Biomechanical analysis of limited-contact plate used for osteosynthesis

This paper presents the results of numerical analysis aimed at determining the state of stresses and displacements of compression plate used in osteosynthesis of tibia, carried out by applying finite element method using the ANSYS program. The analysis took into account two variants of the osteosynthesis. Variant I included the osteosynthesis in which plate was attached directly to the bone, in variant II, the plate was moved away from the bones by about 5 mm. Biomechanical characteristics of the corrective osteotomy plate–tibia was determined for implants made of Ti-6Al-4V alloy. The boundary conditions adopted for the analysis reflect phenomena occurring in a real system. Based on the results of the analysis relative displacements and reduced stresses in various components were determined as a function of the applied load within the range of F = 500–1500 N. The maximum forces, both variant I and variant II determined during analysis, ensure that the generated stress does not exceed yield strength of the material and compressive strength of the bone, and do not exceed safety movement in the fracture gap. In addition, it was found that the locking of the compressive plate to the bone has a little effect on the distribution of displacements and stresses on the plate–tibia system in the case of a simple fracture.