四维结构锁定板固定股骨干骨折的有限元分析△

A finite element analysis on four-dimensional locking plate for fixation of femoral shaft fracture

摘要:

[目的]比较四维结构锁定板及常规锁定板的力学特性。[方法] 采集志愿者的股骨 CT 数据后建立股骨干斜行骨折模型，分别构建以四维结构锁定接骨板、常规锁定接骨板内固定模型。在 ANSYS 软件中添加轴向、四点折弯两种载荷， 分析两组模型的位移、应力及云图分布情况。[结果] 在 600 N 的轴向加载下，四维组的接骨板位移均值显著小于常规组 [(0.1±0.0) mm vs (0.4±0.0) mm, P＜0.001]，螺钉位移均值 [(0.6±0.0) mm vs (0.4±0.0) mm, P＜0.001] 和股骨位移均值 [(1.2±0.0) mm vs (0.8±0.0) mm, P＜0.001] 显著大于常规组；接骨板应力 [(11.3±0.0) MPa vs (15.4±0.0) MPa, P＜0.001]、螺钉应力均值 [(9.3±0.0) MPa vs (10.1±0.0) MPa, P＜0.001] 均显著小于常规组，而股骨应力均值 [(2.4±0.0) MPa vs (2.3±0.0) MPa, P＜0.001] 显著大于后者。在 500 N 的四点折弯加载下，四维组的接骨板位移均值 [(0.029±0.00) mm vs (0.044±0.00) mm, P＜0.001] 显著小于常规组，而螺钉位移均值 [(0.058±0.00) mm vs (0.051±0.00) mm, P＜0.001]、股骨的位移均值 [(0.112±0.001) mm vs (0.096±0.00) mm, P＜0.001] 显著大于常规组。四维组的接骨板应力 [(3.685±0.005) MPa vs (5.556±0.001) MPa, P＜0.001]、螺钉应力 [(2.608±0.004) MPa vs (3.024±0.001) MPa, P＜0.001] 显著小于常规组，而股骨应力均值 [(0.326±0.005) MPa vs (0.308±1.160) MPa, P＜0.001] 显著大于常规组。[结论]四维组可相对降低螺钉断裂风险，整体生物力学性能与常规组相近，具有发展成为一种新的骨折内固定物的潜力。

Abstract:

[Objective] To compare the mechanical properties of four-dimensional (4D) locking plate and conventional locking plate. [Methods] The oblique fracture model of femoral shaft was established based on CT data of volunteers, and then the internal fixation model with 4D locking bone plate and routine locking plate were constructed respectively. The axial and four-point bending loads were added by using ANSYS software to analyze the displacement, stress and nephogram distribution of the two models. [Results] Under 600 N axial loading, the 4D group proved significantly less than the routine group in plate displacement [(0.1±0.0) mm vs (0.4±0.0) mm, P＜0.001], while the former was significantly greater than the latter in screw displacement [(0.6±0.0) mm vs (0.4±0.0) mm, P＜0.001] and femur displacement [(1.2±0.0) mm vs (0.8±0.0) mm, P＜0.001]. In addition, the 4D group had significantly less stress on plate [(11.3±0.0) MPa vs 15.4±0.0) MPa, P＜0.001] and stress on screw [(9.3±0.0) MPa vs (10.1±0.0) MPa, P＜0.001], whereas greater stress on femur [(2.4±0.0) MPa vs(2.3±0.0) MPa, P＜0.001] than the routine group. Under 500 N four-point bending load, the 4D group had significantly less plate displacement [(0.029± 0.00) mm vs (0.044±0.00) mm, P＜0.001], while greater screw displacement [(0.058±0.00) mm vs (0.051±0.00) mm, P＜0.001] and femur displacement [(0.112±0.001) mm vs 0.096±0.00) mm, P＜0.001] than the routine group. Furthermore, the 4D group had significantly lessstress on plate [(3.685±0.005) MPa vs (5.556±0.001) MPa, P＜0.001], and screw stress [(2.608±0.004) MPa vs (3.024±0.001) MPa, whereas greater stress on femur [(0.326±0.005) MPa vs (0.308±1.160) MPa, P＜0.001] than the routine group. [Conclusion] The four-dimensional plate has relatively reduced risk of screw fracture, the overall biomechanical properties similar to the conventional plate, which has the potential to develop into a new internal fixation for fracture.