非创伤性生理曲度变直与颈椎退变关系的生物力学研究

Biomechanics Investigation on Atraumatic Straight Physiological Curvature Cervical Spine and Cervical Spine Degeneration

目的:精确建立生理曲度变直的颈椎全节段有限元模型,并进行验证,分析其与颈椎退变的关系。方法:选取符合颈椎曲度变直纳入标准的颈椎病患者采集其CT数据,采用专门的生物力学有限元建模软件从CT扫描数据构建高质量的颈椎全节段有限元模型,然后采用基于离散微分属性的体网格变形技术,将生理曲度变直的模型映射生成曲度正常的有限元模型,再在相同的边界和加载条件下进行有限元对比分析。结果:在前屈、后伸、侧弯、和旋转工况下,生理曲度变直模型的活动度范围比正常值要小并且出现再分配。在应力分布方面,C3～C4,C4～C5之间的小关节、钩突关节,和C3～C4之间的椎间盘出现应力集中。结论:通过构建高质量的生理曲度变直和曲度正常的颈椎全节段有限元模型进行生物力学对比实验证明颈椎生理曲度变直引起椎间活动度明显减少并且出现再分配,同时下颈椎的小关节、钩突关节、椎间盘应力集中,加速颈椎退变。

Objective： The goal is to establish accurate finite element model of complete cervical spine with straight physiological curvature,then do verification,and analyse relationship between straight physiological curvature cervical spine and cervical spine degeneration.Methods： Choose patients with straight cervical spine and collect the CT scan data.By using specailly designed modeling system ＂E-feature Biomedical Modeler＂,a high quality finite element model of complete cervical spine with straight physiological curvature is gernerated,then mapped to build a normal curvature model by volumetric mesh deformation mehtod based on differential property.Then,the same boundary conditions are applied to do comparation.Results： Under the boundary conditions of flexion,extension,lateral bending and rotation,the anysis result demonstrated that the active movement range of straight cervical spine is limited and has different distribution pattern compared to normal configuration.For stress distribution,there are stress concentration at the facet joint cartilage and uncovertebral joint between C3-C4,C4-C5,and at the disk between C3-C4.Conclusion： By using the special biomedical finite element modeling system and new volumetric mesh deformation technology,it proves the active movement range of straight cervical spine is limited and has different distribution pattern,and cervical spine degeneration is accelerated by stress concentration at the facet joint cartilage,uncovertebral joint and disk of lower cervical spine.