桡骨远端骨折锁定钢板刚度的拓扑优化研究

目的对桡骨远端骨折锁定钢板结构进行优化设计,以应对骨折内固定个性化刚度需求。方法运用三维建模和计算机辅助设计软件完成桡骨远端骨折模型和常规钢板的模型构建,基于初始有限元分析结果,以轴向刚度下调33.33%且保留扭转刚度的90.00%以上作为优化目标,对常规钢板进行拓扑优化和重设计;通过有限元分析计算,对比常规钢板和优化钢板在轴向压缩和扭转工况下的内固定刚度和产生的骨折区应变。结果所获得的优化钢板轴向刚度为636.5 N/mm,下调幅度为19.7%,基本接近既定的目标刚度,优化后的扭转刚度为634.12 Nmm/°,下调幅度为8.8%,并未超出既定的目标限值;而骨折区应变变化方面,轴向应变相比切向应变呈现出更为显著的增加趋势,与刚度调控效果基本一致。结论通过拓扑优化的方法从钢板结构层面进行重设计,可实现骨折愈合的个性化内固定刚度调控。

Topological optimization of locking plate stiffness for distal radial fracture

Objective To optimize the topological design of locking plate for distal radial fracture so that the internal fixation stiffness can be customized.Methods Models of both the distal radial fracture and the conventional locking plate fixation were constructed using software for three-dimensional modeling and computer-aided design.Based on the data from our previous finite element analysis,a decrease of 33.33%in axial stiffness but retention of more than 90.00%in torsional stiffness were defined as the optimization limits.The conventional plate was redesigned by way of topological optimization iterations.Finite element analysis was done to compare stiffness and interfragmentary strain(IFS)between the new optimized design and conventional design of the locking plate under both compressive and torsional loads.Results The axial stiffness of the optimized plate was 636.5 N/mm with a downgrading magnitude of 19.7%which was close to the given limit;the torsional stiffness was 634.12 Nmm/°with a downgrading magnitude of 8.8%which remained under the given limit.In the optimized design,a more significant increase was observed in axial IFS than that in shear IFS,leading to a similar effect as the stiffness regulation did.Conclusion The optimized design of locking plate for distal radial fracture can provide a reliable solution for customized regulation of the internal fixation stiffness.