Human lumbar vertebrae. Quantitative three-dimensional anatomy.

This study details the quantitative three-dimensional surface anatomy of human lumbar vertebrae based on a study of 60 vertebrae. The two lower vertebrae (L4 and L5) appeared to be transitional toward the sacral region, whereas the upper two vertebrae (L1 and L2) were transitional toward the thoracic region. Means and standard errors of the means for linear, angular, and area dimensions of vertebral bodies, spinal canal, pedicle, pars interarticularis, spinous and transverse processes were obtained for all lumbar vertebrae. This information provides a better understanding of the spine, and allows for a more precise clinical diagnosis and surgical management of spinal problems. The information is also necessary for constructing accurate mathematical models of the human spine.     

Cervical human vertebrae. Quantitative three-dimensional anatomy of the middle and lower regions

In this study, the three-dimensional quantitative anatomy of middle and lower cervical vertebrae was determined. The three-dimensional coordinates of various marked points on the surface of the vertebra were measured with a specially designed morphometer instrument. From these coordinates, linear dimensions, angulations, and areas of surfaces and cross-sections of most vertebral components were calculated. The results showed two distinct transition regions: 1) toward the thoracic spine by the wider C7 vertebra but narrower spinal canal; and 2) toward the upper cervical region with the larger pedicle and spinous process of C2. Based on the study of 72 human cervical vertebrae, mean and standard error of the mean values of some clinically important dimensions of vertebral body, spinal canal, pedicles, transverse processes, spinous process, and uncovertebral joints are given for C2-C7 vertebrae. The areas of the end plates, spinal canal, and pedicles were modeled by elliptical and triangular shapes, and results were compared with the actual measurements.     

Quantitative three-dimensional anatomy of lumbar vertebrae in Singaporean Asians

This paper details the quantitative three-dimensional anatomy of lumbar vertebrae L1-L5 from Asian (Singaporean) subjects based on 60 lumbar vertebrae from 12 cadavers. The purpose of the study was to measure the dimensions of the various parameters of the lumbar vertebrae and thereafter to compare the data with a study performed on Caucasian specimens. Measurements were taken with the aid of a three-dimensional digitiser. The means and standard errors for linear, angular and area dimensions of the vertebral body, spinal canal, pedicle, and spinous and transverse processes were obtained for each lumbar vertebra. From this comparison, it was found that the dimensions of the vertebral body of the Asian subjects are slightly larger, with a maximum average difference of 8% for the posterior vertebral body height. The dimensions of the spinal canal, pedicle, and spinous and transverse processes of Asian subjects are smaller. The greatest difference can be found in the spinal canal area and pedicle width, which are smaller by an average of 30% and 20%, respectively. With the exception of the spinal canal depth, spinal canal area and pedicle width, all other parameters compared show a similar trend. The findings can provide more accurate modelling for analysis and spinal implant design and also allow more precise clinical diagnosis in sub-Asian groups.     

Quantitative three-dimensional anatomy of cervical<Emphasis Type="Italic">,</Emphasis> thoracic and lumbar vertebrae of Chinese Singaporeans

This paper details the quantitative three-dimensional anatomy of cervical, thoracic and lumbar vertebrae (C3–T12) of Chinese Singaporean subjects based on 220 vertebrae from 10 cadavers. The purpose of the study was to measure the linear dimensions, angulations and areas of individual vertebra, and to compare the data with similar studies performed on Caucasian specimens. Measurements were taken with the aid of a three-dimensional digitiser. The means and standard errors for linear, angular and area dimensions of the vertebral body, spinal canal, pedicle, and spinous and transverse processes were obtained for each vertebra. Compared to the Caucasian data, all the dimensions were found to be smaller. Of significance were the spinal canal area, and pedicle width and length, which were smaller by 31.7%, 25.7% and 22.1% on average, respectively. A slight divergence, instead of convergence, was found from T8 to T12. According to the findings, the use of a transpedicle screw may not be feasible. The results can also provide more accurate modelling for analysis and design of spinal implants and instrumentations, and also allow more precise clinical diagnosis and management of the spine in Chinese Singaporeans.     

Thoracic outlet syndrome: anatomy

The thoracic outlet region contains three important structures: the brachial plexus, the subclavian artery, and the subclavian vein. As they travel from the upper mediastinum to the upper extremity, these structures run through three important spaces: the interscalene triangle, the costoclavicular space, and the subpectoral space. Compression can occur in any of these three spaces because of structural anomalies or trauma.     

显微手术治疗脊髓脊膜膨出6例

目的：为术中寻找突出的髓核三维定位，并为极外侧型腰椎间盘突出症诊治提供参考。方法：解剖１４具中国成人尸体，测量了各腰椎从后正中线至椎板峡部侧缘距离、椎板峡部侧缘至腰椎间盘纵向距离，同时以上下横突为参照，观测了神经根出椎间孔的位置、腰椎节段动脉前支的位置、腰神经前支与动脉的关系。结果：绝大多数神经根出椎间孔的高度位于相邻横突间隙上１／４内，９０％以上节段动脉前支均位于相邻横突间隙上１／２内。同一节段的腰动脉前支总是位于腰神经前支的腹侧，而上一节段下行的腰神经前支又位于下一节段腰动脉前支的腹侧。从Ｌ１～Ｌ５，后正中线至椎板峡部侧缘距离、腰神经前支深度、椎间管外口处腰神经前支至椎间盘的纵向距离均逐渐增加。结论：研究结果为术中三维定位突出髓核提供了解剖学基础；为极外侧型腰椎间盘突出手术术中分离深度、如何避免血管神经的损伤及寻找髓核时的探查范围提出了参考数据。     

下腰椎腰动脉的应用解剖学研究

[目的]研究下腰椎侧方动脉的分布规律,为减少下腰椎侧方入路中的术中出血提供解剖学依据。[方法]解剖观测21具成人尸体的下腰椎腰动脉(lower lumbar artery,LLA)的起点至横突前的走行、分支、外径及其与椎间孔及横突前区的关系,对具有临床意义的数据进行解剖学测量。[结果]各腰动脉(lumbar artery,LA)出现率差异较大;L3A和L4A在椎体侧方走行较恒定,L5A走行变异较大;L3A及L4A主干及其分支多分别行于L3椎弓根外侧缘(71.43%)和L4、5椎间孔上1/3处(62.07%);在横突前区,L3A和L4A的横突前支多分别由横突间隙上1/3内侧斜向外下达中1/3外侧(60%)及由上1/3向下达下1/3处(58.33%)。[结论]腰椎椎体侧方、椎间孔附近及横突前区的动脉走行、分支具有一定的规律性,掌握其解剖学特点可有效减少术中出血,缩短手术时间。     

Quantitative anatomy of the scapula

Thirty adult bony scapulae were used to report detailed bony dimensions of the scapula. The measurements of bony dimensions of the scapula included the glenoid, coracoid, spine, and body. The results of the measurements showed that the thickest bony stock (posteroanterior diameter), with a mean value of 13 mm to 23 mm in the glenoid process, was found in the middle third of the area within 1 cm medial to the glenoid rim. In the scapular spine region, the greatest superoinferior diameter of the bone was noted in the lateral portion of the spine, followed by the medial portion. It was also found that smallest superoinferior diameter (2 mm to 7 mm) of the spine was located at the middle portion between the base and ridge along the whole spine. On the lateral border of the scapula, the posteroanterior diameter of bone was relatively greater for the upper portion (8 mm) than for the lower portion, including the inferior angle (6 mm). This information may be helpful in open reduction and internal fixation of significantly displaced scapular fractures.     

Quantitative three-dimensional ultrasound imaging of partially resected tongues.

OBJECTIVE: We sought to assess the impact of partial lateral glossectomies on tongue function and speech. STUDY DESIGN AND SETTING: Tongue shapes of 12 patients with lateral tumors of the tongue were recorded with three-dimensional ultrasound before their surgery and two months after. Twelve normal participants served as controls. Speech acceptability was also assessed. RESULTS: Principal component analyses demonstrated that the flap reconstructions led to a stiffening of the operated side of the tongue. A concavity index and an asymmetry index demonstrated that the glossectomy patients exhibited decreased midsagittal grooving and increased lingual asymmetry. The change in midsagittal grooving correlated moderately with the decrease in speech acceptability. CONCLUSION: A lateral partial glossectomy affects the tongue's intrinsic deformation, in particular midsagittal grooving and symmetry. This can have a detrimental effect for speech. SIGNIFICANCE: A lateral resection affects the tongue's symmetry and midsagittal groove. The change in midsagittal grooving correlates with a decrease in speech acceptability.     

Andreas Vesalius on the anatomy and function of the lower thoracic vertebrae

Some remarkable statements made by Andreas Vesalius (1514–1564) in his principal work De Humani Corporis Fabrica (1543) about the anatomy and function of the lower thoracic vertebrae are discussed in the light of information from the literature. Their accuracy is evaluated on the basis of several pieces of anatomical evidence and clinical cases.     

腰骶移行椎椎弓根螺钉进钉方法的解剖学研究

目的 探讨腰骶移行椎椎弓根螺钉的进钉方法,为临床应用提供形态学依据.方法 共91具腰骶移行椎标本.生前资料完整者59具,男54具,女5具;平均年龄(41.2±16.7)岁,身高(162.4±7.3)cm.对椎弓根、上关节突、人字嵴、横突后部突起及"V"形槽进行观测,确定进钉点、进钉角度及深度.结果 按照Castellvi分型法,移行椎ⅡA型13具(左6具,右7具),ⅡB型10具.ⅢA型7具(左2具,右5具).ⅢB型60具,Ⅳ型1具.移行椎人字嵴均不明显,横突后结节突起与上关节突形成的"V"形槽均较明显.以移行椎上关节突关节面下缘水平线与"V"形槽最凹陷处交点作为移行椎椎弓根螺钉的进钉点,该点至椎弓根上缘距离,左(8.6±1.2)mm,右(8.3±1.2)mm;与矢状面呈20°时钉道至侧隐窝外侧壁距离,左(7.5±3.1)mm,右(7.2±2.7)mm;进钉角度,左21.3°±4.1°,右21.0°±4.6°;进钉深度,左(39.1±2.8)mm,右(39.1+2.7)mm.结论 腰骶移行椎后部横突变异,人字嵴结构不明显,以此作为进钉定位标志不可靠,而"V"形槽恒定存在,可以将上关节突关节面下缘的水平线与"V"形槽的最凹陷处的交点作为椎弓根螺钉的进钉点.     

In vivo 3D reconstruction of human vertebrae with the three-dimensional X-ray absorptiometry (3D-XA) method

Summary We used a standard DXA device equipped with a C-arm to do in vivo reconstruction of human vertebrae from two orthogonal scans. This new technique, called 3D-XA (three-dimensional X-ray absorptiometry), allows the direct measurement of geometric parameters of the vertebrae with a good accuracy and precision. Introduction Geometric parameters are predictors of bone strength. A technique called three-dimensional X-ray absorptiometry (3D-XA) allows 3D reconstruction of bones from DXA scans. We used the 3D-XA method to reconstruct human vertebrae and to evaluate the method’s in vitro accuracy and in vivo precision. Methods A standard DXA device equipped with a C-arm was used. Calibration of its environment and identification of different anatomical landmarks of the vertebrae allows personalized 3D geometric reconstruction of vertebrae. Accuracy was calculated by reconstructing 16 dry human vertebrae by 3D-XA and CT scanner. In vivo inter-observer precision was calculated using 20 human spines. Results The mean difference between 3D reconstruction by CT and 3D-XA was −0.2 ± 1.3 mm. The in vivo mean difference of the 3D-XA method between the two rheumatologists was −0.1 ± 0.8 mm. For geometric parameters, mean difference ranged from 0.4 to 0.9 mm. For cross-sectional area and vertebral body volume, it was 2.9% and 3.2%, respectively. Conclusion This study shows the good accuracy and precision of 3D-XA using a standard DXA device. It yields complementary information on bone geometry. Further studies are needed to evaluate if, coupled with bone density, it improves vertebral fracture risk prediction.     

Quantitative comparison of the microscopic anatomy of the human ACL femoral and tibial entheses

The femoral enthesis of the human anterior cruciate ligament (ACL) is known to be more susceptible to injury than the tibial enthesis. To determine whether anatomic differences might help explain this difference, we quantified the microscopic appearance of both entheses in 15 unembalmed knee specimens using light microscopy, toluidine blue stain and image analysis. The amount of calcified fibrocartilage and uncalcified fibrocartilage, and the ligament entheseal attachment angle were then compared between the femoral and tibial entheses via linear mixed‐effects models. The results showed marked differences in anatomy between the two entheses. The femoral enthesis exhibited a 3.9‐fold more acute ligament attachment angle than the tibial enthesis (p < 0.001), a 43% greater calcified fibrocartilage tissue area (p < 0.001), and a 226% greater uncalcified fibrocartilage depth (p < 0.001), with the latter differences being particularly pronounced in the central region. We conclude that the ACL femoral enthesis has more fibrocartilage and a more acute ligament attachment angle than the tibial enthesis, which provides insight into why it is more vulnerable to failure. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1811–1817, 2015.     

Quantitative anatomy of cervical spine ligaments. Part I. Upper cervical spine.

The quantitative anatomy of the ligaments of the upper cervical spine was determined from six human cadaveric specimens. For the apical, transverse, and alar ligaments, the origins, lengths, and orientations were determined in three-dimensional space. The apical ligament was 23.5 (3.8) mm long with a 20 degrees anterior tilt from the frontal plane. The transverse ligament was 21.9 (3.7) mm long, whereas the alar ligaments averaged 10.3 (2.0) mm in length. The alar ligaments were oriented 70 degrees from the sagittal plane with much variation in its angle with both the frontal and transverse planes.     

Anal canal anatomy showed by three-dimensional anorectal ultrasonography

Background Demonstrate precisely the anatomic configuration of the anal canal and the length and thickness of the anal sphincters using three-dimensional (3-D) anorectal ultra-sonography in both genders. Methods Twelve normal volunteer males and 14 females, with a mean age of 52.4 and 50.3 years, respectively, were prospectively enrolled in this study. All individuals from both groups were submitted to anorectal ultra-sonography. The anal canal was analyzed, measuring the length and thickness of the external anal sphincter (EAE), internal anal sphincter (IAS), puborectalis muscle (PR) and the gap (distance from the anterior EAS to the anorectal junction) in the midline longitudinal (ML) and transverse (MT) planes, and the results were compared between quadrants and genders. Results The distribution of sphincter muscles is asymmetric in both genders. The anterior upper anal canal is an extension of the rectal wall with all layers clearly identified. The anterior IAS is formed in the distal upper anal canal and is significantly shorter in female than in male in all quadrants. The anterior IAS length is shorter than the posterior and lateral in both genders. The anterior EAS length is significantly shorter (2.2 cm) and the gap is longer (1.2 cm) in female than in male (3.4 cm) (0.7 cm) (p < 0.05), respectively. The posterior and lateral EAS-PR is significant longer in males (3.6 cm) (3.9 cm) than in females (3.2 cm) (3.5 cm) (p < 0.05), respectively. The lateral EAS-PR is significant longer than the posterior part in both genders. The anterior IAS is significantly thicker in males (0.19 cm) than in females (0.12 cm) (p = 0.04). Conclusion 3-D anal endosonography enabled measurement of the different anatomical structures of the anal canal and demonstrated its asymmetrical configuration. The shorter anterior EAS and IAS associated with a longer gap could justify the higher incidence of pelvic floor dysfunction in females, especially fecal incontinence and anorectocele with rectal intussusception.     

Acetabular coverage: three-dimensional anatomy and radiographic evaluation

The three-dimensional relationship between acetabulum and femoral head, known as coverage, was evaluated radiographically using a modified inlet view of the pelvis. The relationship of the anterior edge, the center of the femoral head, and the posterior edge of the acetabulum is a straight line (180 degrees) in normal coverage but less in dysplastic hips. This radiographic method provides anatomical information concerning anterior and posterior coverage. Evaluation of 26 hips delineated problems, including possible danger of anterolateral rotation of the acetabulum in the face of posterior deficiency and inadequacy of posterior coverage after Chiari osteotomy.