颞骨撞击生物力学变化与骨折特点

Biomechanical changes and characteristics of impact temporal bone fractures

目的探讨颞骨撞击应力分布、应力波的传播与颞骨骨折的关系。方法选取捐赠的新鲜尸头12具，分别在800，1200，1400kPa的驱动压力进行撞击，借助64排CT的三维立体结构图像，经计算机仿真模拟计算颞骨撞击过程生物应力的分布与传播。结果（1）撞击驱动压力的增加，使撞击速度、撞击加速度、撞击能量、撞击锤在颅骨颞部的位移幅度均增大。（2）在颞骨撞击瞬间，形成以撞击点为中心的VonMises应力集中区，在颅骨一脑组织耦合处急剧衰减，随之又在颅底汇聚成应力集中区域。（3）撞击驱动压力为800kPa时，同侧线性骨折；以1200kPa撞击时，同侧均出现不同程度的凹陷性骨折，1例对侧颞骨形成继发性骨折；以1400kPa撞击颞骨时，同侧均发生混合型骨折，对侧颞骨均形成继发性骨折，并造成颅底骨折。（4）颞骨骨折线与撞击应力集中区的分布相符合。结论颞骨各项撞击参数、撞击应力的分布和传递与颞骨骨折相吻合。这对颞骨撞击伤的诊断和防护有重要的临床意义。

Objective To investigate the relationship of impact stress distribution and stress wave dissemination with temporal bone fracture. Methods Twelve donated fresh corpse were selected and impacted with driving force of 800 kPa, 1 200 kPa and 1 400 kPa to establish the model of impact temporal bone fractures. With aid of three-dimensional stereochemical structure image of 64-slice CT, the vitodynamic distribution and dissemination of impacted temporal bone was calculated by using computer simulation. Results （ 1 ） The instant velocity, acceleration and energy of impact as well as displacement scope of the hammer increased with higher driving force in the tempus. （2） Instantaneous impact of the temporal bone resulted in Von Mises stress concentration area around the impact point. The stress was weakened suddenly in the skull-brain tissue coupling place but later accumulated in the skull base. （3） Only ipsilateral linear fracture occurred when the driving force of impact was 800 kPa. While impact different degrees of depressed fractures could be seen and one case showed secondary fracture of the opposite side when the driving force of impact was 1 200 kPa. The impact with driving force for 1 400 kPa begot complex ipsilateral fractures, secondary fracture of the opposite side and skull basal fracture. （4） Fracture line of the temporal bone accorded with impact stress concentration area. Conclusions All parameters, stress distribution and dissemination of impact are in accordance with temporal bone fracture during impact process of the temporal bone, which is of vital significance for diagnosis and protection of impact temporal bone fractures.