Tropea A, Tisano A, Bruschetta A, Borzelli D, Migliorato A, Nirta G, Leonardi G, Trimarchi F, Alito A
Dep. of Research and Internationalization, Via C. del mare 41, 98121, Messina, Italy.
Dep. of clinical e sperimental Medicine, University of Messina, 98125, Messina, Italy.
J Orthop. 2022 May 19;32:78-84. doi: 10.1016/j.jor.2022.05.011. eCollection 2022 Jul-Aug.
In this study a multi fragment humeral fracture, treated with locking plate system implant, was investigate and compared with a healthy humerus by the mining of a Finite Element (FE) analysis. Locking plate implant, in this case AxSOS 3® Titanium produced by Stryker is the preferred solution in presence of multiple fracture or osteoporosis.
Loading conditions were imposed by rotating of 52,5° respect the vertical axe, both the humeri (healthy and fractured), fixing distal end, and loading the top of bones with a vertical force of 543 N (Newton). This finite element analysis aimed to compare stability of implanted humerus, implant-bone interface, stress shielding, with those related to a healthy one. A microbial adhesion analysis was also performed on the implant's material.
Results obtained by FE analysis confirm a good agreement of the mechanical behavior of the models tested. The maximum values of the registered stressed, are of about 45 MPa (Mega Pascal) for the intact humerus and 113 MPa for the fractured one. Displacements, confirm higher values on the fractured humerus and no viable bacteria were found after microbial adhesion analyses.Conclusion: comparison between healthy and fractured humerus showed an optimal stability of the implant, when contact surfaces optimization and screws insertion are correctly performed.
在本研究中，通过有限元（FE）分析，对采用锁定钢板系统植入物治疗的多段肱骨骨折进行研究，并与健康肱骨进行比较。在存在多处骨折或骨质疏松的情况下，锁定钢板植入物（在本案例中为史赛克公司生产的AxSOS 3®钛合金）是首选解决方案。
通过使两根肱骨（健康的和骨折的）相对于垂直轴旋转52.5°、固定远端并在骨头顶端施加543牛顿的垂直力来施加加载条件。该有限元分析旨在比较植入肱骨的稳定性、植入物与骨的界面、应力遮挡，以及与健康肱骨相关的情况。还对植入物材料进行了微生物粘附分析。
有限元分析获得的结果证实了所测试模型的力学行为具有良好的一致性。完整肱骨记录到的最大应力值约为45兆帕（MPa），骨折肱骨的最大应力值为113兆帕。位移情况表明骨折肱骨的位移值更高，并且在微生物粘附分析后未发现有存活细菌。
健康肱骨与骨折肱骨的比较表明，当正确进行接触表面优化和螺钉插入时，植入物具有最佳稳定性。
