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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Biomateriais com aplicabilidade na ortopedia: avanços e desafios na área da infectologia / Biomaterials with applicability in orthopedics: advances and challenges in the infectology area

Marques, Daniella Maia 05 July 2018 (has links)
O controle na formação do biofilme em implantes e próteses ortopédicas continua sendo um dos grandes desafios acerca da infeção relacionada aos dispositivos na área da saúde. O objetivo desta pesquisa foi investigar biomateriais com aplicabilidade na ortopedia, visando os avanços e enfrentamentos dos desafios na área da infectologia. Uma revisão integrativa foi realizada a respeito da formação de biofilme em biomateriais de próteses de quadril com a finalidade de contribuir com as medidas de prevenção e controle aos agravos infecciosos. Além disso, a formação in vitro do biofilme em função dos biomateriais (titânio e titânio revestido com biovidro F18), microrganismos (Staphylococcus epidermidis e Candida albicans) e tempos de incubação (2, 4 e 8 horas) foi avaliada por microscopia de fluorescência. A revisão integrativa foi realizada no portal PubMed da National Library of Medicine, bem como nas bases Cochrane, Embase, Web of Science, CINAHL e LILACS com a inclusão de estudos primários sobre a temática, publicados online até novembro de 2017, em português, inglês e espanhol. Na fase experimental / laboratorial, biofilmes de S. epidermidis (ATCC 12228) e C. albicans (ATCC 90028) foram formados em corpos de prova de titânio e titânio revestido com biovidro F18 após 2, 4 e 8 horas de incubação a 37?C sob agitação orbital. As áreas das imagens dos corpos de prova, em porcentagem, recobertas com biofilme (células vivas) foram avaliadas por microscopia de fluorescência. Os dados coletados foram submetidos à análise estatística empregando-se os testes de normalidade Shapiro Wilk, U de Mann-Whitney e t de Student por meio do software IBM SPSS Statistics (versão 25) e nível de significância ?=5%. Na revisão integrativa, os resultados demonstraram que dos 16 estudos primários, 81,25% eram pesquisas experimentais in vitro e que novos biomateriais foram desenvolvidos para prevenir a formação de biofilme. Com relação à fase experimental / laboratorial, houve menor formação de biofilme por S. epidermidis e C. albicans (p<0,001) no titânio revestido com biovidro F18 do que no titânio, após 8 horas de incubação. Entretanto, houve maior formação de biofilme por S. epidermidis e C. albicans após 8 horas do que em 2 horas de incubação, tanto no titânio quanto no titânio revestido com biovidro F18 (p<0,05). Em suma, a revista da literatura mencionou o desenvolvimento de biomateriais novos para prevenir a formação de biofilme. Na fase laboratorial / experimental, o titânio revestido com biovidro F18 apresentou atividade antibiofilme em comparação com o titânio, e os tempos de incubação de 2 para 8 horas aumentaram a formação de biofilme em ambos os biomateriais. Ainda, pesquisas futuras acerca do biovidro F18 fundamentadas nos aspectos físicoquímicos, bioquímicos e microbiológicos são importantes para a elucidação dos mecanismos de ação relacionados ao controle dos biofilmes / The control of biofilm formation on implants and orthopedic prostheses still is one of the major challenges concerning infection related to devices in the health field. The objective of this research was to investigate biomaterials with applicability in orthopedics, aiming for advances and facing challenges in the infectology area. An integrative review was performed regarding biofilm formation on hip prosthesis biomaterials in order to contribute to the preventive and infection control measures. Moreover, the in vitro biofilm formation according to biomaterials (titanium and titanium coated with F18 bioglass), microorganisms (Staphylococcus epidermidis and Candida albicans) and incubation times (2, 4 and 8 hours) was evaluated by fluorescence microscopy. The integrative review was performed on PubMed portal from National Library of Medicine as well as on Cochrane, Embase, Web of Science, CINAHL and LILACS databases with the inclusion of primary studies about the topic, published online up until November 2017, in Portuguese, English and Spanish. In the experimental / laboratory step, S. epidermidis (ATCC 12228) and C. albicans (ATCC 90028) biofilms were formed on proof bodies of titanium and titanium coated with F18 bioglass after 2, 4 and 8 hours of incubation at 37?C under orbital shaking. The image areas of proof bodies, in percentage, coated with biofilm (living cells) were evaluated by fluorescence microscopy. The data collected were submitted to statistical analysis using normality tests Shapiro Wilk, U from Mann-Whitney and t from Student through IBM SPSS Statistics (version 25) software and significance level ?=5%. In the integrative review, the results showed that among 16 primary studies, 81.25% were in vitro experimental studies and that new biomaterials were developed to prevent biofilm formation. Regarding experimental / laboratory step, there was less biofilm formation by S. epidermidis and C. albicans (p<0.001) on titanium coated with F18 bioglass than on titanium, after 8 hours of incubation. However, there was more biofilm formation by S. epidermidis and C. albicans after 8 hours than in 2 hours of incubation, both on titanium and on titanium coated with F18 bioglass (p<0.05). In sum, the literature review mentioned the development of new biomaterials to prevent biofilm formation. In laboratory / experimental step, titanium coated with F18 bioglass presented antibiofilm activity in comparison with titanium, and the incubation times of 2 to 8 hours increased biofilm formation on both materials. Besides, future studies about F18 bioglass based on physicochemical, biochemical and microbiological aspects are important for the elucidation of action mechanisms related to biofilms control
32

Modified functional surfaces for increased biointegration : Surface chemistry, mechanical integrity and long-term stability of zirconia and alumina based ceramics / Surfaces fonctionnelles modifiées pour augmenter biointégration : Chimie de surface, intégrité mécanique et la stabilité à long terme de céramiques à la base de zircone et d'alumine

Caravaca, Carlos Francisco 16 September 2016 (has links)
Les céramiques bioinertes (zircone, alumine), sont utilisées dans des dispositifs médicaux pour l’orthopédie et l’odontologie. Leurs surfaces peuvent avoir plusieurs fonctions : fixation du dispositif dans le milieu vivant (ex : implants dentaires), rôle tribologique (prothèses articulaires)… Dans tous les cas, ces surfaces sont traitées pour maximiser leur performance, mais ces modifications peuvent entrainer des conséquences négatives. Ainsi, le 2e chapitre montre qu’introduire de la rugosité par sablage joue sur l’intégrité mécanique et sur la stabilité à long terme de l’alumine, de la zircone et d’un composite alumine-zircone. Par ailleurs, dans les prothèses articulaires, la lubrification joue un rôle fondamental pour minimiser l’usure et donc augmenter la durée de vie moyenne des implants, permettant en outre de favoriser l’adsorption de protéines réduisant le contact direct entre les deux surfaces glissantes. La chimie des surfaces (y compris la présence de contamination) peut modifier ces aspects. Dans le 3e chapitre de ma thèse j’ai étudié l’effet de la contamination et des différentes techniques de nettoyage permettant de la réduire sur la mouillabilité des matériaux typiquement utilisés dans les prothèses de hanche, et sur l’adsorption de protéines à leurs surfaces. Finalement, les cellules utilisent les protéines en surface comme points de fixation et identification. Les implants avec une surface capable de recruter plus de protéines aidant à l’adhésion des cellules auront plus des chances d’être intégrés que des implants recrutant des protéines qui empêchent l’adhésion. Dans le 4e chapitre, j’ai exploré un nouveau concept de modification de surface de la zircone consistant en un greffage d’organosilanes directement sur sa surface, de manière à prouver le potentiel de cette technique à améliorer l’ostéointegration sans diminuer la performance mécanique. / Bioinert ceramics (zirconia, alumina) are used in medical devices in orthopedics and dentistry. Their surfaces may provide different functions: fixation of the device in the living tissue (e.g. dental implants), tribological role(joint substitutions),… In all cases the surfaces are treated to maximize their performance, but this modifications may entail negative consequences. The use of roughness to promote osseointegration of implants is a common practice, especially on dental implants. Roughening is often conducted by mechanical treatments, the most common being sandblasting. Therefore, chapter 2 focus on the implications of roughening by sandblasting on the mechanical behaviour of zirconia, alumina and a zirconia-alumina composite, and the differences between them. The work brought in chapter 3 was carried out entirely during a six-month secondment at CeramTec GmbH. In a bearing couple, lubrication mechanisms are complex and wettability and proteins play a yet-to understand role. The study compared the wettability of different materials, their ability to welcome protein adsorption and the effect of different cleaning procedures on wettability measurements and protein adsorption. Finally, the influence of the surface on cell activity is not driven exclusively by roughness: chemical modifications of the surface may enhance the perception of cells for the surface, and by careful tuning of the surface properties one may achieve a better integration without the downsides of roughness. In chapter 4, we explored a novel modification of zirconia, based on known techniques in chemistry, which introduces molecules with special functional groups capable of rendering the surface friendlier for cell adhesion, and opening the window for new exciting developments in the field of bioinert ceramics.
33

Approche probabiliste de la propagation des incertitudes dans le modèle mécano-numérique du système couplé "fémur-prothèse non cimentée" / Probabilistic approach to the propagation of uncertainties in the mechano-numerical model of the coupled "non-cemented femur-prothesis" system

Hu, XiaoSu 15 November 2010 (has links)
L' arthroplastie de la hanche par prothèse non cimentée est une solution couramment employée pour les patients rencontrant des problèmes du système locomoteur. Une telle solution présente toutefois un inconvénient majeur, souligné par tous les utilisateurs : le manque de stabilité primaire de la prothèse. Or, cette faiblesse peut provoquer des complications graves, voire l'échec de l'opération chirurgicale. Par conséquent, parvenir à une bonne fixation primaire est un point crucial de ce type d'opération chirurgicale pour assurer cliniquement une satisfaction à court et long terme.Dans le but de mieux appréhender cette problématique centrale, une piste préopératoire a été adoptée. Un modèle éléments finis permettant de décrire le comportement mécanique du système couplé « os-prothèse non cimentée : DePuy Corail® » a été développé et validé par des expérimentations in vitro. Puis, pour tenir compte de la forte variabilité des paramètres du modèle, inhérente à la nature même du problème, une modélisation stochastique de ces derniers a été introduite et une stratégie mécano-probabiliste proposée, destinée d'une part à quantifier en termes probabilistes l'effet sur la réponse des incertitudes affectant les paramètres du modèle, et d'autre part à évaluer la stabilité primaire du système os-prothèse en contexte fiabiliste. La mise en oeuvre pratique de cette approche a été réalisée à l'aide d'outils numériques basés sur la méthode de Monte-Carlo standard et une procédure de collocation stochastique.L'originalité du travail présenté réside avant tout dans la proposition d'une méthodologie probabiliste capable de prendre en compte les incertitudes dans la problématique de la stabilité primaire des prothèses de hanche non cimentées. Elle tient également dans la potentialité de cette méthodologie à être facilement transplantable en contexte industriel. / The hip arthroplasty with cementless hip prosthesis is a solution usually used for the patients suffering the problems of the musculoskeletal system. However, such a solution has a major disadvantage, pointed by all users : the lack of primary stability of the prosthesis. This weakness can cause serious complications or failure of the surgery. Therefore, to achieve a good primary fixation is a crucial point of this type of surgery to ensure a short and a long term clinical satisfaction. In order to better understand this central issue, a preoperative track is adopted. A finite element model to describe the mechanical behavior of the coupled system " femur-cementless prosthesis : DePuy Corail® "has been created and validated by the experiments in vitro. Then, in order to take into account the high variability of model parameters, inherent to the nature of the problem, the stochastic modeling of random input parameters has been introduced and a mechanical-probabilistic strategy has been proposed, on the one hand to quantify, in probabilistic terms, the effect, on the response, of the uncertainties affecting the input parameters of the model, and on the other hand to evaluate the primary stability of the bone-prosthesis system in reliability context. The practical implementation of this approach is realized by using the numerical tools based on the standard Monte Carlo method and the stochastic collocation procedure. The originality of the work presented is primarily in the proposition of a probabilistic methodology capable of taking into account the uncertainties in the problem of primary stability of cementless hip prostheses. It also lies in the potentiality of this methodology to be transplantable easily in industrial context.
34

Diagnosis of orthopaedic prosthesis infections with radionuclide techniques; clinical application of various imaging methods

Larikka, M. (Martti) 23 January 2004 (has links)
Abstract A variety of radiopharmaceuticals and imaging techniques are currently available for scintigraphic imaging of infections. However, comparisons on the clinical value of such techniques have been limited, especially in prosthesis infections. This series included 138 cases with suspected prosthesis infections – 94 in hip and 44 in knee prostheses of patients whose final diagnoses were based on clinical, operative and microbiological findings, and who underwent three-phase bone, 99mTc -leukocyte and 99mTc-ciprofloxacin imaging in the Department of Clinical Chemistry, Oulu University Hospital and in the Laboratory, L?nsi-Pohja Central Hospital, during the years from 1993 to 2001. The normal arterial and soft-tissue phase images of three-phase bone imaging practically excluded infection in hip prostheses, whereas these techniques frequently yielded false positive findings in patients with knee prostheses, resulting in specificity of 23% or less. In combined 99mTc-leukocyte/bone imaging, diagnostic accuracy was 80–86% at two- to four-hour images and 87–98% at 24-hour images. The 99mTc-ciprofloxacin images showed unspecific accumulation of tracer in the one-hour and four-hour images, which disappeared in the 24-hour images in most hip and knee prostheses. 99mTc-ciprofloxacin imaging yielded almost as good diagnostic accuracy as combined 99mTc-leukocyte/bone imaging. In conclusion, in suspected hip prosthesis infections, normal findings in three-phase bone imaging exclude infection, whereas abnormal results in the arterial and soft-tissue phases should be confirmed with 99mTc-leukocyte imaging using 24-hour images. Contrary-wise, in suspected knee prosthesis infections, 99mTc-leukocyte imaging with 24-hour images is the first-line examination, and abnormal results in 24-hour images should be confirmed by using 99mTc-bone-metabolic imaging. 99mTc-ciprofloxacin yielded almost equally good results as 99mTc-leukocyte/bone-metabolic imaging, but unfortunately, the tracer is not commercially available, although it has been patented.
35

In-Vivo Corrosion and Fretting of Modular TI-6AL-4V/CO-CR-MO Hip Prostheses: The Influence of Microstructure and Design Parameters

Gonzalez, Jose Luis, Jr 16 April 2015 (has links)
The purpose of this study was to evaluate the incidence of corrosion and fretting in 48 retrieved titanium-6aluminum-4vanadium and/or cobalt-chromium-molybdenum modular total hip prosthesis with respect to alloy material microstructure and design parameters. The results revealed vastly different performance results for the wide array of microstructures examined. Severe corrosion/fretting was seen in 100% of as-cast, 24% of low carbon wrought, 9% of high carbon wrought and 5% of solution heat treated cobalt-chrome. Severe corrosion/fretting was observed in 60% of Ti-6Al-4V components. Design features which allow for fluid entry and stagnation, amplification of contact pressure and/or increased micromotion were also shown to play a role. 75% of prosthesis with high femoral head-trunnion offset exhibited poor performance compared to 15% with a low offset. Large femoral heads (>32mm) did not exhibit poor corrosion or fretting. Implantation time was not sufficient to cause poor performance; 54% of prosthesis with greater than 10 years in-vivo demonstrated none or mild corrosion/fretting.
36

Tribologie et vieillissement de prothèses totales de hanche en biocéramique, in vitro = in vivo ? Enjeux scientifique et sociétal / Tribology and ageing of bioceramic total hip prostheses, in vitro = in vivo? Scientific and societal issues

Perrichon, Armelle 20 January 2017 (has links)
La performance du couple prothétique tête fémorale/cupule impacte fortement la durée de vie d’une prothèse totale de hanche. Les céramiques affichent une excellente combinaison de propriétés de biocompatibilité, mécaniques et tribologiques. Les composites ZTA formés d’une matrice d’alumine renforcée en zircone sont optimisés pour offrir le meilleur compromis de dureté, stabilité chimique, ténacité et résistance mécanique. La prédiction de la performance de ces matériaux doit prendre en compte les trois principaux modes de dégradation identifiés en configuration céramique/céramique (CoC) : le choc avec décoaptation, le frottement et le vieillissement à basse température. Ces modes sont susceptibles d’être simulés in vitro à partir de tests expérimentaux, respectivement, sur une machine de chocs, un simulateur de marche et en autoclave. L’objectif de ce projet est de combiner ces tests afin de mieux résoudre l’équation in vitro = in vivo. Les chocs dominent les processus de dégradation avec la formation de bandes d’usure. Le matériau testé a montré une excellente résistance au vieillissement. La dégradation induite par le test d’usure standard sur simulateur de marche est négligeable et pose la question de la pertinence de ce test pour les couples CoC. L’importance de la prise en compte des chocs dans les tests expérimentaux a été confortée grâce à une analyse d’explants. Une transformation de phase de la zircone a été mécaniquement induite dans les bandes d’usure créées in vitro et in vivo. Un mécanisme de dégradation a été suggéré au sein de ces bandes. La réponse du matériau est en partie déterminée par la force appliquée au cours des chocs. / The performance of the prosthetic couple (femoral head/cup) influences strongly the lifetime of a total hip prosthesis. Ceramics exhibit an excellent combination of biocompatibility, mechanical resistance and tribological properties. Zirconia toughened alumina (ZTA) composites are made of an alumina matrix and well dispersed zirconia particles. They are tailored in order to offer the best compromise of hardness, chemical stability, toughness and mechanical resistance. The prediction of the performance of such materials must take into consideration the three main sources of degradation identified for Ceramic-on-Ceramic (CoC) bearings: shocks due to micro-separation, friction and low temperature degradation (LTD). Experimental tests on a shock machine, a hip-walking simulator and in an autoclave are able to simulate in vitro each of these sources of degradation, respectively. The aim of the project is to combine these tests in order to solve better the equation in vitro = in vivo. Shocks dominate the processes of degradation with the formation of wear stripes. The tested material showed an excellent resistance to LTD. The damage induced by the standard wear test on a hip-walking simulator is negligible, which raises the question about the relevance of this test for CoC couplings. An analysis of explants confirmed the decisive role of shocks in experimental tests. Zirconia phase transformation was mechanically induced within both in vitro and in vivo wear stripes. A degradation mechanism was suggested within the stripes. The material response is partly determined by the force applied during shocks.
37

Proposta de intervenção fisioterapêutica precoce em pacientes submetidos a artroplastia total de quadril.

Bonvicine, Cristiane 29 August 2006 (has links)
Made available in DSpace on 2016-01-26T12:51:09Z (GMT). No. of bitstreams: 1 cristianebonvicine_dissert.pdf: 1983528 bytes, checksum: 28b368ace7fce3a0702c933b45454b76 (MD5) Previous issue date: 2006-08-29 / The loss of hip mobility, spontaneous or surgical, is an important and frequent functional impairment. In the evolvement of operative techniques of the muscoskeletal system, the cemented total hip replacement is pointed out since it improves the patients quality of life. Physiotherapy is an important resource in the patients care after Total Hip Replacement (THR) to aid their functional return. Objective: to analyze the physiotherapy intervention in the improvement of pain, gait, mobility and quality of life in the postoperative period of patients who have undergone THR, moreover, comparing the physiotherapic ambulatory rehabilitation with orientations and self-care guide.Casuistics and Method: This is a randomized clinical trial and double blinded study, in which patients with osteoarthritis submitted to THR in the period of May to October 2005 were evaluated. They were objectively evaluated either for pain, gait or mobility, according to D´Aubigné and Postel´s criteria in the preoperative, with 1 month and 3 months of postoperative, respectively. Life quality was evaluated by means of the questionnaire SF-36. The patients were randomly divide into two groups: the study group and the control group. The patients of the study group were submitted to a protocol of physiotherapic treatment during twelve weeks, with two-week sessions. The control group did not receive the guide of instructions related to postoperative cares. Mood´s median test was used to evaluate the results for the non-parametric values to compare the results between the groups. Wilcoxon´s test was used to compare the evolution of the groups. A level of significance of p=0.05, with a confidence interval (CI) of 95% was used. Results: Twenty patients, 10 from the study group and 10, the control group, finished the study. In the first evaluation, there was a significance just regarding the general state of health. This showed a smaller median in the study group (p=0.025), In the second, at the 30th PO period, there was statistical significance in relation to the study group regarding both the gait (p=0.007) and the mobility (p=0.001). In the third, there was a statistical significance after three months of postoperative, and at the end of the physiotherapeutic intervention in the study group: in the functional capacity (p<0.0005), in the physical aspects (p=0,002), in the pain (p=0,019), in the vitality (p=0,025), in the emotional aspects (p<0.0005), in the gait (p=0.001) and in the mobility (p=0.010). Regarding the evolution, after three months of postoperative period, a greater median was observed in the study group according to the physical capacity (p=0.006), physical aspects (p=0,002), general state of health (p<0,0005), vitality (p=0,025) and emotional aspects (p=0,001). Conclusion: Early physiotherapy procedures can improve the rehabilitation process of patient´s submitted to THR. / A perda de mobilidade do quadril, espontânea ou cirúrgica, é um comprometimento funcional importante e freqüente. Na evolução das técnicas operatórias do aparelho locomotor, destacam-se as relacionadas com a substituição da articulação do quadril por uma prótese total de quadril cimentada que melhora a qualidade de vida dos pacientes. A fisioterapia é um importante recurso nos cuidados de pacientes após a Artroplastia Total de Quadril (ATQ) para auxiliar o retorno funcional. Objetivos: analisar a intervenção da fisioterapia na melhora da dor, marcha, mobilidade e qualidade de vida no pós-operatório de pacientes que realizaram ATQ cimentada, além de comparar a reabilitação fisioterapêutica ambulatorial com um guia de orientações e auto-cuidados. Casuística e Método: Trata-se de um ensaio clínico aleatorizado, mono-cego, no qual foram avaliados os pacientes portadores de osteoartrose submetidos a ATQ no período de maio a outubro de 2005. Os pacientes foram avaliados objetivamente quanto à dor, marcha e mobilidade, de acordo com os critérios estabelecidos por DAubigné e Postel no pré-operatório, com 1 mês e 3 meses de pós-operatório, respectivamente.A qualidade de vida foi avaliada por meio do questionário SF-36. Os pacientes foram divididos, de forma aleatória em dois grupos - o grupo de estudo e o grupo controle. Os pacientes do grupo de estudo foram submetidos a um protocolo de tratamento fisioterapêutico durante doze semanas, com duas sessões semanais. O grupo controle não recebeu intervenção fisioterapêutica padronizada precocemente, tendo recebido apenas o guia de instruções quanto aos cuidados pós-operatórios. Os resultados foram avaliados pelo teste de Mediana de Mood para valores não paramétricos a fim de comparar os resultados entre os grupos. Nota de Resumo A evolução dos grupos foi comparada utilizando-se o teste estatístico de Wilcoxon. Adotou-se um nível de significância de p= 0,05, com intervalo de confiança (IC) de 95%. Resultados: 20 pacientes terminaram o estudo, 10 pertenciam ao grupo de estudo e 10 ao grupo controle. Na avaliação inicial, houve significância apenas com relação ao estado geral de saúde, que demonstrou uma menor mediana no grupo de estudo (p=0.025).Na segunda avaliação, realizada no 30 PO, houve significância a favor do grupo de estudo com relação à marcha (p=0,007) e com relação à mobilidade (p=0,001). Na terceira avaliação, realizada após três meses de pós-operatório e ao término da intervenção fisioterápica no grupo de estudo, houve significância na capacidade funcional (p<0,0005), nos aspectos físicos (p=0,002), na dor (p=0,019), na vitalidade (p=0,025), nos aspectos emocionais (p<0,0005), na marcha (p=0,001) e na mobilidade (p=0,010). Quanto à evolução, após três meses de pós operatório, percebeu-se uma maior mediana no grupo de estudo quanto à capacidade física (p=0,006), aspectos físicos (p=0,002), estado geral de saúde (p<0,0005), vitalidade (p=0,025) e aspectos emocionais (p=0,001). Conclusão: A fisioterapia precoce auxilia no processo de recuperação dos pacientes submetidos a ATQ.
38

Eficácia do uso do Templating na artroplastia total do quadril.

Devito, Fábio Stucchi 17 April 2009 (has links)
Made available in DSpace on 2016-01-26T12:51:22Z (GMT). No. of bitstreams: 1 fabiostuchidevito_tese.pdf: 1050230 bytes, checksum: 52d8e95acef4a4ba2f5e60d301266786 (MD5) Previous issue date: 2009-04-17 / Total hip arthroplasty is a surgery with a high success rate, providing pain relief and improvement of the articular mobility. Long-term success is related to the position and orientation of the acetabular and femoral components. Traditional preoperative planning entails radiographic analysis of the pelvis, in which a template is placed on the image, allowing an analysis of the appropriate size of the Exeter cemented prosthesis. Objective: To evaluate the effectiveness of traditional preoperative planning with the use of templating. Patients and Method: Forty-three anteroposterior X-rays were analyzed by three experienced surgeons. The evaluation of each surgeon was compared with the actual prosthesis used in the surgery and also compared with the assessment of the other two surgeons. Cohen's Kappa concordance test and weighted Kappa indexes using quadratic weighting were used for statistical analysis with a confidence interval of 95%. Results: The preoperative evaluations of Surgeons A, B and C were divided into the analysis of the sizes of the acetabular cup, stem and plug of the distal femoral canal. Surgeon A obtained a moderate agreement in relation to the acetabular component and substantial agreements in relation to the stem and plug. Surgeon B had moderate agreement in relation to both the acetabulum and the stem and substantial agreement in relation to the plug. Surgeon C obtained moderate agreement in relation to the analysis of the acetabulum and the plug and substantial agreement for the stem. The intra-observer agreement test demonstrated a prevalence of slight agreement in relation to the acetabulum and substantial agreement in relation to the stem and to the plug. Conclusion: Templating used in preoperative planning proved effective; however, there was a prevalence of slight and moderate agreement in relation to the size of the acetabular component according to the inter- and intra-observer analysis. / A artroplastia total do quadril é uma cirurgia com alto índice de sucesso, atuando no alívio da dor e melhora da mobilidade articular e seu êxito a longo prazo relaciona-se à posição e orientação do componente acetabular e femoral. O planejamento pré-operatório tradicional consiste na análise radiográfica da bacia, na qual será sobreposto um templating , o que permite a análise do tamanho adequado da prótese Exeter cimentada. Objetivo: Avaliar a eficácia do planejamento pré-operatório tradicional pelo uso do templating . Casuística e Método: Quarenta e três radiografias na posição antero-posterior e foram analisadas por três cirurgiões experientes; as avaliações de cada cirurgião foram comparadas com a prótese utilizada na cirurgia e cada resultado comparado com os resultados dos outros dois. Para avaliação, utilizou-se o teste de concordância do Capa de Cohen e do Capa ponderado, com ponderação quadrática e intervalo de confiança de 95%.Resultados: Os resultados pré-operatório encontrados pelo examinadores A, B e C foram divididos como análise do tamanho do acetábulo, haste e plug do canal femoral distal. O cirurgião A obteve em relação ao componente acetabular uma concordância moderada, e em relação à haste e ao plug uma concordância substancial. O cirurgião B apresentou resultado de concordância moderada em relação ao acetábulo e à haste e substancial em relação ao plug. O cirurgião C na análise acetabular e do plug obteve concordância moderada e substancial quanto à haste. O teste de concordância intra-observador apresentou uma prevalência da concordância leve em relação ao acetábulo e substancial em relação à haste e ao plug. Conclusão: O templating utilizado no planejamento pré-operatório mostrou-se eficaz, no entanto, em relação ao tamanho do componente acetabular houve um predomínio de concordância leve e moderada na análise inter e intraobservador.
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Estudo teórico-experimental do comportamento elastoplástico de poliuretano derivado do óleo de mamona (Ricinus communis) / Theoretical and experimental study of the elastoplastic behavior of the castor oil polyurethane (Ricinus communis)

Ferneda, Amauri Bravo 29 September 2006 (has links)
Os biopolímeros surgem como materiais alternativos no atendimento aos requisitos de desempenho que a área médica tem exigido para implantes ósseos. Nesse contexto o polímero poliuretano derivado de óleo de mamona (Ricinus communis) tem obtido lugar de destaque. Mesmo assim, esse material, considerado um biopolímero regenerador ósseo, ainda necessita de investigação mecânica consistente para uma aplicação de forma confiável. No entanto, há uma grande dificuldade em se prever o comportamento mecânico das estruturas fabricadas por biopolímeros. Diante desse fato, o presente projeto de pesquisa visa através de ensaios experimentais em amostras padronizadas para ensaios de tração e compressão, bem como, ensaios normalizados para próteses de quadril, adquirir propriedades de material adequadas para a implementação dos modelos computacionais, assim como dados de comportamento mecânico sob solicitação. De posse desses dados, através do método dos elementos finitos, são realizadas simulações computacionais com o objetivo de verificar a capacidade do modelo de material de Drucker-Prager representar o comportamento mecânico do biopolímero. Este modelo é aplicado inicialmente na simulação dos ensaios de tração e compressão e posteriormente nas simulações das próteses em biopolímero, onde carregamentos mais complexos estão presentes. Os resultados obtidos nas simulações são analisados e discutidos para fins de validação do uso deste modelo de material em estruturas fabricadas com o biopolímero. / Biopolymers have been widely used as alternative materials to attend the performance requirements that medical area has demanded to bone implants. In this way, the Castor Oil Polyurethane (Ricinus communis) has taken a distinct place. Nevertheless, this material, considered bone constructive, still needs a consisting mechanical investigation for a reliable application, despite the great difficulty to predict the mechanical behavior of biopolymer structures. Face this fact, this work intends through experiments in normalized specimens for tensile and compressive tests, as well as normalized tests for hip implants, to obtain material properties and mechanical behavior data required to implement computational models of the hip prosthesis. Using the finite element method, computational simulations are carried out to verify the capability of Drucker-Prager material model to represent the biopolymer mechanical behavior. This model is first applied in tensile and compressive tests simulations, and further in prosthesis biopolymer simulations, where more complex loadings are present. The results of these simulations are analyzed and discussed in order to validate the use of this material model in biopolymers structures.
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Estudo teórico-experimental do comportamento elastoplástico de poliuretano derivado do óleo de mamona (Ricinus communis) / Theoretical and experimental study of the elastoplastic behavior of the castor oil polyurethane (Ricinus communis)

Amauri Bravo Ferneda 29 September 2006 (has links)
Os biopolímeros surgem como materiais alternativos no atendimento aos requisitos de desempenho que a área médica tem exigido para implantes ósseos. Nesse contexto o polímero poliuretano derivado de óleo de mamona (Ricinus communis) tem obtido lugar de destaque. Mesmo assim, esse material, considerado um biopolímero regenerador ósseo, ainda necessita de investigação mecânica consistente para uma aplicação de forma confiável. No entanto, há uma grande dificuldade em se prever o comportamento mecânico das estruturas fabricadas por biopolímeros. Diante desse fato, o presente projeto de pesquisa visa através de ensaios experimentais em amostras padronizadas para ensaios de tração e compressão, bem como, ensaios normalizados para próteses de quadril, adquirir propriedades de material adequadas para a implementação dos modelos computacionais, assim como dados de comportamento mecânico sob solicitação. De posse desses dados, através do método dos elementos finitos, são realizadas simulações computacionais com o objetivo de verificar a capacidade do modelo de material de Drucker-Prager representar o comportamento mecânico do biopolímero. Este modelo é aplicado inicialmente na simulação dos ensaios de tração e compressão e posteriormente nas simulações das próteses em biopolímero, onde carregamentos mais complexos estão presentes. Os resultados obtidos nas simulações são analisados e discutidos para fins de validação do uso deste modelo de material em estruturas fabricadas com o biopolímero. / Biopolymers have been widely used as alternative materials to attend the performance requirements that medical area has demanded to bone implants. In this way, the Castor Oil Polyurethane (Ricinus communis) has taken a distinct place. Nevertheless, this material, considered bone constructive, still needs a consisting mechanical investigation for a reliable application, despite the great difficulty to predict the mechanical behavior of biopolymer structures. Face this fact, this work intends through experiments in normalized specimens for tensile and compressive tests, as well as normalized tests for hip implants, to obtain material properties and mechanical behavior data required to implement computational models of the hip prosthesis. Using the finite element method, computational simulations are carried out to verify the capability of Drucker-Prager material model to represent the biopolymer mechanical behavior. This model is first applied in tensile and compressive tests simulations, and further in prosthesis biopolymer simulations, where more complex loadings are present. The results of these simulations are analyzed and discussed in order to validate the use of this material model in biopolymers structures.

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