrying out the research practically in all conditions. For a more complete description it is of course indispensable to carry out also the experiments aiming at verification but the latter are easier to conduct in the presence of the first assessment resulting from the use of the numerical model.