颅颈交界区畸形中寰枢外侧关节的结构变异及生物力学研究

The exact pathogenesis of atlantoaxial dislocation (AAD) in congenital craniovertebral junction abnormalities remains unclear. To explore its mechanism has important clinical significance. The conventional in vitro and in vivo models have difficulty in studing the pathogenesis of the congenital disease and stress force change of the spinal internal strucutre. The finite element model could fulfill this work. It could simulate the stress force change in conditions of trauma and operation, and research the biomechanical influence imposed by the structural variation in conditions of deformity, too. In our preliminary research, we found there always exists structural variation of the lateral atlantoaxial articulation (LAA) in craniovertebral junction abnormalities, which had close relationship with the occurrence of AAD. So it provided us a goog point to study the mechanism of the congeniatl AAD from the view of structural variation of LAA. This study is to further research the structural variation and functional effects of the LAA in craniovertebral junction abnormalities based on the multidimensional reconstruction of CT data, and to research the biomechanical change in craniovertebral junction abnormalities by means of the established finite element model. The process of the occurrence of congenital AAD was simulated by changing the parameters and conditions (occipitalization model etc) and the kinematics change was analysed, and the possible pathogenesis of congenital AAD was explored.

先天性颅颈交界区畸形伴随的寰枢椎脱位的发生机制目前尚不明确，对其机理进行研究具有重要临床意义。传统的体内外研究方法难以对先天性疾病的发病过程及脊柱内部结构的应力变化进行研究，有限元模型可弥补此缺陷，可以模拟外伤、手术等状态下的应力变化，亦可研究畸形状态下的结构变异对脊柱生物力学的影响。我们前期研究发现颅颈交界区畸形中常存在寰枢外侧关节的结构变异，并与寰枢椎脱位的发生密切相关。从寰枢外侧关节的结构形态学角度来探讨先天性寰枢脱位的发病机理为我们提供了切入点。本研究即通过三维CT数据的处理和分析进一步对畸形状态下的寰枢外侧关节的结构变化及功能进行分析；通过已构建的枕寰枢有限元模型来研究畸形情况下的颅颈间生物力学变化，通过改变参数（建立寰枕融合、寰枢外侧关节变异模型等）来模拟先天性寰枢椎脱位的发生过程，分析其运动学变化，探讨先天性寰枢椎脱位的可能发生机理。

颅颈交界区畸形伴随的先天性寰枢椎脱位的发生机制目前尚不明确，对其深入研究具有重要临床价值。寰枢椎的承重关节为寰枢外侧关节，该关节结构变异导致的枕颈区生物力学变化与寰枢椎脱位的发生机制密切相关。本研究针对寰枢外侧关节进行结构形态分析及有限元生物力学研究，通过三维CT重建技术和3D打印技术对颅颈交界区畸形的寰枢外侧关节的形态变化及功能结构进行分析，总结出颅颈交界畸形寰枢外侧关节的结构变异特点，建立了影像学分型，提出了新的影像学测量指标，包括前倾角、后倾角及外倾角，写入《中国颅颈交界区畸形诊疗专家共识》；建立了寰枕融合及多种寰枢外侧关节面畸形的有限元模型，进行了生物力学加载实验，发现寰枢外侧关节面矢状位角度变异与寰枢稳定性改变密切相关，初步探索出先天性寰枢椎脱位的发病机理与寰枢外侧关节的变形有关，丰富了对颅颈交界区畸形此类复杂疾病发病机理的认识。