寰椎椎弓根与枢椎侧块关系的解剖与临床研究

目的研究寰椎椎弓根与枢椎侧块的位置关系,建立以枢椎侧块为解剖标志的寰椎椎弓根螺钉进钉定位技术,并通过临床应用评价其可靠性。方法取50套干燥寰枢椎标本,测量寰椎椎弓根和枢椎侧块的内缘、中点(内、外缘中点)、外缘与正中矢状线的垂直距离,计算寰椎椎弓根与枢椎侧块的内缘间距、中点间距和外缘间距,建立寰椎椎弓根螺钉进钉定位技术。临床应用该定位技术进行后路寰椎椎弓根螺钉固定治疗寰枢椎不稳患者6例,男5例,女1例;平均年龄41岁。其中游离齿突1例,齿突发育不良3例,齿突陈旧性骨折2例。结果寰椎椎弓根的内缘、中点、外缘分别在枢椎侧块的内缘、中点、外缘的内侧(1.37±0.51)mm、(1.60±0.61)mm、(2.15±0.60)mm处。确定寰椎椎弓根螺钉的进钉点为:经枢椎侧块内、外缘的中点作纵垂线,与寰椎后弓上缘交点的正下方3.0mm处。6例患者共放置寰椎椎弓根螺钉12枚,术中无脊髓和椎动脉损伤等并发症,术后X线及CT扫描显示螺钉位置均良好。结论枢椎侧块与寰椎椎弓根间存在较恒定的解剖位置关系,枢椎侧块可作为术中确定寰椎后弓显露范围和判断寰椎椎弓根螺钉进钉点的解剖学标志,可简化术中繁琐的定位操作。     

寰椎椎弓根螺钉进钉点的解剖定位研究

目的 建立简易可靠的寰椎后路椎弓根螺钉进钉点的定位技术。方法 设定寰椎椎弓根螺钉的进钉点,利用40套干燥配套寰枢椎标本,测量与进钉点相关的数据参数,分析数据之间的关系。结果 寰椎椎弓根螺钉进钉点和枢椎下关节突中线与后正中矢状面的距离分别是19.61mm、19.21mm,二者仅相差0.40mm。结论 枢椎下关节突中心点可作为术中判断寰椎椎弓根螺钉进钉点的解剖学定位标志。     

中上颈椎侧块与寰椎椎弓根位置关系的解剖研究

目的研究中上颈椎侧块与寰椎椎弓根的位置关系,建立以中上颈椎侧块为解剖标志的寰椎椎弓根螺钉进钉点定位技术。方法20具尸体标本,分别测量寰椎椎弓根和中上颈椎侧块的内缘、中点、外缘与正中矢状面的垂直距离,通过分析测量值间的关系,建立寰椎椎弓根螺钉进钉定位技术。结果C2-4侧块的内缘分别在寰椎椎弓根内缘外侧0．37mm、0．27mm、0．24mm处;C2-4侧块的中点分别在寰椎椎弓根中点外侧1．18mm、1．41mm、1．74mm处;C2-4侧块的外缘分别在寰椎椎弓根外缘外侧1．96mm、2．54mm、3．24mm处。结论中上颈椎侧块与寰椎椎弓根间存在较恒定的解剖位置关系,C3和C4侧块与枢椎侧块一样,可作为术中确定寰椎后弓显露范围和判断寰椎椎弓根螺钉进钉点的解剖学标志。     

寰椎椎弓根螺钉进钉点的解剖定位研究

目的：建立简易可靠的寰椎后路椎弓根螺钉进钉点的定位技术。方法：设定寰椎椎弓根螺钉的进钉点，利用40套干燥配套寰枢椎标本，测量与进钉点相关的数据参数，分析数据之间的关系。结果：寰椎椎弓根螺钉进钉点和枢椎下关节突中线与后正中矢状面的距离分别是19.61mm、19．21mm，二者仅相差0．40mm。结论：枢椎下关节突中心点可作为术中判断寰椎椎弓根螺钉进钉点的解剖学定位标志。     

枢椎以横突后支与下关节突交界处为解剖标志行椎弓根置钉的应用解剖研究

目的 :探讨枢椎以横突后支与下关节突交界处为解剖标志行椎弓根置钉的可行性,为临床应用提供参考。方法:30具湿性成人颈椎尸体标本,显露并以枢椎横突后支与下关节突外侧缘交界处作为参照点标志。经该解剖标志作水平线,以椎弓根内、外侧缘与侧块交界处连线的中点作纵垂线,以两线的交点偏外1~2mm处为进钉点。分别测量枢椎横突后支的宽度,进钉点与该解剖标志、C2神经根、横突孔内下壁和椎管内侧壁的距离。取上述进钉点,经枢椎双侧椎弓根以内倾角25°~30°、头倾角20°~25°共置入60枚螺钉,再行CT扫描观察钉道的完整性,测量置入螺钉的内倾角和头倾角,统计螺钉偏置率。结果:所有解剖参数及螺钉角度左、右侧比较差异均无统计学意义(P0.05),双侧数据合并后计算总体平均数值。枢椎横突后支的宽度为5.13±0.15mm,进钉点与解剖标志、C2神经根、横突孔内下壁和椎管内侧壁的距离分别为5.73±0.62mm、4.04±0.21mm、5.32±0.49mm和4.94±0.38mm。螺钉内倾角和头倾角分别为28.4°±3.1°和22.5°±2.9°。60枚螺钉中,共有4枚螺钉偏置进入横突孔或椎管,螺钉偏置率为6.7%(4/60);4枚螺钉过长穿破椎体前缘骨皮质。结论:枢椎以横突后支与下关节突交界处作为椎弓根置钉进钉点的参照点解剖标志是可行的,但因解剖差异仍存在螺钉误置的可能。     

寰椎椎弓根螺钉置钉的解剖与临床研究

目的：建立和验证寰椎后路椎弓根螺钉固定的进钉技术。方法：利用40套干燥配套寰枢椎标本测量进钉技术的相关参数，而后临床应用该技术方法置钉并行X线、CT复查其准确性。结果：寰椎椎弓根平均宽度为7．78mm，进钉点在寰椎椎弓根中线外侧2．2m，螺钉进钉点可由经枢椎下关节突中点的纵垂线来确定；手术中该方法不仅能简化操作过程，而且术后检查发现螺钉均准确置入。结论：用枢椎下关节突中点作为术中判定寰椎椎弓根螺钉进钉点的方法准确可靠。     

枢椎椎弓根螺钉进钉点及植钉方式的解剖研究

目的对成人尸体枢椎干骨标本进行解剖学测量,探索一种简便、精确的植钉方法,为临床枢椎椎弓根螺钉内固定提供解剖学依据。方法取60具完整且无畸形的成人尸体枢椎干骨标本,以椎弓根内、外侧缘与侧块交界处连线的中点作纵垂线,经横突后支与下关节突外侧缘交界处作水平线,两线交点偏外1~2 mm处为进钉点,经椎弓根植钉,分别测量椎弓根高度及宽度、最大进钉长度、钉道至椎管和横突孔最短距离、进钉角度等解剖参数,评估枢椎椎弓根螺钉植钉的可行性及安全性。结果椎弓根上缘、中部、下缘宽度分别为(7.35±0.89)、(5.50±1.48)、(3.97±1.01)mm,椎弓根高度为(9.94±1.16)mm。最大进钉长度为(25.91±1.15)mm,进钉方向与冠状面夹角为(26.95±1.88)°、与矢状面夹角为(22.81±1.61)°。钉道至椎管、横突孔的最短距离分别为(2.72±0.83)mm和(1.98±0.26)mm。结论分别经椎弓根内、外侧缘与侧块的交界处,以及经横突后支与下关节突外侧缘的交界处作为枢椎椎弓根进钉点坐标的定位标志进行植钉,在解剖形态学方面是安全、可行的。     

枢椎椎弓峡部引导下寰椎椎弓根置钉的CT测量及其应用

目的:探讨在枢椎椎弓峡部引导下实施寰椎椎弓根螺钉置钉的可行性及安全性。方法:对48例成人寰枢椎行三维CT重建,取枢椎椎弓峡部内上缘与寰椎的横断面图像。测量椎管正中线至寰椎椎弓根内壁、外壁及枢椎椎弓峡部内壁、外壁的距离,分别为L1、D1、L2、D2;0°内倾角置钉时,以枢椎椎弓峡部内上壁为解剖标志,确立最内侧进钉点A和最外侧进钉点B,减去螺钉半径1.75mm,A、B点至枢椎椎弓峡部内上壁的距离分别为(L1-L2+1.75mm)、(D1-L2-1.75mm),寰椎后弓上置钉时螺钉允许的最大内倾角与最大外倾角大致相等时的点为最佳进钉点(M点),记录M点至枢椎椎弓峡部内上壁水平间距。自2004年3月～2009年3月对29例患者采用以枢椎椎弓峡部为标志实施后路寰枢椎椎弓根螺钉内固定手术,其中陈旧性齿状突骨折24例,横韧带损伤并寰椎前脱位5例。观察手术过程中与寰椎椎弓根螺钉置钉相关的并发症,术后三维CT重建观察螺钉的位置。结果:0°内倾角置钉时,CT测量最内侧进钉点A、最外侧进钉点B、最佳进钉点M至枢椎椎弓根峡部内上壁的水平间距分别为4.22±0.54mm、8.66±0.73mm、5.79±0.63mm。临床共置入寰椎椎弓根螺钉58枚,术中枢椎椎弓峡部内上壁均得到良好显露,未出现椎动脉、静脉丛损伤出血及脊髓、C2神经根损伤等并发症。术后三维CT复查显示所有寰椎椎弓根螺钉均未误入椎管或椎动脉孔,测量寰椎椎弓根螺钉进钉点与枢椎椎弓峡部内上壁水平间距为5.45±0.82mm,与术前M点测量值相比较无显著性差异。结论:在纠正寰椎旋转移位后,以枢椎椎弓峡部内上壁作为解剖参照,寰椎椎弓根存在一定的置钉安全区间,利用该解剖标志行寰椎椎弓根置钉是安全可行的。     

以枢椎椎弓峡部内上壁为解剖标志行枢椎椎弓根置钉的CT测量及临床应用

目的:探讨以枢椎椎弓根峡部内上壁为解剖标志的枢椎椎弓根螺钉置钉的可行性及安全性。方法:57例成人枢椎行三维CT重建,在三维重建图像上测量枢椎左右侧椎弓根的中部宽度L1和高度L2;以枢椎椎弓峡部内上壁为标志横断面确立左右侧的最外侧模拟进钉点B和最内侧模拟进钉点A到峡部距离;测量最佳进钉点S(经过枢椎椎弓根中部宽度连线的中垂线与峡部后侧皮质交点)到峡部内壁距离,分别测量A、B、S点横断面进钉角度最大置钉角度区间;冠状面上测量S点距离峡部内上壁距离;测量S点进钉最佳内倾角及上倾角。选择2007年10月～2011年7月收治的33例患者采用枢椎椎弓根峡部内上壁为标志实施枢椎椎弓根螺钉内固定术,其中新鲜齿状突骨折13例,陈旧性齿状突骨折10例,横韧带损伤伴寰枢椎脱位7例,寰椎骨折3例。观察手术中与枢椎椎弓根螺钉置钉相关的并发症,术后三维CT重建观察螺钉的位置。结果:CT横断面测量进钉点A、B、S到峡部的距离为1.75mm、9.01±0.62mm、5.77±0.53mm,S点置钉角度区间与A、B点置钉角度区间比较有显著性差异(P<0.05)。冠状面上S点距离峡部内上壁距离为4.30±0.49mm;S点进钉内倾角为30°、上倾角为26°时为最佳进钉角度。临床共置入枢椎椎弓根螺钉66枚,术中显露良好,未出现椎动脉、静脉丛损伤出血及脊髓、神经根损伤等并发症。术后三维CT复查显示所有枢椎椎弓根螺钉均未误入椎管或椎动脉孔,术中测量枢椎椎弓根螺钉进钉点横断面上与枢椎椎弓峡部内壁水平间距为5.44±0.72mm,冠状面上距离峡部内上壁为4.50±0.52mm,与术前S点测量值相比较均无显著性差异。结论:枢椎椎弓根与峡部存在恒定位置关系,以枢椎椎弓峡部内上壁为解剖参照行枢椎椎弓根置钉是安全可行的。     

后路寰枢椎侧块关节融合器置入的临床应用解剖

目的了解国人寰枢椎侧块关节周围血管、神经的解剖关系,为后路寰枢椎侧块关节融合器准确、安全置入提供解剖学依据。方法选用成人尸体标本20具,冠状面上观察寰枢椎侧块关节后缘周围解剖关系;平枢椎侧块上关节面后缘测量C1、2间椎动脉内缘至颈髓硬脊膜外缘的距离,确定手术冠状位的"安全操作空间";测量枢椎下关节突后内缘的纵垂线与枢椎椎弓上缘交点(G点)至枢椎椎弓根上缘中线延长线的水平距离,确定手术切入点。结果 "安全操作空间"为(19.72±1.84)mm,水平距离为(2.23±0.45)mm。寰枢椎后膜下的静脉丛主要集中在寰枢椎侧块关节的外缘、上方和内缘,其下方尤其枢椎椎弓根上缘的静脉丛稀疏。位于寰椎椎弓根下方、寰枢椎侧块关节内上侧的C2神经根,距颈硬脊膜外缘5~7 mm处膨大成颈神经节,并发出前、后支。结论 G点恒定在枢椎椎弓根上缘中线延长线的内侧2.5 mm处,以此点向外水平旁开2.5 mm,向上推开寰枢后膜,内上骨膜下剥离并沿枢椎椎弓根上缘中线一并剥离枢椎椎弓根骨膜和寰枢椎侧块关节囊,即可显露寰枢椎侧块关节并置入融合器。以此入路在"安全操作空间"内置入融合器,可避免切开寰枢后膜而损伤血管和神经,保证了手术的安全。     

经后路寰椎椎弓根螺钉固定的置钉研究

目的探讨经后路寰椎椎弓根螺钉固定的可行性. 方法利用20具颈椎尸体标本,模拟经后路寰椎椎弓根螺钉固定.在寰椎后弓后缘表面,经枢椎下关节突中心点纵垂线与寰椎后弓上缘下方3 mm水平线的交点作为进钉点,按内斜10度、上斜5度钻孔,经寰椎椎弓根置入直径3.5 mm的皮质骨螺钉.测量进钉点与寰椎椎弓根中线平面的距离、螺钉最大进钉深度、螺钉内斜角度和螺钉上斜角度等解剖指标,观察螺钉是否突破椎弓根和侧块骨皮质,以及椎动脉、硬膜、脊髓是否损伤等. 结果共放置40枚寰椎椎弓根螺钉,测得进钉点与寰椎椎弓根中线的平均距离为(2.20±0.42) mm,螺钉最大进钉深度平均(30.51±1.59) mm,螺钉内斜角度平均(9.70±0.67)度,上斜角(4.60±0.59)度.其中1枚螺钉因上斜角度过大穿破椎弓根上缘,8枚因后弓高度过小而突破椎弓根下缘,5枚进钉过深突破寰椎侧块前缘皮质,但均未对脊髓和椎动脉造成损伤. 结论经后路行寰椎椎弓根螺钉固定是安全可行的,但应注意进钉角度和深度.     

Applied anatomy of the lower cervical pedicle screw insertion

OBJECTIVE: To ascertain an accurate approach to inserting the pedicle screw into C3-C7 segments of the cervical vertebra. METHODS: Anatomic morphology of lateral mass and pedicle, and their anatomic relationship with the adjacent tissue were observed on C3-C7 segments of 25 adult embalmed cadavers (50 sides). RESULTS: 1) The inferior edge of the base of the posterior tubercle of the transverse process and the inferior edge of the pedicle were connected with each other on 25 adult embalmed cadavers (50 sides). The transverse section which passed through the median point between the superior edge and the inferior edge of the base of the posterior tubercle of the transverse process, and the transverse section which passed through the central axis between the superior edge and the inferior edge of the pedicle, were in the same horizontal plane. The superior and inferior position of placing the pedicle screw was determined by this transverse section, which passed through the median point between the superior and the inferior edge of the base of the posterior tubercle of the transverse process. 2) There was a directed internal-downwards "triangular sulcule" between the base of the posterior tubercle of the transverse process and the anterolateral edge of the inferior articular process. The anterior wall of the triangular sulcule was the base of the posterior tubercle of the transverse process, the posterior wall was the anterolateral edge of the inferior articular process, and the bottom of the sulcule was connected with the interior edge of the pedicle. The vertical length between the top of triangle and the planes of inferior edge of the pedicle was (2.78+/-1.71) mm. The inferior edge of the cervical pedicle could be detected using a blunt probe along the "triangular sulcule" between the base of the posterior tubercle of the transverse process and the anterolateral edge of the inferior articular process in surgical operation. 3) The lateral fovea of the articular process was observed on all lateral masses (50 sides). The internal and external position of the entrance point could depend on anatomic landmarks: the lateral edge of the lateral fovea of the articular process. The horizontal length between the lateral fovea of the articular process and the entrance point was (3.14+/-1.45) mm. 4) The diameter of pedicle screw, about (2.78+/-1.71) mm, was the transverse diameter of the cancellous bone of the greatest narrow part of the cervical pedicle. CONCLUSIONS: The median point between the superior edge and the inferior edge of the base of the posterior tubercle of the transverse process, the lateral fovea of the articular process, and the triangular sulcule between the base of the posterior tubercle of the transverse process and the anterolateral edge of inferior articular process, are easy to be exposed and identified in surgical operation. The pedicle screw can be precisely inserted through this method.     

The segmental pectoralis major free flap: anatomical features of its vascular pedicle

BACKGROUND: The pectoralis major muscle may be suited for free transplantation of a segment of the muscle. We investigated the length and diameter of its vascular pedicle to determine its feasibility. METHODS: The length of the pedicle, its arterial diameter, and its entry point into the muscle were determined in 17 cadaveric flaps. RESULTS: The pedicle length up to the medial border of the pectoralis minor muscle averaged 6.6 cm. The mean external arterial diameter was 1.8 mm, and the venous diameter was consistently larger. The vascular pedicle consistently entered the muscle lateral to the midpoint of, and a mean of, 8.8 cm caudal to the clavicular line. CONCLUSION: The vascular length and diameter are sufficient for microvascular anastomosis. Although an anatomic landmark for the cranial border of the flap could not be defined, the sternocostal part of the pectoralis major muscle may potentially be used as a segmental free flap.     

Accuracy of pedicular screw placement in vivo

The accuracy of pedicular screw placement was assessed in 40 consecutive patients treated with the AO "Fixateur Interne." Postoperative CT scans were used to measure canal encroachment from the medial border of the pedicle, the angle of insertion and the point of entry. Eighty-one percent of the screws were placed within 2 mm of the medial border of the pedicle and 6% had 4-8 mm of canal encroachment with two patients developing minor neurological complications that spontaneously resolved. Four percent were inserted lateral to the pedicle. The parameters linked to satisfactory screw placement include entry point, angle of insertion and pedicular isthmus widths. Improvement in accuracy was noted in the latter 25% of screw insertions, reflecting the learning curve associated with this technique.     

枢椎棘突螺钉与椎弓根螺钉的解剖学比较

目的：比较枢椎棘突螺钉和椎弓根螺钉的技术难度和相关解剖学参数,探讨枢椎棘突螺钉固定的可行性和安全性。方法：自2010年2月至7月,选取10具颈椎标本,男5具,女5具,年龄45～76岁,平均60.5岁。将标本俯卧,颈部置于中立位。从C1-C3剔除颈部后侧所有的软组织,以清楚地暴露枢椎侧块和峡部。枢椎椎体左右侧任意选择进行棘突螺钉和椎弓根螺钉固定,各10枚螺钉,置入直径为4.0mm的皮质骨螺钉。枢椎棘突螺钉以枢椎棘突螺钉的进钉点选择为棘突的基底部、棘突和椎板的交界处,进钉角度水平置钉,螺钉由对侧棘突基底部穿出,形成双层皮质固定;枢椎椎弓根螺钉进钉点为枢椎下关节突根部中点,钉道方向与矢状面夹角15°～20°,与横断面夹角约30°。螺钉置入后,使用多层螺旋CT扫描机对标本进行扫描重建。测量螺钉在骨内的实际深度,记录椎弓根螺钉和棘突螺钉置钉失败、穿破椎弓根、进入椎管或置入横突孔的螺钉数目。结果：枢椎棘突螺钉和椎弓根螺钉的置入均无明显的技术困难。棘突螺钉未见螺钉置入椎管和劈裂棘突,但椎弓根螺钉有1枚螺钉突出椎弓根外侧皮质,侵犯横突孔。枢椎棘突螺钉的平均钉道长度为（21.4±1.4）mm,稍短于枢椎椎弓根螺钉的（23.7±1.0）mm,但两者间差异无统计学意义（t=-4.387,P〉0.05）。结论：枢椎棘突基底部具有螺钉固定的可行性,枢椎棘突螺钉较椎弓根螺钉固定相对安全、简单。     

Pedicle screw fixation of the C7 vertebra using an anteroposterior fluoroscopic imaging technique

Cervical pedicle screws have been reported to be biomechanically superior to lateral mass screws. However, placement of these implants is a technical challenge. The purpose of this investigation was to use an anatomic and a clinical study to evaluate a technique for placement of the pedicle screws in the C7 vertebra using fluoroscopic imaging in only the anteroposterior (A/P) plane. Ten adult cadaver C7 vertebrae were used to record the pedicle width, inclination and a suitable entry point for placement of pedicle screws. A prospective study of 28 patients undergoing posterior instrumentation of the cervical spine with C7 pedicle screw placement was also performed. A total of 55 C7 pedicle screws were placed using imaging only in the A/P plane with screw trajectory values obtained by the anatomic study. Radiographs and CT scans were performed post-operatively. The average posterior pedicle diameter of C7 vertebra was 9.5 ± 1.2 mm in this study. The average middle pedicle diameter was 7.1 mm and the average anterior pedicle diameter was 9.2 mm. The average transverse pedicle angle was 26.8 on the right and 27.3 on the left. CT scans were obtained on 20 of 28 patients which showed two asymptomatic cortical wall perforations. One screw penetrated the lateral wall of the pedicle and another displayed an anterior vertebral penetration. There were no medial wall perforations. The preliminary results suggest that this technique is safe and suitable for pedicle screw placement in the C7 vertebra.