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1.
PLoS One ; 15(2): e0229457, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084224

RESUMO

PURPOSE: To measure intervertebral disc (IVD) health parameters in middle-aged long-term runners compared to matched non-physically active controls. METHODS: Seventeen males aged 44-62yr were included in the study: 9 runners with a running history of >10yr, averaging >50km/week, and eight matched non-physically active controls, the data from one participant had to be excluded. T2-relaxometry, diffusion weighted imaging, T1- and T2-weighted MR scanning, as well as T2 time mapping were performed. Morphological data relating to IVD were extrapolated. RESULTS: Compared to controls on average, runners had 20% greater IVD height (p = 0.002) and seven percentage points greater IVD-vertebral body height ratio (p = 0.001). No significant differences were observed between groups for mean(SD) IVD hydration status, as indicated by similar T2-times (runners: 94.4(11.1)ms, controls: 88.6(23.6)ms), or apparent diffusion coefficients (runners: 249.0(175.2)mm2/s, controls: 202.3(149.5)mm2/s). Average Pfirrmann score for the L5-S1 IVD was 2.2(0.7) for runners and 3.3(1.0) for controls (p = 0.026), average scores for all lumbar levels (L2-S1) were 1.9(0.2) and 2.5(0.7), respectively (p = 0.036). Anterior annulus T2-time and overall average lumbar level Pfirrmann grades were strongly correlated (r = 0.787, p = 0.021 and r = -0.704, p = 0.034, respectively) with greater distances run per week. Average lumbar level Pfirrmann grades were also strongly correlated (r = -0.823, p = 0.006) to total years of running. CONCLUSION: Middle-aged long-term endurance runners exhibit less age-related decline in their lumbar IVDs. In addition, the measures of IVD morphology appeared to be better in those who had been running for a greater number of years, as well as in those who ran a greater distance per week.


Assuntos
Disco Intervertebral/fisiologia , Vértebras Lombares/fisiologia , Corrida , Adulto , Estudos de Casos e Controles , Estudos Transversais , Humanos , Disco Intervertebral/anatomia & histologia , Vértebras Lombares/anatomia & histologia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Fatores de Tempo
2.
Clin Anat ; 33(1): 34-40, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31325341

RESUMO

Numerous authors over the years have reported that the lumbar ligamentum flavum has two layers. Our routine cadaveric dissections raised the question whether this understanding is correct, as we always have observed only one layer. Thus, the goal of this cadaveric study was to reevaluate the layers of the ligamentum flavum. Twenty lumbar levels from five fresh-frozen cadaveric specimens were used in this study. After dissection of the lumbar spine, the ligamentum flavum and interspinous ligament were exposed. Each lumbar level was transected through the zygapophyseal joint, and hematoxylin and eosin staining, Masson's trichrome staining and Verhoeff-van Gieson staining were performed. Continuation of the interspinous ligament and ligamentum flavum were observed invariably. There was no evidence of the existence of a two-layered ligamentum flavum. The lumbar ligamentum flavum does not consist of two layers, but is confluent instead with the interspinous ligament that attaches to the zygapophyseal joints. To convey this anatomy better, we suggest describing the lumbar ligamentum flavum as a structure that consists of interlaminar and interspinous parts. Precise knowledge of the ligamentum flavum's anatomy can be of clinical value, particularly when epidural anesthesia or lumbar puncture are performed. Clin. Anat. 32:34-40, 2019. © 2019 Wiley Periodicals, Inc.


Assuntos
Ligamentos Articulares/anatomia & histologia , Ligamento Amarelo/anatomia & histologia , Vértebras Lombares/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
Proc Natl Acad Sci U S A ; 117(1): 278-284, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31871170

RESUMO

Oreopithecus bambolii (8.3-6.7 million years old) is the latest known hominoid from Europe, dating to approximately the divergence time of the Pan-hominin lineages. Despite being the most complete nonhominin hominoid in the fossil record, the O. bambolii skeleton IGF 11778 has been, for decades, at the center of intense debate regarding the species' locomotor behavior, phylogenetic position, insular paleoenvironment, and utility as a model for early hominin anatomy. Here we investigate features of the IGF 11778 pelvis and lumbar region based on torso preparations and supplemented by other O. bambolii material. We correct several crucial interpretations relating to the IGF 11778 anterior inferior iliac spine and lumbar vertebrae structure and identifications. We find that features of the early hominin Ardipithecus ramidus torso that are argued to have permitted both lordosis and pelvic stabilization during upright walking are not present in O. bambolii However, O. bambolii also lacks the complete reorganization for torso stiffness seen in extant great apes (i.e., living members of the Hominidae), and is more similar to large hylobatids in certain aspects of torso form. We discuss the major implications of the O. bambolii lower torso anatomy and how O. bambolii informs scenarios of hominoid evolution.


Assuntos
Fósseis , Hominidae/anatomia & histologia , Hominidae/classificação , Filogenia , Tronco/anatomia & histologia , Animais , Evolução Biológica , Hominidae/fisiologia , Humanos , Locomoção/fisiologia , Lordose , Vértebras Lombares/anatomia & histologia , Pelve/anatomia & histologia , Caminhada/fisiologia
4.
BMC Evol Biol ; 19(1): 226, 2019 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842740

RESUMO

BACKGROUND: Recently we proposed an evolutionary explanation for a spinal pathology that afflicts many people, intervertebral disc herniation (Plomp et al. [2015] BMC Evolutionary Biology 15, 68). Using 2D data, we found that the bodies and pedicles of lower vertebrae of pathological humans were more similar in shape to those of chimpanzees than were those of healthy humans. Based on this, we hypothesized that some individuals are more prone to intervertebral disc herniation because their vertebrae exhibit ancestral traits and therefore are less well adapted for the stresses associated with bipedalism. Here, we report a study in which we tested this "Ancestral Shape Hypothesis" with 3D data from the last two thoracic and first lumbar vertebrae of pathological Homo sapiens, healthy H. sapiens, Pan troglodytes, and several extinct hominins. RESULTS: We found that the pathological and healthy H. sapiens vertebrae differed significantly in shape, and that the pathological H. sapiens vertebrae were closer in shape to the P. troglodytes vertebrae than were the healthy H. sapiens vertebrae. Additionally, we found that the pathological human vertebrae were generally more similar in shape to the vertebrae of the extinct hominins than were the healthy H. sapiens vertebrae. These results are consistent with the predictions of the Ancestral Shape Hypothesis. Several vertebral traits were associated with disc herniation, including a vertebral body that is both more circular and more ventrally wedged, relatively short pedicles and laminae, relatively long, more cranio-laterally projecting transverse processes, and relatively long, cranially-oriented spinous processes. We found that there are biomechanical and comparative anatomical reasons for suspecting that all of these traits are capable of predisposing individuals to intervertebral disc herniation. CONCLUSIONS: The results of the present study add weight to the hypothesis that intervertebral disc herniation in H. sapiens is connected with vertebral shape. Specifically, they suggest that individuals whose vertebrae are towards the ancestral end of the range of shape variation within H. sapiens have a greater propensity to develop the condition than other individuals. More generally, the study shows that evolutionary thinking has the potential to shed new light on human skeletal pathologies.


Assuntos
Fósseis , Hominidae/anatomia & histologia , Deslocamento do Disco Intervertebral/patologia , Vértebras Lombares/patologia , Pan troglodytes/anatomia & histologia , Vértebras Torácicas/patologia , Animais , Evolução Biológica , Humanos , Disco Intervertebral/patologia , Vértebras Lombares/anatomia & histologia , Vértebras Torácicas/anatomia & histologia
5.
Br J Radiol ; 92(1104): 20190342, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31596119

RESUMO

OBJECTIVES: Standardised comparison of abdominal muscle and adipose tissue is often utilised in morphometric clinical research. Whilst measurements are traditionally standardised against the patient's height, this may not be always practically feasible. The aim of this study was to investigate the relationship between measurements of the vertebral body and patient height. METHODS: We analysed cross-sectional CT scans. Measurements of the vertebral body area (VBA), anteroposterior vertebral body diameter (APVBD) and lateral vertebral body diameter (LVBD) were made by two independent investigators by manual tracing. Patients were randomly divided into two groups: Group 1 standardisation and Group 2 validation. We compared height and vertebral body parameters from patients in Group 1 and mathematically modelled this relationship. We then utilised the model to predict the height of patients in Group 2 and compared this with their actual height. Observer variability was assessed using Bland-Altman plots and t-tests of differences. RESULTS: CT scans from 382 patients were analysed. No significant intraobserver or interobserver differences were apparent when measuring vertebral body parameters. We describe models which enable the prediction of the patients' height using the measured VBA, APVBD and LVBD. No significant differences were observed between the patients predicted and actual heights in the validation group. CONCLUSIONS: We demonstrate an important relationship between measurements of the patient's height and the vertebral body. This can be utilised in future research when the patient's height has not been measured. ADVANCES IN KNOWLEDGE: In the absence of the patient's height, we demonstrate that two-dimensional vertebral body parameters may be reliably used to standardise morphometric measurements.


Assuntos
Estatura , Vértebras Lombares/diagnóstico por imagem , Modelos Teóricos , Idoso , Feminino , Humanos , Vértebras Lombares/anatomia & histologia , Masculino , Variações Dependentes do Observador , Distribuição Aleatória , Tomografia Computadorizada por Raios X
6.
BMC Musculoskelet Disord ; 20(1): 454, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31630684

RESUMO

BACKGROUND: The paraspinal and psoas muscles have been considered to be essentially important for stabilizing the spinal column, and the muscle degeneration was found to exist in degenerative spinal kyphosis (DSK) patients. However, it is still not clear the relationship between muscle degeneration and spinal-pelvic alignment. The purpose of this study was to determine the correlations between the individual muscle degeneration at each lumbar spinal level and spinal-pelvic parameters in DSK patients. METHODS: The imaging data of 32 patients with DSK were retrospectively analyzed. The fat infiltration (FI) and relative cross-sectional area of muscle (RCSA) were quantitatively measured for multifidus (MF), erector spinae (ES) and psoas (PS) at each spinal level from L1/2 to L5/S1. The correlations were analyzed between RCSA and the sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT) and pelvic incidence (PI). RESULTS: The FI of MF and ES at L3/4, L4/5 and L5/S1 were higher than that at L1/2 and L2/3. The FI of PS at L4/5 and L5/S1 were lower than that of L1/2, L2/3 and L3/4. The RCSA of ES and PS from L1/2 to L5/S1 gradually increased, whereas the RCSA of ES from L1/2 to S5/S1 gradually decreased. The RCSA of MF at the L1/2 level was negatively correlated SVA (r = - 0.397,p = 0.024); the RCSA at L3/4, L4/5 and L5/S1 levels were negatively correlated with TK (r = - 0.364, p = 0.04; r = - 0.38, p = 0.032; r = - 0.432, p = 0.014); the RCSA at L4/5 level was positively correlated with LL (r = 0.528, p = 0.002). The RCSA of ES at L3/4 and L4/5 levels were positively correlated with PI (r = 0.377, p = 0.037) and SS (r = 0.420, p = 0.019). CONCLUSIONS: FI of MF and ES at lower lumbar level is higher than that at upper level, but FI of PS at upper lumbar level is higher than that at lower level. MF and ES have different roles for maintaining the sagittal spinal-pelvic balance.


Assuntos
Cifose/complicações , Atrofia Muscular/fisiopatologia , Músculos Paraespinais/patologia , Postura/fisiologia , Músculos Psoas/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Cifose/fisiopatologia , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/diagnóstico por imagem , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Atrofia Muscular/etiologia , Músculos Paraespinais/diagnóstico por imagem , Músculos Paraespinais/fisiopatologia , Ossos Pélvicos/anatomia & histologia , Ossos Pélvicos/diagnóstico por imagem , Músculos Psoas/diagnóstico por imagem , Músculos Psoas/fisiopatologia , Estudos Retrospectivos
7.
BMC Musculoskelet Disord ; 20(1): 423, 2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31510985

RESUMO

BACKGROUND: Percutaneous kyphoplasty (PKP) can effectively treat osteoporotic vertebral compression fractures (OVCFs). Although satisfactory clinical outcomes can be achieved, bone cement leakage remains a primary complication of PKP. Previous studies have found many high risk factors for bone cement leakage into the spinal canal; however, less attention to the posterior wall morphologies of different vertebral bodies may be one reason for the leakage. Here, we investigated the effect of posterior vertebral wall morphology in OVCF patients on bone cement leakage into the spinal canal during PKP. METHODS: Ninety-eight OVCF patients with plain computed tomography (CT) scans and three-dimensional (3D) reconstruction images from T6 to L5 were enrolled. 3D-CT and multiplanar reconstructions (MPR) were used to measure the concave posterior vertebral wall depth (PVWCD) and the corresponding midsagittal diameter of the nonfractured vertebral body (VBSD), and the PVWCD/VBSD ratio was calculated. All subjects were divided into the thoracic or lumbar groups based on the location of the measured vertebrae to observe the value and differences in the PVWCD between both groups. The differences in PVWCD and PVWCD/VBSD between the thoracic and lumbar groups were compared. Three hundred fifty-seven patients (548 vertebrae) who underwent PKP within the same period were also divided into the thoracic and lumbar groups. The maximal sagittal diameter (BCSD), the area of the bone cement intrusion into the spinal canal (BCA), and the spinal canal encroachment rate (BCA/SCA × 100%) were measured to investigate the effect of the thoracic and lumbar posterior vertebral wall morphologies on bone cement leakage into the spinal canal through the Batson vein during PKP. RESULTS: The PVWCDs gradually deepened from T6 to T12 (mean, 4.6 mm); however, the values gradually became shallower from L1 to L5 (mean, 0.6 mm). The PVWCD/VBSD ratio was approximately 16% from T6 to T12 and significantly less at 3% from L1 to L5 (P < 0.05). The rate of bone cement leakage into the spinal canal through the Batson vein was 10.1% in the thoracic group and 3.7% in the lumbar group during PKP. In the thoracic group, the BCSD was 3.1 ± 0.5 mm, the BCA was 30.2 ± 3.8 mm2, and the BCA/SCA ratio was 17.2 ± 2.0%. In the lumbar group, the BCSD was 1.4 ± 0.3 mm, the BCA was 14.8 ± 2.2 mm2, and the BCA/SCA ratio was 7.4 ± 1.0%. The BCSD, BCA and BCA/SCA ratio were significantly higher in the thoracic group than in the lumbar group (P < 0.05). CONCLUSIONS: The PVWCD in the middle and lower thoracic vertebrae can help reduce bone cement leakage into the spinal canal by enabling avoiding bone cement distribution over the posterior 1/6 of the vertebral body during PKP. The effect of the difference between the thoracic and lumbar posterior vertebral wall morphology on bone cement leakage into the spinal canal through the Batson vein in OVCF patients during PKP is one reason that the rate of bone cement leakage into the thoracic spinal canal is significantly higher than that into the lumbar spinal canal.


Assuntos
Cimentos para Ossos/efeitos adversos , Corpos Estranhos/epidemiologia , Cifoplastia/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Canal Vertebral/lesões , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Corpos Estranhos/diagnóstico por imagem , Corpos Estranhos/etiologia , Fraturas por Compressão/diagnóstico por imagem , Fraturas por Compressão/cirurgia , Humanos , Imageamento Tridimensional , Cifoplastia/métodos , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas por Osteoporose/cirurgia , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Fatores de Risco , Canal Vertebral/irrigação sanguínea , Canal Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/cirurgia , Vértebras Torácicas/anatomia & histologia , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento , Veias
8.
Eur. j. anat ; 23(5): 315-323, sept. 2019. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-183861

RESUMO

Anatomic characterization and fine structure of the human ligamentum flavum (LF), especially at different spinal levels, represent an attractive focus for the scientific and surgical application. Descriptive anatomical and structural study of LF at the cervical, thoracic and lumbar levels of the vertebral column in human cadavers is carried out here. The aim of the work is to clarify the anatomical features and fine structural differences in the human LF at different vertebral levels (cervical, thoracic and lumbar). Specimens of vertebral column were obtained from 34 human preserved cadavers. Their average age ranged between 56 and 69 years. Morphometric parameters including height, width and thickness of the ligament flavum at the midlevels of cervical, thoracic and lumbar regions were measured. Sections obtained from different levels were stained with different stains. Morphometric measurements involved the relative elastic area, relative collagen area, elastic area and collagen area% were measured.The results of the height, width and thickness of the LF at different spinal levels showed gradual increase in their mean values respectively. The LF midline gaps were found in the cervical, thoracic and lumbar regions. The morphometrical measurements showed that the average elastic area was highest in the cervical region and lowest in the thoracic region. In the lumbar region, the percentages of both elastic area and the collagen area were nearly the same. The characterization of morphological and histological aspects of the LF at different spinal levels will be of great importance for applications in spinal surgery, biomechanical and physical rehabilitation of vertebral column


No disponible


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Ligamento Amarelo/anatomia & histologia , Plexo Cervical/anatomia & histologia , Vértebras Lombares/anatomia & histologia , Cadáver , Tecido Elástico/anatomia & histologia , Dissecação/instrumentação , Estudos Transversais , Fotomicrografia/métodos
9.
World Neurosurg ; 132: 75-80, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31470159

RESUMO

BACKGROUND: Incomplete ossification of the pars interarticularis will result in a pars defect, a common cause of low back pain in youth and strongly associated with participation in high-impact sports. If left untreated, it can result in spondylolisthesis, causing dynamic canal stenosis, low back pain, and radiculopathy. The treatment of pars defect was first described by Bucks in 1970, who used screws in the lamina placed through an upward and outward direction. However, because of the multiple inclusion and exclusion criteria and narrow margin of error, the Bucks pars repair technique is not commonly performed. METHODS: A 28-year-old woman had with low back pain that she had been experiencing since mid-adolescence. Computed tomography revealed a bilateral L5 pars defect without spondylolisthesis. Her L5 vertebra was reconstructed virtually. The screw trajectories, a 3-dimensional (3D) model of the vertebra, and a patient-specific drill guide (PSDG) were designed and printed using positioning guide software (MySpine MC Guides [Medacta International SA, Castel San Petro, Switzerland]). A modified Bucks procedure using cannulated compression screws and the PSDG was performed. RESULTS: Follow-up computed tomography revealed accurate placement of the compression screws, mirroring the planned trajectory. The patient was pain free at 3 months postoperatively, and early union across the defect was visualized on the 5-month radiographic imaging study. CONCLUSION: Using 3D planning software, complex surgical procedures can be planned using the patient's anatomy and computed tomography. With the aid of 3D-printed PSDGs, screw placement in narrow corridors, such as was shown in our case, is safe, efficient, and achievable.


Assuntos
Vértebras Lombares/cirurgia , Modelos Anatômicos , Espondilólise/cirurgia , Adulto , Parafusos Ósseos , Transplante Ósseo , Fios Ortopédicos , Feminino , Humanos , Imageamento Tridimensional , Vértebras Lombares/anormalidades , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/diagnóstico por imagem , Tamanho do Órgão , Modelagem Computacional Específica para o Paciente , Impressão Tridimensional
10.
Leg Med (Tokyo) ; 40: 5-16, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31279223

RESUMO

Although body mass is not a stable trait over the lifespan, information regarding body size assists the forensic identification of unknown individuals. In this study, we aimed to study the potential of using the fourth lumbar vertebra (L4) for body mass estimation among contemporary Finns. Our sample comprised 1158 individuals from the Northern Finland Birth Cohort 1966 who had undergone measurements of body mass at age 31 and 46 and lumbar magnetic resonance imaging (MRI) at age 46. MRI scans were used to measure the maximum and minimum widths, depths, and heights of the L4 body. Their means and sum were calculated together with vertebral cross-sectional area (CSA) and volume. Ordinary least squares (OLS) and reduced major axis (RMA) regression was used to produce equations for body mass among the full sample (n = 1158) and among normal-weight individuals (n = 420). In our data, body mass was associated with all the L4 size parameters (R = 0.093-0.582, p ≤ 0.019 among the full sample; R = 0.243-0.696, p ≤ 0.002 among the normal-weight sample). RMA regression models seemed to fit the data better than OLS, with vertebral CSA having the highest predictive value in body mass estimation. In the full sample, the lowest standard errors were 6.1% (95% prediction interval ±9.6 kg) and 7.1% (±9.1 kg) among men and women, respectively. In the normal-weight sample, the lowest errors were 4.9% (±6.9 kg) and 4.7% (±5.7 kg) among men and women, respectively. Our results indicate that L4 dimensions are potentially useful in body mass estimation, especially in cases with only the axial skeleton available.


Assuntos
Índice de Massa Corporal , Antropologia Forense/métodos , Vértebras Lombares/anatomia & histologia , Imagem por Ressonância Magnética , Feminino , Finlândia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
11.
Comput Methods Biomech Biomed Engin ; 22(15): 1163-1173, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31361152

RESUMO

The spine or 'back' has many functions including supporting our body frame whilst facilitating movement, protecting the spinal cord and nerves and acting as a shock absorber. In certain instances, individuals may develop conditions that not only cause back pain but also may require additional support for the spine. Common movements such as twisting, standing and bending motions could exacerbate these conditions and intensify this pain. Back braces can be used in certain instances to constrain such motion as part of an individual's therapy and have existed as both medical and retail products for a number of decades. Arguably, back brace designs have lacked the innovation expected in this time. Existing designs are often found to be heavy, overly rigid, indiscrete and largely uncomfortable. In order to facilitate the development of new designs of back braces capable of being optimised to constrain particular motions for specific therapies, a numerical and experimental design strategy has been devised, tested and proven for the first time. The strategy makes use of an experimental test rig in conjunction with finite element analysis simulations to investigate and quantify the effects of back braces on flexion, extension, lateral bending and torsional motions as experienced by the human trunk. This paper describes this strategy and demonstrates its effectiveness through the proposal and comparison of two novel back brace designs.


Assuntos
Braquetes , Coluna Vertebral/fisiologia , Simulação por Computador , Desenho Assistido por Computador , Análise de Elementos Finitos , Humanos , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/fisiologia , Modelos Anatômicos , Movimento , Desenho de Prótese , Amplitude de Movimento Articular , Coluna Vertebral/anatomia & histologia , Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Torção Mecânica
12.
Australas Phys Eng Sci Med ; 42(3): 689-700, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31183739

RESUMO

The human lumbar spine incorporates the best joints in nature due to its optimal static and dynamic behavior against the internal and external loads. Developing an elemental structure based on this joint requires simplification in terms of the materials employed by keeping the mechanical and anatomical behaviors of the human lumbar spine. In the present study, the finite element (FE) of two motion segments of the human lumbar spine (L3/L4) was developed based on the CT scan data as the base for vertebrae geometry, verified geometry properties for another part of two motion segments, and combination of materials and loads obtained from the validated resources. Then, simplification occurred in four continuous steps such as omitting the annual fibers of annual matrix, representing the material of the annual matrix to the nucleus, demonstrating the material of annual matrix to the endplates too, and omitting the trabecular part of vertebrae. The present study aimed to propose the method for developing the basic structure of the human lumbar spine by simplifying its materials in the above-mentioned steps, analyzing the biomechanical effects of these four steps in terms of their internal and external responses, and validating the data obtained from the FE method. The validated simplified way introduced in this study can be used for future research by making implants, prosthesis, and modeling based on the human lumbar spine in other fields such as industrial design, building structures, or joints, which results in making the model easier, cheaper, and more effective.


Assuntos
Vértebras Lombares/anatomia & histologia , Modelos Anatômicos , Osso Esponjoso/anatomia & histologia , Humanos , Disco Intervertebral/anatomia & histologia , Vértebras Lombares/diagnóstico por imagem , Movimento (Física) , Pressão , Amplitude de Movimento Articular/fisiologia , Software , Estresse Mecânico , Tomografia Computadorizada por Raios X
13.
Anat Histol Embryol ; 48(4): 358-365, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31106459

RESUMO

There are numerous publications about feline renal imaging information; however, none have established reference values for kidney size using computed tomography (CT). This study aimed to determine renal size and shape as well as the morphology of renal-related structures in clinically normal cats (Felis catus) that underwent CT. Twenty-seven healthy cats underwent pre- and post-iodinated contrast-enhanced CT. Most cat (59%) kidneys were located at the same level. The average pre-contrast dimensions of the left kidney included a width of 2.46 ± 0.28 cm, a length of 3.52 ± 0.44 cm and a height 2.19 ± 0.31 cm, whereas those of the right kidneys were 2.45 ± 0.27 cm, 3.54 ± 0.46 cm and 2.05 ± 0.23 cm, respectively. After contrast enhancement, kidneys were slightly enlarged though not significantly. Additionally, renal length (LK or RK) was compared with second lumbar vertebra (L2) length and abdominal aorta diameter (AO). AO was significantly larger in male cats whereas L2 length appeared longer in male cats, but was not statistically different from the female cats. The LK/L2 and RK/L2 ratios were 2.29 ± 0.23 and 2.36 ± 0.20, respectively, and the LK/AO and RK/AO were 11.72 ± 1.37 and 12.05 ± 1.47, respectively. Renal vessels were examined. The renal vein was obviously larger than the renal artery, and paired renal veins were observed periodically. This study provides CT information about the feline kidney, which may help to establish reference values and information regarding renal structure prior to surgery in practice.


Assuntos
Gatos/anatomia & histologia , Rim/diagnóstico por imagem , Animais , Aorta Abdominal/anatomia & histologia , Aorta Abdominal/diagnóstico por imagem , Análise de Dados , Feminino , Rim/anatomia & histologia , Rim/irrigação sanguínea , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/diagnóstico por imagem , Masculino , Orquiectomia/veterinária , Ovariectomia/veterinária , Radiografia Abdominal/veterinária , Radiografia Torácica/veterinária , Artéria Renal/anatomia & histologia , Artéria Renal/diagnóstico por imagem , Veias Renais/anatomia & histologia , Veias Renais/diagnóstico por imagem , Fatores Sexuais , Tomografia Computadorizada por Raios X/veterinária , Ultrassonografia/veterinária
14.
J Orthop Res ; 37(8): 1805-1816, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31042323

RESUMO

Total disc arthroplasty (TDA) is a motion-preserving surgical treatment for spinal disorders. However, adverse surgical outcomes, such as abnormal kinematics, facet joint (FJ) overloading, and polyethylene (PE) failures, have limited wide application of lumbar TDAs. The objectives of this computational study were to elucidate how implant design and FJ articulation both influence metal-on-polyethylene (MoP) motion and contact mechanics, as well as to propose and refine a new mobile-bearing TDA concept which enhanced postoperative performance. Simulation results show that abnormal motions (lift-off and/or unsymmetrical motion) are alleviated in fixed-/mobile-bearing TDA-treated segments, as the FJ gap increases. It clearly demonstrates that FJ articulation guides segmental motion and interferes with intended MoP articulation. For an existing biconvex mobile-bearing design, component impingement leads to a peak PE stress of 20.8 MPa (yield stress: 13 MPa), indicating a high risk of PE creep/fracture. Therefore, we proposed a new TDA concept featuring a biconcave PE core with a smooth shape, in order to strengthen the PE rim and mitigate edge-loading. Furthermore, the biconcave-core TDA was optimally designed to promote normal segmental range of motion (ROM), or to minimize polyethylene contact pressure (PCP). In extension (the severest loading scenario), the biconvex-core TDA design caused a ROM 3.6° (+88%) greater than the intact segment and a peak PCP of 116.5 MPa. In contrast, ROM-optimal or PCP-optimal biconcave-core TDA designs decreased the ROM difference to 0.0° or the peak PCP to 24.3 MPa. Therefore, this new TDA design can potentially reduce the incidence of hypermotion and PE damage. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1805-1816, 2019.


Assuntos
Artroplastia/instrumentação , Vértebras Lombares/cirurgia , Modelos Biológicos , Desenho de Prótese , Articulação Zigapofisária/anatomia & histologia , Análise de Elementos Finitos , Humanos , Vértebras Lombares/anatomia & histologia
15.
Clin Anat ; 32(6): 783-793, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31056783

RESUMO

The adult vertebral level of the splanchnic branches of the abdominal aorta relies on a complex series of fusion and regression steps during embryological development, such that variation is common. Little is known however regarding the anatomy of the abdominal aorta in children. This study aimed to investigate the spatial relationship between the abdominal aorta and the vertebral column during childhood development to inform clinical management of pediatric patients. Retrospective multislice computed tomography abdominopelvic angiograms of children aged neonate to 19 years (n = 232) were used to examine vertebral levels of the celiac trunk (CoT), superior mesenteric artery (SMA), inferior mesenteric artery (IMA), and aortic bifurcation (AB) using multiplanar formatting views in OsiriX. The abdominal aorta length, AB angle, and displacement of the aorta from the midline were quantified with the effect of age and sex analyzed using multinomial logistic regression and general linear models. The most frequent origins of CoT, SMA, IMA, and AB were T12, L1, L3, and L4, respectively, with significant variation in vertebral level for each vessel. SMA level was significantly more proximal with age, and CoT and AB demonstrated marked sex differences in vertebral level. As the age of the child increased, AB angle decreased, aortic displacement increased, and the length of the abdominal aorta increased at a slower velocity to the vertebral column (P < 0.001). Our study highlights the variation of the location and geometry of the abdominal aorta in children; this knowledge will positively impact pediatric surgical approaches and endovascular procedures. Clin. Anat. 32:783-793, 2019. © 2019 Wiley Periodicals, Inc.


Assuntos
Aorta Abdominal/anatomia & histologia , Vértebras Lombares/anatomia & histologia , Vértebras Torácicas/anatomia & histologia , Adolescente , Fatores Etários , Aorta Abdominal/crescimento & desenvolvimento , Criança , Pré-Escolar , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Imageamento Tridimensional/métodos , Lactente , Recém-Nascido , Modelos Lineares , Vértebras Lombares/crescimento & desenvolvimento , Masculino , Estudos Retrospectivos , Fatores Sexuais , Vértebras Torácicas/crescimento & desenvolvimento
16.
BMC Musculoskelet Disord ; 20(1): 252, 2019 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-31128590

RESUMO

BACKGROUND: Safe placement of pedicle screws without jeopardizing neurovascular structures medially and anteriorly is important during spine surgery. Inferior breach of pedicle is also dangerous due to low margin of error. Lumbar morphology and identical pedicle orientation at L1 to L5 shown on CT scan of young Taiwanese patients (90 patients) were analyzed and compared with findings reported for Caucasian subjects. METHODS: Previously reported techniques were employed to quantitatively elucidate the parameters regarding lumbar morphology and identical pedicle orientation at each vertebra. The parameters for pedicle angle (PA), pedicle diameter (PD), pedicle axis distance (PAD), midline axis distance (MAD), transverse pedicle axis distance (TPAD) and transverse intertangential angle (TITA) were measured. RESULTS: Taiwanese subjects had different PA, PD, PAD, MAD at L1 to L5 and TITA at L3 to L5 compared with Caucasian subjects. L5 had the most convergent pedicle axis, the widest PD and the shortest antero-posterior axis morphology. CONCLUSIONS: This study provides detailed information for identifying pedicle orientation during pedicle screw placement and elucidate racial differences in lumbar morphology and pedicle orientation between Taiwanese and Caucasian populations.


Assuntos
Variação Biológica da População/etnologia , Vértebras Lombares/anatomia & histologia , Parafusos Pediculares/efeitos adversos , Fusão Vertebral/métodos , Adulto , Grupo com Ancestrais do Continente Asiático/estatística & dados numéricos , Grupo com Ancestrais do Continente Europeu/estatística & dados numéricos , Feminino , Humanos , Doença Iatrogênica/prevenção & controle , Complicações Intraoperatórias/etiologia , Complicações Intraoperatórias/prevenção & controle , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Fusão Vertebral/efeitos adversos , Fusão Vertebral/instrumentação , Taiwan , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Adulto Jovem
17.
BMC Musculoskelet Disord ; 20(1): 260, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31142310

RESUMO

BACKGROUND: The risk of posterior cage migration (PCM) exists when a fusion cage is used for transforaminal lumbar interbody fusion (TLIF). This complication is influenced by contact pressure between the endplate and the cage. Previous reports demonstrated that anteriorly located cages bore more load and had greater strain than posteriorly located cages. However, there have been no detailed reports on the correlation between cage positioning and PCM. METHODS: From March 2014 to October 2015, we reviewed 953 patients receiving open transforaminal lumbar interbody fusion (TLIF) and bilateral pedicle screw instrumentation. One hundred patients without PCM were randomly sampled as the control group. Postoperative sagittal and coronal cage positions in the disc space were evaluated with the 'depth ratio' and the 'coronal ratio'. The demographic data of patients with and without PCM were compared to detect patient-related factors. Radiographic and cage related parameters, including cage position, preoperative disc height, preoperative spine stability, cage geometry, cage size, and height variance (= cage height - preoperative disc height) were compared between the PCM group and the control group. Univariate analyses and a multivariate logistic model were used to identify risk factors of PCM. RESULTS: Posterior cage migration occurred in 24 (2.52%) of 953 patients. The univariate and multivariate analyses revealed that those with a decreased depth ratio (OR, 9.78E-4; 95% CI, 9.69E-4 - 9.87E-4; p < 0.001) and height variance (OR, 0.757, 95% CI, 0.575-0997, p = 0.048) had a significantly higher risk of developing PCM. CONCLUSIONS: Our results verified that posteriorly located cages and undersized cages are more prone to developing PCM, which may aid surgeons in making optimal decisions during TLIF procedures.


Assuntos
Migração de Corpo Estranho/epidemiologia , Fixadores Internos/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Doenças da Coluna Vertebral/cirurgia , Fusão Vertebral/efeitos adversos , Idoso , Estudos de Casos e Controles , Tomada de Decisão Clínica , Feminino , Seguimentos , Migração de Corpo Estranho/diagnóstico por imagem , Migração de Corpo Estranho/etiologia , Humanos , Disco Intervertebral/anatomia & histologia , Disco Intervertebral/diagnóstico por imagem , Disco Intervertebral/patologia , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/patologia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/etiologia , Prevalência , Estudos Retrospectivos , Fatores de Risco , Doenças da Coluna Vertebral/diagnóstico por imagem , Doenças da Coluna Vertebral/patologia , Fusão Vertebral/instrumentação , Fusão Vertebral/métodos
18.
World Neurosurg ; 128: e51-e58, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31035020

RESUMO

OBJECTIVE: To provide anatomic evidence of preoperative assessment of oblique lumbar interbody fusion (OLIF) for Chinese patients. METHODS: From the hospital picture archiving and communication system, 400 lumbar magnetic resonance imaging studies of adults performed between November 2016 and January 2017 were selected. L2-3, L3-4, L4-5, and L5-S1 transverse and sagittal images were studied, and anatomic parameters associated with OLIF surgery, including bare window and psoas window, were measured and recorded. SPSS software was used for data summarization, sorting, and analysis to explore the significance of various anatomic parameters. RESULTS: OLIF surgical corridors to the L2-S1 discs were found in most magnetic resonance imaging scans studied. The size of the psoas affects the difficulty of psoas muscle traction. It is relatively easy to perform OLIF surgery in older women. Most of the human iliac arteries were bifurcated and aggregated in front of the L4-5 intervertebral disc. The lower the aggregate level of the common iliac vein, the less likely it was to have the OLIF surgical corridor in the L5-S1 segment. The most frequently used lengths for a lumbar interbody cage for OLIF for Chinese patients are 50 mm and 55 mm. CONCLUSIONS: OLIF can be a good choice for lumbar intervertebral fusion, including L5-S1 segment, in most Chinese patients. Older women are likely to have more scope of OLIF surgery. As a routine preoperative examination, lumbar magnetic resonance imaging is of great importance to OLIF surgery preoperative assessment.


Assuntos
Artéria Ilíaca/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Músculos Psoas/diagnóstico por imagem , Fusão Vertebral/métodos , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Grupo com Ancestrais do Continente Asiático , China , Feminino , Humanos , Artéria Ilíaca/anatomia & histologia , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/cirurgia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Músculos Psoas/anatomia & histologia , Fatores Sexuais , Adulto Jovem
19.
Biomech Model Mechanobiol ; 18(5): 1363-1369, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30980210

RESUMO

There is a growing interest in the development of patient-specific finite element models of the human lumbar spine for both the assessment of injury risk and the development of treatment strategies. A current challenge in implementing these models is that the outer annulus fibrosus of the disc is composed of concentric sheets of aligned collagen fibers, the helical angles of which vary spatially. In finite element models, fiber angle is typically assumed to be constant, based on average experimental measurements from a small number of locations. The present study hypothesized that the full spatial distribution of fiber angles in the annulus fibrosus may be predicted for any disc geometry by assuming growth from a thin cylinder with constant fiber angle. This hypothesis was tested by developing an analytical model of disc growth and calibrating it with fiber angle measurements of adult bovine caudal discs. The calibrated model was then run on a representative human lumbar disc geometry. The model was able to accurately predict fiber angle distributions in both the experimental bovine caudal disc measurements and literature-reported human lumbar disc measurements. Despite its theoretical basis in development, the model requires only mature state geometry, making it practical for implementation in patient-specific finite element analyses, in which disc geometry is obtained from clinical imaging.


Assuntos
Anel Fibroso/anatomia & histologia , Disco Intervertebral/anatomia & histologia , Modelos Biológicos , Animais , Bovinos , Humanos , Vértebras Lombares/anatomia & histologia
20.
World Neurosurg ; 127: e1112-e1119, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30980982

RESUMO

BACKGROUND: Recently, interspinous stabilization with the interspinous process device (IPD) has become an alternative to treat lumbar spinal stenosis. The biomechanical influence of different design features of IPDs on intradiscal pressure (IDP) and facet joint force (FJF) has not been fully understood. The aim of this study was to investigate the biomechanical performance of different IPDs using finite element (FE) method. METHODS: A FE model of the L1-5 segments was developed and validated. Four surgical FE models were constructed by inserting different implants at the L3-4 segment (Coflex-F, DIAM, Wallis, and pedicle screw system). The 4 motion modes were simulated. RESULTS: The IPDs decreased range of motion (ROM) at the surgical level substantially in flexion and extension, but little influence was found in lateral bending and torsion. Compared with the DIAM and Wallis devices, the Coflex-F device showed advantages in stabilizing the surgical level, especially in flexion and extension, while it increased FJF at adjacent levels by 26%-27% in extension. Among the 3 IPDs, the DIAM device exhibited the most comparable ROM, IDP, and FJF at adjacent levels compared with the intact lumbar spine. The influence of the Wallis device was between that of the Coflex-F and DIAM devices. CONCLUSIONS: Compared with rigid fixation, the IPDs demonstrated less compensation at adjacent levels in terms of ROM, IDP, and FJF, which may lower the incidence of adjacent segment degeneration in the long term.


Assuntos
Análise de Elementos Finitos , Imageamento Tridimensional/métodos , Vértebras Lombares/anatomia & histologia , Vértebras Lombares/fisiologia , Modelos Anatômicos , Fusão Vertebral/instrumentação , Adulto , Fenômenos Biomecânicos/fisiologia , Feminino , Humanos , Vértebras Lombares/cirurgia , Parafusos Pediculares , Fusão Vertebral/métodos
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