寰椎后弓交叉螺钉-新旋转中心控制方式的寰枢椎固定

Atlanto-axial joint is complex structure, if unstable,there will be great risk for life, while it is the most difficult part for fixation in orthopedics. In order to find an easy and effect method, we designed a new mode of fixation - screws cross atlas posterior arch, then combined with axial screws. And we conside about these kind of fixation methods to form a "new rotating center control" theory, that is, according to the special movement of the atlantoaxial joint, in the location far away from the opposite direction to the original center of rotation of the biomechanical stability system, the establishment of a fixed center of rotation of the system, can achieve the effect that minimal internal fixation control the rotation of three-dimensional directionand displacement effectively. The law is proven by the anatomical and imaging studies, preliminary three-dimensional finite element model analysis confirmed that the fixed requirements, fixation strength was significantly better than the wire and laminar hooks, and achieve the effect of pedicle screw fixation model in sagittal and horizontal plane; it is simple to exposure the organization, reduce the risk of the vice injury of the blood vessels and nerves. By finite element analysis and biomechanical experiments, this topic is designed to further validation the form of atlantoaxial fixation, like the stress distribution of atlanto-axial joint and the fixations, the intensity of the new center of rotation mode in several injury patterns,the stability in real-time, and the difference between the way of pedicle screw fixation. Long-term fixation strength is examined by fatigue test. Supports is provide for the new fixation system and its clinical application. We will write 3 to 5 papers, and design 2 to 3 patents.

寰枢椎结构复杂，不稳定危及生命，是脊柱外科的最难固定部位之一.为寻求易行又符合临床要求的固定，我们设计一种新的经寰椎后弓交叉螺钉固定方式，与枢椎螺钉结合。并提出"新旋转中心控制"理论，即据寰枢椎间的特殊运动方式，在原生物力学稳定系统的旋转中心位置相反方向的最远处，建立固定系统的旋转中心，能达到用最小的内固定器械最能有效控制三维方向的旋转和位移。该法经解剖学及影像学研究证实可行，初步三维有限元模型分析证实达到固定要求，固定强度明显优于钢丝及椎板钩，矢状面和水平面能达到椎弓根钉固定的效果；且操作简单，暴露的组织少，减少血管神经副损伤的风险。本课题通过有限元分析和生物力学实验进一步验证寰枢椎及内固定物的应力分布情况、新的旋转中心模式在几种损伤模式下的固定强度、即时稳定性、与椎弓根钉系统固定方式的差别；通过疲劳试验测试远期固定强度。为新的内固定系统和其临床应用提供支持。论文3~5篇，专利2~3项。

探讨一种新型寰椎固定方式，通过寰椎后弓进行交叉螺钉，结合枢椎螺钉，达到有效固定寰枢椎不稳的目的，并提出“新旋转中心有效控制”的理论。寰椎后弓交叉螺钉固定操作简单，暴露的组织少，减少了椎弓根螺钉，侧块螺钉等血管神经副损伤的风险，而其固定强度明显优于钢丝及椎板钩的固定方式。通过解剖及影像学方法证实可行性，三维力学实验证实即时稳定性，旋转中心变化；疲劳试验验证远期固定强度；通过三维有限元测试寰枢椎及内固定物的应力分布情况，探讨此法成为寰枢椎固定的可供选择的方法。寰枢椎是完全不同于其他部位脊柱的运动节段，有其独特的运动特点，损伤后三维运动的旋转中心发生变化，对其进行不同的固定后，旋转中心又因为内固定而发生变化，对此提出有效的控制新的旋转中心的固定理论，即新的固定系统应尽量远离旋转中心，这样可以即可以节省固定强度又能够有效控制活动，通过该理论指导术中选择有效固定