engleski

Influence of loading direction on assessment of biomechanical stability of distal humeral fracture: A finite element analysis

Double-plating techniques using two-plate (90-90º or 180-180º) pattern are generally accepted for distal humeral fractures. The latest articles have proven the parallel configuration to be superior biomechanically. A finite element analysis was done for axial, varus and bending loading on the distal part of humerus with parallel and perpendicular reconstruction plates configuration. All numerical simulations were conducted using the finite element software Abaqus 6.7 (Simulia, Dassault Systèmes) with a load of 100 N on articular surfaces with supracondylar gap of 10 mm. The displacement of bone fragments in axial loading is significantly smaller than under bending and varus loading. In the model with parallel plates configuration the displacements are also 41% smaller for axial loading, while in bending they are approximately 33%. The perpendicular plate construct has a smaller displacement in varus loading, about 4%. Consequently, the parallel configuration has greater stiffness for axial and bending loads, and the perpendicular one under varus loading. In addition to single loads, simulations were also carried out for complex loading with all three loads at the same time. In both models maximal displacements appeared in the distal articular part on the radial column. However, when all three loads are applied at the same time, there is no significant displacement difference between the models. The displacements on the articular surface in the perpendicular position are even less than 12%. Significantly smaller displacements in axial loading indicate a significantly lesser importance of this load in the overall assessment of biomechanical stability of distal humerus fractures.

distal humeral fracture; biomechanical stability; plate configuration; displacement; finite element analysis

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