目的 提出一种相对于传统拓扑优化方法能有效降低应力集中，并进一步提高断骨愈合效果的接骨板拓扑优化设计方法。方法 依据接骨板在断骨-接骨板系统中的载荷约束条件，采用改进的基于传力路径的拓扑优化方法对接骨板结构进行优化设计。随后采用基于偏应变的骨再生模拟模型，对胫骨骨干横向骨折情况进行骨再生模拟，依据骨再生过程数据对优化接骨板的受力状态、固定稳定性及愈合性能进行评估。结果 使用基于传力路径优化方法的优化接骨板在体积分数f=0.55、0.65时，接骨板最大应力分别为55.68、42.23 MPa，相较于传统拓扑优化方法优化接骨板分别降低32.96%、29.95%；骨愈合过程后骨痂平均弹性模量分别为1 439.47、1 355.71 MPa，相较于传统接骨板分别提升145.86%、131.06%。结论 提出的改进基于传力路径的拓扑优化方法，可以用于接骨板结构优化设计，优化后接骨板相比传统拓扑优化方法优化接骨板受力更加均匀，使用安全性更高，骨愈合性能相较传统接骨板有明显提升。研究结果为骨折内固定植入物的优化设计提供了一种新思路和方法。

Objective To propose a topology-optimized design method for bone plates that effectively reduces stress concentration and improves bone healing compared with traditional topology-optimized methods. Methods Based on the load constraints of a bone plate in a broken bone-splint system, an improved topology optimization method based on the load path is used to optimize the design of the bone plate structure. Subsequently, a bone regeneration simulation model based on bias strain was used to simulate the transverse fracture of the tibial tuberosity, and the force state, fixation stability, and healing performance of the optimized plate were evaluated based on data from the bone regeneration process. Results Using the optimized bone plate based on the load path optimization method, the maximum stresses of the bone plate were 55.68 MPa and 42.23 MPa at volume fractions f=0.55 and 0.65, respectively, which were reduced by 32.96% and 29.95%, respectively, compared with the optimized bone plate using the traditional topology optimization method. The average elastic moduli of the callus after the bone-healing process were 1 439.47 MPa and 1 355.71 MPa, respectively. These values were 145.86% and 131.06% higher than those of traditional bone plates, respectively. Conclusions In this study, the proposed improved topology optimization method based on the load path was used to optimize bone-plate structures. Compared to the bone plate obtained using the traditional topology optimization method, the optimized bone plate was more uniformly loaded and safer. The bone-healing performance was significantly improved compared to the traditional bone plate. These results provide a new method for the optimal design of internal fixation implants for fractures.

国家自然科学基金项目（51975380），上海市自然科学基金项目（22ZR1442800）