Análise numérica e biomecância do reforço femoral com cimento de fosfato de cálcio e polimetilmetacrilato

Abstract

Femoroplasty using calcium phosphate cement (CPC) or polymethylmethacrylate (PMMA) have been studied aiming femoral reinforcement osteoporotic promotion in bones. However, further studies are needed in order to optimize its use and determine its position and volume. Objective – it was evaluated a fill formatting with CPC and PMMA proximally (trochanteric region and neck) of synthetic femurs, and the result of the resistance in this region during fall simulation on the big trocanter. Method -15 synthetic femurs were used, Sawbone brand and model 1130-130, also divided into three groups: CPC, PMMA and control. In the group, controlled femurs were used to their full formatting, without violation of its structure, to produce tomography images and biomechanical evaluation; but those of the two other groups were filled with use of CPC or PMMA after previous preparation three orifices, which followed form and preset positions. Analyses were divided into Phase 1: Using Bi-directionalEvolutionaryStructuralOptimization program (BESO) and finite element; and Phase 2: Mechanical testing using one MTS testing machine (Materials Testing System) Model 810 - 40 FlexTest simulating the mechanism of trauma to fall on trocanter. Results – In Phase 1 it was observed by analysis of BESO and finite element a 53-increment %, with the use of CPC and 58% with the use of PMMA. In Phase 2, the mechanical tests showed no statistically significant difference between the increase in resistance between the groups, however there was a positive statistical trend to the use of PMMA. Conclusion - The use of CPC and PMMA cement for formatting and positioning defined by the authors presented an increase in mechanical strength to the proximal end of the femur in synthetic models,but in the the numerical analysis, this result was not reproducible in biomechanical analysis.