Anatomic measurement and clinical significance of the middle and lower thoracic segments in normal adults / Medición anatómica e importancia clínica de los segmentos torácico medio e inferior en adultos normales

Thoracic disc herniation (TDH) has high technical difficulty and serious complications, and the clinical anatomy of thoracic intervertebral foramen is less. Collecting 10 adult male cadavers, measuring the longitudinal diameter of the dorsal root ganglion (D1), the transverse diameter of the dorsal root ganglion (D2), horizontal sagittal diameter of the upper edge of the intervertebral disc (S1), the high of intervertebral foramen (H1), the height of articulationes costovertebrales (H2), the height of intervertebral disk (H3), the angel of the dorsal root ganglion (a). The aim of this study is to explore the safe area of middle and lower thoracic section and provide anatomical basis for the selection of operative cannula. Mastering the certain rules of the anatomical structure of the middle and lower thoracic segments, and referring to the above parameters in clinical, is conducive to the selection of the working casing during surgery.

La hernia de disco torácico (TDH) tiene una alta dificultad técnica y complicaciones graves, y la anatomía clínica del agujero intervertebral torácico es menor. Recolectando 10 cadáveres machos adultos, midiendo el diámetro longitudinal del ganglio de la raíz dorsal (D1), el diámetro transversal del ganglio de la raíz dorsal (D2), el diámetro sagital horizontal del borde superior del disco intervertebral (S1), el colmo del intervertebral agujero (H1), la altura de las articulaciones costovertebrales (H2), la altura del disco intervertebral (H3), el ángel del ganglio de la raíz dorsal (α). El objetivo de este estudio es explorar el área segura de la sección torácica media y baja y proporcionar una base anatómica para la selección de la cánula operatoria. Dominar ciertas reglas de la estructura anatómica de los segmentos torácicos medio e inferior, y referirse a los parámetros anteriores en clínica, es propicio para la selección de la carcasa de trabajo durante la cirugía.

Energy supply and demand in the intervertebral disc / Fornecimento e demanda de energia no disco intervertebral / Suministro de energía y demanda en el disco intervertebral

ABSTRACT The intervertebral disc (IVD) is one of the parts of the body most commonly affected by disease, and it is only recently that we have come closer to understanding the reasons for its degeneration, in which nutrient supply plays a crucial role. In this literature review, we discuss the basic principles and characteristics of energy supply and demand to the IVD. Specifically, we review how different metabolites influence IVD cell activity, the effects of mechanical loading on IVD cell metabolism, and differences in energy metabolism of the annulus fibrous and nucleus pulposus cell phenotypes. Determining the factors that influence nutrient supply and demand in the IVD will enhance our understanding of the IVD pathology, and help to elucidate new therapeutic targets for IVD degeneration treatment.

RESUMO O disco intervertebral (IVD) é uma das partes mais comuns do corpo e apenas recentemente nos aproximamos de compreender as razões da sua degeneração, em que o suprimento de nutrientes desempenha um papel crucial. Nesta revisão da literatura, discutimos os princípios básicos e as nuances do fornecimento e da demanda de energia para o IVD. Específicamente, analisamos como os diferentes metabólitos influenciam na atividade das células IVD, os efeitos da carga mecânica no metabolismo das células IVD, a diferença no metabolismo energético dos fenótipos das células fibrosas e do núcleo do pulposus anelar. A determinação de fatores que influenciam o suprimento e a demanda de nutrientes no IVD aumentará nossa compreensão da patologia IVD e ajudará a elucidar novos alvos terapêuticos para o tratamento da degeneração IVD.

RESUMEN El disco intervertebral (IVD, por sus siglas en inglés) es una de las partes más comúnmente enfermas del cuerpo y solo recientemente nos acercamos a la comprensión de los motivos de su degeneración, de los cuales el suministro de nutrientes juega un papel crucial. En esta revisión de la literatura discutimos los principios básicos y los matices de la oferta y demanda de energía para el IVD. Específicamente, revisamos cómo los diferentes metabolitos influyen en la actividad de las células IVD, los efectos de la carga mecánica sobre el metabolismo de las células IVD y las diferencias en el metabolismo energético de los fenotipos de las células del anillo fibroso y el núcleo pulposo. La determinación de los factores que influyen en la oferta y demanda de nutrientes en el IVD mejorará nuestra comprensión de la patología IVD y ayudará a dilucidar nuevos objetivos terapéuticos para el tratamiento de la degeneración IVD.

Anatomic-imaging correlations of lumbar disk-vertebral morphometric indices / Correlaciones anatomopatológicas de los índices morfométricos disco-vertebral lumbar

SUMMARY: This study represents a morphometric assessment of the anterior segment of the lumbar spine, focused on the vertebral body - intervertebral disk assembly, calculating some specific indicators and then completing direct morphometry data with the data resulting from the imaging interpretation and subsequently correlating the same to map an anatomic-imaging model. The study was carried out with anatomic items from personal archive and images obtained from Computer Tomography (CT) and Magnetic Resonance Imaging (MRI) assessment. The morphometric assessment was carried out for intervertebral disks, the disk height in the anterior and posterior sections and correlated with the disk angle degree. Direct morphometric data was compared and correlated with the data resulting from the imaging interpretation. Direct morphometric assessment was carried out for 11 vertebral blocks; the vertebral blocks were sectioned and turned into 22 vertebral semi-blocks allowing easy access to absolutely all dimensional values pursued, including the ones covered by the posterior arc. The assessment of imaging data was made with CT, CT 3D and MRI investigations from the 120 subjects in the study. The disk sizes were assessed by direct measurements on the anatomic items and directly measured by means of the software for modern imaging examination. In case of significant differences between the vertebral bodies, the calculation of disk sizes was made indirectly, on grounds of the geometric interpretation of the vertebral body face sizes. The vertebral body / intervertebral disk (IVD) assembly represents a dynamic structure, permanently subject to changes and adaptation, IVD being capable of incurring changes for the entire life time, including growth changes; the growth, however, is not lineal, but a succession of thickening and getting thinner, in full concordance with the structural stresses and changes occurring inside.

RESUMEN: El estudio representa una evaluación morfométrica del segmento anterior de la columna lumbar, centrado en el conjunto del cuerpo vertebral - disco intervertebral, calculando algunos indicadores específicos y completando los datos morfométricos directos. El objetivo del trabajo fue mapear un modelo de imagen anatómica con los datos de la interpretación de la imagen, posteriormente correlacionando los datos. El estudio se llevó a cabo con artículos anatómicos de archivos personales y de las imágenes obtenidas de tomografía computarizada (TC) y resonancia magnética (RM) de evaluación. La evaluación morfométrica se realizó en los discos intervertebrales, la altura del disco en las secciones anterior y posterior y se correlacionó con el grado del ángulo del disco. Se compararon los datos morfométricos directos y se correlacionaron con los datos resultantes de la interpretación de la imagen. Se realizó una evaluación morfométrica directa de 11 bloques vertebrales; Los bloques vertebrales se seccionaron y se convirtieron en 22 semibloques vertebrales permitiendo el fácil acceso a todos los valores dimensionales, incluyendo aquellos cubiertos por el arco posterior. La evaluación de los datos de imagen se realizó en 120 sujetos con CT, CT 3D y MRI. Los tamaños de los discos se evaluaron mediante medidas directas de los elementos anatómicos y se midieron con el software para la examinación de imágenes. En caso de diferencias significativas entre los cuerpos vertebrales, el cálculo de los tamaños de los discos se realizó indirectamente, debido a la interpretación geométrica de los tamaños de la cara del cuerpo vertebral. El conjunto cuerpo vertebral / disco intervertebral (CVDV) representa una estructura dinámica, permanentemente sujeta a transformaciones y adaptación, siendo (CVDV) capaz de incurrir en cambios durante toda la vida, incluyendo aquellos relacionados con crecimiento. El crecimiento, sin embargo, no es lineal, sino una sucesión de engrosamiento y adelgazamiento, en plena concordancia con las tensiones estructurales y los cambios que se producen en su interior.

Aging and degeneration of the intervertebral disc: review of basic science / Envelhecimento e degeneração do disco intervertebral: revisão da ciência básica / El envejecimiento y la degeneración del disco intervertebral: revisión de la ciencia básica

Currently there is a growing interest in the study of intervertebral discs due to loss of manpower brought to society by low back and neck pains. These papers seek to delineate the difference between normal aging and disc degeneration, trying to understand what factor would be determining for the second condition. Thus, the morphology field was expanded and knowledge on the structure of intervertebral discs currently uses the research field of cell and molecular biology, and genetics. The results indicate that regardless of age or condition, the intervertebral disc undergoes long and extensive remodeling of its constituents, which are influenced by several factors: environmental, soluble, cell growth and extracellular matrix. In this literature review we describe the biological characteristics of the cervical and lumbar intervertebral disc with a focus on basic science of aging and degeneration, selecting the latest findings and discussions of the area, which influence future research and clinical thoughts.

Atualmente ocorre um crescente interesse no estudo dos discos intervertebrais em virtude da perda da força de trabalho que a lombalgia e a cervicalgia trazem à sociedade. Esses trabalhos buscam delinear a diferença entre envelhecimento normal e degeneração discal, tentando entender qual fator seria determinante para a segunda condição. Assim, o campo da morfologia foi ampliado e o conhecimento sobre a estrutura dos discos intervertebrais hoje utiliza investigações no campo da biologia celular, molecular e da genética. Os resultados apontam que, independentemente da idade ou condição de enfermidade, o disco intervertebral sofre extenso e longo remodelamento de seus constituintes, os quais sofrem influências de diversos fatores: ambientais, solúveis e de crescimento das células e da matriz extracelular. Nesta revisão da literatura, descrevem-se as características biológicas do disco intervertebral cervical e lombar, com foco na ciência básica do envelhecimento e degeneração, selecionando as mais recentes descobertas e discussões da área, as quais influenciam futuras pesquisas e pensamentos clínicos.

Actualmente existe un creciente interés en el estudio de los discos intervertebrales debido a la pérdida de mano de obra que el dolor del cuello y lumbar aportan a la sociedad. Estas obras tratan de delimitar la diferencia entre el envejecimiento normal y la degeneración del disco, tratando de entender qué factor sería decisivo para la segunda condición. Así, el campo de la morfología se amplió y los conocimientos sobre la estructura de los discos intervertebrales utiliza actualmente la investigación en el campo de la biología celular y molecular, además de la genética. Los resultados indican que, independientemente de su edad o estado de la enfermedad, el disco intervertebral sufre una remodelación extensa y larga de sus componentes, que son influenciados por varios factores: el ambiente, solubles y de crecimiento celular y de la matriz extracelular. En esta revisión de la literatura se describen las características biológicas del disco intervertebral cervical y lumbar, con un enfoque en la ciencia básica del envejecimiento y la degeneración, seleccionando los últimos descubrimientos y discusiones del área, que influyen en la futura investigación y pensamientos clínicos.

Are Spinal or Paraspinal Anatomic Markers Helpful for Vertebral Numbering and Diagnosing Lumbosacral Transitional Vertebrae?

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.

Lesão iatrogênica meningomedular em um cão submetido à espondilectomia ventral para tratamento de extrusão crônica de disco intervertebral cervical / Iatrogenic meningo-medullary lesion in a dog undergoing ventral spondylectomy for treatment of a chronic cervical intervertebral disc extrusion

Objetivou-se descrever a ocorrência de lesão iatrogênica meningomedular em um cão da raça Dachshund, macho, oito anos de idade, apresentando tetraparesia flácida há dois meses, que foi submetido à espondilectomia ventral para tratamento de extrusão crônica de disco intervertebral cervical. Durante remoção do material de disco herniado com removedores de tártaro e pinça hemostática, observou-se severa hemorragia dos seios venosos, descolamento meníngeo com laceração medular e imediata queda dos parâmetros cardiovasculorrespiratório, com evolução para a morte ante a ausência de respostas às medidas de ressuscitação cardiopulmonar.

Our objective was to describe the occurrence of an iatrogenic meningo-medullary lesion and the trans-surgical complications in an eight-year-old male Daschund, which presented flacid tetraparesis for two months, and underwent ventral spondylectomy to treat a chronic cervical intervertebral disc extrusion. During the removal of the herniated disc with dental picks and hemostatic forceps, we observed meningeal dislocation with medullary laceration and an immediate reduction in cardiovasculatory and respiratory parameters, which progressed to a cardiorespiratory arrest that was non-responsive to medication and finally led to the death of the patient.

Evaluation of lumbar vertebral body and disc: a stereological morphometric study / Evaluación del cuerpo y disco vertebral lumbar: estudio morfométrico estereológico

Anterior access to the L1-L5 vertebrae and disc spaces can be technically challenging, frequently requiring the use of an approach to a surgeon for an adequate exposure. The technique is used for lesion excision, corpectomy, vertebral body reconstruction with cages, realignment, and/or plating or screwing. For a successful anterior approach and a suitable instrumental design via screw, adequate morphometric knowledge about body of lumbar vertebrae and disc spaces and standardized volumetric data are also required for neurosurgeons. We aimed morphometric and volumetric evaluation of lumbar bodies and discs to contribute to a safe anterior approach during surgery. We evaluated vertebral body and disc morphometry using stereology in right-handed 25 adult subjects on MRI in the same population with no history of vertebral fractures and degenerative spinal disease. The shape, defining concavity index and volumetric measurements of the body L1-L5 vertebrae, morphometric parameters such as length, height, width of the vertebral body were measured. Also morphometric and volumetric analysis of discs between L1 and L5 were evaluated selected axial and sagittal slices. As expected, the average dimensions of male vertebrae are greater than those of females, but most of them do not differ statistically. Only three dimensions, the mean difference between anterior and central heights of L3, L4 and L5 showed statistically significant difference, indicating smaller central height in both males and females.The transverse and anterior-posterior diameters of the vertebral body, intervertebral disc height and volume displayed no sexual dimorphism (p>0.05). But, the intervertebral disc height and volume increased from L1 to L5 (p <0.01). Concavity indexes for all lumbar vertebrae for both sexes did not differ statistically. The method is important to estimate applying implant size and amount in decompression operations for neurosurgeons.

El acceso anterior a las vértebras L1-L5 y espacios entre los discos puede ser técnicamente difícil, con frecuencia requiere la participación de un cirujano para una exposición adecuada. La técnica se utiliza para la extirpación de la lesión, corpectomía, la reconstrucción del cuerpo vertebral con jaulas, realineamiento y / o placas o tornillos. Para un enfoque exitoso anterior y un diseño adecuado instrumental a través de tornillo, un acabado conocimiento sobre la morfometría del cuerpo de las vértebras lumbares y de los espacios entre los discos y la evaluación volumétrica son necesarias para el neurocirujano. El objetivo fue la evaluación morfométrica y volumétrica de los cuerpos lumbares y los discos, para contribuir al abordaje seguro durante la cirugía. Se evaluó en 25 sujetos adultos, diestros, sin antecedentes de fracturas vertebrales y de enfermedad degenerativa espinal, el cuerpo vertebral y la morfometría del disco mediante estereología con RM. La forma de las vértebras, el índice de concavidad y la definición de las medidas volumétricas de los cuerpos L1-L5. Además, se midieron los parámetros morfométricos como longitud, altura, ancho del cuerpo vertebral. Se efectuó un análisis morfométrico y volumétrico de loss cortes axiales y sagitales de los discos entre L1 y L5. Como era de esperar, las dimensiones promedio de las vértebras en los hombres fueron mayores que en las mujeres, pero la mayoría de ellos no son estadísticamente significativas. Sólo tres dimensiones, la diferencia promedio entre la altura anterior y central de las vertebras L3, L4 y L5 mostraron diferencias estadísticamente significativas, indicando menor altura central tanto en los hombres como en las mujeres. Los diámetros transversal y anteroposterior del cuerpo vertebral, la altura del disco intervertebral y el volumen no mostraron dimorfismo sexual (p> 0,05). Sin embargo, aumentaron la altura del disco intervertebral y el volumen de L1 a L5 (p< 0,01). Los índices de concavidad...

The midpedicular and interpedicular distance of thoracolumbar vertebrae.

OBJECTIVES: 1. To introduce the measurement of the midpedicular distance (MPD) as an alternative to the interpedicular distance (IPD). 2. To measure the IPD and MPD of T11, T12, L1 and L2 vertebrae on anteroposterior (AP) plain film of the normal spine. 3. To study the relationship of the IPD and MPD of T11 to L2 of the normal spine. STUDY DESIGN: Thoracolumbar AP plain film of 89 subjects (39 males, 50 females) with an average age of 47.6 years (range 21-78 years) from the roentgenographic files were included. Both the IPD and MPD of T11, T12, L1 and L2 were measured by two observers. The mean difference of IPD and MPD at these four levels were compared by using a one-way ANOVA. The relationship of the IPD and MPD measured from the T11 to L2 levels were evaluated using the simple linear regression model. RESULTS: The mean IPD was progressively wider (p = 0.000) from the T11 to L1 level, but no significant difference (p = 0.308) was found between the mean IPDs of L1 and L2. The mean MPD of each level was significantly different from the others (p = 0.000) except the mean MPDs of T12 and L1 (p = 1.000). Both the IPD and MPD had a statistically significant linear relationship with the level of the vertebrae from T11 to L2 (p = 0.000) with the coefficients of determination (R2) of 0.39 and 0.28, respectively. CONCLUSION: More care should be taken in clinical practice when measuring the IPD of a fractured vertebra relative to those of adjacent lower levels in order to determine whether or not widening has occurred, especially IPD L1 vis-à-vis IPD L2. MPD measurement has no advantage over the IPD measurement but is a useful alternative when a comparison of the pedicular distance of L1 and L2 is needed.

Diurnal variation in lumbar MRI: Correlation between signal intensity, disc height, and disc bulge

There have been no reports indicating diurnal variations in MRI at different portions of each lumbar disc. Eight asymptomatic healthy volunteers between 22 and 29 years old had MRI of their lumbar spine, twice on the same day (in the morning and evening). Forty lumbar discs were studied and the signal intensity change was measured from three portions of each disc (a total of 120 portions). No visible changes could be detected between scans by blinded observers. However, the calculated signal intensity changes showed an average loss of -20.0% (ant., 5 cases), -19.0% (mid, 2 cases), and -17.5% (post., 1 case). Height loss of the disc showed an average loss of -9.9% (ant., 4 cases), -8.3% (mid., 2 cases), and -10.4% (post., 2 cases). An increase of disc bulge at L4-5 level (18.3%) was pronounced, but L5-S1 level was less than others. Loss of body height averaged a loss of 7 mm (0.39% of body height). There was no correlation between reduced signal intensity and height loss at the ant./post. portion (p = 0.42), but there was a close relation at the mid. portion (p = 0.008). Diurnal change of the disc bulge was not correlated with reduced signal intensity (p = 0.48) or height loss (p = 0.16). Intradiscal fluid change was not necessarily influenced by the disc height loss, and height loss did not necessarily have an effect on disc bulge. But diurnal change showed a trend that was reflected in reduced signal intensity, height loss, and an increase of disc bulge which was more apparent from the ant. portion to the post, portion on moving down to the lower levels. Loss of disc height was one factor in the reduction of body height. These changes occurred randomly throughout 5 lumbar disc levels in each case.

Estudo experimental da rigidez do disco intervertebral lombar de cadáveres humanos / Experimental study of intervertebral lombar disc stiffness in human cadavers

Foram retirados dez segmentos de coluna lombar humana de cadáveres adultos, com idade entre 23 e 81 anos, e transformados em 30 corpos de prova compostos do disco intervertebral e das placas basais das vértebras adjacentes. Foi feito estudo biomecânico dos corpos de prova sob compressäo axial com cargas lentas e progressivas e comparada a rigidez com o nível anatômico do disco e com seu grau de degeneraçäo (método de Galante). A comparaçäo dos resultados mostrou inexistência de diferenças da rigidez do disco intervertebral entre os níveis anatômicos e diminuiçäo da rigidez com a progressiva degeneraçäo discal.