【作者】 陈前芬；

【导师】 金大地； 肖增明；

【作者基本信息】 南方医科大学 ， 外科学， 2009， 博士

【摘要】 1.研究背景寰椎和枢椎位于生命中枢对应的部位,具有独特及复杂的解剖结构,被称为“上颈椎”。上颈椎疾患极易造成脊髓受压,导致患者出现临床症状、瘫痪,甚至危及生命,治疗极为棘手。寰枢椎后路手术是治疗上颈椎疾患常用的手术方式,先后有寰枢椎的线缆固定技术（Gallie技术和Brooks技术）、椎板夹（Halifaxclamp）和椎板钩（Apofix）技术、经关节螺钉技术（Magerl技术）、寰椎侧块螺钉技术、寰椎椎弓根螺钉固定技术和枢椎椎板螺钉+寰椎侧块螺钉技术,各种技术均具有各自的优缺点和生物力学特性。Margel+Gallie法是目前较为公认的在治疗寰枢椎不稳方面的有效方法之一。寰椎侧块螺钉+枢椎椎弓根螺钉的稳定性与Magerl螺钉相同,但显露困难,容易引起颈髓、C₂神经根和椎动脉的损伤;寰椎椎弓根螺钉联合枢椎椎弓根螺钉的钉板固定稳定性与Magerl螺钉相当,且无需显露寰枢椎侧块关节,但进钉标志不明显,显露困难,影响置钉的安全性和准确性。目前的寰椎椎弓根螺钉进钉技术研究主要有谭明生、马向阳和校佰平等提出的方法,三种进钉技术均具有各自的优点和缺点,均非准确和简易的寰椎椎弓根螺钉进钉技术。马向阳等对单层皮质骨寰椎椎弓根螺钉固定,与双层皮质骨寰椎侧块螺钉固定及单层皮质C3椎弓根螺钉固定之间比较,认为在寰椎椎弓根固定时,单皮质螺钉的固定强度就已经足够。上颈椎位置深在,解剖复杂,变异较大,上颈椎疾患多样,单从解剖学研究显然是不够的,不能提供个体化的处理方案,而三维CT能直观地、形象地和多角度地显示复杂的上颈椎的结构改变,显示其空间位置变化,能充分弥补普通X-ray、常规CT、常规MRI和导航系统的不足,可提供治疗上颈椎疾患个体化方案。因此,本研究从应用解剖学、剖面解剖学、生物力学和三维CT影像学进行寰枢椎的观察和测量,寻找简易和准确的寰枢椎椎弓根螺钉进钉的骨性标志,明确进钉深度,为临床提供进行寰枢椎椎弓根螺钉技术的可行性依据、进钉点、进钉方向和进钉深度;探讨和判定先天性寰枢椎脱位和颅底陷入症的诊断指标和脊髓神经损伤的严重程度,强调不同患者需提供不同的个体化处理方案,为临床提供诊断和治疗先天性寰枢椎脱位和颅底陷入症的依据。2.目的2.1探讨寰枢椎椎弓根螺钉进钉的骨性标志,提出简易和准确的寰枢椎椎弓根螺钉进钉技术。2.2探讨寰枢椎皮质骨的分布情况和寰枢椎椎弓根螺钉进钉技术的限制因素。2.3探讨不同的寰枢椎椎弓根螺钉进钉技术和不同进钉深度的生物力学特性。2.4探讨先天性寰枢椎脱位和颅底陷入症的诊断指标和脊髓神经损伤严重程度的判定依据。2.5探讨先天性寰枢椎脱位和颅底陷入症的三维CT影像学特点,强调不同患者需提供不同的个体化治疗方案。3.研究方法3.1寰枢椎的应用解剖学研究选取60例120侧无破损和畸形的寰椎（C₁）和枢椎（C₂）防腐头颈标本,不分种族,性别和年龄。解剖出C₁和C₂湿骨标本后用游标卡尺测量长度（精确度0.02mm）,用量角器测量角度（精确度0.1度）,观察寰枢椎的形态和形态变化,测量其相关解剖学参数。3.2寰枢椎的剖面解剖学研究选取30例60侧无破损和畸形的寰椎（C₁）和枢椎（C₂）防腐头颈标本,不分种族,性别和年龄,解剖出C₁和C₂湿骨标本后即进行剖面解剖和观察,用游标卡尺测量长度（精确度0.02mm）,量角器测量角度（精确度0.1度）,测量其相关解剖学数值。3.3寰枢椎椎弓根螺钉技术的螺钉拔出力测定选取28具年龄20-40岁的寰枢椎防腐湿骨标本,排除颈椎外伤、变性疾病、肿瘤和骨质增生等,采用3.5mm直径皮质骨螺钉分别随机选用左右交叉组合固定方式固定于寰椎和枢椎,固定于WDW3100微机控制电子万能实验机的特殊底座和专用的把持器,测量不同进钉技术的不同深度的螺钉最大拔出力,并进行统计学分析。3.4正常人的寰枢椎三维CT应用研究选用30例于2008年1月-2008年12月因外伤导致下颈椎骨折但不涉及寰枢椎损伤的青壮年患者进行寰枢椎螺旋CT（SOMATOM Plus 4型）扫描,采用配备的三维重组软件（SUN magic view 1000）进行三维CT重建和测量相关的三维CT参数,观察寰椎和枢椎的形态及其形态变化。3.5先天性寰枢椎脱位的寰枢椎三维CT应用研究选用和收集12例于2007年1月-2008年12月初步诊断为先天性寰枢椎脱位并进行寰枢椎螺旋CT（SOMATOM Plus 4型）扫描患者的病例资料和三维CT影像学资料,采用配备的三维重组软件（SUN magic view 1000）进行回顾性三维CT重建,观察寰椎和枢椎的形态及其形态变化,测量相关的三维CT参数并与病例资料进行相关分析。3.6颅底陷入症的寰枢椎三维CT应用研究选用和收集10例于2007年1月-2008年12月初步诊断为颅底陷入症并进行寰枢椎螺旋CT（SOMATOM Plus 4型）扫描患者的病例资料和三维CT影像学资料,采用配备的三维重组软件（SUN magic view 1000）进行回顾性三维CT重建,观察寰椎和枢椎的形态及其形态变化,测量相关的三维CT参数并与病例资料进行相关分析。3.7统计学方法采用SPSS13.0统计软件对测量数据进行统计学处理,统计分析方法包括描述性统计分析、多个样本均数比较的方差分析及两两比较分析的q检验、两样本均数比较的t检验、线性相关分析。4.结果4.1后面观见寰椎后弓上缘呈坡状,接近50%左右后弓于椎动脉最内切迹处明显下降后接近水平与侧块和横突相连接,称之为“典型后弓”,可分为顶部、平稳下降部、明显下降部、接近水平部和连接部等五部,少数不规则连于侧块和横突;左、右侧面观多数见后结节隆起,后弓前缘-椎弓根上缘-侧块后缘连成一线,类似“U”形,称“U”形线;后弓前缘-椎弓根上缘-横突上缘连成一线,类似“L”形,称“L”形线,两线底部为椎弓根。后弓典型时,椎弓根螺钉垂直进钉点位于明显下降部和接近水平部交汇处的后弓中央;后弓不典型时,寰椎椎弓根螺钉垂直进钉技术的进钉点应位于距离后中线18mm,向内不能小于14mm,向外不能大于22mm。椎弓根螺钉内倾进钉点位于接近水平部和连接部交汇处的后弓中央。4.2寰椎侧块的宽度和高度明显大于螺钉的直径（3.5mm）,说明侧块可经过直径为3.5mm的螺钉,寰椎后弓（椎弓根）最薄处的宽度明显大于螺钉的直径（3.5mm）,大多数寰椎后弓（椎弓根）最薄处的高度＞4mm,说明大多数寰椎后弓（椎弓根）可经过直径为3.5mm的螺钉;寰椎垂直进钉技术的进钉深度为椎弓根中点至侧块前缘的距离,约为28mm,寰椎内倾进钉技术的进钉深度为侧块的长度,约为24mm;寰椎垂直进钉技术的进钉方向为上倾5⁰（上倾角）,不内倾,寰椎内倾进钉技术的进钉深度为内倾25⁰（侧块角）,不上倾;少数寰椎后弓最薄处的高度＜4mm,是寰椎垂直进钉技术的限制因素,寰椎内倾进钉技术的限制因素是暴露范围大,内倾角度大,损伤椎动脉和C₂神经根等周围组织的可能性大。4.3枢椎椎弓根宽度和高度明显大于螺钉的直径（3.5mm）,说明枢椎椎弓根可置入直径为3.5mm的螺钉;枢椎椎弓根螺钉技术的进钉深度为椎弓根+侧块的长度,约为28mm;进钉方向为内斜约15⁰（内斜角）,上倾约35⁰（上倾角）。4.4寰椎椎弓根部的皮质骨较厚,松质骨较少,甚至没有松质骨;枢椎椎弓根部的皮质骨较厚,松质骨较少。4.5相同进钉深度（分别进钉1/3、2/3、3/3和4/3）的C₁垂直进钉组、C₁内倾进钉组和C₂进钉组之间的最大拔出力的两两比较均无统计学差异（P＞0.05）,但是,C₁垂直进钉的不同深度最大拔出力均＞相应C₁内倾进钉的不同深度最大拔出力均＞相应C₂进钉的不同深度最大拔出力;进钉1/3的最大拔出力最小,进钉2/3的次小,进钉3/3的次大,进钉4/3的最大拔出力最大,但容易出现崩裂,三种进钉方式的进钉1/3组、进钉2/3组、进钉3/3组和进钉4/3组之间的最大拔出力的两两比较均具有统计学差异（P＜0.01）。4.6 SAC/矢状径比值的正常范围为0.55-0.65,比值＜0.50,可考虑先天性寰枢椎脱位或颅底陷入症的存在;比值＜0.40,可能存在脊髓神经的损伤,SAC/矢状径比值越小,ADI/矢状径比值越大,JOA评分分数越小,脊髓神经损伤的严重程度越大。4.7先天性寰枢椎脱位患者的寰椎中轴角＞颅底陷入症患者的寰椎中轴角＞正常成人的寰椎中轴角,先天性寰枢椎脱位患者的寰椎中轴角与正常成人的寰椎中轴角具有统计学差异（P＜0.01）,寰椎中轴角的正常范围为10⁰-35⁰,角度＞35⁰,可考虑先天性寰枢椎脱位的存在;角度＞40⁰,可能存在脊髓神经的损伤,寰椎中轴角越大,SAC/矢状径比值越小,ADI/矢状径比值越大,JOA评分分数越小,脊髓神经损伤的严重程度越大。颅底陷入症患者的寰椎中轴角与正常成人的寰椎中轴角也具有统计学差异（P＜0.01）,角度＞30⁰,可能存在颅底陷入症,但寰椎中轴角分别与SAC/矢状径比值、ADI/矢状径比值和JOA评分分数的统计学分析均无相关性（P＞0.05）。4.8大多数齿状突和枢椎椎体连接处可见线形、柱形、椭圆形、类圆形的骨质未融合区,长轴与齿状突纵轴垂直,内含纤维组织,沿骨质未融合区长轴划一横线,位于齿状突枢椎椎体连接处,称“齿体间线”;少数齿状突和枢椎椎体连接处骨质完全融合,未见骨质未融合区。正常的齿体比值为0.50-0.60,比值＞0.65,可考虑为先天性寰枢椎脱位;比值＞0.70,可考虑为颅底陷入症。4.9三维CT个体化地发现先天性寰枢椎脱位的寰枢椎形态改变和寰椎旋转移位、成角移位或旋转并成角移位等,并进行个体化的测量。个体化地发现颅底陷入症的寰枢椎形态变化,并进行个体化的测量齿状突顶点至Chamberlain线的距离和齿状突顶点至McRae线距离,分别为-7.9mm±1.5mm和-4.9mm±1.7mm。5.结论5.1寰椎后弓典型时,寰椎椎弓根螺钉垂直进钉点位于明显下降部和接近水平部交汇处的后弓中央;后弓不典型时,寰椎椎弓根螺钉垂直进钉技术的进钉点应位于距离后中线18mm,向内不能小于14mm,向外不能大于22mm。寰椎椎弓根螺钉内倾进钉点位于接近水平部和连接部交汇处的后弓中央。5.2大多数寰椎椎弓根螺钉垂直进钉技术是可行的,进钉深度约为28mm,进钉方向为上倾约5⁰,不内倾,限制因素是寰椎后弓最薄处的高度＜4mm;寰椎椎弓根螺钉内倾进钉技术也是可行的,进钉深度约为24mm,进钉方向为内倾约25⁰,不上倾,限制因素是暴露范围大,内倾角度大,损伤椎动脉和C₂神经根等周围组织的可能性大。5.3枢椎椎弓根螺钉技术是可行的,进钉深度约为28mm,进钉方向为内斜约15⁰,上倾约35⁰。5.4寰枢椎椎弓根部的皮质骨较厚,松质骨较少,提醒术者注意。5.5寰椎垂直进钉技术,寰椎内倾进钉技术和枢椎进钉技术的螺钉具有均等的抗拔出力,进钉3/3足以稳定,不必超过皮质。5.6 SAC/矢状径的比值是先天性寰枢椎脱位或颅底陷入症的诊断指标之一,可反映先天性寰枢椎脱位和颅底陷入症的脊髓神经损伤的严重程度。5.7寰椎中轴角是先天性寰枢椎脱位的诊断指标之一,可反映先天性寰枢椎脱位脊髓神经损伤的严重程度。5.8齿体间线是一个重要的解剖学标志,齿体比值是先天性寰枢椎脱位的诊断指标之一,也是颅底陷入症的诊断指标之一。5.9三维CT可个体化地观察先天性寰枢椎脱位和颅底陷入症的寰枢椎形态改变并可进行个体化的测量,从而提供个体化治疗方案。更多还原

【Abstract】 BackgroundAtlas and axis which anatomic structure is peculiarity and complicate is located in the corresponding position of vital center and is called "upper cervical vertebrae". The disease in upper cervical vertebrae is result in spinal cord compression very easily and the patient present clinical symptoms, even present palsy or threat to life, so it is very difficult to treat it. Atlantoaxial posterior approach is common operation for treat the disease in upper cervical vertebrae, there are Gallie technology, Brooks technology, Halifax clamp technology, Apofix technology, Magerl technology, massa lateralis atlantis screw fixation, atlantoaxial pedicle screw fixation and massa lateralis atlantis screw fixation combined with axial vertebral plate screw fixation, very technology has respectively advantage, disadvantage and biomechanical characteristics. It is one of effective way to treat atlantoaxial unstability by Magerl technology combined with Gallie technology at present. The stability that treated by Massa lateralis atlantis screw fixation is as same as by Magerl technology, but it is difficult to reveal and is easy to injury the spinal cord, nerve root and vertebral artery by massa lateralis atlantis screw fixation. The stability that treated by atlantoaxial pedicle screw fixation is as same as by Magerl technology, and it isn’t essential to reveal lateral mass, but it is difficult to reveal and needling mark is not clear by atlantoaxial pedicle screw fixation. Three needling technology which has respective advantage and disadvantage are used for atlantoaxial pedicle screw fixation at present, but they aren’t facility and accurate needling technology for atlantoaxial pedicle screw fixation. Ma had found that the stability was sufficient that used atlantoaxial atlantoaxial pedicle screw fixation with unilayer cortical screw. The upper cervical vertebrae is located in deep position, anatomic structure is complicate, variation is obvious and the disease is multiplicity, so it is apparently insufficient that upper cervical vertebrae would be studied only by anatomic study which couldn’t individually provided treatment scheme, but the complicate structure of the upper cervical vertebrae can be clearly showed by 3D-CT which could retrieved the shortage by common X-ray, CT, MRI and orthopedic navigation, so 3D-CT could individually provided treatment scheme for treat the disease in the upper cervical vertebrae.Therefore, in this study which contain applied anatomy, section anatomy, biomechanical study and 3D-CT exploratory development, we should observe the morphous of atlantoaxial vertebrae and measured the related parameter of atlantoaxial vertebrae, we should search the bony mark of needling and determine needling way and identify needling depth for atlantoaxial pedicle screw fixation, we should provide the feasible evidence, needling point, needling depth and needling direction for atlantoaxial pedicle screw fixation; we should evaluate and provide diadynamic criteria of congenital atlantoaxial dislocation and basilar invagination and provide assessment evidence of severity of spinal cord or nerve injury; we should evaluate the 3D-CT characteristics of congenital atlantoaxial dislocation and basilar invagination and emphasize that different treatment regimen must be provided individually to different patient.Objectives1. To search the bony mark of needling for atlantoaxial pedicle screw fixation, to produce a facility and precise needling technology for atlantoaxial pedicle screw fixation.2. To observe atlantoaxial os integumentale distribution and to evaluate the limiting factor of atlantoaxial pedicle screw needling technology.3. To evaluate biomechanical characteristics of different needling depth of different atlantoaxial pedicle screw needling technology.4. To evaluate diadynamic criteria of congenital atlantoaxial dislocation and basilar invagination and to provide assessment evidence of severity of spinal cord or nerve injury.5. To evaluate the 3D-CT characteristics of congenital atlantoaxial dislocation and basilar invagination, to emphasize that different treatment regimen must be provided individually to different patient.Materials and methods1. 60 antiseptic atlantoaxial vertebrae were harvested, the morphous and morphologic change of every specimen was observed carefully, the related anatomic parameters were measured by vernier caliper and conimeter.2. 30 antiseptic atlantoaxial vertebrae were harvested and dissected, the morphous and morphologic change of every specimen was observed carefully, the related anatomic parameter were measured by vernier caliper and conimeter.3. 28 antiseptic atlantoaxial vertebrae with 20-40 years old were harvested, the maximum draw power of different depth of different atlantoaxial pedicle screw needling technology with left and right cross combination way were measured by WDW3100 biomechanical tester4. 30 patients that were suffered with inferior cervical fracture but weren’t involve to atlantoaxial vertebrae were scanned by SOMATOM Plus 4 model, the altantoaxial vertebral morphous and morphologic change of every patient was observed carefully, the related 3D-CT parameter were measured by SUN magic view 1000.5. The case data and 3D-CT data of 12 patients suffered with congenital atlantoaxial dislocation were harvested, the altantoaxial vertebral morphous and morphologic change of every patient was observed carefully, these related 3D-CT parameters were measured by SUN magic view 1000 and analyzed mutually with the case data.6. The case data and 3D-CT data of 10 patients suffered with basilar invagination were harvested, the altantoaxial vertebral morphous and morphologic change of every patient was observed carefully, these related 3D-CT parameters were measured by SUN magic view 1000 and analyzed mutually with the case data.7. The measured parameters were analyzed by SPSS 13.0, statistical analytical method were contained descriptive statistical analysis, variance analysis of multi-sample mean comparison and q test of two-two comparison, t test of two-sample mean comparison, linerar correlation analysis.Results1. The superior border of posterior arch of atlas was looked as a clivas from norma posterior, about 50% posterior arch of atlas were connected with lateral mass and transverse process near horizontally in the most interior notch of vertebral artery after descended obviously, so called it as "typical posterior arch of atlas" and could be divided to five regions which regions were top region, stable descend region, manifest descend region, near horizontal region and connect region, and a few posterior arch of atlas which morphous was irregularity were connected with lateral mass and transverse process. Most posterior tubercle of atlas were eminence from norma lateralis, anterior border of posterior arch and superior border of pedicle and posterior border of lateral mass were connected to a line, which was looked as "U" shape, so called "U" shape line; anterior border of posterior arch and superior border of pedicle and superior border of transverse process were connected to a line, which was looked as "L" shape, so called "L" shape line, the basal part of both line was pedicle. Therefore, while the posterior arch of atlas is typical, the vertical needling point would be located in the midpoint of posterior arch of altas between obvious descending part and near horizontal part; while the posterior arch of atlas is not typical, the vertical needling point would be located in midpoint of posterior arch of altas (the distance from midpoint of posterior arch of altas to posterior median line is 18mm, it couldn’t be less than 14mm inwardly and couldn’t be more than 22mm ectadly).The introversion needling point would be located in the midpoint of posterior arch of altas between near horizontal part and connective part.2. The width and height of lateral mass of atlas and the width of the thinnest part of posterior arch of altas were more than the screw diameter (3.5mm) obviously, the height of the thinnest part of posterior arch of altas were more than 4mm mostly, needling depth of this technology was 28mm approximately, the needling direction would be upward about 5°and wouldn’t be introversion, the limiting factor was the height of the thinnest part of posterior arch of altas. Introversion needing technology of altas pedicle screw fixation was feasible too, needling depth of this technology was 24mm approximately, the needling direction would be inward about 5°and wouldn’t be upward, the limiting factor was exposure latitude, introversion angle and injury to the periphery tissue. 3. The pedicle width and height of axis were more than the screw diameter (3.5mm) obviously, needling depth of this technology was 28mm approximately, needling direction was inward about 15°and upward about 35°.4. The os integumentale was thickness and cancellated bone was thinness even no in pedicle part of atlas. The os integumentale was thickness and cancellated bone was thinness in pedicle part of axis.5. There wasn’t statistics difference of the maximum draw power between these three needling technology groups of the same needling depth, The maximum draw power of different needling depth of atlas pedicle screw vertical needling technology were more than the maximum draw power of different needling depth of atlas pedicle screw introversion needling technology, and both maximum draw power were more than the maximum draw power of different needling depth of axis pedicle screw needling technology; The maximum draw power of needling 1/3 of three needling technology was minimum, needling 2/3 was secondary small, needling 3/3 was secondary big, needling 4/3 was maximum, but the atlas or axis was easy to burst apart when it was drown in needling 4/3, there was statistics difference of the maximum draw power between these four needling depths groups of three needling technology.6. The normal ratio of SAC/sagittal diameter was 0.55-0.65, if this angle was less than 0.50, it would be diagnosed as congenital atlantoaxial dislocation or basilar invagination ; if this ratio was less than 0.40, it would be present injury of spinal cord or nerve. The less the ratio of SAC/sagittal diameter was, the more the ratio of ADI/sagittal diameter was, the less the JOA score was, and the more the severity of spinal cord or nerve injury.7. The central altas angle of congenital atlantoaxial dislocation was more than the central axis angle of basilar invagination, and both angle were more than the central axis angle of adult normal, there was statistics difference between the central axis angle of congenital atlantoaxial dislocation and the central axis angle of adult normal. the normal central altas angle was 10°-35°, if the angle was more than 35 , it would be diagnosed as congenital atlantoaxial dislocation; if the angle was more than 40°, it would be present injury of spinal cord or nerve. The more the central altas angle was, the less the ratio of SAC/sagittal diameter was, the more the ratio of ADI/sagittal diameter was, the less the JOA score was, and the more the severity of spinal cord or nerve injury. there was statistics difference between the central axis angle of basilar invagination and the central axis angle of adult normal too, if the angle was more than 30°, basilar invagination maybe be presented, but there was not statistics difference respectively between the central axis angle and the ratio of SAC/sagittal diameter, the ratio of ADI/sagittal diameter, the JOA score of basilar invagination.8. Most sclerotin no fusion area which contained fibrous tissue were found in the junction between odontoid process and axial vertebral body, which long axis was perpendicular to longitudinal axis of odontoid process, a transversal line which was drown follow the long axis of sclerotin no fusion area was located in the junction between odontoid process and axial vertebral body, so called "the interstitial line between odontoid process and atlas"; A few sclerotin complete fusion area were found in the junction between odontoid process and axial vertebral body. The normal ratios of the distance from the culminated point of odontoid process to the interstitial line between odontoid process and atlas/the distance from the culminatedpoint of odontoid process to the inferior border of atlas was 0.50-0.60, if this ratio was more than 0.65, it would be diagnosed as congenital atlantoaxial dislocation; if this ratio was more than 0.70, it would be diagnosed as basilar invagination. 9. We could individually observe morphologic change and displacement of atlantoaxial vertebrae in the patient with congenital atlantoaxial dislocation, and individually measure by 3D-CT; we could individually observe morphologic change of atlantoaxial vertebrae in the patient with basilar invagination and measure the distance from the culminated point of odontoid process to Chamberlain line and the distance from the culminated point of odontoid process to McRae line, these measure results were -7.9mm±1.5mm and-4.9mm±1.7mm respectively.Conclusions1. While the posterior arch of atlas is typical, the vertical needling point would be located in the midpoint of posterior arch of altas between obvious descending part and near horizontal part; while the posterior arch of atlas is not typical, the vertical needling point would be located in midpoint of posterior arch of altas (the distance from midpoint of posterior arch of altas to posterior median line is 18mm, it couldn’t be less than 14mm inwardly and couldn’t be more than 22mm ectadly). The introversion needling point would be located in the midpoint of posterior arch of altas between near horizontal part and connective part.2. Most vertical needing technology of altas pedicle screw fixation is feasible, needling depth of this technology is 28mm approximately, the needling direction would be upward about 5 and wouldn’t be introversion, the limiting factor is the height of the thinnest part of posterior arch of altas. Introversion needing technology of altas pedicle screw fixation is feasible too, needling depth of this technology is 24mm approximately, the needling direction would be inward about 5°and wouldn’t be upward, the limiting factor is exposure latitude, introversion angle and injury to the periphery tissue. 3. Needling technology of axis pedicle screw fixation is feasible , needling depth of this technology is 28mm approximately, the needling direction would be inward about 15°and upward about 35°.4. It must be remarked for operator that the os integumentale was thickness and cancellated bone was thinness in pedicle part of atlantoaxial vertebrae.5. The screw of vertical needing technology of altas pedicle screw fixation, introversion needing technology of altas pedicle screw fixation and needling technology of axis pedicle screw fixation has the same power to resist extraction. The stability of atlantoaxial vertebrae that fixated by atlantoaxial atlantoaxial pedicle screw fixation with needling 3/3 is sufficient, so it isn’t essential to exceed the os integumentale.6. The ratios of SAC/sagittal diameter is one of diadynamic criteria for congenital atlantoaxial dislocation or basilar invagination, it could be reflected and assessed the severity of spinal cord or nerve injury for congenital atlantoaxial dislocation and basilar invagination.7. The central atlas angle is one of diadynamic criteria for congenital atlantoaxial dislocation, it could be reflected and assessed the severity of spinal cord or nerve injury for congenital atlantoaxial dislocation.8. The interstitial line between odontoid process and axis is an important anatomic marker. The ratios of the distance from the culminated point of odontoid process to the interstitial line between odontoid process and axis/the distance from the culminated point of odontoid process to the inferior border of axis is one of diadynamic criteria for congenital atlantoaxial dislocation and one of diadynamic criteria for basilar invagination.9. Morphologic change of atlantoaxial vertebrae can be individually observed and measured by 3D-CT for congenital atlantoaxial dislocation and basilar invagination, so treatment plan can be provided individually by 3D-CT.更多还原