颅颈交界区畸形寰枢关节生物力学分析及手术策略研究

发布时间：2018-08-03 13:34

【摘要】：背景与目的:颅颈交界区畸形是从颅底到枢椎C2(Cervical 2)和第三颈椎C3(Cervical 3)椎间盘之间的病变,如寰枢椎脱位、颅底凹陷等,造成神经功能损伤,使患者出现四肢乏力,行走不稳等症状。颅颈交界区后路内固定是目前治疗畸形的有效方法,通常包括寰枢椎内固定术和枕颈后路内固定术,具有稳定的生物力学和广泛的适用性,但对于颅颈交界区畸形患者,常存在寰枕融合、椎动脉走行存在广泛异常等畸形解剖情况,造成螺钉植钉位置选择不同于正常人,例如枢椎椎弓根解剖变异,此时如果行椎弓根固定,临床上易造成脊髓和椎动脉损伤,或者根本无法固定,瘫痪及死亡的发生率较高。一般的内固定器械基于椎弓根螺钉设计,畸形时枢椎椎弓根常存在变异问题,不能满足对于颅颈交界区畸形的复位和固定治疗要求,而枢椎椎板在具有良好植钉条件。针对以上问题,本文从颅颈交界区畸形医学数据出发,建立几何精度较高和参数设定可靠的颅颈交界区畸形有限元模型,通过对其生物力学的分析获得了不同生理状况下畸形有限元模型寰枢椎外侧关节面的应力分布情况,为下一步手术方案的选择以及内固定装置的设计提供了一个思路。方法:获取1例颅颈交界区畸形枕骨和颈椎的CT扫描图像,利用三维造型和有限元软件建立颅颈交界区的三维有限元模型。施加生理载荷和边界条件,通过比较该模型与正常模型活动度的差异结合临床观察经验,验证模型的有效性,同时分析寰枢椎外侧关节应力分布;选取38例颅颈交界区畸形的患者,根据解剖学测量、有限元分析的结果,术中在数字化导航的帮助下进行手术。结果:建立几何精度较高和参数设定可靠的颅颈交界区畸形有限元模型,各节段的活动度与相关尸体实验和有限元模型数据的结果相比总体呈偏小趋势,与一般颅颈交界区畸形患者临床实际运动表现相符合。获得了不同生理状况下畸形有限元模型寰枢椎外侧关节面的应力分布情况,可以合理解释寰枢外侧关节结构变异及其在维持寰枢椎之间稳定的重要作用;根据解剖测量及有限元分析,术中分4种方式进行手术,术后复查CT及MRI显示手术成功。结论:颅颈交界区畸形患者寰枢外侧关节结构发生变异,其生物力学稳定性对于术前的诊断和术中治疗操作具有一定价值;在临床中创新性提出了手术4种分型,为医生提供了一种全新准确、安全、可靠的方法,在脊柱外科具有较大的应用前景。
[Abstract]:Background & objective: Craniocervical junction malformation is a lesion from the base of the skull to the disc of C _ 2 (Cervical _ 2) and C _ 3 (Cervical _ 3) of the third cervical spine, such as atlantoaxial dislocation, skull base depression and so on. A symptom of unsteady walking. Posterior internal fixation of the craniocervical junction is an effective method for the treatment of deformities. It usually includes atlantoaxial internal fixation and posterior occipitocervical internal fixation. It has stable biomechanics and wide applicability, but it can be used in patients with craniocervical junction malformation. There is often atlantooccipital fusion, extensive malformation of vertebral artery and so on, which result in the screw placement being different from that of normal people, such as the anatomical variation of pedicle of axial vertebrae, if pedicle fixation is performed at this time, Clinically, spinal cord and vertebral artery injuries are likely to occur, or no fixation at all, with a high incidence of paralysis and death. The common internal fixation device is based on pedicle screw design. When the pedicle is malformed, the pedicle often has the problem of variation, which can not meet the requirement of reduction and fixation for the deformity of craniocervical junction, and the axial lamina has good screw planting condition. Based on the medical data of craniocervical junction malformation, a finite element model of craniocervical junction malformation with high geometric accuracy and reliable parameter setting is established in this paper. The stress distribution of atlantoaxial lateral articular surface under different physiological conditions was obtained by analyzing its biomechanics, which provided a way for the choice of operation plan and the design of internal fixation device. Methods: the CT scanning images of occipital bone and cervical vertebrae in a case of craniocervical junction malformation were obtained, and the three-dimensional finite element model of craniocervical junction was established by using 3D modeling and finite element software. Applying physiological load and boundary condition, the difference between the model and the normal model was compared with the clinical observation experience to verify the validity of the model, and the stress distribution of the lateral atlantoaxial joint was analyzed at the same time. 38 patients with craniocervical junction malformation were operated with the help of digital navigation according to the results of anatomical measurement and finite element analysis. Results: a finite element model of craniocervical junction deformity with high geometric accuracy and reliable parameter setting was established. The range of motion of each segment was smaller than that of related cadaveric experiment and finite element model data. It is consistent with the clinical manifestation of general craniocervical junction malformation. The stress distribution of atlantoaxial lateral articular surface was obtained under different physiological conditions, which can reasonably explain the structural variation of the lateral atlantoaxial joint and its important role in maintaining the stability between atlantoaxial joints. According to anatomical measurement and finite element analysis, the operation was performed in 4 different ways. Ct and MRI showed that the operation was successful. Conclusion: the structure of atlantoaxial lateral joint changes in patients with craniocervical junction malformation, and its biomechanical stability is valuable for preoperative diagnosis and intraoperative treatment. It provides a new accurate, safe and reliable method for doctors and has great application prospect in spinal surgery.
【学位授予单位】：第三军医大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R687

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