Sheep are commonly used as a model for human spinal orthopaedic research due to their similarity in morphological and biomechanical features. This study aimed to document the volumes of vertebral bodies and compare the generated results as well as morphometry of the sheep lumbar spine to human published data. For this purpose, computed tomography scans were carried out on five adult Merino sheep under general anaesthesia. Transverse 5 mm thick images were acquired from L1 to L6 using a multi-detector-row helical CT scanner. Volume measurements were performed with dedicated software. Four spinal indices and Pavlov's ratio were calculated. Thereafter, the generated data were compared to published literature on humans. The mean vertebral body volume showed an increase towards the caudal vertebrae, but there were no significant differences between the vertebral levels (P>0.05). Compared to humans, sheep vertebral body volumes were 48.6% smaller. The comparison of absolute values between both species revealed that sheep had smaller, longer and narrower vertebral bodies, thinner intervertebral discs, narrower spinal canal, longer transverse processes, shorter dorsal spinous processes and narrower, higher pedicles with more lateral angulations. The comparison of the spinal indices showed a good similarity to human in terms of the vertebral endplates and spinal canal. The results of this study may be helpful for using the sheep as a model for human orthopaedic spinal research if anatomical differences are taken into account.
Adult ; Anatomy, Comparative ; Humans* ; Intervertebral Disc ; Sheep* ; Spinal Canal ; Spine* ; Tomography, Spiral Computed

We observed the structure and form of adult annulus fibrosus of lumbar intervertebral disc at the fibrous layer level. The annulus fibrosus of lumbar interverbral disc was delaminated by using microsurgical technique. 8 testing points were taken in each layer and the angles between their fibers going and horizontal plane were measured. The results showed that the fiber going angle at each measurement point continually increased with the increase of fibrous layer from outside to inside along the radial direction in horizontal plane. The least fiber going angle was 25 degrees - 30 degrees. The fiber going angle at the same layer gradually increased from front to back. The fiber going angle was 70 degrees - 90 degrees at the middle of the back of annulus fibrosus of lumbar interverbral disc. The fiber going was consistent with the posterior longitudinal ligament going. Through the normalized equation and normalized line, the fiber going angle at any point in any layer could be obtained conveniently. We also observed that the annuli fibrosus were interlaced in the front, left and right of annulus fibrosus of lumbar intervertebral disc. And there were more interlaced areas in local sides of lumbar intervertebral disc, but there was no interlaced areas between layers near the middle of posterior annulus fibrosus. So we came to the conclusion: Annulus fibrosus of lumbar intervertebral disc has a special micro-structure in adaptation with its function.
Adult ; Compressive Strength ; Fibrillar Collagens ; physiology ; Humans ; Intervertebral Disc ; anatomy & histology ; physiology ; Lumbar Vertebrae ; anatomy & histology ; Male ; Middle Aged

OBJECTIVETo provide a theoretical basis for designing of lumbar intervertebral disc prosthesis by collecting the data of the lumbar endplate morphology.

METHODSA total of 100 healthy adults were measured about the following parameters: lumbar lordosis, the Cobb angle of each segment, the concavity depth (ECD) of the endplate, the location of concavity apex (ECA) of the endplate. And a correlation analysis on lumbar lordosis and ECD, ECA was made, respectively.

RESULTSIn total, 100 volunteers were measured. The mean age of the volunteer was 40 years (range 20 - 50 years); the average depth of ECD was (2. 37 ± 1. 42) mm, the average location of ECA was (52. 21 ± 9. 70) %; the average depth of ECD of inferior endplate (IEP) was (2. 81 ± 1. 52) mm (0. 54 - 7. 60 mm), and the parameter of the superior endplate (SEP) was (1. 94 ± 1. 16)mm(0. 39 - 6. 10 mm). The average depth of ECD of the IEP was bigger than of the SEP for each lumbar vertebral body. Most of the location of ECA was at the back of the intervertebral body, the average location of ECA of IEP was (49. 60 ± 8. 78) % (22. 57% - 75. 58%), and the parameter of the SEP was (55. 03 ± 9. 90) % (16. 03% -75. 58%); the mean angle of lumbar lordosis was 39. 760 11. 25°(13. 8° - 72. 00°). There was no obvious correlation between the lumbar lordosis and the ECD (r -0. 193, P =0. 195), neither was the location of ECA(r =0. 080, P =0. 592).

CONCLUSIONMost of the location of ECA is at the back of the intervertebral body, the average depth of ECD is 2. 37 mm, the average location of ECA is 52. 21%.

Adult ; Humans ; Intervertebral Disc ; Lumbar Vertebrae ; anatomy & histology ; Lumbosacral Region ; anatomy & histology ; Middle Aged ; Prostheses and Implants ; Reference Standards ; Spine ; anatomy & histology ; Young Adult

OBJECTIVE: To evaluate 3-dimensional magnetic resonance imaging (MRI) of Kambin’s safe zone to calculate maximum cannula diameter permissible for safe percutaneous endoscopic lumbar discectomy.METHODS: Fifty 3D MRIs of 19 males and 31 females (mean, 47 years) were analysed. Oblique, axial and sagittal views were used for image analysis. Three authors calculated the inscribed circle (cannula diameter) individually, within the neural (original) and bony Kambin’s triangle in oblique views, disc heights on sagittal views and root to facet distances at upper and lower end plate levels on axial views and their averages were taken.RESULTS: The mean root to facet distances at upper end plate level measured on axial sections increased from 3.42±3.01 mm at L12 level to 4.57±2.49 mm at L5S1 level. The mean root to facet distances at lower end plate level measured on axial sections also increased from 6.07±1.13 mm at L12 level to 12.9±2.83 mm at L5S1 level. Mean maximum cannula diameter permissible through the neural Kambin’s triangle increased from 5.67±1.38 mm at L12 level to 9.7±3.82 mm at L5S1 level. The mean maximum cannula diameter permissible through the bony Kambin’s triangle also increased from 4.03±1.08 mm at L12 level to 6.11±1 mm at L5S1 level. Only 2% of the 427 bony Kambin’s triangles could accommodate a cannula diameter of 8mm. The base of the bony Kambin’s triangle taken in oblique view (3D MRI) was significantly higher than the root to facet distance at lower end plate level taken in axial view.CONCLUSION: The largest mean diameter of endoscopic cannula passable through “bony” Kambin’s triangle was distinctively smaller than the largest mean diameter of endoscopic cannula passable through “neural” Kambin’s triangle at all levels. Although proximity of exiting root to the facet joint is always taken into consideration before PELD procedure, our 3D MRI based anatomical study is the first to provide actual maximum cannula dimensions permissible in this region.
Anatomy, Regional ; Catheters ; Diskectomy ; Endoscopy ; Female ; Humans ; Intervertebral Disc ; Lumbosacral Region ; Magnetic Resonance Imaging ; Male ; Zygapophyseal Joint

OBJECTIVETo construct a human cervical spine with bilateral vertebral artery fluid-solid coupling model.

METHODSHelical CT images under the principle of reverse engineering and meshed in finite element model（FEM） related software were used to establish a human cervical spine with bilateral vertebral artery fluid-solid coupling model. In the process of modeling of vertebral body, vertebral artery, ligament, intervertebral disc, cartilage and endplate large anatomic data and cadaver experiments results were referenced. From the morphology and function the simulation of model with real physiological status was tested.

RESULTSThe study showed that the stress concentration on the surface of vertebral body and the blood wall of the bilateral vertebral artery, and the result of the volume flow rate-time curve of bilateral vertebral artery of the model were consistent with the published literatures. This model was well consistent with the clinical phenomenon.

CONCLUSIONThe three-dimensional FEM of the human cervical spine established by the introduced method has been effectively verified. The modeling method would provide a new tool for research on the cervical spine biomechanics.

Biomechanical Phenomena ; Cadaver ; Cervical Vertebrae ; anatomy & histology ; Finite Element Analysis ; Humans ; Intervertebral Disc ; Models, Anatomic ; Tomography, Spiral Computed ; Vertebral Artery ; anatomy & histology

In the present study, a finite element model of L4-5 lumbar motion segment was established based on the CT images and a combination with image processing software, and the analysis of lumbar biomechanical characteristics was conducted on the proposed model according to different cases of flexion, extension, lateral bending and axial rotation. Firstly, the CT images of lumbar segment L4 to L5 from a healthy volunteer were selected for a three dimensional model establishment which was consisted of cortical bone, cancellous bone, posterior structure, annulus, nucleus pulposus, cartilage endplate, ligament and facet joint. The biomechanical analysis was then conducted according to different cases of flexion, extension, lateral bending and axial rotation. The results showed that the established finite element model of L4-5 lumbar segment was realistic and effective. The axial displacement of the proposed model was 0.23, 0.47, 0.76 and 1.02 mm, respectively under the pressure of 500, 1 000, 1 500 and 2 000 N, which was similar to the previous studies in vitro experiments and finite element analysis of other people under the same condition. The stress distribution of the lumbar spine and intervertebral disc accorded with the biomechanical properties of the lumbar spine under various conditions. The established finite element model has been proved to be effective in simulating the biomechanical properties of lumbar spine, and therefore laid a good foundation for the research of the implants of biomechanical properties of lumbar spine.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Intervertebral Disc ; anatomy & histology ; Lumbar Vertebrae ; anatomy & histology ; Models, Anatomic ; Pressure ; Prostheses and Implants ; Range of Motion, Articular ; Rotation

OBJECTIVE: To evaluate the value of spinal and paraspinal anatomic markers in both the diagnosis of lumbosacral transitional vertebrae (LSTVs) and identification of vertebral levels on lumbar MRI. MATERIALS AND METHODS: Lumbar MRI from 1049 adult patients were studied. By comparing with the whole-spine localizer, the diagnostic errors in numbering vertebral segments on lumbar MRI were evaluated. The morphology of S1-2 disc, L5 and S1 body, and lumbar spinous processes (SPs) were evaluated by using sagittal MRI. The positions of right renal artery (RRA), superior mesenteric artery, aortic bifurcation (AB) and conus medullaris (CM) were described. RESULTS: The diagnostic error for evaluation of vertebral segmentation on lumbar MRI alone was 14.1%. In lumbarization, all patients revealed a well-formed S1-2 disc with squared S1 body. A rhombus-shaped L5 body in sacralization and a rectangular-shaped S1 body in lumbarization were found. The L3 had the longest SP. The most common sites of spinal and paraspinal structures were: RRA at L1 body (53.6%) and L1-2 disc (34.1%), superior mesenteric artery at L1 body (55.1%) and T12-L1 disc (31.6%), and AB at L4 body (71.1%). CM had variable locations, changing from the T12-L1 disc to L2 body. They were located at higher sacralization and lower lumbarization. CONCLUSION: The spinal morphologic features and locations of the spinal and paraspinal structures on lumbar MRI are not completely reliable for the diagnosis of LSTVs and identification on the vertebral levels.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Anatomic Landmarks/*anatomy & histology ; Aorta, Abdominal/anatomy & histology ; Diagnostic Errors ; Female ; Humans ; Intervertebral Disc/anatomy & histology ; Lumbar Vertebrae/*anatomy & histology ; Lumbosacral Region ; Magnetic Resonance Imaging ; Male ; Mesenteric Artery, Superior/anatomy & histology ; Middle Aged ; Renal Artery/anatomy & histology ; Reproducibility of Results ; Sacrum/*anatomy & histology ; Spinal Cord/anatomy & histology ; Spine ; Young Adult

PURPOSE: All structures of the spine, including the spinal canal, change continuously with age. The purpose of this study was to determine how the spinal canal of the lumbar spine changes with age. The L4/5 is the most common site of spinal stenosis and has the largest flexion-extension motion, whereas the T5/6 has the least motion. Therefore, we measured the spinal canal diameter and vertebral body height at T5, T6, L4, and L5 with age. MATERIALS AND METHODS: This was a retrospective study of aged 40 to 77 years. We reviewed whole spine sagittal MRIs of 370 patients with lumbar spinal stenosis (LSS) (Group 2) and 166 herniated cervical disc (HCD) (Group 1). Each group was divided into four age groups, and demographic parameters (age, gender, height, weight, BMI), the mid-spinal canal diameter, and mid-vertebrae height at T5, T6, L4, L5 were compared. Within- and between-group comparisons were made to evaluate changes by age and correlations were carried out to evaluate the relationships between all parameters. RESULTS: Height, weight, and all radiologic parameters were significantly lower in Group 2 than Group 1. Group 1 did not show any differences, when based on age, but in Group 2, height, weight, and T6, L4, and L5 height were significantly decreased in patients in their 70's than patients in their 40's, except for spinal canal diameter. Age was associated with all parameters except spinal canal diameter. CONCLUSION: Vertebral height decreased with age, but spinal canal diameter did not change in patients with either LSS or HCD. Mid-spinal canal diameter was not affected by aging.
Adult ; Age Factors ; Aged ; Cervical Vertebrae/anatomy & histology ; Female ; Humans ; Intervertebral Disc Displacement/pathology ; Lumbar Vertebrae/*anatomy & histology ; Male ; Middle Aged ; Retrospective Studies ; Spinal Canal/*anatomy & histology ; Spinal Stenosis/pathology

The clinical practice of bloodletting method on the face is introduced in this paper through 4 medical cases: post-operative periarthritis of the shoulder in lung cancer, dizziness and vertigo, protrusion of lumbar intervertebral disc and keratitis. It is believed that the change in facial luster, vein condition on the face, the site with the most obvious change in facial luster and local skin abnormality are commonly regarded as the reaction points or areas of facial disease. According to the reaction points or areas on the face and in association with the syndrome differentiation in Lingshu: Wuse (Miraculous Pivot : Five Colors), the acupoints are selected and stimulated with bloodletting method in the treatment of some difficult and complicated cases, and the good efficacy could be obtained. But, this therapeutic method needs a further research and deserves to be promoted in practice.
Acupuncture Points ; Adult ; Aged ; Bloodletting ; Face ; anatomy & histology ; blood supply ; Female ; Humans ; Intervertebral Disc Displacement ; therapy ; Keratitis ; therapy ; Male ; Periarthritis ; therapy ; Vertigo ; therapy

OBJECTIVETo evaluate the normal appearance of large field diffusion weighted imaging (DWI) on 3.0T magnetic resonance imaging (MRI).

METHODSTwenty healthy volunteers and thirty patients with benign prostate hyperplasia were included in this study. All patients were examined with large field DWI on 3.0T MRI. Normal tissue appearance was analyzed and apparent diffusion coefficient (ADC) of normal tissue with high signal intensity was measured. The ADC values of bilateral symmetrical tissue were also compared. The ADC values of intervertebral disks of healthy people younger than 50 years and exceeding 50 years were compared.

RESULTSSalivary gland, spleen, kidney, gallbladder, bladder, prostate, seminal vesicle, testis, intervertebral disk, liquid in articular cavity and lymph node showed high signal intensity on large field DWI, while lung, liver and bone showed hypo-signal intensity. The mean ADC values of partial hyperintensity tissue were as followed: parotid gland (1.088 +/- 0.114) x 10(-3) mm2/S, submaxillary gland (1.309 +/- 0.189) x 10(-3) mm2/s, kidney (1.909 +/- 0.143) x 10(-3) mm2/s, seminal vesicle (1.669 +/- 0.168) x 10(-3) mm2/s, testis (1.028 +/- 0.075) x 10(-3) mm2/s, spleen (0.963 +/- 0.108) x 10(-3) mm2/s, bladder (2.898 +/- 0.267) x 10(-3) mm2/s, prostate (1.448 +/- 0.132) x 10(-3) mm2/s, intervertebral disks (1.360 +/- 0.140) x 10(-3) mm2/s. No statistical significance was found between the ADC values of bilateral symmetrical tissues. The difference of ADC values of intervertebral disks of healthy people younger than 50 years [(1.372 +/- 0.142) x 10(-3) mm2/s] and exceeding 50 years [(1.344 +/- 0.134) x 10(-3) mm2/s] showed statistical significance (P = 0.040).

CONCLUSIONUnderstanding the high signal intensity of normal tissue on large field DWI may help to differentiate the normal tissues and abnormal ones.

Adult ; Aged ; Diffusion Magnetic Resonance Imaging ; instrumentation ; methods ; Female ; Humans ; Intervertebral Disc ; anatomy & histology ; pathology ; Male ; Middle Aged ; Prostatic Hyperplasia ; pathology ; Whole Body Imaging ; instrumentation ; methods