EVALUATION OF A BONE REINFORCEMENT TECHNIQUE USING FINITE ELEMENT ANALYSIS

ABSTRACT Objectives: To compare the results of a simulated fall on the greater trochanter in the proximal portion of a synthetic femur before and after femoral reinforcement with tricalcium phosphate bone cement (TP) and polymethyl methacrylate (PMMA), using finite element analysis (FEA). Methods: Using two synthetic proximal femurs, a FEA simulating a fall on the greater trochanter was performed, using the Bi-directional Evolutionary Structural Optimization (BESO) program. For this analysis, the femurs were filled with TP and PMMA after perforations were created in the trochanteric region and neck. The results were compared with the strength values obtained from testing the control specimen, a synthetic bone without reinforcement. Results: FEA showed a value of 600 N prior to reinforcement. After cementing with PMMA, the load increased by 57.5% (945 N), and by 53% (920 N) after cementing with TP. Conclusion: Synthetic femurs gained resistance to fracture-causing forces in a simulated fall on the trochanter after bone reinforcement with PMMA and TP. Level of Evidence III; Experimental study.摘要：研究目的：采用有限元分析（finite element analysis, FEA），对比合成股骨近端大转子区域在分别经磷酸三钙骨水泥（tricalcium phosphate bone cement, TP）与聚甲基丙烯酸甲酯（polymethyl methacrylate, PMMA）进行股骨强化前后，模拟大转子跌倒撞击的实验结果。研究方法：选取2根合成股骨近端节段，在转子区与股骨颈制备穿孔后，分别填充TP与PMMA骨水泥，采用双向进化结构优化（Bi-directional Evolutionary Structural Optimization, BESO）程序开展大转子模拟跌倒撞击的有限元分析，并以未强化的合成骨空白对照样本的强度测试值作为参照进行结果比对。研究结果：有限元分析显示，股骨强化前的承载阈值为600 N。经PMMA骨水泥强化后，承载载荷提升57.5%（达945 N）；经TP骨水泥强化后，承载载荷提升53%（达920 N）。研究结论：经PMMA与TP骨水泥进行骨强化后，合成股骨在模拟大转子跌倒撞击的致骨折载荷下的抗断裂性能显著提升。本研究证据等级为III级，属于实验性研究。