Khodabakhsh Majd Mahsa, Bahrami Mehran, Haghbin Nazarpak Masoumeh, Nouri Alireza
Biomedical Engineering Department, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, PA, USA.
J Mech Behav Biomed Mater. 2023 May;141:105777. doi: 10.1016/j.jmbbm.2023.105777. Epub 2023 Mar 17.
Internal fixation devices made of nickel-titanium (NiTi) staples have the advantage of producing compressive stress at the fracture site due to their unique shape memory effect and superelasticity. In the present study, a comparison was made between two commercial NiTi staples of the same size but with different bridge configurations, used for scaphoid fracture fixation. The staple and scaphoid anatomical configurations were modeled using SolidWorks, while ABAQUS software was used to analyze the stress and displacement caused by staples and distributed in the scaphoid waist. In the staple with a straight bridge, the regions under the tips of the staple legs underwent the largest stress, whereas there was negligible stress in the regions closer to the staple bridge. In the staple with an S-shaped bridge, the stress concentration was highly localized in the region close to the staple bridge, with a maximum stress that was over eight times higher than in the staple with a straight bridge. Considering the amount and distribution of stress in both staples, neither of the staples was able to create the ideal healing condition on the fracture surface.
由镍钛（NiTi）钉制成的内固定装置因其独特的形状记忆效应和超弹性，在骨折部位产生压应力方面具有优势。在本研究中，对两种尺寸相同但桥接结构不同的商用NiTi钉进行了比较，它们用于舟骨骨折固定。使用SolidWorks对钉和舟骨的解剖结构进行建模，而ABAQUS软件则用于分析由钉引起并分布在舟骨腰部的应力和位移。在具有直桥的钉中，钉腿尖端下方的区域承受最大应力，而在靠近钉桥的区域应力可忽略不计。在具有S形桥的钉中，应力集中高度局限于靠近钉桥的区域，其最大应力比具有直桥的钉高出八倍以上。考虑到两种钉中的应力大小和分布，两种钉都无法在骨折表面创造理想的愈合条件。
