La present tesi investiga l'ús de la modelització amb elements finits per a l'estudi de la biomecànica lumbar per a l'avaluació clínica. Els estudis bibliogràfics del capítol 1 mostren relacions funcionals clares entre les forces externes i les estructures i formes del teixit lumbar. Els estudis clínics demostraren que independentment del seu origen, el dolor lumbar pot veure's empitjorat per sobrecàrregues dels teixits. Les mesures experimentals són insuficients per descriure la distribució de càrrega entre els diferents teixits lumbars, és així que s'han utilitzat models d'elements finits. No obstant, la fiabilitat dels models a l'hora de predir les càrregues locals en els teixits no ha estat demostrada, essent aquest un dels objectes d'estudi.En el Capítol 2 s'elaborà un model bisegment de la columna lumbar. El model inicial es completà incloent el còrtex vertebral, una definició complerta de les juntes sinovials, les plaques terminals de cartílag i una descripció millorada de l'estructura de l'anell. Es van simular càrregues simplificades per als estudis in vitro per calcular les distribucions de tensions, deformacions i energia. El model bisegment és vàlid per interpretar les distribucions de càrrega funcionals a L3-L5 en el cas d'estructures conegudes de teixit, però el conjunt de la geometria L3-L5 necessitava ser millorat.Així al Capítol 3 es creà un model geomètric bisegment precís de L3-L5. El nou model incloïa les corregides: dimensions i formes, alçades de disc, localitzacions del nucli, formes posteriors de l'os, i distribució dels lligaments. Després de comparar a nivell biomecànic l'antiga geometria amb la nova, els resultats mostraren que els rols relatius dels teixits modelats depenen de la geometria. En general, les distribucions de càrrega predites eren més fisiològiques en el nou model. En canvi, ambdós models, reprodueixen rangs experimentals de moviment, així doncs la seva validació hauria de tenir en compte les transferències de càrrega locals.El Capítol 4 es centra en la variabilitat dels angles creuats del col·lagen de l'anell. Es crearen quatre models bisegment amb organitzacions d'anell fibrós basats en la bibliografia comparant-se sota diverses càrregues. A més es proposà un paràmetre d'estabilització de l'anell per analogia a un tub de parets gruixudes. La biomecànica del model depenia en gran mesura de l'organització de l'anell fibrós, però el paràmetre d'estabilització era soviet contradictori amb les tensions i forces predites. Així, s'assumí que la geometria de la columna i l'organització de l'anell fibrós estaven lligades. Les xarxes d'anell de col·lagen adaptades es poden determinar numèricament, però els models d'anell haurien d'estar bastats en relacions mecanobiològiques.Al Capítol 5 es presenta un model de disc artificial acoblat amb el model de L3-L5. Models bisegment amb i sense implant van ser comparats amb càrregues controlades per força o desplaçament, incloent o no l'aproximació del pes del cos. La rigidesa de la pròtesi alterava generalment les distribucions de càrrega i les rotacions controlades per desplaçament conduint a grans efectes adjacents. Incloent el pes del cos les condicions de contorn semblaven més fisòlogiques que sense. Malgrat la rigidesa del nou disc, aquest sembla més prometedor que altres dispositius comercials.En aquesta tesi s'han creat sis models nous elements finits de la columna lumbar osteoligamentosa. Les simulacions han mostrat que l'ús fiable dels models requereix d'una descripció precisa de les càrregues locals i respostes mecàniques de teixits. Les prediccions locals van estar limitades qualitativament degudes al desconeixement de les estructures de teixit tou, equacions constitutives i condicions de contorn. En canvi, els models poden ser emprats com a laboratoris in silico per superar aquestes limitacions. Basat en la informació numèrica i experimental, s'ha proposat un procediment jeràrquic per al desenvolupament qualitativament fiable de models elements finits de la columna lumbar. / This PhD thesis investigated the use of finite element modelling to study lumbar spine biomechanics for clinical assessment. Bibliographic studies reported in the first Chapter showed clear functional relations between external forces and lumbar spine tissue structures and shapes. Clinical research revealed that independently of its origin, low back pain may be worsened by altered tissue mechanical environments. Experimental measurements alone cannot truly describe the load distributions between the different lumbar spine tissues. Thus, finite element models have been used in the past. But model reliability in predicting local tissue loadings is still not manifest and has been explored in this thesis as described in the following chapters.In Chapter 2, a L3-L5 lumbar spine bi-segment model was built. An initial model was completed to include the vertebral cortex, a full definition of the facet joints, the cartilage endplates, and an improved description of the annulus fibre-reinforced structure. Simplified load-cases used for in vitro studies were simulated to calculate stress and strain energy distributions. Predictions within the L3-L5 lumbar spine bi-segment model could be interpreted in terms of functional load distributions related to known tissue structures, but the overall L3-L5 bisegment model geometry needed further update.Thus, in Chapter 3, a geometrically accurate L3-L5 lumbar spine bi-segment model was created. The new model included corrected L3 and L5 body shapes and dimensions, corrected disc heights and nucleus placements, corrected posterior bone shapes, dimensions, and orientations, and corrected ligament distributions. The new and old geometries were biomechanically compared. Results showed that the relative roles of modelled tissues greatly depend on the geometry. Predicted load distributions were generally more physiological in the new model. However, new and old models could both reproduce experimental ranges of motion, meaning that their validation should take into account local load transfers.Chapter 4 focuses on the variability of the annulus collagen criss-cross angles. Four bi-segment models with literature-based annulus fibre organizations were created and compared under diverse loads. Moreover, an annulus stabilization parameter was proposed by analogy to a thick walled pipe. Model biomechanics greatly depended on the annulus fibre organization, but annulus stabilization parameter was often contradictory with the predicted stresses and strains. Spine geometry and annulus fibrous organization were hypothesized to be linked together. Adapted annulus collagen networks may be numerically determined, but annulus modelling should be based on mechano-biological relationships.In Chapter 5, a case-study of a novel artificial disc design coupled with the L3-L5 lumbar spine model is presented. Bi-segment models with and without implant were compared under load- or displacement-controlled rotations, with or without body-weight like load. Prosthesis stiffness generally altered the load distributions and displacement-controlled rotations led to strong adjacent level effects. Including body weight-like loads seemed to give more realistic results. Although the novel disc substitute is too stiff, it is more promising than other existing commercial devices.In this thesis, six new osteoligamentous lumbar spine bi-segment finite element models were created. Simulations showed that reliable use of lumbar spine finite element models requires precise descriptions of local tissue loading and response. Local predictions were qualitatively mainly limited by a lack of knowledge about soft tissue structural organisations, constitutive equations, and boundary conditions. However, models can be used as in silico laboratories to overcome such limitations. A hierarchical procedure for the development of qualitatively reliable lumbar spine finite element models was proposed based on available numerical and experimental inputs.

[Truncated abstract] An important field of research in orthopaedic biomechanics is the elucidation and mathematical modelling of the mechanical response of cartilaginous tissues. Such research has applications in the understanding of joint function and degenerative processes, as well as in surgical planning and simulation, and engineering of tissue replacements. In the case of surgical and tissue engineering applications especially, patient-specific mechanical properties are highly desirable. Unfortunately, obtaining such information would generally involve destructive mechanical testing of patient tissue, thus rendering the tissue functionally unusable. Development of a laser scanning confocal arthroscope (LSCA) within our School will soon allow non-invasive extraction of 3D microstructural images of cartilaginous tissues in vivo. It is also envisaged that, linked to a suitably formulated constitutive formulation, such information could allow estimation of tissue mechanical response without physical biopsy. This thesis describes the development of techniques to potentially allow non-invasive patient-specific estimation of tissue mechanical response based on confocal arthroscopy data. A microstructural constitutive model is developed which is capable of directly incorporating LSCA-derived patient-specific structural information. A fibre composite type homogenisation approach is used as the basis for the model. ... The result is a series of orientation tensors describing the 3D orientation of linear features in the image stack. The developed analysis techniques are used to estimate fibre volume fraction and orientation distribution for each of the meniscal specimens. The developed constitutive model and image-derived structural parameters are finally used to estimate the reaction force history of two meniscal cartilage specimens subjected to partially confined compression. The predictions are made on the basis of the specimens? individual structural condition as assessed by confocal microscopy and involve no tuning of material parameters. Although the model does not reproduce all features of the experimental curves, as an unfitted estimate of mechanical response the prediction is quite accurate. In light of the obtained results it is judged that more general non-invasive estimation of tissue mechanical properties is possible using the developed framework. The likely limitations and potential areas of improvement are discussed.

Text in Afrikaans / In this quantitative study emphasis is placed on the role of the nurse as a member of the rehabilitation team. Furthermore, the role of the nurse in patient education as well as the importance of effective patient education during the rehabilitation process after hip replacement surgery is emphasised. Various factors that impacted on the rehabilitation process are highlighted. A structured interview schedule was used to interview a group of 20 respondents. All of the respondents participated voluntarily. Orem's Selfcare Theory was used as a theoretical basis for the study. The researcher determined which information respondents regarded as important to attain functional independence during the rehabilitation process. The data gathered would serve as recommendation for a planned information brochure that could in future be given to patients at their first visit to the surgeon before surgery. The brochure could then be used as a basis for patient education in the course of the rehabilitation process. / Advanced Nursing Sciences / M.A. (Verpleegkunde)

Made available in DSpace on 2016-08-03T16:31:11Z (GMT). No. of bitstreams: 1 Flavio Augusto Meffe Andreolli.pdf: 1172177 bytes, checksum: 116719d034801dc93f6e4ae71a9f488a (MD5) Previous issue date: 2008-02-21 / The aim of this study consisted of comparing dental, skeletal and soft tissue effects promoted by Frankel-2 functional regulator with a control group, besides observing the stability of those effects, in an average post-treatment period of 7.11 years. The sample had a total of 90 lateral cephalometric radiographs, with 54 cephalometric radiographs of 18 FR-2 treated patients assessed in three phases (T1: treatment beginning; T2: treatment ending and T3: post-treatment) and 36 cephalometric radiographs of 18 control patients observed in two time periods (T1 and T2). To compare control and treated groups a Student non-paired t-test was used. The comparison of the treated group values in the three times (T1, T2, and T3) was done by the one criterion Analysis of Variance (ANOVA) and Tukey test (p<0.05). The main changes provided by the FR-2, observed, by means of comparison with treated and control groups, involved mandibular effects: mostly protrusion and mandibular length increase associated with clockwise rotation of the mandible, which resulted in an increased total (N-Me) and lower (AFAI) facial height, besides a soft counterclockwise rotation of the palatine plane (SN.PP). The maxillary incisors retracted and the mandibular incisors tipped to buccal side. There was a relative distalization of the maxillary molars in conjunction with the overjet decrease, so, the convexity of the soft tissue facial profile was better. In post-treatment period, it was observed a sagittal stability of maxilla SNA) and mandible (SNB), of the facial pattern variables, of the maxillary incisor inclination, of the nasolabial angle and of the overjet. The maxilla and the mandible continued to grow in the anterior-posterior direction, together with the facial heights. There were also the incisors and molars extrusion. Already, the oclusal plane and the gonium angle decreased in this phase.(AU) / O objetivo desta pesquisa consistiu em comparar as alterações dentárias, esqueléticas e tegumentares promovidas pelo aparelho de Fränkel-2 com um grupo controle, além de observar a estabilidade desses efeitos promovidos pelo tratamento, num período médio de 7,11 anos pós-tratamento. A amostra compreendeu um total de 90 telerradiografias em norma lateral, sendo 54 telerradiografias provenientes de 18 pacientes tratados com o RF-2 avaliados em três fases (T1:início de tratamento;T2: final de tratamento e T3: pós-tratamento) e 36 telerradiografias de 18 pacientes-controle, observados em dois tempos. Para comparação entre os grupos tratado e controle foi utilizado o teste t de Student não pareado. Já para a análise dos valores do grupo tratado nos três tempos (T1, T2 e T3) foi utilizada a Análise de Variância (ANOVA) a um critério e o teste de Tukey (p<0,05). As principais alterações proporcionadas pelo aparelho RF-2 observadas a partir da comparação do grupo tratado com o controle envolveram efeitos mandibulares, principalmente a protrusão e aumento do comprimento mandibular associado com uma rotação horária, que resultou em uma maior altura facial total (N-Me) e ântero-inferior (AFAI), além de suave rotação anti-horária do plano palatino (SN.PP). Os incisivos superiores retruíram e o inferior vestibularizou. Houve uma distalização relativa dos molares superiores juntamente com a diminuição do overjet , desta forma a convexidade do perfil facial tegumentar melhorou. No período pós-tratamento (T3) observou-se uma estabilidade sagital de maxila (SNA) e mandíbula (SNB), das variáveis do padrão facial, da inclinação do incisivo superior, do ângulo nasolabial e do overjet . A mandíbula e a maxila continuaram a crescer no sentido antero-posterior, juntamente com as alturas faciais Houve também a extrusão de incisivos e molares. Já o plano oclusal e o ângulo goníaco diminuíram na fase pós-tratamento.(AU)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this study was to identify and determine the prevalence of fractures and traumatic appendicular luxations in dogs treated between January 2004 and December 2013 at the Hospital Veterinário Universitário da Universidade Federal de Santa Maria. In a population of 1200 dogs with suspected traumatic orthopedic diseases in the locomotor system, 955 (79.58%) had appendicular fractures and 245 (20.42%) had appendicular luxations. Of the 955 dog with fractures, 23.56% had fractures of the femur (n = 225), 23.36% pelvic fractures (n = 223), 21.99% tibial and fibula fractures (n = 210), 17.58% radius and ulna fractures (n = 168), 7.54% humerus fractures (n = 72) and 5.97% distal fractures to the tarsus and carpus (n = 57), with the most frequent cause by car accidents (72.21%). The most affected dogs with fractures were male (52.46%), young (41.99%), mixed breed (51.41%) and small size (42.7%). Of the 245 dogs (20.42%) with traumatic luxations, 57.14% were composed by hip luxations (n = 140), patellar luxation 15.1% (n = 37), 9.8% elbow luxations (n = 24), 5.71% sacroiliac luxations (n = 14), 4.49% shoulder luxations (n = 11) and 7.76% of dogs had other luxations (n = 19), with the most frequent cause by car trauma (66.12%). The most affected dogs with traumatic luxations were males (50.2%), mature adults (36.73%), mixed breed (43.67%) and small size (50.48%). In conclusion, in the population of dogs evaluated, the most prevalent appendicular fractures were femoral fractures, pelvic fractures, fractures of the tibia and the fibula and radius and ulna fractures; and the most prevalent traumatic appendicular luxations were hip luxations, patellar luxations and elbow luxations. / O objetivo deste estudo foi identificar e determinar a prevalência das fraturas e luxações apendiculares traumáticas em cães atendidos entre janeiro de 2004 e dezembro de 2013 no Hospital Veterinário Universitário da Universidade Federal de Santa Maria. De um total de 1.200 cães com suspeita de doença ortopédica de origem traumática no sistema locomotor, 955 (79,58%) apresentaram fraturas apendiculares e 245 (20,42%) luxações apendiculares. Dos 955 cães com fraturas, 23,56% foram fraturas do fêmur (n=225), 23,36% fraturas da pelve (n=223), 21,99% fraturas da tíbia e da fíbula (n=210), 17,58% fraturas do rádio e da ulna (n=168), 7,54% fraturas do úmero (n=72) e 5,97% fraturas distais ao tarso e ao carpo (n=57), decorrentes principalmente de acidentes automobilísticos (72,21%). Os cães mais afetados por fraturas foram machos (52,46%), filhotes (41,99%), sem raça definida (51,41%) e de pequeno porte (42,7%). Dos 245 cães (20,42%) com luxações traumáticas, 57,14% foram constituídas de luxações coxofemorais (n=140), 15,1% luxações de patela (n=37), 9,8% luxações do cotovelo (n=24), 5,71% luxações sacroilíacas (n=14), 4,49% luxações escapuloumerais (n=11) e 7,76% dos cães apresentaram outras luxações (n=19), decorrentes principalmente de acidentes automobilísticos (66,12%). Os cães mais afetados por luxações foram machos (50,2%), adultos maduros (36,73%), sem raça definida (43,67%), de pequeno porte (50,48%). Com base nos resultados encontrados, na população de cães avaliada, conclui-se que: as fraturas apendiculares mais prevalentes foram: fraturas do fêmur, fraturas da pelve, fraturas da tíbia e da fíbula e fraturas do rádio e da ulna; e as luxações apendiculares traumáticas mais prevalentes foram: luxações coxofemorais, luxações de patela e luxações do cotovelo.

The aim of this study was to evaluate the dimensional alterations of dental arches of cleft lip and palate children after cheiloplasty at two rehabilitation centers. The sample was composed of 94 digital models and divided in two groups: Group I 23 children, assisted at University of Zurich with presurgical orthopedic intervention (Hotz plate); Group II 24 children, assisted at Hospital for Rehabilitation of Craniofacial Anomalies of the University of São Paulo without presurgical orthopedic intervention. The three dimensional images were used to evaluate before lip repair (stage 1) and approximately 1 year old (stage 2). The obtained measures were: intercanine distance, intertuberosity distance, anterior-posterior arch distance, anterior-posterior cleft length, anterior and posterior cleft width. The comparison between stages 1 and 2 was evaluated in group I, group II and between group I and II. The alterations between groups were verified by Independent t test. If the sample did not present a normal distribution, Wilcoxon and Mann-Whitney tests were used. In Group I, the comparisons between stages 1 and 2 showed that the intertuberosity and anterior-posterior arch distance increased and the intercanine, anterior and posterior cleft distances decreased. In Group II, the comparisons between stages 1 and 2 showed that intertuberosity distance increased and intercanine, anteriorposterior cleft length distances, anterior and posterior cleft widths decreased. The comparison of the dimensional alterations of dental arches between the two rehabilitation centers exhibited differences: in the stage 1, the intercanine distance decreased in Group II; in the stage 2, the anterior cleft width, the intercanine distance and the anterior-posterior cleft length decreased in Group II, suggesting the superposition of maxillary segments; in Group II, there was a greater narrowing of the anterior and posterior cleft widths, suggesting that Hotz plate induced a more evenly and equidistant approximation of maxillary segments in Group I. It is worth emphasizing that more studies should be conduct to reduce the variability in treatment protocols for cleft lip and palate patients, thus assuring the best evidencebased treatment. / O propósito deste estudo foi avaliar as alterações dimensionais dos arcos dentários de crianças com fissura de lábio e palato após a queiloplastia em dois centros de reabilitação. A amostra foi composta por 94 imagens digitais de modelos de gesso, e dividida em dois grupos: Grupo I - 23 crianças, tratas na Universidade de Zurique, com intervenção ortopédica pré-cirúrigica (placa de Holtz); Grupo II - 24 crianças tratadas no Hospital de Reabilitação de Anomalias Craniofaciais da Universidade de São Paulo, sem intervenção ortopédica pré-cirúrgica. As imagens tridimensionais dos modelos de gesso foram avaliados antes da queiloplastia (estágio 1) e com aproximadamente 1 ano de idade (estágio 2). As seguintes dimensões foram obtidas: comprimento anteroposterior da fissura, amplitude anterior da fissura, amplitude posterior da fissura, comprimento anteroposterior do arco, distância intercaninos e distância intertuberosidades. As comparações foram realizadas entre os estágios 1 e 2 e entre os grupos I e II. As diferenças entre os grupos foram verificadas pelo teste t independente, os testes de Wilcoxon e Mann-Whitney foram usados. No Grupo I, entre os estágios 1 e 2, as distâncias intertuberosidade aumentou e as distâncias intercaninos, distância anteroposterior da fissura, amplitude anterior e posterior da fissura diminuíram. A comparação entre as alterações dimensionais dos arcos dentários entre os dois centros de reabilitação apresentaram diferenças: no estágio 1, a distância intercaninos foi menor no Grupo II que no Grupo I; e no estágio 2, a amplitude anterior da fissura, a distância intercaninos e o comprimento anteroposterior da fissura foram menos no Grupo II que no Grupo I, sugerindo sobreposição dos segmentos maxilares. No Grupo II, houve maior estreitamento nas amplitudes anterior e posterior da fissura, sugerindo que a placa de Holtz no Grupo I induziu a aproximação dos segmentos maxilares de forma mais uniforme e equidistante. É importante salientar que mais estudos longitudinais precisam ser conduzidos a fim de reduzir a variabilidade de protocolos de tratamento em pacientes com fissura de lábio e palato, garantindo o melhor tratamento baseado em evidências científicas.

Estima-se que há mais de 50 anos, as furadeiras elétricas (FE) têm sido empregadas em cirurgias ortopédicas nos hospitais brasileiros para a perfuração óssea. Trata-se de equipamento elétrico, termossensível, não indicado para uso cirúrgico, não avaliado anteriormente quanto à eficácia da esterilização, suspeitando-se de risco potencial para infecções do sítio cirúrgico ou relacionadas a próteses ortopédicas. Os objetivos desse estudo foram: avaliar a carga microbiana de FE do uso cirúrgico e avaliar a eficácia da esterilização por óxido de etileno (ETO) de FE novas intencionalmente contaminadas. Trata-se de pesquisa experimental, laboratorial, randomizada e aplicada desenvolvida no laboratório de pesquisas experimentais da Escola de Enfermagem da Universidade de São Paulo. O trabalho foi realizado em duas fases. As condições assépticas foram rigorosamente seguidas para o controle das variáveis. Quinze FE analisadas na fase I, tiveram distribuição aleatória e cega, capturadas em um centro cirúrgico de um hospital escola. Foram cultivados: o ar gerado pelo motor e alíquotas de 10 µL do lavado das superfícies interna e externa das FE. Ainda nessa fase foi realizado um controle positivo onde uma FE foi contaminada com Serratia marcescens e um teste do método de filtração por membrana de porosidade de 0,45 µm com uma FE limpa, onde as membranas que filtraram diferentes quantidades do lavado foram cultivadas. Na fase II foram analisadas 22 FE e três perfuradores de osso (PO). Dezesseis FE constituíram o grupo experimental (GE), seis o controle positivo (GCP) e três PO constituíram o controle negativo (GCN). Todos os equipamentos previamente limpos e esterilizados foram submetidos à contaminação com esporos de Bacillus atrophaeus. As FE do GCP foram analisadas após a exposição ao contaminante, furadeiras do GE e perfuradores do GCN foram submetidos à limpeza e esterilização por ETO antes de serem analisados. Foram cultivados: ar gerado pelo motor e membrana filtrante após a filtração do lavado das superfícies interna e externa dos equipamentos. Foram realizadas coloração e microscopia: Gram para culturas positivas; Wirtz-Conklin para culturas positivas com bacilos Gram positivos. Os resultados mostraram que a carga microbiana de FE do uso cirúrgico é baixa e foi detectada em duas ocasiões no cultivo do ar, 1 ufc/FE e em uma ocasião no cultivo de alíquotas do lavado, 9 ufc/FE. O controle positivo realizado com Serratia marcescens comprovou a sensibilidade do método para amostras contendo alta concentração de contaminantes. O método filtração por membrana mostrou-se sensível para detectar baixa contaminação das FE, sendo o eleito para o teste de esterilidade. Os controles positivos apresentaram crescimento do microrganismo contaminante, comprovando a aderência ao material. Os controles negativos não apresentaram crescimento. Das 16 FE do GE, duas apresentaram crescimento sendo cada uma delas de 1ufc do contaminante inicial respectivamente no cultivo do ar e no cultivo da membrana. Foi comprovada a eficiência de 99,99999881% do processo de esterilização por ETO, com a probabilidade de sobrevivência de 1,19 x 10-8. Nas condições do desenvolvimento do experimento, a eficácia da esterilização das FE por ETO foi comprovada / Electric drills have been used to perform orthopedic surgeries in Brazilian hospitals for almost more than 50 years. This electric equipment is heat-sensitive and it is not appropriate to use in surgical procedures. Until now the efficacy of sterilization of this item had been not evaluated as a potential risk for the occurrence of surgical site infection or infection related to orthopedic prosthesis. The objectives of this study were to evaluate the bioburden of the used electric drills and to evaluate the sterility of the new electric drills contaminated artificially. It is an experimental and randomized study performed in the research laboratory of the Nursing School of the São Paulo University. The study was performed in two phases following rigorous aseptic techniques to control the variables. In the first phase fifteen electric drills were taken in the operating room of the university hospital and included in the study using aleatory and blind methods. Cultures were performed from the air produced by the drill engine and the aliquots of 10µL of the rinsed water from the internal and external surface of the electric drill. One electric drill was included as a positive control and was contaminated with Serratia marcescens. A membrane filter with porous of 0,45 µm were cultured after had been exposed to the rinsed water from the internal and external surface of the clean electric drill. In the second phase were analyzed twenty two electric drills and three orthopedic drilling machines. Sixteen electric drills were included in the experimental group, six were the positive control group and three orthopedic drilling machines in the negative control group. All the equipments previously cleaned and sterilized were submitted to the contamination with Bacillus atrophaeus. The electric drills included in the positive control group were analyzed after exposed to the contaminant and the electric drills of the experimental group and orthopedic drills included in the negative control group were submitted to clean and ethylene oxide sterilization before to start the analysis. The air produced by the drill engine and the membrane filter after exposed to the rinsed water of the internal and external surface of the electric drill were cultured. It was performed Gram microscopy and Wirtz-Conklin to Gram positive bacilli. The results showed low bioburden in the electric drills in two episodes. So, 1 cfu/electric drill was found in one episode of the air culture and 9 cfu/electric drill in one episode of culture of the aliquot. The positive control with Serratia marcescens demonstrated the sensibility of the method in samples with high concentration of contaminants. The method of membrane filtration showed sensible to detect low bioburden of the electric drills. So it is elected for the sterility test. The positive controls showed the growth of the contaminant microrganism demonstrating the adherence to the material surface. The negative controls did not show growth. Two of the sixteen electric drills included in the experimental group showed each one growth of 1cfu of the initial contaminant of the air and the membrane cultures respectively. So the efficiency of the sterilization process was 99,99999881% and the probability of find survivor was 1,19 x 10-8. In these conditions the study demonstrates that the efficacy of the ethylene oxide sterilization was proved

Introdução: O tratamento dos tumores ósseos benignos é frequentemente realizado por abordagem intralesional com curetagem do tumor e preenchimento da falha óssea com substâncias biológicas ou sintéticas. Entre as biológicas estão os vários tipos de enxertos e o maior representante das sintéticas é o cimento ósseo ou polimetilmetacrilato (PMMA). O uso do cimento ósseo compacto pode apresentar problemas devido à necrose térmica, ao afrouxamento asséptico, à incapacidade de remodelação e à elasticidade inadequada em relação ao osso normal. O desenvolvimento de um cimento ósseo esponjoso que atenda a estas demandas mecânicas e biológicas e que seja de fácil manipulação no ambiente cirúrgico tem estimulado alguns pesquisadores. Basicamente, é possível formar poros no interior do cimento por mistura de substâncias hidrossolúveis ou por reação química produtora de gás. Objetivo: Desenvolver e caracterizar fisicamente e mecanicamente um cimento ósseo com poros intercomunicantes de aspecto estrutural esponjoso. Material e métodos: A produção de cimento esponjoso foi realizada misturando-se o PMMA com bicarbonato de sódio e ácido cítrico. Foram confeccionados 90 corpos de prova com 40 mm de altura por 20 mm de diâmetro distribuídos em 6 grupos (n=15): G1 formado por cimento esponjoso em que antes da polimerização do cimento foram adicionados bicarbonato de sódio e ácido cítrico na proporção de 10% em relação ao componente sólido do cimento (polímero); G2 - cimento esponjoso na proporção de 20%; G3 - cimento esponjoso na proporção de 30%; G4 - cimento ósseo de PMMA compacto; G5 - formado por cimento de poliuretana de mamona (Bioósteo®) na proporção de 20%; G6 formado de corpos de prova cilíndricos de osso esponjoso extraído com trefina de côndilos tibiais proximais de bovinos. A qualidade do cimento esponjoso foi avaliada por macroscopia, cálculo de densidade, imersão em azul de metileno, tomografia computadorizada, microscopia eletrônica de varredura e ensaio mecânico de compressão. Resultados: A melhor forma de produção de cimento esponjoso foi pela mistura de PMMA e componentes efervescentes. O teste da imersão em azul de metileno mostrou que os G2 e G3 apresentaram melhor intercomunicabilidade. As análises com o microscópio eletrônico de varredura (MEV) mostraram uma ampla variação no tamanho e distribuição dos poros que medem de 50m a 3mm. Em relação aos ensaios mecânicos não houve diferenças significativas entres os grupos de cimento esponjoso G1, G2 e G3. Estes grupos apresentaram valores pouco inferiores aos do grupo G6 de osso esponjoso bovino. O grupo G4 (PMMA compacto) apresentou valores extremamente altos quando comparado ao osso esponjoso bovino e ao cimento esponjoso. O grupo G5 de cimento ósseo de mamona não atingiu os valores aceitáveis de resistência mecânica. Conclusão: Foi possível desenvolver um cimento esponjoso à base de polimetilmetacrilato pela mistura com os aditivos efervescentes, bicarbonato de sódio e ácido cítrico, que apresenta características físicas e mecânicas desejadas como substituto ósseo esponjoso nas curetagens para tratamento de tumores ósseos benignos. O cimento de mamona esponjoso na forma testada mostrou-se inadequado para os fins pretendidos. / Introduction: Benign bone tumors are usually treated by intralesional curettage. The bone defect may be filled with synthetic or biological substitutes. Polymetylmethacrylate (PMMA) is the most popular synthetic substitute and the solid form is associated to thermal necrosis, aseptic loosening, bone remodeling prevention and distinct elasticity. Research of porous cement that solves these drawbacks and can be molded intraoperatively has encouraged many authors. For surgical purposes, porosity can be achieved by mixing hydrosoluble substances or by gas-foaming reactions. Objective: Development and physical and mechanical characterization of a bone cement with interconnecting pores and cancellous bone like structural aspect. Methods: Porous cement was produced by adding the effervescent components sodium bicarbonate and citric acid to PMMA. Six groups of fifteen cylindrical samples (40 mm height, 20 mm diameter) were compared. G1, G2 and G3 groups consisted of porous cement specimens of PMMA with 10%, 20% and 30% of effervescent components respectively. G4 consisted of solid PMMA cement specimens. G5 group consisted of porous ricinic polyurethane cement (Bioósteo®) with 20% effervescent components specimens. The control group G6 consisted of bovine cancellous bone samples. The porous cements were characterized in terms of porosity, density, pore interconnectivity and compressive strength. Macroscopic evaluation and measuring, methylene blue immersion, Scanning Electron Microscopy (SEM), mechanical testing and a special computed tomography reading software were employed for these evaluations. Results: The pilot study showed that adding effervescent components to PMMA was the best solution for porous cement production. The methylene blue immersion test showed that G2 and G3 groups had better pore interconnection. Scanning electron microscopy (SEM) showed a wide variation in pore size, from 50m to 3mm, and pore distribution. No significant differences between G1, G2 and G3porous cement groups were found regarding to mechanical strength and Young Modulus. Cancellous bovine bone, G6, was slightly stronger and less elastic than these groups. This property is potentially beneficial considering osteointegration as a consequence of Wolfs law. Solid PMMA is extremely strength and inelastic. These properties do not match with cancellous bone. The porous ricinic polyurethane cement (Bioósteo®) is unacceptably weak. Conclusion: Porous cement was developed by adding effervescent components, sodium bicarbonate and citric acid, to polymethylmetacrylate. Physical and mechanical properties are very similar to cancellous bone. Further investigations to evaluate its bone substitute potential should be encouraged. The porous ricinic polyurethane cement (Bioósteo®) is inadequate these purpose.

Orientador: William Dias Belangero / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T13:05:04Z (GMT). No. of bitstreams: 1 Sawaia_RogerioNaim_D.pdf: 9806060 bytes, checksum: d75ddfca6472ebb85dbfad46a0daa1a4 (MD5) Previous issue date: 2011 / Resumo: INTRODUÇÃO: O tratamento cirúrgico das fraturas intertrocanterianas do fêmur ainda é motivo de estudo e controvérsias. As vantagens da utilização de técnicas minimamente invasivas para essas fraturas já despontam na literatura. O objetivo deste estudo foi avaliar as complicações da técnica minimamente invasiva que utiliza um implante e um instrumental desenvolvidos especificamente (Sistema Minus) para o tratamento dessas fraturas. CASUÍSTICA E MÉTODO: Foram estudados 172 pacientes com fratura intertrocanteriana do fêmur, tratados com o Sistema Minus, dos quais 52 pacientes foram excluídos do estudo por não terem preenchido os critérios de inclusão. No protocolo inicial foram registrados o gênero, a idade, detalhes operatórios como tempo cirúrgico, tempo de uso da fluoroscopia, qualidade da redução e da fixação da fratura. Como parâmetros clínicos foram incluídos a capacidade de marcha, dor, classificação da fratura segundo os critérios de Tronzo e o risco anestésico segundo a classificação de ASA. Dividimos as complicações em dois grupos. As complicações gerais, subdivididas em infecção e mortalidade e as complicações específicas, subdivididas em migração do implante, a perda da redução e a falta de união. Embora a migração do pino deslizante não seja considerada na literatura como uma complicação do DHS (Hrubna e Skotak, 2010)1, no presente estudo ela foi incluída. Cabendo salientar que foi considerada como migração, a impacção lateral da fratura sem a ocorrência de perda de redução. RESULTADOS: O gênero feminino ocorreu em 93 casos e obteve percentual de 77,5%, foi prevalente em relação ao masculino com 27 casos e 22,5%. A idade variou de 52 a 95 anos, com a média de 80,06 anos e desvio padrão de 7,87 anos. A média de idade do gênero masculino foi de 76,19 anos e desvio padrão de 8,321. O gênero feminino obteve a média de 81,18 anos com desvio padrão de 7,407. O tempo cirúrgico médio foi de 39,35 minutos, variando de 25 a 65 minutos. O tempo médio de radioscopia foi 1min7s, variando de 0,6 a 2 minutos e 3s. A redução foi considerada adequada em 92 casos (76,6%), quando obteve-se o alinhamento do eixo de carga, como valgo em 20 casos (16,6%) e como varo em oito casos (6,6%). O somatório médio do TAD (Tip Apex Distance) na incidência Ântero-posterior (AP) foi de 1,19cm, variando de 0,2 a 2,8cm; e no Perfil (P), de 1,14cm, variando de 0,3 a 2,52cm. Dos pacientes, 112 (93,3%) voltaram a andar e a dor pós-operatória em uma escala de 0 a 10, teve a média de 4,44. Dos 120 pacientes, 11 foram classificados como Tronzo I (9,1%), 24 como Tronzo II (20%), 58 como Tronzo III (48,3%), sete Tronzo III variante (5,8%) e 20 Tronzo IV (16,7%). As fraturas instáveis ocorreram em 85 (70,8%) pacientes, os quais 74 (61,6%) tinham idade superior a 75 anos. Já as fraturas estáveis em 35 (29,1%) pacientes, os quais 17 (14,1%) possuíam idade superior a 75 anos. Em relação ao risco anestésico, oito (6,6%) foram classificados como ASA I, 33 (27,5%) ASA II, 74 (61,6%) ASA III e cinco ASA IV (4,16%). Houve um caso de infecção (0,83%). Ocorreram 13 óbitos (10,8%) dentro do primeiro ano de pós-operatório. Desses, um (0,83%) foi classificado como Asa II, cinco (4,16%) como Asa III e sete (5,83%) Asa IV. Dos 85 pacientes com fraturas instáveis, 36 (30%) apresentaram complicações, como perda de redução em 7(5,88%) e migração do pino deslizante em 29 (24,1%). No grupo das 35 fraturas estáveis, as complicações ocorreram em 4 casos (3,33 %), sendo que a perda de redução ocorreu em um caso (0,83%) e a migração em 3 casos (2,5%). No total, a migração ocorreu em 33 casos (27,6%), sendo que desses, todos evoluíram para consolidação. A perda de redução ocorreu em oito (6,7%) e a falta de união, em um caso (0,83%). CONCLUSÃO: Concluímos que a técnica minimamente invasiva, Sistema Minus, é uma técnica segura, que permite a realização da cirurgia com baixa incidência de complicações, quando comparada aos demais métodos existentes / Abstract: INTRODUCTION: The surgical treatment of intertrochanteric fractures is still controversial, resulting in further studies. Many papers have appeared in reference to the advantages of minimal invasive procedures for these fractures. The aim of this study was to evaluate the complications of a minimal invasive procedure using a specific implant and instruments developed for the treatment of intertrochanteric fractures (Minus System). MATERIAL AND METHOD: One hundred and seventy two patients with intertrochanteric fractures of the femur were studied, and submitted to treatment with the Minus System. Fifty two patients were excluded from the study as they did not fulfil all criteria for inclusion. The initial protocol registered gender, age, operative details such as length of operation, length of fluoroscopy use, quality of reduction and fixation of the fracture. The clinical parameters considered included deambulatory ability, pain, Tronzo fracture classification and anesthesia risk according to ASA classification. Complications were divided into two groups: general complications (infection and mortality rate) and specific complications (implant migration, loss of reduction and non-union). Although the migration of a sliding nail has not been considered in the literature as a DHS complication (Hrubna e Skotak, 2010)1 RESULTS: There were 93 feminine cases (77.5%) prevailing on 27 masculine cases (22.5%). Age span was 52 to 95 years, with an average of 80.06 years (standard deviation of 7.87 years). The average age for men was 76.19 years with a standard deviation of 8.321. The average age for women was 81.18 years with a standard deviation of 7.407. The average operative length of time was 39.35 minutes (25 to 65 minutes). The average time of fluoroscopy was 1min 7sec (0.6 to 2min 3sec). Fracture reduction was considered adequate in 92 cases (76.6%), , in the present study it was taken into account. It is important to mention that migration here is the lateral impaction of the fracture without loss of reduction. when alignment with weight-bearing axis was obtained, valgus in 20 cases (16.6%) and varus in eight cases (6.6%). The average Tip Apex Distance (TAD) on an anteroposterior view was 1.19cm (variation of 0.2 to 2.52 cm) and lateral view was 1.14cm (variaton of 0.3 to 2.52cm). One hundred and twelve patients (93,3%) were able to walk with postoperative pain (average of 4.4 on a pain scale of 0 to 10). The classification of the 120 patients is as follows: 11 patients with Tronzo I (9,1%), 24 cases of Tronzo II (20%), 58 Tronzo III (48.3%), seven Tronzo III variant (5.8%) and 20 Tronzo IV (16.7%). Unstable fractures occured in 85 (70.8%) patients, and 74 (61.6%) were over 75 years of age. There were 35 stable fractures (29.1%), with 17 patients (14.1%) over 75 years of age. As to the anesthesia risk eight (6.6%) were classified as ASA I, 33 (27.5%) ASA II, 74 (61.6%) ASA III and five patients as ASA IV (4.16%). There was one case of infection (0.83%). During the first postoperative year there were 13 deaths (10.8%). Of these, one patient (0.83%) had been classified as ASA II, five (4.16%) as ASA III and seven (5.83%) as ASA IV. There were 36 patients (30%) with complications out of 85 patients with unstable fractures, with loss of reduction in seven (5.88%) and migration of the sliding nail in 29 (24.1%). In the group of 35 stable fractures there were complications in four cases (3.3 %), with loss of reduction in one case (0.83%) and migration in three (2.5%). The total number of migrations was 33 (27.5%), but resulted in union in all patients. The loss in reduction occurred in eight patients (6.7%) and non-union in one case (0.83%). CONCLUSION: The minimal invasive procedure, the Minus System, is a safe procedure, that provides adequate surgery with a low incidence of complications, when compared to other existing techniques / Doutorado / Fisiopatologia Cirúrgica / Doutor em Ciências

Les chirurgiens orthopédistes utilisent actuellement des guides de coupes adaptés à chaque patient afin d’effectuer l’opération d’arthroplastie totale du genou. Notamment, l’intervention chirurgicale est préparée grâce à des outils de planification où le chirurgien peut manipuler des images virtuelles du patient, construites à partir d’une imagerie médicale préopératoire. Des points de repère anatomiques permettent d’effectuer plusieurs mesures sur la jambe virtuelle afin de contrôler le positionnement des guides de coupes personnalisés par rapport aux modèles 3-D des os du genou. Nous proposons une méthode multi-atlas pour le positionnement automatique des points anatomiques pré-définis sur les maillages surfaciques modélisant le fémur et le tibia du patient. Nous exploitons un groupe d’atlas (exemples expert) constitué de plusieurs maillages triangulaires pour lesquels les points anatomiques définis ont été placés par des experts. Nous transférons les points anatomiques d’un exemple expert vers le maillage patient à travers le calcul d’un recalage global initial avec l’algorithme Iterative Closest Point (ICP) où une contrainte de courbure est utilisée en tant que dimension supplémentaire de façon à améliorer la robustesse du recalage. Des recalages locaux rigides permettent d’affiner l’adaptation pour la projection des points anatomiques sur la surface du maillage patient. Après avoir traité le maillage patient avec le groupe d’atlas, nous générons une position définitive pour chaque point de repère anatomique en utilisant une sélection automatique du jeu des meilleurs points transférés. Nous avons développé un environnement informatique accessible via internet pour la construction des modèles 3-D des os du genou du patient. Notre méthode de positionnement automatique des points de repère anatomiques est mise en œuvre sur ce système. Nous comparons notre positionnement automatique avec le positionnement manuel par des opérateurs expérimentés ainsi qu’avec des résultats rapportés dans les travaux des publications scientifiques du domaine. / Nowadays, orthopedic surgeons utilize patient-specific systems based on custom cutting guides for total knee arthroplasty. Particularly, the chirurgical operation is prepared by using planning tools where the surgeon can manipulate virtual images of the patient, built from pre-surgical medical images. Identified anatomical landmarks provide various measurements on the virtual lower limb allowing to control the positioning of the cutting guides relative to the 3-D models of the knee bones. We propose a multi-atlas method for the automatic positioning of the pre-defined landmarks on the surface of the models of the femur and the tibia of the patient. We exploit a group of atlases (expert examples) consisting of multiple triangular meshes for which the defined landmarks have been placed by experts. We transfer identified landmarks from an expert example to the patient mesh by computing an initial coarse global registration with an Iterative Closest Point (ICP) algorithm where a curvature constraint serves as a supplementary dimension in order to improve robustness. Adaptive local rigid registrations refine the fit for the projection of reference landmarks onto the surface of the patient mesh. After the patient mesh has been processed with the group of atlases, we compute a definite position for each landmark using an automatic selection of a set of best transferred landmarks. We developed a Web framework for the construction of the 3-D models of the bones of the patient. Our positioning method is implemented in this system. We compare our positioning method against the manual positioning of trained operators and against the results of published scientific works on the domain.