胫骨内侧、外侧解剖锁定钢板固定胫骨中下段外旋型螺旋骨折的有限元分析

Finite element analysis of medial and lateral locking plates for fixation of externally rotated spiral fractures of the lower tibia

背景:目前缺乏胫骨内侧、外侧解剖锁定钢板治疗胫骨中下段外旋型螺旋骨折的生物力学性能研究。目的:采用三维有限元分析技术对比胫骨内侧、外侧解剖锁定钢板固定胫骨中下段外旋型螺旋骨折的力学分布情况。方法:选择1名健康志愿者的胫骨CT图像,使用数字化技术构建胫骨远端内、外侧锁定钢板模型,根据内固定原则设置模型组合,分别给予轴向力、侧向力及扭转力加载,模拟人体在不同受力情况下内固定受力及胫骨骨折模型的位移情况。结果与结论:①轴向暴力中,胫骨远端外侧解剖钢板的最大等效应力、骨折面位移量比胫骨远端内侧解剖锁定钢板小约31.6%,8.8%;②扭转-逆时针暴力中,内侧、外侧解剖钢板的最大等效应力相近,骨折面位移相近;③扭转-顺时针暴力中,外侧解剖钢板的最大等效应力、骨折面位移量比内侧解剖锁定钢板小约23.8%,65.3%;④外翻时外侧解剖锁定钢板的最大等效应力、骨折面位移量比内侧解剖锁定钢板小约38.2%,86.5%;内翻时外侧解剖锁定钢板的最大等效应力、骨折面位移量比内侧解剖锁定钢板小约4.8%,7.6%;⑤结果表明,对胫骨中下段外旋型螺旋骨折,胫骨远端外侧解剖锁定钢板对抗轴向暴力、翻转暴力、扭转-顺时针的能力明显优于胫骨远端内侧解剖锁定钢板,更具生物力学优势。

BACKGROUND:At present,there is a lack of research on the biomechanical properties of the medial and anterolateral anatomical locking plates of the tibia for the treatment of external rotation fractures of the tibia.OBJECTIVE:To compare stress distribution of the medial and anterolateral anatomical locking plates of the tibia for the treatment of external rotation fractures of the tibia using three-dimensional finite element analysis.METHODS:Tibia CT images of one healthy volunteer were selected.Digital technology was used to construct the medial and anterolateral locking plate model of the distal tibia.The model combination was set according to the principle of internal fixation.The axial compression force,valgus/varus force,and torsion force were given respectively to simulate the internal fixation force of human body under different stress conditions and analyze the displacement of the tibial fracture model.RESULTS AND CONCLUSION:(1)In the axial compression force,the maximum equivalent stress and the fracture surface displacement of the distal lateral plate were about 31.6%and 8.8%smaller than those of the distal medial plate.(2)In torsion-external rotation,the maximum equivalent stress was similar and the displacement of the fracture surface was also similar between the distal medial and lateral plates.(3)Under torsion-internal rotation,the maximum equivalent stress and torsional angular displacement of the fracture surface of distal lateral plate was about 23.8%and 65.3%smaller than those of the distal medial plate.(4)When subjected to valgus violence,the maximum equivalent stress and displacement of the fracture surface of distal lateral plate were about 38.2%and 86.5%smaller than those of distal medial plate.When subjected to varus violence,the maximum equivalent stress and the displacement of the fracture surface of distal lateral plate were about 4.8%and 7.6%smaller than those of distal medial plate.(5)In external rotation spiral fractures of the middle and lower tibia,distal tibial anterior lateral plate has better ability to resist axial,twist-clockwise rotation,varus and valgus violence.The distal lateral plate has more biomechanical advantages than the distal medial plate.