寰椎骨折的生物力学分析

目的采用有限元方法,预测寰椎在不同位置条件下寰椎应力的分布,并以此推断可能出现的寰椎骨折类型。方法构建寰椎三维骨性结构,分析寰椎在中立、屈曲、后伸三种位置下应力分布状况。结果寰椎高应力在中立位时,出现在寰椎前部和双侧椎弓根;屈曲位时,分布在寰椎前部;后伸位时,存在寰椎前弓和双侧椎弓根。结论寰椎前弓和前结节交界处、前弓和侧块交界处、后弓和侧块交界处、后弓和后结节交界处是应力较为集中的部位,也是寰椎骨折容易发生的部位。骨折部位和骨折类型与寰椎损伤时所处的位置、寰椎几何形状、外力的方向以及寰椎的力学特征密切相关。

Biomechanical Study of Atlas Fracture by Finite Element Method

Objective To predict the stress distribution of atlas under different pre-trauma postures by finite element method, and to deduce the sites of atlas fracture accordingly. Methods To set up the three-dimensional geometrically and mechanically finite element model and analyze the stress distribution of atlas under three different pre-trauma postures. Results In neutral posture, the high stress distribution occur at anterior arch and the junction between the posterior and lateral mass; in flexion posture, the high stress distribution occur at anterior arch;in extension posture, the high stress distribution occur at anterior arch and the junction between the posterior and lateral mass. Conclusion Since the high stress usually occur at the junction between the anterior arch and anterior nods, the junction between the anterior arch and lateral mass, and the junction between the posterior and lateral mass, these sites of atlas are likely to be the fracture sites. The type and sites of atlas fractures are highly dependent on the force vector applied to head, head posture at the time of trauma, atlas geometry and physical properties.