寰椎横韧带的形态特点及其生物力学特性研究

目的 :研究寰椎横韧带的形态特点及其抗拉伸性能。方法 :成人寰枢椎固定标本 2 4例及新鲜寰椎横韧带标本 9例。测量横韧带中点处的厚度、宽度以及左右两端的宽度。取 2例新鲜横韧带标本行组织学片观察。 7例新鲜横韧带标本 ,通过MTS -85 8材料试验机测试其抗拉伸性能。结果 :寰椎横韧带的长度为 ( 2 0 .0± 2 .4)mm ;中点处的厚度为 ( 2 .1± 0 .5 )mm ;中点处的宽度为 ( 10 .7± 1.6)mm ;左右两端的宽度分别为 ( 6.6± 1.1)、( 6.7± 1.0 )mm ;左右两端的厚度分别为 ( 3 .8± 1.1)、( 3 .7± 1.1)mm。横韧带与枢椎齿突的关系可分为三种类型 :①横韧带将齿状突后面完全包裹 ,占 3 0 .3 % ( 10例 ) ;②横韧带包裹齿状突后面的大部 ,超过 1/ 2 ,占 5 4.5 % ( 18例 ) ;③部分覆盖齿状突的后部 ,不超过其 1/ 2 ,占 14 .5 % ( 5例 )。寰椎横韧带的齿状突面的中部可见有纵行的纤维 ,组织切片显示为较疏松的结缔组织。横韧带的最大载荷为( 60 5 .5± 89.6)N ,最大变形量为 ( 4 .3± 0 .5 )mm。结论 :( 1)本文结果与国外的相关报道比较 ,在长度上较白种人稍短 ,而与黄种人相近 ,这与人种的高矮有关。 ( 2 )寰椎横韧带与齿突接触面的中部可有条索状的疏松结缔组织存在。 ( 3 )寰椎横韧带与枢椎齿突的关系不恒定 ,     

胸腰椎脊柱韧带拉伸性能的实验研究

目的：测试胸腰段脊柱韧带拉伸性能。方法：采用７例新鲜青年男性尸体胸腰椎脊柱韧带，进行解剖学观察和力学测试，每个韧带的测试除外其它因素单一进行。记录最大载荷－位移曲线和韧带的形态、力学改变，峰值为韧带断裂的标志。结果：前纵韧带、后纵韧带、棘间、棘上韧带最大破坏载荷依次为：６５４±６３Ｎ，２９１±４９Ｎ，９８±４３Ｎ，３８５±９３Ｎ；最大位移依次为：１１．４±２．６ｍｍ，４．５±１．５ｍｍ，３．８±１２．２ｍｍ，１６．０±５．０ｍｍ；结构刚度依次为：６０．４Ｎ／ｍｍ，５６．２Ｎ／ｍｍ，２５．０Ｎ／ｍｍ，４０．５Ｎ／ｍｍ。结论：不同种韧带的解剖形态和生理特点不同，具有不同的生物力学特性。     

寰枢椎的临床应用解剖学研究进展

寰枢椎作为枕颈移行部,形态结构复杂,功能特殊。因其邻近颈髓、椎动脉和颈神经等重要结构,此区的畸形与病损常导致严重的临床后果。又因其部位深在及生物力学性质独特,其病损的诊断和治疗相对复杂和棘手,一直是脊柱外科的难点之一。本文拟就与临床床有关的寰枢椎的解剖形态结构作一文献综述。     

新型钉尾横连在后路寰枢椎固定中的生物力学分析

背景：后路寰-枢椎椎弓根钉棒内固定是治疗寰枢椎脱位的主要方法,横连接在内固定系统抗旋转能力中起着重要作用。新型寰椎钉尾横连可以有效克服传统横连安装不便、影响植骨床和脊髓损伤可能等缺点,但不同安装模式的新型钉尾横连的生物力学性能尚不清楚。目的：测试不同安装模式的新型寰椎钉尾横连在后路寰-枢椎椎弓根钉棒内固定系统中的生物力学特性,为临床选择最佳安装模式提供理论依据。方法：6具新鲜人体枕颈标本作为完整组(A组),在完整组基础上建立Ⅱ型齿状突骨折的寰枢椎失稳模型(B组),在失稳组基础上对每具标本先后进行后路寰-枢椎椎弓根钉、棒内固定(C组),在C组上依次安装不同模式新型寰椎钉尾横连,其中包括上水平横连(两寰椎螺钉钉尾)为D组,下水平横连(两枢椎螺钉钉尾)为E组,斜形横连(左上右下为F组,左下右上为G组),交叉横连为H组。在三维运动机上将标本模型按顺序进行前屈、后伸、左右侧屈和左右旋转测试,获取各个内固定状态下的寰枢椎活动度。运用重复测量方差分析评价各组模型的生物力学特性。结果与结论：(1)在6种工况下,A、C、D、E、F、G、H组寰枢椎活动度小于B组,差异均有显著性意义(P <0.05)...     

寰椎椎弓和枢椎椎板的应用解剖

目的：为颈后路寰枢椎钛缆固定术和相关器械设计提供解剖学依据。方法：在100例中国成人干燥标本上,观察寰椎后弓和枢椎椎板的形态学特点并进行解剖学测量。结果：(1)寰椎后弓较纤弱,上面与椎管不平行,从后上方向内下方倾斜;(2)枢椎椎板较粗大,上窄下宽,内面基本平行椎管,内面下缘多形成一骨嵴。结论：(1)寰椎后弓和枢椎椎板穿绕钛缆时宜自上向下操作,为方便操作,可以咬除部分枢椎椎板上缘;(2)设计枢椎椎板穿绕钛缆的引导器械时需考虑到其内面的骨嵴。     

寰椎枕骨化对枕颈部生物力学影响的实验研究

目的 :建立人类寰椎枕骨化模型 ,进行生物力学测试 ,阐明寰椎枕骨化畸形对枕颈部生物力学的影响。方法 :采用新鲜人体枕颈部标本制作人类寰椎枕骨化实验模型 ,分别对标本和模型进行生物力学测试 ,确定寰枕关节和寰枢关节的运动参数 ,进行统计学分析。结果 :与标本比较 ,模型的枕寰关节各轴向的运动几近消失 (P <0 .0 0 1 ) ,最大的运动参数是后伸运动范围 ,仅 0 .2 1°。寰枢关节屈曲运动的弹性区和运动范围分别从正常的 1 1 .71°和 1 5 .55°增加至 1 6 .63°和 2 1 .0 4°,相差显著 (P <0 .0 5) ,旋转运动的中性区和运动范围分别从正常的 36 .88°和 48.2 4°增加至 41 .70°和 52 .2 4° ,相差显著 (P <0 .0 5) ,屈曲运动的中性区、旋转运动的弹性区及后伸和侧曲运动各运动参数均相差不显著 (P >0 .0 5)。结论 :1 .寰椎枕骨化畸形造成寰枕关节运动丧失 ,寰枢关节的负荷和旋转不稳定趋势增加 ,容易导致寰椎横韧带退变、松弛和寰枢关节不稳。 2 .建议对寰椎枕骨化畸形的患者密切观察 ,证实寰枢关节临床不稳 ,尽早手术融合     

新型钉尾横连在后路寰枢椎内固定中的三维有限元分析

背景：在寰枢关节疾病采用后路寰枢椎椎弓根螺钉内固定术(C₁-C₂ pedicle screw-rod fixation,C₁-C₂ PSR)中加用传统的棒-棒横连可以为螺钉/棒结构提供更坚固抗旋转稳定性,但有安装困难、影响植骨床和脊髓损伤的风险。作者设计的新型寰椎钉尾横连(horizontal screw-screw crosslink,hS-S CL)可以有效克服上述缺点,但其生物力学性能尚不清楚。目的：利用三维有限元分析新型寰椎钉尾横连在C₁-C₂ PSR中的生物力学特性。方法：采集1名成人健康男性志愿者枕骨底到枢椎(C_0-2)的CT薄层扫描数据,分别建立寰枢椎有限元模型：正常组、失稳组、失稳+C₁-C₂ PSR(无横连组)、C₁-C₂ PSR+hS-S CL(钉尾横连组)。对各个有限元模型加载1.5 Nm的扭矩,计算出4组模型在屈伸、左右侧屈...     

寰枢椎穿刺入路的应用解剖

目的 :为临床寰枢椎穿刺入路提供解剖学依据。方法 :对 2 0例上颈段脊柱标本进行了徒手解剖和横切面解剖观察。结果 :①经咽入路至寰椎前弓和枢椎齿突的穿刺点为与腭垂相对的咽后壁正中线上 ,定为A点 ,向后水平进针 ,深度分别为 ( 0 .95± 0 .0 4)cm和 ( 1.5 2± 0 .0 8)cm。经咽后壁至寰椎侧块的穿刺点为A点旁开 1.5cm处 ,深度为 ( 1.2 3± 0 .0 5 )cm。至枢椎体的穿刺点为A点下移 2 .0cm处 ,即B点 ,深度为 ( 1.13± 0 .0 6)cm。至枢椎侧块的穿刺点为B点旁开 1.8cm ,深度为 ( 1.3 6± 0 .0 6)cm。②经颈后外侧入路至寰椎前弓、寰椎侧块和枢椎齿突的穿刺点为枕外隆突至乳突尖连线的中外 1/ 3交界处 ,为C点 ,深度和角度分别为 ( 6.3 2± 0 .97)cm和 66.0 0°± 1.62°、( 4 .2 3± 0 .3 0 )cm和 63 .0 0°± 1.77°、( 5 .85±0 .5 1)cm和 71.0 0°± 1.83°。至枢椎体及侧块的穿刺点为C点向下 2 .0cm处 ,称为D点 ,深度和角度分别为 ( 4 .41± 0 .2 9)cm和 65 .0 0°± 1.68°、( 5 .46± 0 .48)cm和 70 .0 0°± 1.78°。③对穿刺入路的层次结构做了详尽的描述。结论 :上述两种穿刺入路有关测量结果可为术中准确定位有关结构提供参考依据 ,并有效避免损伤颈部大血管和神经。     

寰枢椎的临床解剖及其不稳的研究进展

寰枢椎的临床解剖及其不稳的研究进展孙俊①②综述徐达传①朱青安①审校寰枢椎在整个脊柱中结构最为复杂和特殊，寰椎无椎体，两者间无椎间盘，关节和韧带是其主要连结结构，对维持寰枢椎稳定有重要作用。任何原因所致的寰枢椎和韧带损伤，均可引起寰枢椎不稳，若处理不及...     

The transverse genicular ligament: anatomical study and review of the literature

There is scant information in the literature regarding the transverse genicular ligament. In order to elucidate further the anatomy and controversial function of this structure, we dissected 28 cadavers. This ligament was identified in 55% of knee joints. Morphometrically, we found a mean length and width of this ligament of 35.4 and 2.5 mm, respectively. Two (3.7%) specimens were found to have a duplicated ligament. The mean distance between the anterior attachment site of the anterior cruciate ligament onto the tibia to the transverse genicular ligament was 2.5 mm and the mean distance to this ligament to a midpoint of the tibial tuberosity was 40.5 mm The transverse genicular ligament was found to be slightly taut in extension and lax in flexion of the knee joint. Lateral and medial forces applied manually to the knee had no effect on this ligament. No tension was noted of the transverse genicular ligament with rotation of the knee. With transection of the ligament, no discernable difference in the integrity of the knee joint was observed. The mean tensile strength of this ligament was 67 N. Based on our study, the transverse genicular ligament plays a minimal part in the proper function of the knee joint. Moreover, with only approximately one-half of the knees in our study harboring this structure, one would expect a significant portion of the population to exhibit signs of biomechanical dysfunction of the knee joint which is not the case. This structure may represent a vestigal/insular part of the mesenchyme forming the menisci.     

Biomechanical tensile strength analysis for medial patellofemoral ligament reconstruction

Background

Medial patellofemoral ligament (MPFL) reconstruction is a surgery for acute and chronic dislocating patella. Several surgical techniques have been described. No biomechanical study has compared suture anchors, interference screws, and suspensory cortical fixation for MPFL reconstruction using human gracilis allograft.

膝横韧带和板股前、后韧带的MRI观测及其在外侧半月板“假撕裂征”诊断中的应用

目的 探讨膝横韧带(TLK)和板股前、后韧带(aMFL、pMFL)的MRI影像解剖学特征,及其对鉴别膝关节外侧半月板真假撕裂的价值。方法 回顾性分析2014年8月―2015年8月在广西医科大学第三附属医院关节外科行膝关节MRI检查,且关节镜排除半月板真性撕裂的101例患者的影像资料,其中男60例,女41例,平均年龄42(18~75)岁。行MR多序列、多平面扫描,观测TLK、aMFL、pMFL的出现率、中点径、走行方式及“假撕裂征”出现率等,应用χ²检验对“假撕裂征”出现率行性别及侧别间比较。结果 TLK的出现率为67.3%(68/101),横断面多呈卵圆形、圆形,其平均中点矢状径(1.88±0.35)mm、冠状径(1.79±0.60)mm,于外侧半月板前角“假撕裂征”出现率为2.9%(2/68)。aMFL、pMFL的出现率分别为13.9%(14/101)、77.2%(78/101),横断面呈卵圆形、扁平形及不规则形等多种形状;aMFL平均中点矢状径(1.53±0.39)mm、冠状径(2.8±0.92)mm,pMFL平均中点矢状径(2.04±1.03) mm、冠状径(3.10±1.08)mm;板股韧带于外侧半月板后角“假撕裂征”出现率为18.5%(17/92)。外侧半月板“假撕裂征”出现率在性别、侧别间差异均无统计学意义(P值均﹥0.05)。结论 在膝关节MRI检查中,外侧半月板有时显示“假撕裂征”;通过对TLK及aMFL、pMFL进行影像形态学研究,根据其在MRI上的形态、走行及外侧半月板假撕裂的方向、位置,可鉴别外侧半月板后角撕裂的真假属性,从而减少不必要的手术治疗。     

Morphological study of the inferior transverse scapular ligament

The suprascapular nerve can be compressed by the inferior transverse scapular ligament (ITSL), also known as the spinoglenoid ligament, and this entrapment results in dysfunction of the external rotation of the upper arm owing to isolated weakness of the infraspinatus muscle. The morphology of the ITSL has not been adequately characterized. The aim of this study was to clarify the morphological characteristics of the ITSL. In total, 110 shoulders from 72 cadavers were dissected in this study. The ITSL was present in 73 (66.4%) of the 110 specimens, and comprised membrane in 40 (36.4%), ligament in 25 (22.7%), and both membrane and ligament in eight (7.3%). This structure could be classified into three types on the basis of its shape: band‐like (33.6%, type I), triangular (15.5%, type II), or irregular (17.3%, type III). In the spinoglenoid notch, the suprascapular nerve was always close to the lateral margin of the scapular spine. The length of the ligament between its origin and insertion sites ranged from 8.7 to 23.4 mm at its superior margin and from 8.9 to 17.5 mm at its inferior margin. The ligament width and thickness at its midportion ranged from 1.6 to 10.0 mm and from 0.1 to 1.2 mm, respectively. The results of this study improve understanding of the ITSL and will be helpful for successful diagnoses and treatments for selective suprascapular nerve entrapment. Clin. Anat. 27:707–711, 2014. © 2013 Wiley Periodicals, Inc.     

Effect of aging on the transverse toughness of human cortical bone: evaluation by R-curves

The age-related deterioration in the quality (e.g., strength and fracture resistance) and quantity (e.g., bone-mineral density) of human bone, together with increased life expectancy, is responsible for increasing incidence of bone fracture in the elderly. The present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness properties of human cortical bone specifically in the transverse (breaking) orientation. Because bone exhibits rising crack-growth resistance with crack extension, the aging-related transverse toughness is evaluated in terms of resistance-curve (R-curve) behavior, measured for bone taken from a wide range of age groups (25–74 years). Using this approach, both the ex vivo crack-initiation and crack-growth toughness are determined and are found to deteriorate with age; however, the effect is far smaller than that reported for the longitudinal toughness of cortical bone. Whereas the longitudinal crack-growth toughness has been reported to be reduced by almost an order of magnitude for human cortical bone over this age range, the corresponding age-related decrease in transverse toughness is merely ∼14%. Similar to that reported for X-ray irradiated bone, with aging cracks in the transverse direction are subjected to an increasing incidence of crack deflection, principally along the cement lines, but the deflections are smaller and result in a generally less tortuous crack path.     

Fiber orientation of the transverse carpal ligament

The transverse carpal ligament is the volar roof of the carpal tunnel. Gross observation shows that the ligament appears to have fibers that roughly orient in the transverse direction. A closer anatomical examination shows that the ligament also has oblique fibers. Knowledge of the fiber orientation of the transverse carpal ligament is valuable for further understanding the ligament's role in regulating the structural function of the carpal tunnel. The purpose of this study is to quantify collagen fiber orientation within the transverse carpal ligament using the small angle light scattering technique. Eight transverse carpal ligament samples from cadaver hands were used in this study. Individual 20-μm sections were cut evenly along the thickness of the transverse carpal ligament. Sections of three thickness levels (25%, 50%, and 75% from the volar surface) were collected for each transverse carpal ligament. Fibers were grouped in the following orientation ranges: transverse, longitudinal, oblique in the pisiform-trapezium (PT), and oblique in the scaphoid-hamate (SH) directions. In analyzing the fiber percentages, the orientation types for the different thickness levels of the ligament showed that the transverse fibers were the most prominent (>60.7%) followed by the PT oblique (18.6%), SH oblique (13.0%), and longitudinal (8.6%) fibers.     

The discomallear ligament and the anterior ligament of malleus: An anatomic study in human adults and fetuses

According to some reports, movement of the malleus, resulting from anterior hypertension on the discomallear ligament (DML), could produce aural symptoms related with damage to middle ear structures. The aim of this study was to examine the topographic relationship of the DML and the anterior ligament of malleus (ALM). Four fetuses and 16 adult hemi-sectioned heads were used to determine the anatomic-clinical relevance of DML and ALM in temporomandibular disorder. In fetal specimens, the DML was distinctly interposed between the malleus and the disc of the temporomandibular joint (TMJ), and the ALM had a structure apparently composed of the superior and inferior lamellae, running anteriorly in continuation with the sphenomandibular ligament (SML) through the future petrotympanic fissure (PTF). In all adult specimens, the DML was inserted into the malleus, and it expanded broadly toward the disc and capsular region of the TMJ in a triangular shape and inserted into the disc and capsule of the TMJ. The two-lamellae structure of the ALM was not distinguishable in adult specimens. The overstretched ALM resulted in movement of the malleus in five cases, but similar tension applied to the DML did not cause any movement of the malleus. This result provides an indication of the clinical significance of the ALM, a ligamentous structure continuous with the SML. It is apparent that the ALM has the potential to cause aural symptoms as a result of damage to the middle ear structure.     

Up-regulated osteogenic transcription factors during early response of human periodontal ligament stem cells to cyclic tensile strain

Introduction

As one group of periodontal ligament (PDL) cells, human periodontal ligament stem cells (hPDLSCs) have been isolated and identified as mesenchymal adult stem cells (MSCs) since 2004. It has been well accepted that PDL sensitively mediates the transmission of stress stimuli to the alveolar bone for periodontal tissue remolding. Besides, the direction of MSCs differentiation has been verified regulated by mechanical signals. Therefore, we hypothesized that tensile strain might act on hPDLSCs differentiation, and the early response to mechanical stress should be investigated.

Material and methods

The hPDLSCs were cultured in vitro and isolated via a magnetic activated CD146 cell sorting system. After investigation of surface markers and other experiments for identification, hPDLSCs were subjected to cyclic tensile strain at 3,000 µstrain for 3 h, 6 h, 12 h, and 24 h, without addition of osteogenic supplements. In the control groups, the cells were cultured in similar conditions without mechanical stimulation. Then osteogenic related genes and proteins were analyzed by RT-PCR and western blot.

Results

Cyclic tensile strain at 3,000 µstrain of 6 h, 12 h, and 24 h durations significantly increased mRNA and protein expressions of Satb2, Runx2, and Osx, which were not affected in unloaded hPDLSCs.

Conclusions

We indicate that hPDLSCs might be sensitive to cyclic tensile strain. The significant increase of Runx2, Osx and Satb2 expressions may suggest an early response toward osteogenic orientation of hPDLSCs.