Foi avaliada a participação dos corpos vertebrais e discos intervertebrais na lordose lombar e, a contribuição destes nas curvaturas lombares de diferentes magnitudes. Foram avaliadas as radiografias lombares em perfil de 350 adultos assintomáticos (143 homens e 207 mulheres, idade média 29 anos). Foram mensuradas a curvatura lombossacra (L1S1), a curvatura lombolombar (L1L5), a angulação de cada corpo vertebral e cada disco intervertebral por meio de uma variação do método de Cobb. A participação percentual dos corpos vertebrais e dos discos intervertebrais na curvatura lombossacra também foi determinada. Comparações entre os sexos e as faixas etárias foram realizadas. Os indivíduos foram divididos em três subgrupos populacionais, de acordo com a magnitude da lordose lombossacra, de modo a separar os indivíduos pertencentes aos extremos da curva de distribuição. Os componentes da curvatura lombar (corpos vertebrais e discos intervertebrais) foram comparados nestes três subgrupos. A medida da curvatura lombossacra no grupo inicial foi -60,9o (-33o a -89o). Os corpos vertebrais eram cifóticos em L1 (2,15o), tendiam ao neutro em L2 (-0,36o) e eram progressivamente lordóticos de L3 (-1,56o) a L5 (-9,23o). Os discos intervertebrais eram progressivamente lordóticos (variando de -4,99o em L1-L2 a -15,58o em L5-S1). Os corpos vertebrais e discos intervertebrais apresentaram participação progressivamente maior na curvatura lombossacra no sentido crânio-caudal. Os discos intervertebrais participaram com cerca de 80% da curvatura lombossacra, sendo que os elementos mais caudais (corpos vertebrais L4 e L5 e discos intervertebrais L4-L5 e L5-S1) corresponderam a mais de 65% da curvatura lombossacra. Os indivíduos mais velhos apresentaram medidas das curvaturas lombares maiores cerca de 4º em comparação aos indivíduos mais jovens, havendo diferença significante para as medidas dos corpos vertebrais L2 e L5 e o disco intervertebral L3-L4, sendo maiores as medidas nos indivíduos mais velhos. As medidas das curvaturas lombares e dos corpos vertebrais L2 e L4 apresentaram diferença estatisticamente significante entre os sexos, sendo as medidas maiores nos indivíduos do sexo feminino. A curvatura lombossacra apresentou média de -46,9° no subgrupo lordose menor; -61,59° no subgrupo lordose intermediária e; -74,13° no subgrupo lordose maior. A curvatura lombolombar apresentou média de -33,28° no subgrupo lordose menor; -45,34° no subgrupo lordose intermediária e; -56,96° no subgrupo lordose maior. Os corpos vertebrais e os discos intervertebrais apresentaram medidas absolutas menores no subgrupo lordose menor do que as dos subgrupos lordose intermediária e lordose maior, mas a participação dos discos intervertebrais na curvatura lombossacra no subgrupo lordose menor (88%) foi maior que nos subgrupos lordose intermediária (81%) e no subgrupo lordose maior (75%). Complementarmente, os corpos intervertebrais apresentaram maior participação nos subgrupos lordose maior e lordose intermediária. Individualmente, os corpos vertebrais apresentaram maior participação no subgrupo lordose maior, exceto pelo corpo vertebral L5 que apresentou maior participação no subgrupo lordose menor. A maior participação percentual dos discos intervertebrais no subgrupo lordose menor era devida à inclinação cifótica dos corpos vertebrais mais cefálicos (especialmente L1 e L2) no subgrupo lordose menor do que nos demais subgrupos, que, por um efeito compensatório, causava uma maior participação discal nas curvaturas menores. Os demais subgrupos apresentavam os corpos vertebrais cefálicos com inclinação muito mais lordótica do que o observado no subgrupo lordose menor. Concluímos que os discos intervertebrais são os principais responsáveis pela curvatura lombar e que a contribuição dos corpos vertebrais e discos intervertebrais na lordose lombar difere entre indivíduos com curvaturas de diferentes magnitudes. Apesar de ocorrer um aumento gradual do acunhamento lordótico do corpo e disco a cada nível vertebral conforme aumenta a medida da lordose, as vértebras mais cefálicas provocam uma diferença na contribuição percentual entre discos intervertebrais e corpos vertebrais nas curvaturas de tamanhos diferentes. / The vertebral bodies and intervertebral discs participation in lumbar lordosis and their contribution between lumbar curves of different size were studied. 350 lumbar spine radiographs of asymptomatic adults (143 men and 207 women, average age 29 years) were evaluated. Lumbosacral (L1S1) and lumbolumbar (L1L5) curves and the angular inclination of each vertebral boby and intervertebral disc were measured using a Cobb method variant. The percentile participation of each vertebral body and intervertebral disc in the lumbossacal curve was calculated. Sex and age were compared. The subjects were separated in tree subgroups, in acording to lumbosacral curve size. The compounds of lumbar curve (discs and vertebrae) were compared in these tree subgroups. The mean lumbosacral curve was ?60,9º (-33º to ?89º). L1 vertebral body was kyphotic (2,15º), L2 was neutral (-0,36º), and the other ones were progressively lordotic from L3 (-1,56º) to L5 (-9,23º). The intervertebral discs were progressively lordotic from L1-L2 (?4,99º) to L5-S1 (?15,58º). Both vertebrae and discs showed a progressive participation in cephalic-caudal direction. The participation of discs was about 80% of lumbosacral curve, and the caudal elements (L4, L5 vertebrae and L4-L5, L5-S1 discs) contributed far 65% of the curve. The older subjects presented lumbar curves larger than younger 4º average, with significant statistical difference to L2, L5 and L3-L4 measures, with older subjects presenting bigger angular values. There were statistical differences of lumbar curves, L2 and L4 measures between sexes, with females presenting bigger values. The lumbosacral curve presented average -46,9º in minor lordosis subgroup, -64,59º in intermediate lordosis sugbroup, and ?74,13º in major lordosis subgroup. The lumbolumbar curve presented average ?33,28º in minor lordosis subgroup, -45,34º in intermediate lordosis subgroup, and ?56,96º in major lordosis subgroup. The absolut values of vertebrae and discs angles were smaller in minor lordosis subgroup than in major lordosis subgroup, but the intervertebral discs participation of was bigger in minor lordosis subgroup (88%) than intermediate lordosis (81%) and major lordosis (75%) subgroups. Complementarely, the vertebrae had a bigger participation in intermediate and major lordosis subgroups. Individually, the vertebrae presented a larger participation in major lordosis subgroup, excepting L5 that presented bigger participation in minor lordosis subgroup. The discs presented larger participation in minor lordosis subgroup. That is consequence of a more kyphotic inclination of the cephalic vertebrae in minor lordosis subgroup than the other ones, causing a compensating effect, with a larger disc participation in the small curves. The intermediate and major lordosis subgroups had the cephalic vertebrae more lordotic than that of the minor lordosis subgroup. We concluded that the intervertebral discs are the main responsible for the lumbar curve angulation and that the contribution of vertebrae and discs in lumbar curves of different sizes is not equal. In spite of a gradual increase of lordotic wedging while lumbar curve increase, the cephalic vertebrae make the disc and vertebrae participation different between different magnitude lumbar curves.

Abstract Low back pain (LBP) is a truly enervating condition, presenting with considerable negative socioeconomic and health impacts on many levels. Although LBP may be attributed to many factors, there is increasing evidence that disc degeneration (DD) of the lumbar spine is a strong contributing factor, especially among young individuals. Understanding the aetiopathogenesis of DD has changed over the past few decades as numerous studies have indicated that inherited factors are largely responsible for the development of DD. Despite the many genetic associations in DD that have been reported, these associations have proven difficult to validate. The genetic component of DD is still unexplained for the most part. Previous studies have focused on adults, who have been exposed to environmental risk factors of DD, which may mask genetic associations. Thus, investigations among young individuals are well justified. The purpose of this study was to validate the associations between DD defined by magnetic resonance imaging (MRI) and genetic polymorphisms in two study populations of Finnish and Danish young individuals. New polymorphisms that have not been associated with DD were also included in the study. Associations with progression of DD were also investigated among Danish individuals. Furthermore, this study aimed to clarify the level of evidence of previously identified associations. Among Finnish individuals, polymorphisms in IL6, SKT and CILP were associated with moderate DD, but the association in CILP was significant only in women. Among Danish individuals, polymorphisms in IL6 and IL1A were associated with early DD and progression of DD. The genetic associations among the Danish teenagers were gender-specific as they were mainly observed in girls. Among both populations, the individuals with DD were significantly taller than individuals without DD. In the systematic analysis of previous reports, polymorphisms in GDF5, THBS2, MMP9, COL11A1, SKT and ASPN were found to have a moderate level of association evidence. The results mostly support earlier findings in adults. However, unexpected differences between genders were observed. In conclusion, this study increased the knowledge of genetics in DD but more investigations are needed to draw any solid conclusions. / Tiivistelmä Alaselkäkipu on yksi merkittävimmistä toimintakykyyn vaikuttavista sairauksista. Alaselkäkivun riskitekijöitä tunnetaan useita, mutta näyttö siitä, että selän välilevyrappeuma on yksi tärkeimmistä riskitekijöistä, erityisesti nuorilla henkilöillä, lisääntyy jatkuvasti. Aiemmat tutkimukset ovat osoittaneet, että perintötekijöillä on merkittävä osuus välilevyjen rappeutumisessa. Useiden geenien on raportoitu vaikuttavan välilevyrappeumaan. Positiivisten tulosten toistaminen on kuitenkin osoittautunut vaikeaksi, ja kokonaiskuva on vielä suurelta osin epäselvä. Aikaisemmat tutkimukset aiheesta ovat keskittyneet aikuisiin, joilla nuoria pidempi altistus ympäristötekijöille saattaa peittää geneettisten tekijöiden yhteyttä. Tämän tutkimuksen tavoitteena oli varmentaa yhteyksiä magneettikuvauksella (MRI) määritetyn välilevyrappeuman ja geneettisten monimuotoisuuskohtien (polymorfioiden) välillä käyttäen yhtä suomalaisista ja yhtä tanskalaisista nuorista koostuvaa aineistoa. Työssä analysoitiin myös polymorfioita, joita ei ole aiemmin yhdistetty välilevyrappeumaan. Yhteyttä polymorfioiden ja välilevyrappeuman etenemisen välillä tutkittiin tanskalaisessa aineistossa. Lisäksi tutkimuksen tavoitteena oli selvittää aiemmin tunnistettujen geneettisten yhteyksien näytön aste. Suomalaisten nuorten aineistossa polymorfiat IL6-, SKT- ja CILP-geeneissä olivat yhteydessä kohtalaista astetta olevaan välilevyrappeumaan. Tanskalaisten nuorten aineistossa polymorfiat IL6- ja IL1A-geeneissä olivat yhteydessä varhaiseen välilevyrappeumaan ja sen etenemiseen. Tanskalaisten nuorten aineistossa nämä yhteydet olivat sukupuolesta riippuvaisia, koska yhteyksiä havaittiin pääasiassa tytöillä. Suomalaisten nuoren aineistossa yhteys CILP-geenissä havaittiin ainoastaan nuorilla naisilla. Kummassakin tutkimusaineistossa nuoret, joilla oli välilevyrappeuma, olivat pidempiä, kuin nuoret, joilla ei ollut välilevyrappeumaa. Aikaisempien tutkimusten systemaattinen analyysi osoitti, että tunnistetun geneettisen yhteyden näytön aste on kohtalainen GDF5-, THBS2-, MMP9-, COL11A1-, SKT- ja ASPN-geenien polymorfioissa. Tutkimusten tulokset ovat pääosin samansuuntaisia aiempien tutkimuksien kanssa, mutta nyt nähty eroavaisuus sukupuolten välillä on uusi havainto. Kokonaisuudessaan tämä väitöstutkimus kasvattaa ymmärtämystä välilevyrappeumasta, mutta lisätutkimuksia aiheesta tarvitaan.

No description available.

published_or_final_version / abstract / Orthopaedics and Traumatology / Doctoral / Doctor of Philosophy

published_or_final_version / Biochemistry / Master / Master of Philosophy

Abstract Background: The process that involves the migration of the nucleus pulposus from the innermost annular layers and culminates with the final extrusion of the nucleus has been limited to a few studies. This investigation was directed towards a better understanding of the herniation process. The architecture of the annulus fibrosus and the mechanism of progressive disc herniation were analyzed, using a controlled porcine model. Microscopic and histochemical techniques were employed. <br /><br /> Methodology: Two studies were performed. In the first stage, the macroscopic and microscopic structures of twelve cervical intervertebral discs were compared with young human disc data from studies reported in the literature. Important structural features were studied such as annulus fibrosus thickness, number of lamellae, lamellae thickness, orientation of the lamellae fibers and blood supply. In the second study, sixteen fresh-frozen functional spine units were submitted to repetitive flexion?extension motions combined with a low compressive load in a servo-hydraulic dynamic testing system. Discograms, dissections and histochemical techniques were applied to characterize the cumulative damage. The experiment produced eight complete herniations, four partial herniations and four specimens without any microscopic detectable annular damage. <br /><br /> Results and Discussion: The structure of the cervical porcine disc resembles the lumbar human disc. Some differences are evident. The size of the annulus is smaller, the thickness of the lamellae is narrower and the number of layers is fewer in the pig. It is hypothesized that the flexion-extension motion combined with a low-level load produced an increased hydraulic pressure in the inner wall of the posterior annulus. This pressure and repetitive motion first produced a small cleft, spreading the collagen bundles inside the first layer. The nuclear material was "pumped" through the small cleft to the first layer filling the layer creating a fluid-filled pocket between the collagen fibers. Once the "pocket" acquired enough pressure a new cleft was produced in the weakest part of the layer allowing the nuclear material to create a new "pocket" in the second layer. This was the first stage of damage and disc herniation production. This mechanism was repeated until the nucleus traveled along the annulus reaching the posterior longitudinal ligament. At this point a complete extrusion herniation was produced. <br /><br /> Conclusion: The porcine model appears to be suitable as a model to understand the mechanism of disc herniation when the spine is subjected to flexion-extension motions combined with a low-level load. The first cumulative injury appears to be a cleft between the lamellae bundles produced by the nuclear hydraulic pressure. A cumulative load/cumulative injury model approach was used to create the damage that was quantified in the study.

Continuous monitoring during tissue culture is important for the success of engineered tissue development. It is also challenging due to lack of suitable established monitoring techniques. In this study, microdialysis, a sampling technique for measuring the unbound solute concentrations in the tissues and organs of the living body, was adopted to monitor functional tissue growth in a bioreactor with explanted bovine caudal intervertebral discs (IVD) as the test tissue. Apart from cell metabolic activities, cell and tissue biological functions were investigated for the development of microdialysis for monitoring purposes. Methodologies of microdialysis with large pore size membrane probes for sampling macromolecular bio-functional markers were established. The effects of pumping methods, including 'push', 'pull' or 'push-and-pull', and the effect of the resulting transmembrane pressure on the fluid balance, and the relative recovery of small molecules and of macromolecules (proteins) were experimentally studied. The validity of the internal reference in-situ calibration was examined in detail. It was concluded that a push-and-pull system was the only effective method to eliminate fluid loss or gain. The relative recovery of small solutes was hardly affected by the applied pumping methods; however the relative recovery of macromolecules was significantly influenced by them. The in situ calibration technique using Phenol Red can provide reliable results for small molecules including glucose and lactic acid. Using lOkDa and 70kDa fluorescent dextrans as the internal standard for in situ calibration of large molecules of similar size, it was found that the pull pump system did not work well but that the push-and-pull pumping method did work well. A novel bioreactor system for in vitro IVD culture with static load and microdialysis monitoring was developed. Explanted IVDs were cultured under three different loads for up to 7 days. A single microdialysis probe with 3000 kDa membrane was inserted into each of the IVDs at a defined location. The in situ calibration technique was proved valid in the experiments and membrane fouling was not significant. The tissue metabolism and extracellular matrix turnover during 7 day culture were continuously monitored to investigate the effect of different loads. Microdialysis proved to be a feasible and efficient method for multi-parameter monitoring of tissue culture. Substantial effort was directed towards the identification of functional macromolecular markers in conjunction with microdialysis sampling. Amongst several proteins sampled, chitinase-3-like protein 1 (CHI3L1), a major soluble protein secreted by cultured IVD cells in alginate beads and by cultured IVD explants was identified following its successful isolation. Then it was established as a suitable functional marker. The effect of physico-chemical and mechanical stimuli (e.g. osmolarity, pH, oxygen tension and mechanical load) on secretion of CHI3L1 by cultured IVD cells and chondrocytes in alginate beads and by cultured IVD explant were investigated. CHI3L1 release was sensitive to physico-chemical stimulation. The production of CHI3L1 was directly correlated with the cell metabolism and this could be readily monitored with microdialysis.

Breakdown of the disc extracellular matrix is thought to arise from increased activity of matrix metalloproteinases (MMPs). Aggrecan, one of the major disc matrix macromolecules, is degraded through action of MMPs and aggrecanases and its concentration falls early in the degeneration process. Loss of the constituent glycosaminoglycans (GAGs), which are osmotically active, leads to a decrease in osmotic pressure and subsequently to a fall in tissue hydration. Apart from the major biomechanical consequences, fall in extracellular osmolarity is known to influence cell function. Apart from aggrecan, other macromolecules such as fibronectin are also broken down by MMPs. Fibronectin fragments (Fnfs) have been identified in degenerate discs. Such Fnfs have been found to stimulate production and activity of MMPs in articular cartilage but little is known about the effect of these fragments on disc cells. The aim of the work was thus to determine whether Fnf stimulated expression of MMPs and hence induced aggrecan breakdown and loss in the disc and whether extracellular osmolarity influenced this potential response. NP cells or explants were harvested from adult bovine caudal discs. They were cultured in DMEM culture medium over a range of osmolarities with or without Fnf treatment. Profiles of gene expression of MMPs and their inhibitors and effect of changes in osmolarity on expression of selected MMPs were determined. The effect of Fnf on responses of cells and tissue explants from the central region of the disc, the nucleus pulposus (NP) and the role of changes in extracellular osmolarity in relation to GAG loss and expression of selected MMPs was then examined both at the protein level and by gene profiling using a microarray. My results showed that expression of MMPs by disc cells is regulated by extracellular osmolarity rather than the 30 kD Fnf, with the level of some MMPs secreted by disc cells and involved in degradation of disc matrix rising as osmolarity falls. These results could explain in part the finding that MMP expression increases with degree of disc degeneration i.e. with loss of aggrecan and fall in extracellular osmolarity. These also suggested that a fall in osmolarity could induce a degenerative cascade with proteolytic digestion of aggrecan leading to a fall in osmolarity and hence a further increase in proteinase expression and matrix degradation.

Memoria para optar al Título Profesional de Médico Veterinario / Se realizó un estudio series de casos con el propósito de reconocer y comprender los cambios ocurridos en la médula espinal tras ser afectada por una hernia discal tipo I a nivel toracolumbar y ser sometida a hemilaminectomía. Para esto se realizó una mielografía prequirúrgica y 48 horas después de la cirugía, una postquirúrgica en cada paciente de un grupo de 10 caninos de talla no gigante. Para cada mielografía se obtuvieron cuatro vistas radiográficas que incluyeron una proyección latero – lateral, ventro – dorsal, oblicua izquierda y oblicua derecha, y se registró la presencia de los patrones mielográficos extradural (ED), intradural – extramedular (ID – EM) e intramedular (IM). En las mielografías prequirúrgicas se observó la presencia del patrón ED e IM, y la ausencia del patrón ID – EM en todos los pacientes. En las mielografías postquirúrgicas se observó la permanencia del patrón ED en ocho pacientes, mientras que el patrón IM estuvo ausente o leve en todos los pacientes, lo que representa una buena respuesta hemodinámica medular frente al tratamiento quirúrgico. Se observó también el patrón ID – EM en cinco pacientes, cuyo origen podría estar determinado por un divertículo subaracnoídeo o un artefacto mielográfico

Introdução: A microdiscectomia para tratamento de hérnia de disco lombar, mesmo apresentando ótimos resultados, pode resultar em danos consequentes à lesão tecidual local. As cirurgias endoscópicas já são consideradas padrão ouro em outras áreas da medicina devido ao mínimo dano colateral causado e consequente melhora dos resultados. Autores internacionais demonstraram a eficácia e segurança da técnica, mas ainda não existem estudos na América Latina que validem esses estudos. Objetivo: Comparar os resultados cirúrgicos da abordagem endoscópica e convencional para tratamento da hérnia de disco lombar quanto à melhora da dor, da incapacidade e suas complicações. Métodos: Estudo prospectivo randomizado envolvendo pacientes com hérnia de disco lombar, submetidos a tratamento cirúrgico. Quarenta e sete pacientes foram randomizados prospectivamente em dois grupos, discectomia endoscópica e microdiscectomia, e foram acompanhados ao longo de 12 meses. Questionário de incapacidade de Oswestry validado para o português e escala analógica de dor foram aplicados durante o seguimento. Os eventos adversos também foram recordados. Resultados: Após a cirurgia os pacientes tiveram melhoras significativas da dor irradiada (68%), mas sem diferença entre os grupos estudados e apresentaram significativa melhora da incapacidade. Quanto a dor lombar, a discectomia endoscópica resultou em menor dor lombar pós-operatória nas avaliações de uma semana, um e três meses quando comparada a microdiscectomia. Entretanto não se observou diferença entre os grupos no sexto e décimo segundo mês de seguimento. Não foram evidenciadas diferenças estatísticas quanto a recidiva, infecções e cirurgias subsequentes. Conclusão: Os resultados clínicos da discectomia endoscópica são semelhantes aos da microdiscectomia quanto à melhora da dor irradiada e da incapacidade, mas oferecem uma vantagem quanto à dor lombar pós-operatória até o terceiro mês. A discectomia endoscópica consiste em uma técnica segura e eficaz representando uma alternativa ao tratamento padrão ouro representado pela microdiscectomia / Introduction: Microdiscectomy, despite the good results, may result in damages to the local tissue. In other fields, endoscopic surgeries are considered the gold standard due to the minimal collateral damage. There aren\'t studies comparing both methods performed in Latin America. Objective: Compare the traditional microdiscectomy and percutaneous endoscopic lumbar discectomy for the treatment of disc herniation regarding pain, disability and complications. Methods: Prospective randomized trial with patients with sciatica due to lumbar disc herniation comparing two different surgical techniques. Forty-seven patients were divided in two groups and monitored for twelve months. Oswestry disability index and visual analog scale for pain were recorded. Results: After surgery the leg pain and disability improved significantly, but without significant difference between the groups. There was significantly less back pain after surgery until the third month. After that the groups were statistically the same. There were no statistical differences regarding recurrence, infection and subsequent surgeries. Conclusion: Endoscopic discectomy results are similar than conventional microdiscectomy according to pain and disability improvement, however, lumbar pain are less during the first three months. Endoscopic discectomy consists in a safe and efficient alternative to microdiscectomy