Is there effect of intervertebral disc herniation on the lumbar spine in early period? A morphometric and stereological study / ¿Existe algún efecto de la hernia de disco intervertebral en la columna lumbar en el período temprano? Un estudio morfométrico y estereológico

The degeneration of the Lumbar Intervertebral Disc (LIVD) and the other elements of the spine are an inevitable result of aging. However, it is observed that the same degree of degenerative change does not occur in each individual. In the present study, the purpose was to compare the morphometric changes on the lumbar spine with or without intervertebral disc herniation in early period. Group 1 (the Patient Group) consisted of the patients who were diagnosed with lumbar intervertebral disc hernia and who were not operated at least one month clinical duration. Group 2 (the Control Group) consisted of individuals who were selected randomly, had only back pain, underwent magnetic resonance imaging (MRI), and were determined to have intact intervertebral disc. The sagittal and axial MRI sections of lumbar spine was used for measurements and statistical evaluation. There were no statistically significant differences between the intervertebral disc volumes, vertebral body volumes and intervertebral disc anterior and posterior heights of Group 1 and 2 (p>0.05). In terms of anterior-posterior length, the length of the L5 vertebral body was determined to be more in the Patient Group (p<0.05). A correlation was determined in terms of the increase in L2, L4 and L5 volumes with increasing age; however, there were no statistically significant correlations between age increase and a decrease in the intervertebral disc volumes. There were no correlations between the increase in age and the decrease in intervertebral disc heights (p>0.05). There were no apparent relations between the change on the lumbar vertebra corpus and intervertebral disc in early period. It was concluded that the intact intervertebral disc could protect the lower lumbar vertebra corpus from degenerative changes. Although the herniation of the intervertebral disc is newly formed, it is understood that the physiological process or morphometric changes started earlier.

La degeneración del disco intervertebral lumbar y de otros elementos de la columna vertebral son un resultado inevitable del envejecimiento. Sin embargo, no se observa el mismo grado de degeneración en cada individuo. En el presente estudio, el objetivo era comparar los cambios morfométricos en la columna lumbar con o sin hernia de disco intervertebral en el período temprano. El grupo 1 (grupo de pacientes) estaba formado por los pacientes diagnosticados con hernia de disco intervertebral lumbar y que no fueron operados durante al menos un mes. El Grupo 2 (Grupo de Control) consistió en sujetos que fueron seleccionados al azar, reportaban solamente dolor de espalda, fueron sometidos a una resonancia magnética (MRI) y se determinó un disco intervertebral intacto. Las secciones de resonancia magnética sagital y axial de la columna lumbar se utilizaron para las mediciones y la evaluación estadística. No hubo diferencias estadísticamente significativas entre los volúmenes del disco intervertebral, los volúmenes del cuerpo vertebral y las alturas anterior y posterior del disco intervertebral de los Grupos 1 y 2 (p> 0,05). En términos de longitud anterior-posterior, se determinó que la longitud del cuerpo vertebral L5 era mayor en el grupo de pacientes (p <0,05). Se determinó una correlación en términos del aumento en los volúmenes L2, L4 y L5 con el aumento de la edad; sin embargo, no hubo correlaciones estadísticamente significativas entre el aumento de la edad y una disminución en los volúmenes del disco intervertebral. No hubo correlaciones entre el aumento de la edad y la disminución de las alturas de los discos intervertebrales (p> 0,05). No hubo relaciones aparentes entre el cambio en el cuerpo de la vértebra lumbar y el disco intervertebral en el período temprano. Se concluyó que el disco intervertebral intacto podría proteger el cuerpo de la vértebra lumbar inferior de los cambios degenerativos. Aun cuando la formación de la hernia del disco fue reciente, se entiende que el proceso fisiológico o los cambios morfométricos habían comenzado antes.

Post mortem evaluation of spinal cord and protruded intervertebral discs in dogs without neurological abnormalities / Avaliação post mortem da medula espinhal e de discos intervertebrais protrusos em cães sem alterações neurológicas

The aim of this study was to verify the presence of protrusion of the intervertebral disc (IVD) causing compression of the spinal cord and/or roots of cauda equina in 30 dogs above seven years of age with no evidence of previous neurological abnormalities. After the occurrence of death or euthanasia, a laminectomy was performed from C2 to the sacral vertebra to verify the presence of IVD protrusions. The protruded IVD were macroscopically graded according to the Thompson scale, and the corresponding spinal cord segment was histologically analyzed for nervous tissue compression. Of the 30 dogs, twelve (40%) presented disc protrusion, and of these 12 dogs, seven (58%) presented more than one protruded disc. Disc protrusion was observed in 3.2% (25/780) of all IVD evaluated. Of the six chondrodystrophic dogs, five (83%) presented disc protrusion. Of the 24 nonchondrodystrophic dogs, seven (29%) presented IVD protrusion. The site that showed the highest frequency of protrusion was L4-L5 (6/25) followed by the L6-L7 region (3/25) and C6-C7 (3/25). Only two of the medullary segments evaluated showed histological changes, with presence of focal lymphocytic infiltration and multifocal mild hemorrhage in the gray matter. Under the conditions of this study, 40% of dogs older than seven years old showed IVD protrusions without showing neurological signs, with no abnormality of the nervous tissue in 92% of the evaluated segments. Thus, the protrusion of the IVD in some dogs, can only be a finding of no clinical relevance.(AU)

O objetivo do presente estudo foi verificar a presença de protrusão do disco intervertebral (DIV) causando compressão da medula espinhal e/ou raízes da cauda equina em cadáveres de cães, sem histórico de alterações neurológicas. Para isso, após a ocorrência de óbito ou realização de eutanásia em 30 cães com mais de sete anos de idade, sem histórico de alterações neurológicas, foi realizada a laminectomia entre C2 até a vértebra sacral para verificar a presença de protrusões do DIV. Os DIV protrusos foram graduados macroscopicamente quanto à degeneração segundo a escala de Thompson, e o segmentos medular correspondente à localização da compressão foi analisado microscopicamente em busca de lesões compressivas ao tecido nervoso. Quarenta por cento dos cães (12/30) apresentaram protrusão do DIV, e destes, 58% (7/12) apresentavam mais de um DIV protruso. A protrusão estava presente em 3,2% (25/780) de todos os DIV avaliados. Cães de raças condrodistróficas apresentaram protrusões em 83% dos casos (5/6) e raças não condrodistróficas em 29% (7/24). O local que apresentou maior frequência de protrusão foi L4-L5 (6/25), seguido da região L6-L7 (3/25) e C6-C7 (3/25). Apenas dois segmentos medulares avaliados na histopatologia apresentaram alterações, com presença de infiltrado linfoplasmocitário focal e hemorragia discreta multifocal na substância cinzenta. Nas condições do presente estudo, 40% dos cães com mais de sete anos de idade apresentaram protrusões do DIV sem que houvesse sinais neurológicos, com normalidade do tecido nervoso em 92% dos segmentos avaliados. Assim, a protrusão do DIV, em alguns cães, pode ser apenas um achado sem relevância clínica.(AU)

Analysis of Relationship between Injury and Disease in 17 Cases of Cervical Trauma with Cervical Vertebra Degeneration / 法医学杂志

OBJECTIVES@#To study the characteristics of the relationship between injury and disease in forensic identification cases of cervical trauma with cervical vertebra degeneration, and to explore the problems about how to identify the participation rates of injury and disease using the clinical information, forensic examination and imaging examination.@*METHODS@#Seventeen forensic identification cases of cervical trauma with cervical vertebra degeneration were collected. The age distributions, injury formations, injury severities and imaging findings of these cases were analyzed and the relationship between injury and disease was evaluated comprehensively.@*RESULTS@#Middle-aged and elderly were common in 17 cases and every case was involved with intervertebral disc herniation. The main reasons of injuries were hyperextension. The degree of injury severity and vertebra degeneration were graded according to the imaging findings. The participation rates of injury and disease were also calculated comprehensively.@*CONCLUSIONS@#The forensic identification cases of cervical trauma with cervical vertebra degeneration should be evaluated with clinical information, forensic examination and imaging finding.

Quantitative Analysis of Disc Degeneration Using Axial T2 Mapping in a Percutaneous Annular Puncture Model in Rabbits

OBJECTIVE: To evaluate T2 relaxation time change using axial T2 mapping in a rabbit degenerated disc model and determine the most correlated variable with histologic score among T2 relaxation time, disc height index, and Pfirrmann grade. MATERIALS AND METHODS: Degenerated disc model was made in 4 lumbar discs of 11 rabbits (n = 44) by percutaneous annular puncture with various severities of an injury. Lumbar spine lateral radiograph, MR T2 sagittal scan and MR axial T2 mapping were obtained at baseline and 2 weeks and 4 weeks after the injury in 7 rabbits and at baseline and 2 weeks, 4 weeks, and 6 weeks after the injury in 4 rabbits. Generalized estimating equations were used for a longitudinal analysis of changes in T2 relaxation time in degenerated disc model. T2 relaxation time, disc height index and Pfirrmann grade were correlated with the histologic scoring of disc degeneration using Spearman's rho test. RESULTS: There was a significant difference in T2 relaxation time between uninjured and injured discs after annular puncture. Progressive decrease in T2 relaxation time was observed in injured discs throughout the study period. Lower T2 relaxation time was observed in the more severely injured discs. T2 relaxation time showed the strongest inverse correlation with the histologic score among the variables investigated (r = -0.811, p < 0.001). CONCLUSION: T2 relaxation time measured with axial T2 mapping in degenerated discs is a potential method to assess disc degeneration.

Relación entre la degeneración discal, el dolor y la estabilidad lumbar: degeneración discal / Relation entre la dégénérescence discale, la douleur et la stabilité lombaire: discopathie dégénérative / Relationship between disc degeneration, lumbar pain and stability: disc degeneration

El envejecimiento y la degeneración producen cambios en la columna vertebral, los discos pierden la capacidad de cumplir sus funciones. Se realizó una revisión critica acerca de la degeneración del disco intervertebral, el dolor y la estabilidad de la columna lumbar para lo cual se examinaron los avances en el conocimiento del proceso de degeneración discal, los factores que influyen en este fenómeno y los procesos celulares que tienen lugar en él, así como la clasificación anatomopatológica más empleada y su reflejo en imágenes de resonancia. Los cambios celulares en el disco ocurren a través de seis procesos que ocasionan cambios bioquímicos en la matriz extracelular y pérdida de las funciones. Las células desempeñan el papel principal en los cambios biológicos y bioquímicos de la degeneración del disco intervertebral. En este proceso, además del envejecimiento, participan otros factores como: predisposición genética, aporte nutricional y de oxígeno y el estrés mecánico.

Aging and degeneration result in changes in the spine; the discs lose their ability to fulfill their functions. A critical review on the intervertebral disc degeneration, pain and stability of the lumbar spine was carried out for which progress in the understanding of disc degeneration process, the influence factors and its cellular processes, as well as the most widely used pathologic classification and its reflection in resonance images were reviewed. The disk cell changes occur through six processes; which causes biochemical changes in the extracellular matrix and loss of function. Cells play the major role in biological and biochemical changes of intervertebral disc degeneration. Genetic predisposition, nutritional and oxygen supply and mechanical stress are involved as other factors in this process, in addition to aging.

Le vieillissement et la dégénérescence provoquent des changements au niveau du rachis. Les disques vertébraux perdent la capacité de réaliser leurs fonctions. Une revue critique de littérature a été effectuée sur la dégénérescence des disques intervertébraux, la douleur et la stabilité du rachis. C’est pourquoi, on a examiné les nouvelles informations concernant le processus de dégénérescence discale, les facteurs influant sur ce phénomène et les processus cellulaires en développement, ainsi que la classification anatomo-pathologique la plus souvent utilisée et les images par RM. Les changements cellulaires du disque se produisent à travers six processus conduisant à des changements biochimiques de la matrice extracellulaire et une perte des fonctions. Les cellules jouent un rôle essentiel dans les changements biologiques et biochimiques de la dégénérescence du disque intervertébral. En plus du vieillissement, il y a d’autres facteurs tels que la prédisposition génétique, l’apport nutritionnel et d’oxygène et le stress mécanique, qui participent dans ce processus.

Does a small size needle puncture cause intervertebral disc changes?

PURPOSE:Small size needles have been regularly used for intradiscal injection of innocuous/potential therapeutic compounds in experimental conditions, but also in clinic procedures, such as discography. Our aim was to investigate if a 30-gauge needle could trigger observable changes on intact intervertebral discs. We compared these effects to those induced by a large size needle (21-gauge), a well-known intervertebral disc degenerative model based on needle puncture.METHODS:Coccygeal intervertebral discs (Co8-9) of adult male Wistar rats were punctured with a 21-gauge needle, while the coccygeal levels Co7-8 and Co9-10 remained intact. The 30-gauge needle was used to inject a safe volume of saline (2 µl) on both intact (Co9-10) and punctured (Co8-9) discs. MRI and histological score were performed at 2, 15 and 42 days after procedure.RESULTS: MRI analyses revealed significant reduction on signal intensity of 21-gauge punctured discs. Intact discs which received a saline injection through a 30-gauge needle also revealed significant alterations in the MRI signal when compared with control discs. No histological changes were observed in the intact saline injected discs at any time analyzed.CONCLUSION: Since significant intervertebral image changes were observed with a 30-gauge needle, cautious interpretation of the pharmacological inoculation findings is required.

Experimental model of intervertebral disc degeneration by needle puncture in Wistar rats

Animal models of intervertebral disc degeneration play an important role in clarifying the physiopathological mechanisms and testing novel therapeutic strategies. The objective of the present study is to describe a simple animal model of disc degeneration involving Wistar rats to be used for research studies. Disc degeneration was confirmed and classified by radiography, magnetic resonance and histological evaluation. Adult male Wistar rats were anesthetized and submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7 and 8-9 of the coccygeal vertebrae. The needle was inserted into the discs guided by fluoroscopy and its tip was positioned crossing the nucleus pulposus up to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s. To grade the severity of intervertebral disc degeneration, we measured the intervertebral disc height from radiographic images 7 and 30 days after the injury, and the signal intensity T2-weighted magnetic resonance imaging. Histological analysis was performed with hematoxylin-eosin and collagen fiber orientation using picrosirius red staining and polarized light microscopy. Imaging and histological score analyses revealed significant disc degeneration both 7 and 30 days after the lesion, without deaths or systemic complications. Interobserver histological evaluation showed significant agreement. There was a significant positive correlation between histological score and intervertebral disc height 7 and 30 days after the lesion. We conclude that the tail disc puncture method using Wistar rats is a simple, cost-effective and reproducible model for inducing disc degeneration.

Correlations between radiographic, magnetic resonance and histological examinations on the degeneration of human lumbar intervertebral discs / Correlação entre exame radiológico, ressonância magnética e exame histológico na degeneração dos discos intervertebrais lombares humanos

CONTEXT AND OBJECTIVE: There is controversy regarding which imaging method is best for identifying early degenerative alterations in intervertebral discs. No correlations between such methods and histological finds are presented in the literature. The aim of this study was to correlate the thickness of intervertebral discs measured on simple radiographs with the degree of degeneration seen on magnetic resonance images and the histological findings relating to nerve ends inside the discs. DESIGN AND SETTING: Cross-sectional correlation study on the lumbar spines of human cadavers, at Universidade Federal de São Paulo (Unifesp), São Paulo, Brazil. METHODS: Ten lumbar spinal columns were extracted from human cadavers and subjected to magnetic resonance imaging and simple radiography. They were classified according to the degree of disc degeneration seen on magnetic resonance, and the thickness of the discs was measured on radiographs. The intervertebral discs were then extracted, embedded in paraffin and analyzed immunohistochemically with protein S100, and the nerve fibers were counted and classified. RESULTS: No correlation was observed between the thickness of the intervertebral discs and the degree of degeneration seen on magnetic resonance images. Only the uppermost lumbar discs (L1/L2 and L2/L3) presented a correlation between their thickness and type I and IV nerve endings. CONCLUSION: Reduced disc thickness is unrelated to increased presence of nerve ends in intervertebral discs, or to the degree of disc degeneration.

CONTEXTO E OBJETIVO: Há controvérsia sobre qual o melhor método de imagem para identificar alterações degenerativas precoces do disco intervertebral. Falta na literatura correlação desses métodos com os achados histológicos. O objetivo deste estudo foi relacionar a altura dos discos intervertebrais medidos em radiografias simples com o grau de degeneração nas imagens de ressonância magnética e os achados histológicos das terminações nervosas encontradas no interior do disco. TIPO DE ESTUDO E LOCAL: Estudo transversal de correlação em coluna lombar de cadáveres humanos, na Universidade Federal de São Paulo (Unifesp), São Paulo, Brasil. MÉTODOS: Dez colunas lombares foram retiradas de cadáveres humanos e submetidas a imagens de ressonância magnética e radiografias simples. Foram classificadas de acordo com o grau de degeneração dos discos pela ressonância e mensuradas as alturas dos discos nas radiografias. Os discos intervertebrais foram retirados, incluídos em parafina e foi realizado estudo imunoistoquímico com proteína S100; as fibras nervosas foram contadas e classificadas. RESULTADOS: Não foi observada correlação entre a altura dos discos intervertebrais com o grau de degeneração nas imagens de ressonância magnética. Apenas os discos lombares altos (L1/L2 e L2/L3) apresentaram correlação entre a altura e as terminações nervosas dos tipos I e IV. CONCLUSÃO: A diminuição da altura dos discos não está relacionada ao aumento de terminações nervosas nos discos intervertebrais e nem com o grau de degeneração dos discos.