T形接骨板与定制式Y形接骨板治疗内侧胫骨平台骨折的有限元分析

Finite element analysis of T-Plate and customized Y-Plate in the treatment of medial tibial plateau fractures

目的比较定制式内侧Y形接骨板与传统T形接骨板在治疗Wahlquist不同亚型内侧胫骨平台骨折中的生物力学效益。方法采集1名健康成年女性膝关节CT断层扫描数据,重建胫骨几何形态,基于Wahlquist分型建立内侧胫骨平台骨折模型,矢状骨折线分别位于髁间内侧(A型)、经髁间嵴(B型)、髁间嵴外侧(C型),代表3种骨折亚型,分别使用定制Y形接骨板与传统T形接骨板固定。使用Ansys 2021软件进行有限元分析,输出两种固定方式下各成分所有节点的应力与位移。基于Mann-Whitney非参数检验对输出结果进行统计学分析。结果对于A、B、C 3种骨折类型,无论使用T形接骨板或Y形接骨板固定,最大应力点均位于最远端钉孔处;Y形接骨板固定组的骨应力均显著高于T形接骨板组,差异均有统计学意义(P<0.0001);Y形接骨板组内侧骨折块的内-外方向位移显著高于T形接骨板组,前-后方向及上-下方向位移显著低于T形接骨板组,差异均有统计学意义(P<0.0001)。结论定制式内侧Y形接骨板较T形接骨板显著降低应力屏蔽效应,同时能够为内侧骨折块提供更强的抗轴向、抗前后方向滑移能力,在治疗Wahlquist不同亚型内侧胫骨平台骨折时具有更佳的综合力学表现。

Objective To compare the biomechanical behavior of customized medial Y-plate with conventional T-plate in the treatment of different Wahlquist subtypes of medial tibial plateau fractures.Methods CT scan data from a healthy adult female knee were used to recreate the tibia's geometry and model a medial tibial plateau fracture according to the Wahlquist classification.The fracture was categorized into three subtypes:type A with sagittal fracture lines positioned in the medial intercondylar region,type B with sagittal fracture lines passing through the intercondylar crest,and type C with sagittal fracture lines situated laterally to the intercondylar crest.Each subtype was fixed using either a customized Y-shaped plate or a conventional T-shaped plate.Finite element analysis was conducted via Ansys 2021 software to generate stress and displacement outputs for all nodes within each component utilizing both fixation methods.The data were then analyzed statistically using the Mann-Whitney nonparametric test.Results The maximum stress location for the three fracture types A,B,and C was at the distal nail hole,regardless of T-or Y-plate fixation.The bone stress in the Y-plate fixation group was significantly higher than that in the T-plate group(P<0.0001);and the displacement of the medial fracture fragment in the medial-lateral direction in the Y-plate group was significantly higher than that in the T-plate group(P<0.0001);The Y-plate group showed a significantly higher medial-lateral displacement of the medial fracture fragment compared to the T-plate group(P<0.0001),whereas significantly lower displacement than the T-plate group in the anteroposterior and superior-inferior directions(P<0.0001).Conclusions In treating various types of medial tibial plateau fractures in Wahlquist,customized medial Y-plates have been found to significantly reduce the stress-shielding effect when compared to T-plates.Furthermore,Y-plates provide greater resistance to axial and anteroposterior sliding of the medial fracture fragment,as well as better overall mechanical performance.