Estudio del comportamiento biomecánico de una placa de tibia distal tipo LCP (placa de compresión de bloqueo), bajo condiciones estáticas y dinámicas en la marcha

Abstract

The study of the biomechanical behavior of a LCP-type medial distal tibia plate (Locking Understanding Plate) under static and dynamic situations was carried out through a finite element analysis with the help of the Ansys Workbench 2020 R1 program, where The load and position parameters of the right leg were assigned for the situations of upright bipodal position, walking on a flat surface, ascent and descent of steps. In this way, the distribution of efforts supported by this type of surgical implants during an osteosynthesis treatment under the execution of daily living activities by the patient was examined.

On the other hand, the bone model of the right leg (tibia, fibula and foot) was made taking into account the anthropometric measurements of a healthy adult man with a height of 168.8 cm and a weight of 69.1 kg. of the implant was generated by 3D scanning and manual modeling with the help of a prosthesis that was physically available, since it is necessary to obtain a 3D model of the leg-plate assembly as close as possible to what is anatomically and surgically real in order to obtain accurate results in the analysis.

In relation to the results, it was shown that one of the main causes of the increase in stress in the analyzed models is directly related to the angle at which the tibia is with respect to the line of application of the vertical load, this was evidenced in the model of running on a flat surface in which the highest magnitudes of total stress were obtained due to the bending stress that the load generated on the geometry. Also, there were important stress concentrators on the areas near the edges of the holes adjacent to the bone fracture point and in the lower area of ​​the plate where it has a series of hollows that reduce plate-bone contact and reduce the area cross section of the surgical element in this area.

To conclude, when comparing the computational analysis with the plate that presented the rupture, it was evidenced that the place of the fracture is the same in which the highest concentration of stress occurred during the simulations. In addition, the fracture pattern of the plate responds to the data obtained in the analyzes, in which a clear distribution of stresses is created with the highest magnitudes in the form of a line, between the lateral ends of the plate where there are hollows on the bottom surface of this and the nearest screw hole.