【作者】 沙勇；

【导师】 张绍祥；

【作者基本信息】 第三军医大学 ， 人体解剖学与组织胚胎学， 2002， 博士

【摘要】 研究背景：(1)后路经寰枢椎关节螺钉内固定术由于其优越的生物力学特性，目前在临床中广泛应用，但部分病人椎弓根较窄，椎动脉沟较深，术中易损伤椎动脉，而不适合此手术。国内目前缺乏此术式全面和精确的解剖研究。(2)随着颈前外侧区手术入路研究的深入，前路经寰枢椎关节螺钉内固定手术已逐渐在临床上应用，但目前国内缺乏对此术式解剖适应性的研究。(3)对不适合后路手术固定的寰枢椎损伤患者，前路经寰枢椎螺钉固定术已经逐渐在临床上应用，但目前国内外未见此术式的生物力学研究报道。(4)枕寰枢区域韧带众多，结构复杂，各韧带位置重叠，方向交错，不同体位的MRI影像差别很大，然而目前缺乏断面解剖与MRI的对照资料。(5)解剖结构的三维显示是目前影像诊断和解剖学研究的重点，三维影像可以从任意角度观察，详细了解解剖结构的空间关系，明确病变的范围和位置，弥补二维影像的不足，并可为外科手术入路和手术方式的选择提供重要参考。而对枕寰枢关节各韧带和经寰枢关节螺钉固定手术的螺钉置入情况进行三维显示，目前国内外未见报道。 目的：(1)对国人后路经寰枢关节螺钉内固定术的解剖学适应性进行评价；(2)对国人两种前路经寰枢关节螺钉内固定术的解剖学适应性进行评价；(3)评价两种前路经寰枢关节螺钉内固定术的力学稳定性；(4)为枕寰枢关节的韧带结构损伤的MRI诊断提供了解剖学依据；(5)枕寰枢关节各结构的三维重建显示；三维显示经寰枢关节螺钉固定手术的螺钉置入情况； 方法：(1)在100例中国成人干燥枢椎标本上，对枢椎标本的椎弓根宽度和侧块内侧高度等进行解剖学测量。(2)在100例(男性70例，女性30例)中国成人干燥寰枢椎标本上，对前路两种螺钉固定手术的螺钉置入角度和长度以及相关解剖结构进行测量。（3）利用脊柱三维运动双平面立体测量系统和MTS858型材料试验机，对18具男性新鲜枕表枢关节标本，进行两种前路螺钉固定手术疲劳实验前后的三维稳定性测量，并与Brooks和后路经襄枢关节螺钉内固定术进行比较。（4）将15具经福尔马林固定的枕表枢关节标本，制成斜冠状、矢状和水平位三个方位的连续断面标本，进行解剖学观察，并与MRI进行对照，找出各结构的最佳显示方位和最佳显示层面。（5）利用生物塑化技术，将3例标本制成1．Zmm厚的薄层断面，3例标本塑化前，分别用木质螺钉进行Magerl、前路经枢椎侧块下螺钉固定术和前路经枢椎体螺钉固定术，然后在 SGI作站上对对枕襄枢关节的各结构和螺钉固定的情况进行三维显示。 结果：＊乃6．5％的标本推弓根宽度大于4．smm，11．5％标本侧块内侧高度小于二．lmm，20石％标本椎弓根内侧高度小于4．smm，左侧占8．l％，右侧占12．5％，其中男性15．7％，女性40％的标本椎弓根内侧高度小于4．smm。螺钉固定的上倾角和内倾角分别为39．2土5．8”和6．2土2．6”。o）前路禁枢关节经枢椎侧块下螺钉固定术的螺钉标准长度为23＊ 士1．87mm，螺钉的外偏角为 24．9士 4．4”，螺钉后倾度为 15．二土 3刀”；经枢椎体螺钉固定的螺钉标准长度为36．96土5．48mm，螺钉的外偏角为24二上二，8”，螺钉后倾度为ZI．9土2．9“。O）两种前路经襄枢关节螺钉内固定术的力学稳定性较Brooks手术明显稳定，尤其在旋转组，与后路经衰枢关节螺钉内固定术相比无显著差异。（4）矢状位断面能够显示枕衰枢关节的大部分韧带，过齿突尖的正中矢状面是其显示的关键层面；过齿突中部的横断面为横韧带的关键显示层面，过齿突中部的斜冠状面为翼状韧带的关键显示层面。（5）在SGI工作站上三维显示了杭筹枢关节的骨骼及主要的韧带结构，所有结构均能够单独显示、任意搭配显示或总体显示。所有结构均可在三维空间位置上绕任意轴旋转任意角度，或者以不同的速度连续旋转。并且在 SGI作站上三维重建了三种经蓬枢关节螺钉固定手术的螺钉置入情况，显示了螺钉与椎动脉之间的位置关系，测量了螺钉的置入角度。 结论：（12．4％的国人不适合后路经衰枢关节螺钉内固定术，女性明 ·VI· 显多于男性，枢椎椎弓根变异较大，术前应进行旁矢状位的薄层CT扫描。 ①两种前路衰枢椎经关节螺钉内固定术较MagCrl术安全，但因个体差异， 手术需在C臂X线机监视下进行，以减少并发症的发生／3）两种前路经衰 枢关节螺钉内固定术具有较好的生物力学稳定性。O）临床上的枕表枢关节“韧带损伤的 MRI诊断，应注意关键层面的观察，并从多方位观察来综合判 断。⑤计算机三维重建能够清楚显示枕衰枢关节各结构的形态特点和空间 毗邻关系。螺钉置入径路的三维显示为临床手术的设计提供了一种新的方 法。更多还原

【Abstract】 Summary of Background Data: (1)Transarticular screw at the Cl to C2level of the cervical spine provide rigid fixation, but there are danger of injury to a vertebral artery. The risk is related to the variations in local anatomy. (2) An anterior surgical approach to exposing the upper cervical spine for internal fixation and bone graft recently has been developed. Few anatomy information regarding two types of the anterior transarticular atlantoaxial screw fixation between Cl and C2 is available in the literature. (3)No Studies to data have investigated the stabilizing effects of two types of the anterior transarticular atlantoaxial screw fixation. (4)The position and orientation of ligaments of the occipito-atlanto-axial joints are different . It is difficult to identify these ligaments with MRI. There are few studies about MRI finding of the ligaments and sections. (5)The value of 3D-images are that a doctor can thoroughly know the injurious condition and define the extent and position of injury in any angle and direction through rotation of the 3D images. They make up the disadvantage of 2D-images and help the surgeries to select the suitable operation technique. Few reports on computerized 3D reconstruction of the occipito-atlanto-axial joints have been reported. There are not reported on displaying the effect after the atlantoaxial transarticular screw fixation operation in three dimensions in literature.Objectives: (1) To provide morphological basis for the posterior atlantoaxial transarticular screw fixation.(2)To provide morphological basis for the anterior atlantoaxial transarticular screw fixation. (3) To evaluate the biomechanical stability provided by two types of the anterior atlantoaxialtransarticular screw fixation techniques. (4)To provide sectional anatomical basis for clinical MRI diagnosis of the ligaments around the occipito-atlanto-axial joints.(5)To provide computerized 3D reconstruction of the ligaments of the occipito atlanto axial joints and display the effect after the atlantoaxial transarticular screw fixation operation in three dimensions.Methods: (l)The data of the internal height of The pedicle width and the lateral mass were observed and measured in 100 dry axes.(2)A hundred series of dry atlas and axis specimens were used to get the significant clinic data.O) Eighteen human cadaveric occiput to C3 specimens were subjected to nondestructive testing in 6 loading modalities on a universal testing machine. Four different groups were examined: l)control group(intact); 2)unstable group (type II odontoid fracture); 3) Brooks group (dorsal atlantoaxial wire fixtion); 4) Magerl group(the posterior atlantoaxial transarticular screw fixation) or two types of the anterior atlantoaxial transarticular screw fixation(4mm above the inferior edge of C2 arch or the inferior edge of C2 centrum for the entry point of the screw placement). In a second experimental series, failure loads of the Magerl fixion and two types of the anterior atlantoaxial transarticular screw fixation methods were determined. (4) Cryosections of 15 cadaver occipito-atlanto-axial joints were compared with MR imaging matching with them in oblique coronal, sagittal, and axial planes.(5)Plastination was used to make equidistant serial thin sections with 1.2mm in thickness. The specimens were fixed with the wood screw before plastination. A SGI work station was employed to manifest the structures of the ligaments of the occipito-atlanto-axial joints and the screw fixation in three dimensions.Results: (1)The pedicle width was >4.5mm in 96.5% of all specimens. In 11.5% of them, the internal height of the lateral mass was thinned out to < 2.1mm. The internal height of the pedicle was less than 4.5mm in 20.6% of all specimens, in 12.5% of right side, and in 8.1% of left side. In 15.7% of malespecimens and in 40% of female specimens, the internal height of the pedicle was <4.5mm. The axis of the screw fixation was found to lie at 39.2 + 5.8 in the superior direction and 6.2 + 2.6 in the medial direction.(2)The firs更多还原