The vertebral level of origin of spinal nerves in the rat

Several dissections were performed to determine the level of spinal cord termination and the vertebral level at which the dorsal and ventral roots of spinal nerves C1-S4 emerged from the spinal cord in the rat. These levels of emergence were then compared to the level of exit from the vertebral canal. The dissections demonstrated that the effect of differential growth between spinal cord and vertebral column begins in the lower cervical region and becomes progressively more pronounced throughout thoracic and lumbar levels. The disparity between the vertebral level of emergence of spinal roots from the spinal cord and their level of exit via intervertebral foramina was found to be considerably larger than was previously reported by Greene ('68). It was further noted that the spinal cord terminated at the level of the intervertebral disc between the third and fourth lumbar vertebrae, not between the fourth and fifth lumbar vertebrae as reported by Greene ('68).     

Geometry of the Intervertebral Volume and Vertebral Endplates of the Human Spine

Replacement of a degenerated vertebral disc with an artificial intervertebral disc (AID) is currently possible, but poses problems, mainly in the force distribution through the vertebral column. Data on the intervertebral disc space geometry will provide a better fit of the prosthesis to the vertebrae, but current literature on vertebral disc geometry is very scarce or not suitable. In this study, existing CT-scans of 77 patients were analyzed to measure the intervertebral disc and vertebral endplate geometry of the lumbar spine. Ten adjacent points on both sides of the vertebrae (S1-superior to T12-inferior) and sagittal and transverse diameters were measured to describe the shape of the caudal and cranial vertebral planes of the vertebrae. It was found that the largest endplate depth is located in the middle or posterior regions of the vertebra, that there is a linear relationship between all inferior endplate depths and the endplate location (p < 0.0001) within the spinal column, and that the superior endplate depth increases with age by about 0.01 mm per year (p < 0.02). The wedge angle increases from T12-L1 to L5-S1. The results allow for improvement of the fit of intervertebral disc-prostheses to the vertebrae and optimized force transmission through the vertebral column.     

Anatomical relation between the accessory process and pedicle in the lumbar vertebrae

The pedicle screw is one of the most common medical devices used in spinal surgery. Although there are well-established insertion points based on anatomical landmarks, such as the mammillary process and the transverse process, morphological data on the relationship between the accessory process and the pedicle are still scarce. To clarify this relationship, we recruited 50 cases of hernia of lumbar intervertebral disc, diagnosed using three-dimensional computed tomography of the lumbar vertebrae. We identified the pedicle isthmus in a transverse plane parallel to the upper endplate and measured the angles and distances from the tip of the accessory process to the intersection points at the medial or lateral surface, or at the midpoint between the two intersection points. In a sagittal plane showing the pedicle isthmus, we measured the wedging angle of the vertebral body as well as the angle from the tip of accessory process to the posterior edge of the upper endplate of vertebral body, or to the lower end of the pedicle root. We found that from the tip of the accessory process passing through the pedicle isthmus, a line should be directed 20 (± 6.6) degrees medially in the transverse plane and 5 (± 4.3) degrees cranially in the sagittal plane. This distance from the tip of the accessory process to the isthmus was 1.5 (± 0.3) cm. Our study provides a new anatomical basis for the use of the accessory process as a landmark for insertion of the pedicle screw.     

起床过程中腰椎应力动力学响应

目的揭示起床过程中腰椎间盘的应力响应特征。方法根据实验数据,建立并验证考虑材料非线性和各向异性属性的全腰椎有限元模型,在此基础上模拟并计算人体从仰卧、起身、左转到坐在床沿完整过程中腰椎主要结构的应力分布和动态变化情况。结果起床过程中腰椎间盘纤维环、髓核及终板的应力大小和分布不断变化,各节段的应力集中在背侧,L4~5上最大,应力峰值出现在当躯干从仰卧起转过35°~62°之时,分别是坐稳时的3倍、仰卧时的17倍。结论 L4~5椎间盘后侧是损伤和退变高发区,在日常活动中实际承受的应力可能要比以往按静态测算的应力更高,影响范围也更大。动力学模拟能更全面深入地了解腰椎间盘的负载特点,为防治相关腰椎疾病提供科学依据。     

腰椎小关节不对称与椎间盘及小关节退变的关系

背景：腰椎小关节不对称与椎间盘退变程度之间的关系一直存在争议,并且国内在下腰痛患者中对小关节不对称与小关节退变程度之间关系的研究较少。 目的：调查分析腰椎小关节不对称在腰椎间盘退变与小关节退变过程中的作用。 方法：测量312例下腰痛患者共936个脊柱功能单位的小关节角度差值,差值<7°定义为小关节对称,差值≥7°定义为小关节不对称。对936个脊柱节段的椎间盘退变程度及小关节退变程度进行分级。 结果与结论：①小关节是否对称在年龄及性别上差异无显著性(P > 0.05)。②小关节不对称与椎间盘退变程度之间无显著关联(P > 0.05)。③在L4~L5节段小关节不对称组比小关节对称组的小关节退变程度更重(P < 0.01)。提示小关节不对称与椎间盘退变无明显影响,但在腰椎活动度最大的L4~L5节段,小关节不对称可能会引起小关节的退变。     

Radiographic and Magnetic Resonance Imaging Identification of Thoracolumbar Spine Variants with Implications for the Positioning of the Conus Medullaris in Rhesus Macaques

The anatomy of the vertebral column in mammals may differ between species and between subjects of the same species, especially with regards to the composition of the thoracolumbar spine. We investigated, using several noninvasive imaging techniques, the thoracolumbar spine of a total of 44 adult rhesus macaques of both genders. Radiographic examination of the vertebral column showed a predominant spine phenotype with 12 rib‐bearing thoracic vertebrae and 7 lumbar vertebrae without ribs in 82% of subjects, whereas a subset of subjects demonstrated 13 rib‐bearing thoracic vertebrae and 6 lumbar vertebrae without ribs. Computer tomography studies of the thoraco‐lumbar spine in two cases with a pair of supernumerary ribs showed facet joints between the most caudal pair of ribs and the associated vertebra, supporting a thoracic phenotype. Magnetic resonance imaging (MRI) studies were used to determine the relationship between the lumbosacral spinal cord and the vertebral column. The length of the conus medullaris portion of the spinal cord was 1.5 ± 0.3 vertebral units, and its rostral and caudal positions in the spinal canal were at 2.0 ± 0.3 and 3.6 ± 0.4 vertebral units below the thoracolumbar junction, respectively (n = 44). The presence of a set of supernumerary ribs did not affect the length or craniocaudal position of the conus medullaris, and subjects with13 rib‐bearing vertebrae may from a functional or spine surgical perspective be considered as exhibiting12 thoracic vertebrae and an L1 vertebra with ribs. Anat Rec, 300:300–308, 2017. © 2016 Wiley Periodicals, Inc.     

Trajectory architecture of the trabecular bone between the body and the neural arch in human vertebrae

The cancellous structure of vertebrae has been studied to investigate the direction of trabeculae and thus the lines of stress. The trabecular bone of the pedicle, connecting the body to the lamina, differed in different regions of the vertebral column. At C2 level, it was found that trabeculae are involved in transfer of th column. At C2 level, it was found that trabeculae are involved in transfer of the compressive forces from the superior articular surface to the inferior articular process and body. Throughout the thoracic region, trabeculae in the pedicle were inclined anteriorly towards the body, indicating that compressive forces in the thoracic spine are transferred from the neural arch to the body. In the lower lumbar region, trabeculae run from the body towards the neural arch. Trabeculae in the thoracic transverse processes extend from the costal facet to the lamina, suggesting that weight brought by the ribs to the costotransverse articulations is transmitted to laminae through transverse processes.     

The Significance of Calcified Fibrocartilage on the Cortical Endplate of the Translational Sheep Spine Model

To gain an understanding of the vertebral cortical endplate and factors that may affect the ability to achieve skeletal attachment to intervertebral implants and fusion, this study aimed to characterize the hypermineralized tissue on the cortical endplate of the vertebral body on a commonly used animal model. Skeletally mature sheep were injected with tetracycline prior to euthanasia and the C2‐C3, T5‐T6, and L2‐L3 spinal motion segments were excised and prepared. Vertebral tissues were imaged using backscatter electron (BSE) imaging, histology, and tetracycline labeling was used to assess bone remodeling within different tissue layers. It was determined that the hypermineralized tissue layer was calcified fibrocartilage (CFC). No tetracycline labels were identified in the CFC layer, in contrast to single and double labels that were present in the underlying bone, indicating the CFC present on the cortical endplate was not being actively remodeled. The average thickness of the CFC layer was 146.3 ± 70.53 µm in the cervical region, 98.2 ± 40.29 µm in the thoracic region, and 150.89 ± 69.25 µm in the lumbar region. This difference in thickness may be attributed to the regional biomechanical properties of the spine. Results from this investigation indicate the presence of a nonremodeling tissue on the cortical endplate of the vertebral body in sheep spines, which attaches the intervertebral disc to the vertebrae. This tissue, if not removed, would likely prevent successful bony attachment to an intervertebral device in spinal fusion studies and total disc replacement surgeries. Anat Rec, 296:736–744, 2013. © 2013 Wiley Periodicals, Inc.     

下腰椎骨性结构参数与腰椎间盘突出症的关系

背景：腰椎各骨性结构参数的变化是下腰部脊柱骨性结构的形态改变的直接反应,这种改变很可能是在长期受到外在或内在因素影响后脊柱正常结构应变的结果,但不同参数反映的情况是否相同以及与对应的临床症状是否有相关性尚待探讨。 目的：测量和比较下腰椎间盘突出症患者的腰椎骨性结构参数,分析参数变化与下腰椎间盘突出症的相关关系。探讨腰椎骨性结构的异常是否为腰椎间盘突出症的病因,以及在腰椎间盘退行性变中的意义。 方法：纳入2008年3月至2010年3月解放军南京军区福州总院第一附属医院骨科收治的腰椎间盘突出症患者207例,同期于放射科行CT检查显示非腰椎间盘突出者143例作为对照组。按性别差异分为男、女组;按年龄分为25-34岁组、35-44岁组、45-54岁组、55-65岁组。测量的腰椎骨性结构参数包括棘突偏斜角、关节突关节角、腰椎曲度、腰椎曲度角、腰骶关节角。 结果与结论：腰椎间盘突出症组与对照组的棘突偏斜角在L4、L5水平存在差异,数据不呈正态分布,应用秩和检验,Z值为-10.609,-12.074,P < 0.01。腰椎间盘突出症组与对照组的关节突非对称性、腰椎生理曲度、腰椎曲度角、腰骶关节角在各年龄组及总体比较差异无显著性意义(P > 0.05)。从性别上看,男、女组仅在腰骶关节角上差异有显著性意义(P=0.007 < 0.01);各年龄段间比较,55-65岁组关节突非对称性、腰椎生理曲度、腰椎曲度角、腰骶关节角分别与25-34岁组、35-44岁组之间比较差异有显著性意义(P < 0.01),在45-54岁组和25-34岁组之间差异有显著性意义(P < 0.01)。提示腰椎骨性结构参数的变异不是直接导致腰椎间盘突出症的发病原因,但腰椎骨性结构参数的异常在腰椎间盘退行性改变中的作用是不可否认的。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

Association of rudimentary sacral zygapophyseal facets and accessory and ligamentous articulations: Implications for load transmission at the L5‐S1 junction

Weight transmitted from the fifth lumbar vertebrae to the sacrum is distributed as three separate components between (a) the vertebral bodies anteriorly, (b) the transverse elements intermediately, and (c) the lumbosacral facet joints, posteriorly. The posterior components of the fifth lumbar vertebra share greater proportion of load in comparison with the posterior elements of the upper lumbar vertebral levels. This study focuses on rudimentary lumbosacral facet articulations and their possible effects on load sharing at this region. Twenty sacra bearing rudimentary articulations were collected for analysis. Sixteen of these sacra presented unilateral rudimentary facets, and the remaining four had facets that were bilaterally rudimentary. Thirteen of the sacra with unilateral rudimentary facets showed an accessory articulating area on the upper surface of the ala on the same side as the rudimentary zygapophyseal facet. The remaining three sacra (out of the 16) showed evidence of strong ligamentous attachments between the L5 and S1 transverse elements on the sides of the rudimentary facets. All the sacra with bilateral rudimentary facets demonstrated bilateral accessory L5–S1 articulations. These observations indicated that load transmission at lumbosacral junctions bearing a rudimentary facet joint is not normal and that their associations with strong L5–S1 lumbosacral ligamentous attachments or accessory articulations at the transverse elements serve a compensatory mechanism for load sharing. Clin. Anat. 23:707–711, 2010. © 2010 Wiley‐Liss, Inc.     

不同扭矩作用下腰椎有限元模型分析

应用有限元方法研究扭矩作用下腰椎内部结构的应力变化。用ABAQUS6.1有限元软件建立腰椎L4-5有限元模型。对模型加载不同的扭矩。结果为随着作用扭矩的增大以及旋转角度的加大,作用在小关节上的力量也加大。椎间盘内轴向有效应力加大,髓核内压力,纤维环的应力和应变增加。     

腰骶段椎间盘与相应椎体的应用解剖

目的　为临床诊断椎间盘疾患提供参数。方法　对 31例正常男性脊柱第 1腰椎至第 1骶椎间 15 5个椎间盘及其相应的 186个椎体上下面的矢径、横径、斜径进行了测量和比较 ,同时对其周围毗邻结构进行了观察。结果　椎间盘各径均大于其相应椎体各径 ,且自上而下逐渐增大 ,获得了腰骶段周围毗邻结构的观察结果。结论　提示结果与各椎骨间所负体重逐渐增加相适应 ,为临床应用提供解剖学依据     

腰椎关节突关节的应用解剖与在微创术中的定位价值

目的　通过解剖标本和影像资料测量腰椎关节突关节及毗邻结构的相关数据,探讨关节突关节作为腰椎微创术中重要解剖定位标志的可行性。 方法　收集新鲜成年人体腰椎标本10具20侧,共计80个节段。腰椎X线影像资料50例,200个节段。以关节突关节最高点(Highest point of lumbar zygapophysial joint, HP)作为测量中心,从微创手术应用解剖的角度,分别观测HP与手术相关结构的距离和角度。 结果　HP至腰神经距离随椎间隙向下,数值逐渐增大,而角度趋于变小;HP至邻近椎间盘的距离,向下逐渐增大;HP和相邻椎间盘中平面垂直距离为0.8~1.5 mm,HP垂直高度位于椎间盘厚度范围内。 结论　腰椎关节突关节具备位置稳定、显露简单、容易辨认、对应关系易于掌握、准确性高的特点。是理想的解剖标志。在临床腰椎后路微创手术中可发挥一定的解剖定位作用。     

模拟腰椎后路间盘摘除植骨与置融合器术T12-S1腰段脊柱粘弹性实验研究

根据国人腰椎的特点，设计研制了一种纯钛腰椎置入融合器，并进行生物力学测试，方法是取18具新鲜成年男性T12－S1腰椎标本,测定完整腰椎（正常组）模拟后路间盘摘除植骨组（对照1组）和模拟后路间盘摘除置入融合器组（对照2组）T12－S1段腰椎 的应力松弛和蠕变－时间曲线及数据。用回归分析的方法处理实验数据，得出了归一化应力松弛函数、蠕变函数及曲线，对后路间盘摘除植骨与置入纯钛融合器对 脊柱稳定性的影响进行分析讨论。     

Synovial recesses and bursae of the lumbosacral joint]

There are four types of cavities of the lumbosacral joints. Type A: The synovial membrane is all around attached to the margin of the articular facet of the superior articular process of the sacrum. Type B: The synovial membrane extends to the posterior surface of the sacrum forming a recess at the root of the superior articular process; this recess communicates widely with the cavity of the joint. Type C: The synovial membrane also forms a recess similar to that of type B, but the gap of communication is narrowed by a fibro-adipose meniscoid. Type D: The synovial membrane is attached in the same way as described in type A; besides a synovial bursa non communicating with the cavity is found at the root of the superior articular process. We have found 43% showing type A, 33% type B, 16% type C and 8% type D. The recesses and bursae described above enable the inferior articular process of the fifth lumbar vertebra to slide at the posterior surface of the sacrum, thus avoiding a painful rubbing during dorsiflexion of the lumbar spine. The existence of these sliding facilities does not depend on the range of the lumbosacral angle nor on the quality of the lumbosacral intervertebral disc.     

K-Rod动态稳定系统治疗腰椎退行性疾病的中期疗效

目的 探讨K-Rod动态稳定系统治疗腰椎退行性疾病的中期疗效及其对邻近上位节段的影响。方法 回顾性分析昆明市第一人民医院骨科2011年2月至2013年6月65例采用K-Rod动态稳定系统治疗腰椎退行性疾病患者的临床资料。其中，男31例，女34例，年龄21 ～ 73岁，平均（53.4±10.8）岁；融合组（n=21），非融合组（n=20），“融合+非融合”组（n=24）。记录术中失血量、手术时间、住院时间及并发症；根据术前及各随访时间腰痛、下肢痛VAS评分，ODI评分评价临床疗效。比较3组病例术前及随访时间腰椎侧位X线片、腰椎MRI手术及邻近上位节段椎间隙高度、椎间盘退变Pfirrmann''s分级情况。结果 经72 ～ 84个月，平均（72.0±8.6）个月随访。3组组内术后3、6个月及末次随访时腰痛、下肢痛VAS评分及ODI评分与术前比较，差异均有统计学意义（P<0.05）。末次随访时，腰痛、下肢痛VAS评分改善率，融合组为66.4%、76.7%，非融合组为84.4%、72.4%，“融合+非融合”组为70.8%、77.8%；邻近上位节段椎间盘退变Pfirrmann''s分级：非融合组、“融合+非融合”组与术前比较差异无统计学意义（P>0.05），融合组与术前比较差异有统计学意义（P<0.05）。手术节段椎间高度指数: 3组组内术后1周与术前比较，差异有统计学意义（P<0.05），术后3个月、6个月、末次随访时与术后1周比较差异无统计学意义（P>0.05）。邻近节段椎间高度指数：非融合组、“融合+非融合”组术后1周、3个月、6个月、末次随访时与术前比较，差异无统计学意义（P>0.05）；融合组末次随访与术前比较，差异有统计学意义（P<0.05）。结论 应用K-Rod动态稳定系统对腰椎退行性疾病行非融合及“非融合+融合”术治疗，中期随访疗效良好，一定程度上可延缓邻近节段椎间盘退变，对退变的椎间盘有一定的保护作用。     

Ⅰ型腰骶移行椎与正常第5腰椎的形态学比较及其临床意义

目的　探讨Ⅰ型腰骶移行椎与正常第5腰椎椎体的形态学差异,为临床应用提供形态学依据。 方法　选取Ⅰ型腰骶移行椎和正常第5腰椎标本各60例,观测：椎体上下终板前后径、横径;椎体前缘高度、后缘高度及其前/后高比值;椎弓根纵、横径。统计学分析并进行t检验。 结果　I型移行椎与正常第5腰椎相比,椎体上、下终板前后径及横径差异均有显著意义（P<0.01）;椎体的上、下前后径大1~2 mm,上、下横径大2~3 mm,前高大0.7~1.2 mm,后高大0.8~1 mm,统计均有显著意义;椎体的前/后高度比值及椎弓根纵横径I型移行椎与正常第5腰椎之间差异均无显著意义。 结论　I型腰骶移行椎椎体各径线较正常第5腰椎椎体稍大, 但形态相近; I型移行椎椎体与正常第5腰椎椎体无明显区别,I型腰骶移行椎椎弓根螺钉进钉可按正常第5腰椎方法进行。     

腰椎间盘突出症力学特征的仿真计算方法

目的建立腰椎间盘突出症力学特征的数值计算分析模型,为腰椎间盘突出症的力学机理提供一种检测评估方法。方法利用健康成人L4～5腰椎运动节段CT影像,采用Mimics 10.01医学图像处理软件和Geomagic10.0逆向工程软件分别建立L4～5腰椎运动节段的椎骨和椎间盘,并在Ansys软件中附加腰椎相关韧带及通过改变椎间盘突出后对应的材料属性,建立腰椎L4～5运动节段有限元模型,构建正常模型和腰椎间盘突出模型;运用有限元方法模拟正常椎间盘和突出椎间盘在轴向压力、前弯、侧弯、旋转和后伸5种载荷下的生物力学特征参数。结果椎间盘突出后,椎间盘的应力分布及传递载荷的能力改变,应力集中于纤维环后外侧;在相同的载荷情况下,突出的椎间盘的最大形变量比正常椎间盘的大;椎间盘突出模型的小关节突接触力比正常模型的小关节突接触力大。结论椎间盘突出后,椎间盘的承载功能下降,关节突的应力水平升高,小关节的负荷增加,从而导致腰椎稳度下降。     

Preureteric inferior vena cava with possible rudiment of the proper inferior vena cava

A right single preureteric inferior vena cava (IVC) was found in the cadaver of a 77-year-old Japanese male during a student dissection course at Kumamoto University School of Medicine in 2003. The ureter emerged from the lower end of the hilum of the right kidney at the second lumbar vertebral level. It ran inferomedially to pass behind the IVC, and turned inferolaterally to cross the vein superficially at the level of the third to the fourth lumbar vertebrae. Then, the ureter was situated to the right of the IVC, and descended ordinarily. The second lumbar vein of each side united bilaterally, as did the third lumbar veins. The common stem of the second lumbar veins drained into the left side of the IVC posterolaterally at the level of the second intervertebral disc, and the third common stem opened into the left border of the IVC at the fourth lumbar vertebral level. The ureter hooked around the IVC between the openings of those common stems. There was a small continuation (0.2 mm in diameter) between the left second lumbar and the right third lumbar veins along the vertebral column slightly right of the midline. It passed superficial to the right third lumbar artery, as did the IVC. The right testicular vein opened into the IVC at the level of the lower end of the third lumbar vertebral body. Generally, the level of the opening of the gonadal vein corresponds to the level of the caudal end of the remaining subcardinal vein, but it is lower than usual in this case. Furthermore, the segment from the confluence of the common iliac veins to the common trunk of the third lumbar veins, and to the small continuation can be regarded as the proper IVC, and the part where the ureter hooks around it may have derived from the anastomosis between the common trunk of the third lumbar veins and the subcardinal vein.     

后路椎体间植骨融合椎弓根钉内固定治疗复发性腰椎间盘突出症

目的 探讨后路椎体间植骨融合椎弓根钉内固定术治疗复发性腰椎间盘突出症的临床疗效.方法 回顾性分析本院2002年4月至2007年10月19例复发性腰椎间盘突出症患者的临床资料,包括临床表现、初次手术方式、再次手术方式、术后效果及其预后.结果 所有复发性腰椎间盘突出症患者经后路椎体间植骨融合椎弓根钉内固定术治疗,术后优良比例为84.2%(16/19),有效比例为94.7%(18/19);下腰痛JOA评分术前(10.0±1.9)分,术后(22.5±0.9)分(P<0.05).随访发现除1例患者外,其余患者腰背部疼痛明显缓解,植骨融合情况良好,未出现脊柱不稳定.结论 后路椎体间植骨融合椎弓根钉内固定术可明显缓解复发性腰椎间盘突出症患者下腰痛症状,促进相邻椎体达到骨性愈合,恢复脊柱稳定.