Most carpal bone fractures occur in the scaphoid. The most suitable size of NiTi shape memory alloy (nitinol) staples to heal scaphoid fractures was found by comparing two commercially available compression staples (DynaClip™ Bone Fixation System, 10×10 and 14×14 mm). The scaphoid bone was selected for simulating a model in SolidWorks software. To accurately investigate the effect of staple size on the bone the scaphoid was assumed to be a three-layer composite structure consisting of collagen and mineral crystals. The stress distributions along a path located at the waist of the scaphoid were assessed. The finite element analysis was carried out in ABAQUS software based on the nitinol staple shape memory effect and super-elasticity behavior. The results indicated that the smaller size of staples induced a more significant stress on the central zone of the scaphoid, whereas the larger size of staples showed a peak stress concentration on the peripheral zones with a reduced stress concentration at the center. Hence, it is suggested to utilize the two of these staples in different orientations or in parallel with each other to improve the biomechanical behavior of the regenerated bone.

大多数腕骨骨折发生在舟骨。通过比较两种市售压缩钉（DynaClip™ 骨固定系统，10×10 和 14×14 毫米），发现最适合愈合舟状骨骨折的 NiTi 形状记忆合金（镍钛诺）钉尺寸。选择舟状骨在SolidWorks软件中模拟模型。为了准确研究吻合钉尺寸对骨骼的影响，舟骨被假定为由胶原蛋白和矿物晶体组成的三层复合结构。评估了沿着位于舟状骨腰部的路径的应力分布。基于镍钛诺短纤维形状记忆效应和超弹性行为，在ABAQUS软件中进行有限元分析。结果表明，较小尺寸的U形钉在舟状骨的中心区域引起更显着的应力，而较大尺寸的U形钉在周边区域显示出峰值应力集中，而在中心处的应力集中降低。因此，建议以不同方向或彼此平行地使用这两个钉来改善再生骨的生物力学行为。