La scoliose de l’adulte est une pathologie dont la prévalence augmente avec de le vieillissement de la population. De plus, la demande fonctionnelle est de plus en plus importante chez ces patients. De nombreuses études ont montré un bénéfice du traitement chirurgical de la déformation de l’adulte par rapport au traitement médical en termes d’amélioration des scores fonctionnels, de qualité de vie et de satisfaction. Néanmoins, cette chirurgie est associée à de nombreuses complications (jusque 50% dans certaines séries), pour la plupart mécaniques telle la pseudarthrose, la rupture d’implant, la dégradation des étages adjacents. Ainsi, si l’analyse radiographique de la scoliose a bien été explorée, certaines questions demeurent comme les phénomènes responsables d’une aggravation brutale de la déformation chez certains patients ou les causes d’échecs. L’objectif de ce travail était d’analyser la scoliose de l’adulte, en 3D à l’aide de la stéréoradiographie et d’évaluer le système musculaire de ces patients afin de mettre en évidence des relations entre déformations rachidiennes notamment par l’analyse du plan horizontal, et dégénérescence musculaire.La 1e partie de ce travail était consacrée à l’analyse 3D de la scoliose : tout d’abord avec l’analyse de reproductibilité chez l’adulte des mesures 3D effectuées par stéréoradiographie, puis par l’analyse de l’alignement global de ces patients avec une déformation rachidienne, à l’aide d’un nouveau paramètre prenant en compte la position de la jonction cervico-céphalique. Apres avoir analysé l’alignement postural, le système musculaire pelvi-rachidien a été étudié dans la 2e partie. En effet, en plus de l’alignement du squelette, c’est l’activation du système musculaire qui est responsable du maintien d’une posture érigée. Nous avons décrit les caractéristiques musculaires des patients avec une scoliose lombaire et analysé les relations avec les paramètres radiographiques de la déformation, montrant que selon le type de déformation certains groupes musculaires étaient plus touchés par l’atrophie et l’infiltration graisseuse. En les comparant à des sujets jeunes et âgés sans déformation, nous avons observé que les patients avec une scoliose avaient une dégénérescence musculaire à la fois liée à la déformation et au vieillissement. Dans une 3e partie, en faisant le lien entre les données de la posture par la stéréoradiographie et les données musculaires de l’IRM, nous avons utilisé un modèle musculosquelettique personnalisé pour mieux comprendre les contraintes exercées sur les segments vertébraux et donc pour essayer d’expliquer les faillites mécaniques.Ainsi, l’association de mesures 3D radiographiques et de l’analyse musculaire pourrait permettre en comprenant mieux les phénomènes dégénératifs, de mieux prédire l’aggravation de la déformation et donc de la prévenir par une rééducation ciblée. Par exemple, un renforcement des érecteurs du rachis mais aussi des fléchisseurs pourrait permettre de mieux maintenir la posture. Et, un renforcement des érecteurs et fléchisseurs de hanche pourrait permettre d’activer de manière plus efficace, les mécanismes de compensation telle la rétroversion pelvienne. De plus, la mise en évidence de facteur de risque musculosquelettique d’aggravation de la déformation entrainerait une prise en charge plus précoce de ces patients. Une analyse longitudinale serait donc intéressante. / Adult degenerative scoliosis is a pathology whose prevalence increases with the aging of the population. Moreover, the functional demand is more and more important in these patients. Many studies have shown a benefit of surgical treatment of adult spinal deformity compared to medical treatment in terms of improved functional scores, quality of life and satisfaction. Nevertheless, this surgery is associated with many complications (up to 50% in some series), mostly mechanical such as nonunion, implant rupture, degradation of adjacent levels. Thus, if the radiographic analysis of scoliosis has been well explored, some questions remain like the phenomena responsible for a sudden worsening of the deformation in certain patients or the causes of failures. The aim of this work was to analyze adult scoliosis in 3D using stereoradiography and to evaluate the muscular system of these patients in order to highlight the relationships between spinal deformities, particularly by the horizontal plane analysis, and muscle degeneration.The first part of this work was dedicated to the 3D analysis of scoliosis: first, with the analysis of reproducibility in the adult of 3D stereoradiographic measurements, then by the analysis of the global alignment of these patients with spinal deformity, using a new parameter taking into account the position of the cervico-cephalic junction. After analyzing the postural alignment, the spino-pelvic muscular system was studied in the second part. Indeed, in addition to the alignment of the skeleton, it is the activation of the muscular system that is responsible for maintaining an erect posture. We described the muscular features of patients with lumbar scoliosis and analyzed the relationships with the radiographic parameters of the deformity, showing that depending on the type of deformity some muscle groups were more affected by atrophy and fatty infiltration. Comparing them to young and elderly subjects without deformity, we observed that patients with scoliosis had muscle degeneration that was both related to deformity and aging. In the third part, by linking stereoradiographic posture data with muscular MRI data, we used a personalized musculoskeletal model to better understand the constraints on vertebral segments and therefore to try to explain the mechanical failures.Thus, the combination of 3D radiographic measurements and muscle analysis could better predict muscle degeneration and worsening of deformity and thus prevent it by targeted rehabilitation. For example, a strengthening of the erectors of the spine but also of the flexors could allow better maintaining the posture. And, a strengthening of the erectors and hip flexors could allow activating more effectively, compensation mechanisms such pelvic retroversion. In addition, the demonstration of a musculoskeletal risk factor worsening the deformity would lead to an earlier management of these patients. A longitudinal analysis would be interesting.

O objetivo desta pesquisa foi realizar um estudo cefalométrico radiográfico com o propósito de avaliar as mudanças no perfil tegumentar do terço inferior da face em casos com maloclusões de Classe I, biprotrusos, tratados ortodonticamente com extrações de quatro premolares, por meio da técnica do arco contínuo preconizada por Roth. A amostra constou de 56 radiografias cefalométricas de 26 pacientes leucodermas chilenos, com média de idade de 19,56 + 5,71 anos tomadas ao início e ao término do tratamento. Foram mensuradas as variações na espessura e comprimento do perfil tegumentar, bem como as alterações posturais anteroposteriores dento-alveolares e tegumentares ocorridas. Foram realizadas comparações entre os valores iniciais e finais e correlações entre as variações das grandezas analisadas por meio de análises estatísticas. Após análise dos resultados concluiu-se que, após a retração dos dentes anteriores, a espessura do lábio superior apresentou aumento na sua porção basal e na região do vermelhão labial, enquanto que sua porção intermediária não apresentou variação estatisticamente significante. No lábio inferior, somente a espessura do vermelhão do lábio inferior apresentou aumento significativo. O comprimento total do lábio superior também apresentou aumento estatisticamente significante, enquanto que no comprimento do lábio inferior não foi observado aumento significante. Os lábios superior e inferior sofreram retração estatisticamente significante e o movimento de retração do vermelhão do lábio superior correlacionou diretamente com o movimento do incisivo superior, tanto em nível incisal (0,33:1), como em nível coronário (0,57:1), assim como o movimento de retração do sulco do lábio superior que correlacionou diretamente com o movimento do incisivo superior, tanto em nível incisal (0,26:1) como em nível coronário (0,42:1). O movimento de retração do vermelhão do lábio inferior correlacionou diretamente não só com o movimento da incisal do incisivo inferior (0,54:1) como também com o movimento do incisivo superior tanto em nível incisal (0,57:1), como em nível coronário (0,85:1). Não se constatou correlação entre a alteração postural dos lábios e as alterações tegumentares de espessura e comprimento em todas as variáveis estudadas, exceto a variação do ângulo mentolabial que correlacionou com a variação do comprimento da base do lábio inferior. Essas duas variáveis, no entanto, não apresentaram alterações significativas. / The purpose of this prospective cephalometric study was to evaluate soft tissue profile changes in biprotrusive Class I patients treated with first premolars extractions and maximum anchorage control. The sample was composed of 52 lateral cephalometric roentgenogram from the beginnig and end of treatment of 26 white chilean patients (18 females and 8 males) with age average of 19,56 + 5,71 years old, treated with Roth straight-wire technique. Linear and angular cephalometric values in relation to thickness, lengths, lips posture, convexity of the skeletal and integumental profile, as well as incisors and alveolar profile points posture were evaluated. After statistical analysis, the results showed that upper lip thickness increased in the vermillion and basal area. Lower lip thickness also increased in the vermillion area. Upper lip total length increased while lower lip showed no change in its length. The retraction of the lips as well as the incisors were significant. Upper incisor retraction correlated with upper lip vermillion retraction at the incisor border (0,33 mm :1 mm) and at the crown level (0,57 mm : 1mm). Likewise it was verified with the upper lip sulcus (point A?), that retracted on a proportion of 0,26 mm : 1mm at the upper incisor border level and 0,42 mm : 1 mm at the crown level. Lower lip vermillion retraction correlated with lower incisor retraction at the incisor border level (0,54:1) as well as with upper incisor retraction at the incisor border (0,57:1) and at the crown level (0,85:1). Lip postural changes did not correlated with lip length or thickness changes except lower lip basal length that correlated with the increase of mentolabial angle.

Imatinib mesylate has been associated with the changes in bone turnover. We report a case of the development of tissue calcification in a patient on long-term therapy with this drug. A 48-year-old male patient with gastrointestinal stromal tumor and liver metastasis complained of abdominal pain. His treatment included hepatic artery chemoembolization and partial hepatectomy in addition to chronic imatinib mesylate for 4 years. On physical examination, he had a peritoneal mass just beneath the laparotomy incision scar that, after resection, was found to be dystrophic bone formation. Based on the previous studies suggesting bone changes due to chronic therapy with imatinib mesylate, we believe that the patient's new bone formation was causally related to the use of this drug. To our knowledge, there are no similar reported cases in the literature.

Intervertebral disc (IVD) degeneration is primarily involved in back pain, a morbidity that strongly affects the quality of life of individuals nowadays. Lumbar IVDs undergo stressful mechanical loads while being the largest avascular tissues in our body: Mechanical principles alone cannot unravel the intricate phenomena that occur at the cellular scale which are fundamental for the IVD regeneration. The present work aimed at coupling biomechanical and relevant molecular transport processes for disc cells to provide a mechanobiological finite element framework for a deeper understanding of degenerative processes and the planning of regenerative strategies. Given the importance of fluid flow within the IVD, the influence of poroelastic parameters such as permeabilities and solid-phase stiffness of the IVD subtissues was explored. A continuum porohyperelastic material model was then implemented. The angles of collagen fibers embedded in the annulus fibrosus (AF) were calibrated. The osmotic pressure of the central nucleus pulposus (NP) was also taken into account. In a parallel study of the human vertebral bone, microporomechanics was used together with experimental ultrasonic tests to characterize the stiffness of the solid matrix, and to provide estimates of poroelastic coefficients. Fluid dynamics analyses and microtomographic images were combined to understand the fluid exchanges at the bone-IVD interface. The porohyperelastic model of a lumbar IVD with poroelastic vertebral layers was coupled with a IVD transport model of three solutes - oxygen, lactate and glucose - interrelated to reproduce the glycolytic IVD metabolism. With such coupling it was possible to study the effect of deformations, fluid contents, solid-phase stiffness, permeabilities, pH, cell densities of IVD subtissues and NP osmotic pressure on the solute transport. Moreover, cell death governed by glucose deprivation and lactate accumulation was included to explore the mechanical effect on cell viability. Results showed that the stiffness of the AF had the most remarkable role on the poroelastic behavior of the IVD. The permeability of the thin cartilage endplate and the NP stiffness were also relevant. The porohyperelastic model was shown to reproduce the local AF mechanics, provided the fiber angles were calibrated regionally. Such back-calculation led to absolute values of fibers angles and to a global IVD poromechanical behavior in agreement with experiments in literature. The inclusion of osmotic pressure in the NP also led to stress values under confined compression comparable to those measured in healthy and degenerated NP specimens. For the solid bone matrix, axial and transverse stiffness coefficients found experimentally in the present work agreed with universal mass density-elasticity relationships, and combined with continuum microporomechanics provided poroelastic coefficients for undrained and drained cases. The effective permeability of the vertebral bony endplate calculated with fluid dynamics was highly correlated with the porosity measured in microtomographic images. The coupling of transport and porohyperelastic models revealed a mechanical effect acting under large volume changes and high compliance, favored by healthy rather than degenerated IVD properties. Such effect was attributed to strain-dependent diffusivities and diffusion distances and was shown to be beneficial for IVD cells due to the load-dependent increases of glucose levels. Cell density, NP osmotic pressure and porosity were the most important parameters affecting the coupled mechano-transport of metabolites. This novel study highlights the restoration of both cellular and mechanical factors and has a great potential impact for novel designs of treatments focused on tissue regeneration. It also provides methodological features that could be implemented in clinical image-based tools and improve the multiscale understanding of the human spine mechanobiology.

Segmentation of individual facial soft tissues has received relatively little attention in the literature due to the complicated structures of these tissues. There is a need to incorporate the prior information, which is usually in the form of atlases, in the segmentation process. In this thesis we performed several segmentation methods that take advantage of prior knowledge for facial soft tissue segmentation. An atlas based method and three expectation maximization &ndash / Markov random field (EM-MRF) based methods are tested for two dimensional (2D) segmentation of masseter muscle in the face. Atlas based method uses the manually labeled atlases as prior information. We implemented EM-MRF based method in different manners / without prior information, with prior information for initialization and with using labeled atlas as prior information. The differences between these methods and the influence of the prior information are discussed by comparing the results. Finally a new method based on EM-MRF is proposed in this study. In this method we aim to use prior information without performing manual segmentation, which is a very complicated and time consuming task. 10 MRI sets are used as experimental data in this study and leave-one-out technique is used to perform segmentation for all sets. The test data is modeled as a Markov Random Field where unlabeled training data, i.e., other 9 sets, are used as prior information. The model parameters are estimated by the Maximum Likelihood approach when the Expectation Maximization iterations are used to handle hidden labels. The performance of all segmentation methods are computed and compared to the manual segmented ground truth. Then we used the new 2D segmentation method for three dimensional (3D) segmentation of two masseter and two temporalis tissues in each data set and visualize the segmented tissue volumes.

Feedlot performance, carcass merit and chemical composition were compared using Waguli , Brangus, Hereford x Tuli and Wagyu x Crossbred Gene Combination (CGC) breeds. Steers were penned in the following manner: 6 Waguli steers, 6 Hereford x Tuli, 6 Wagyu x CGC and 8 Brangus. There was a significant difference (P<0.05) between Brangus and Waguli for ADGs. F:G was lower (P<0.05) for Hereford x Tuli compared to the other crossbreeds. A heavier final weight was observed (P<0.05) for the Wagyu x CGC than all other crossbreds. There was a significant difference (P<0.05) for REA between Wagyu x CGC and Hereford x Tuli and Waguli. Wagyu x CGC had higher shear force values (SFV) (P<0.05) than all other crossbreeds. Cost of gain was lower (P<0.05) for Hereford x Tuli compared the other breeds. Hereford x Tuli also had less protein (P<0.05) than to the other breeds.A second study was conducted comparing limit feeding (LF) vs. full feeding (FF) strategies. 23 steers and 27 heifers were penned by sex and were randomly assigned a treatment; 4 pens received the LF treatment and 4 were FF. ADG was lower (P<0.05) for LF and FF heifers compared to both LF and FF steers. Dressing percentage was lower (P<0.05) for LF steers compared to LF and FF Heifers. LF heifers YG was higher (P<0.05) compared to FF steers. Quality grades were higher (P<0.05) for LF and FF heifers compared to LF and FF steers. REA /cwt was significantly higher (P<0.05) for FF heifers compared to LF and FF steers. SFV were11lower (P<0.05) for FF heifers compared to LF and FF steers. A significant difference (P<0.05) in cost of gain was noted between LF steers and the rest, also between LF heifers and FF steers. Primal cut price/cwt was significantly lower (P<0.05) for LF heifers compared to FF steers. Lipid percentage was higher (P<0.05) LF heifers compared to FF steers. Moisture percentage was lower (P<0.05) for LF heifer compared to the other groups.

No description available.

Objectives: To study the treatment practice of chronic tennis elbow (TE) among general practitioners (GPs) and physiotherapists (PTs), the effects of a simple, graded home exercise regime versus expectation, the effects of eccentric versus concentric exercise, and the involvement of the substance P – NK1 receptor system in the peripheral, painful tissue of chronic TE patients by positron emission tomography (PET). Materials and methods: A postal survey regarding therapeutic methods used in patients with chronic TE was sent to 129 GPs and 77 PTs, 81 subjects with chronic TE were randomly and blindly assigned to either an exercise group or a wait list group, 120 subjects were randomly assigned to either eccentric or concentric exercise and ten subjects were examined by PET and the NK1 specific radioligand [11C]GR205171. Results: High proportions of GPs and PTs used ergonomic counselling and stretching in the treatment of chronic TE. The majority of GPs prescribed passive anti-inflammatory measures such as sick leave and anti-inflammatory medication. Many PTs prescribed dynamic, particularly eccentric, exercise. Graded dynamic exercise according to a simple low-cost protocol, has better effect on pain than a wait-and-see attitude. Adjusted for outcome affecting variables, eccentric graded exercise has quicker effect than concentric graded exercise. During PET scan with the NK1 specific radioligand [11C]GR205171, voxel volume and signal intensity of this volume was significantly higher in the affected than the unaffected arm in subjects with unilateral chronic TE. Conclusions: GPs and PTs used many treatments to a similar extent but differed regarding the use of exercise. Chronic TE responds favourably to graded dynamic exercise aimed specifically at the painful tissue. The exercise should stress the eccentric work phase. The substance P – NK1 receptor system seems to play a part in the peripheral, painful tissue of a chronic, soft tissue pain condition such as chronic TE. / Epi-X

Thesis (M.Ost.)--Unitec New Zealand, 2008. / Includes bibliographical references (leaves 92-99).

Ces travaux de thèse portent sur le développement d’outils et de méthodologies innovantes permettant la caractérisation de la paroi artérielle coronarienne. Ce développement est nécessaire pour aider au diagnostic des maladies cardiovasculaires. L’approche mécanique a été utilisée pour mettre en place des méthodes de résolution inverse restituant des informations clés sur les propriétés mécaniques des tissus. La résolution du problème inverse en mécanique utilise entre autres des champs de déformation dont l’estimation est réalisée à l’aide d’algorithmes d’élastographie de déformation. Deux outils de caractérisation ont été étudiés : l’un visant à faciliter la détection par une palpation virtuelle et l’autre l’identification par la reconstruction de cartographies locales du module de Young. Ces outils de palpographie et de modulographie peuvent faciliter la caractérisation in vivo des plaques d’athérosclérose. Les contributions apportées portent successivement sur l’élastographie, la palpographie et la modulographie.Nous avons tout d’abord amélioré l’outil de modulographie iMOD (application existante de reconstruction du module de Young) en l’adaptant aux nouvelles contraintes liées aux modalités IVUS dites de haute définition (HD-IVUS). Les performances de ce nouvel outil perfectionné nommé E-iMOD (Extended iMOD) ont été évaluées en l’appliquant sur des données d’élastographie simulées.Ensuite, nous avons développé une nouvelle version de l’algorithme d’élastographie de déformation. En effet, l’estimation des déformations est un point critique conditionnant la bonne résolution du problème inverse en mécanique. Il a été montré que les améliorations introduites permettent l’amélioration des estimations sur des données simulées et sur des données expérimentales de fantôme.Dans un troisième temps, une analyse de l’apport de la technologie HD-IVUS vis-à-vis de l’imagerie IVUS actuelle a été menée sur données simulées et expérimentales. Elle a montré que les résultats peuvent être prometteurs mais que des efforts de développement sur l’élastographie sont encore nécessaires afin d’exploiter pleinement les avancées techniques de la HD.Une dernière partie traite de l’outil de palpographie relatif à la détection des lésions. Tout d’abord, ce volet est l’occasion de mettre en œuvre une phase expérimentale sur des acquisitions d’artères animales. Le traitement de ces données participe à une phase de validation d’une technique de palpographie développée dans l’équipe. Dans un second volet, une revue de littérature de différentes techniques de palpographie nous permet de mettre en avant les points forts et les faiblesses de ces techniques sur des données simulées. Nous introduisons également un nouvel indice de palpation adapté aux milieux anisotropes. Enfin, une méthode théorique originale repensant les résultats de la palpographie a été proposée. Cette approche permet le calcul d’un premier modulogramme pouvant améliorer le pré-conditionnement des processus d’optimisation de type E-iMOD / This work focuses on the development of innovative tools and methodologies for coronary artery wall characterization. These tools are required to support the diagnosis of cardiovascular disease. A mechanical approach was used to implement inverse resolution methods that provide key data about the mechanical properties of tissues. Resolution of inverse problems in mechanics uses strain fields, which are computed thanks to elastography algorithms. Two main characterization tools were used: one aimed to allow lesions detection by applying a virtual palpation technique and the other aimed to identify a reconstructed distribution of the Young's modulus. Palpography and Modulography tools can facilitate in vivo atherosclerotic plaques characterization. The current dissertation brings contribution in the elastography, palpography and modulography fields.We started by improving the iMOD Modulography tool (previously developed application to compute the Young's modulus map). We adapted iMOD to the new constraints related to high definition IVUS modality (HD-IVUS). This new advanced tool was named E-iMOD (Extended iMOD) and its performances were was evaluated with simulated elastography data.In next step, we developed a new version of the strain elastography algorithm. Indeed, strains estimations are critical to solve of the inverse problem in mechanics. It was shown that the introduced enhancements improved estimation for both vessel simulations and phantom experimental data.In a third stage, an analysis was lead to access the contribution of HD-IVUS technology to current IVUS imaging on simulated and experimental data. Even though hopeful results were showed, further efforts in the elastography algorithm are required in order to fully exploit the HD improvements.The last part of this work deals with the palpography tool that allows the detection of lesions. First, experimental ultrasound acquisitions from animal arteries were processed. These data were involved in a validation prototcol of palpography technique developed in our team. In a second part, a review of several palpography techniques allowed us to highlight their strengths and weaknesses on simulated data. A new palpation index adapted to anisotropic material was also introduced. Finally, an original theoretical method rethinking the results of palpography was proposed. This approach computes a first modulogram to improve the prior preconditioning of optimization processes, such as the optimization process of E-iMOD