侧翼钢板内固定治疗锁骨中段骨折的有限元分析

Finite element analysis of the treatment of middle clavicle fracture with wing plate internal fixation

目的:探讨自行设计的一种新型带侧翼双平面锁定钢板治疗锁骨中段骨折的力学性能。方法:基于1名健康成年男性志愿者锁骨CT数据,通过数字化三维重建技术构建锁骨中段骨折的三维有限元模型,模拟了单平面锁定钢板(SP)、侧翼钢板(WP)的两种固定方式,采用轴向压缩、轴向扭转、悬臂弯曲以及拔出的四种载荷工况分别对两组模型进行分析。结果:WP在轴向压缩、轴向扭转、悬臂弯曲和拔出工况下,相对于SP,其刚度分别提高1.47%、5.82%、1.51%和3.96%,应变能分别下降1.50%、5.39%、1.48%和3.49%,具有更好的内固定稳定性;WP在各种载荷条件下的应力分布特点与SP相似,高应力区位于骨折区上方的钢板钉孔周围;WP在拔出工况下,钉孔表面应力峰值相对于SP有较大幅度的降低,尤其体现在侧翼螺钉两侧钉孔,具有更高的抗拔出能力。结论:侧翼锁定钢板在各种载荷条件下的承载模式与单平面锁定钢板相似,而稳定性略高于单平面锁定钢板;而在抗拔出性能方面,侧翼钢板优势更为明显。双平面固定的带侧翼锁定钢板有望成为锁骨中段粉碎性骨折或合并骨质疏松的患者内固定治疗更为理想的选择。

Objective:To investigate the mechanical properties of a new type of biplane locking plate with wings in the treatment of middle clavicle fractures.Methods:Based on the CT data of a healthy adult male volunteer’s clavicle,a three-dimen-sional finite element model of the middle clavicle fracture was constructed through digital three-dimensional reconstruction technology,and the two kinds of fixation methods of single-plane locking plate(SP)and wing plate(WP)were simulated.Four load cases of axial compression,axial torsion,cantilever bending and pull-out were used to analyze the models.Results:Under axial compression,axial torsion,cantilever bending and pull-out conditions,compared with SP,the stiffness of WP increased by 1.47%,5.82%,1.51%and 3.96%,respectively,and the strain energy decreased by 1.50%,5.39%,1.48%and 3.49%,respectively.The stress distribution characteristics of WP under various load conditions were similar to SP,and the high stress area was located around the screw hole of the steel plate above the fracture gap.Under the pull-out condition,the peak value of screw hole surface stress of WP was greatly reduced compared with SP,especially in the screw hole on both sides of the wing screws,which had higher resistance to pulling out.Conclusion:The load-bearing mode of WP under various load conditions is similar to that of SP,and the stability is slightly higher than that of SP and in terms of pull-out resistance,WP has more obvious advantages.The biplane locking plate with wings is expected to be a more ideal choice for patients with comminuted fracture of the middle clavicle or with osteoporosis.