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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.
1

The design of a new elbow prosthesis

Boddington, Richard John 30 March 2017 (has links)
No description available.
2

Alterações do tecido mole, espaço faríngeo e estabilidade após avanço maxilo-mandibular xom rotação anti-horária e prótese total de ATM /

Pizzol, Karina Eiras Dela Coleta. January 2008 (has links)
Orientador: João Roberto Gonçalves / Banca: Ary dos Santos-Pinto / Banca: Roberto Henrique Barbeiro / Banca: Darceny Zanetta Barbosa / Banca: Terumi Okada / Resumo: Este estudo avaliou a resposta do tecido mole, do espaço faríngeo e a estabilidade após avanço maxilo-mandibular com rotação anti-horária e reconstrução da ATM com próteses totais articulares do tipo TMJ Concepts system®. As mudanças cirúrgicas e pós-cirúrgicas foram analisadas utilizando-se telerradiografias laterais. Com o movimento cirúrgico, houve redução do ângulo do plano oclusal (14,9 ± 8,0°) e aumento do espaço aéreo faríngeo - PASnar (4,9mm). A região anterior da maxila moveu-se para a frente e para cima enquanto a porção posterior, para a frente e para baixo. A mandíbula avançou, e sofreu rotação no sentido anti-horário. No período pós-cirúrgico, a maxila apresentou alterações mínimas no plano horizontal, enquanto todas as medidas mandibulares permaneceram estáveis. A postura da cabeça (OPT/NS) mostrou flexão imediatamente após a cirurgia e extensão em longo prazo, enquanto a curvatura cervical (OPT/CVT) não apresentou mudanças. Os resultados cirúrgicos mostraram ainda aumento das distâncias entre a terceira vértebra cervical (C3) e o mento e desta com o hióide, permanecendo estáveis durante o período de observação. A distância entre o osso hióide e o plano mandibular reduziu durante e após a cirurgia. Já a resposta do tecido mole evidenciou diferentes razões entre tecido duro/mole nos pacientes com e sem genioplastia. As mudanças horizontais na morfologia do lábio superior após avanço, impacção da maxila, sutura em VY e sutura da base alar mostraram maior movimento do que as mudanças observadas em tecido duro. O avanço maxilo-mandibular com rotação anti-horária do plano oclusal associado a próteses totais de ATM (TMJ Concepts system®) mostrou-se estável durante o período de observação. O espaço aéreo faríngeo aumentou... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study evaluated stability, soft tissue response and oropharyngeal airway space changes after maxillo-mandibular advancement and counter-clockwise rotation with TMJ reconstruction using TMJ Concepts system® total joint prostheses. Lateral cephalograms were analyzed to estimate surgical and post surgical changes. During surgery, the occlusal plane angle decreased 14.9 ± 8.0° and the retroglossal airway space (PASnar) increased 4.9mm. The anterior region of maxilla moved forward and upward while the posterior nasal spine moved downward and forward. The mandible changed forward and rotated in a counter-clockwise direction. At long-term follow-up evaluation the maxilla showed minor horizontal changes, while all mandibular measurements remained stable. Head posture (OPT/NS) showed flexure immediately after surgery and extension long-term post surgery, while cervical curvature (OPT/CVT) had no significant changes. Surgery increased the distances between the third cervical vertebrae (C3) and menton, and C3 and hyoid, remaining stable afterwards. The distance from the hyoid to the mandibular plane decreased during surgery and in the longest follow-up. Soft tissue response indicated different hard/soft tissue ratios between patients with or without genioplasties. Horizontal changes in upper lip morphology after maxillary advancement/impaction, VY closure, and alar base cinch sutures showed greater movement, than observed in hard tissue. TMJ Concepts total joint prostheses associated with maxillo-mandibular advancement and counter-clockwise rotation showed to be stable during the follow-up observation period. Immediate increase in oropharyngeal airway dimension, was influenced by post-surgical changes in head posture but remained stable over the follow-up period. Soft tissue changes showed a known predictable response. / Doutor
3

Alterações do tecido mole, espaço faríngeo e estabilidade após avanço maxilo-mandibular xom rotação anti-horária e prótese total de ATM

Pizzol, Karina Eiras Dela Coleta [UNESP] 23 September 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-09-23Bitstream added on 2014-06-13T19:23:12Z : No. of bitstreams: 1 pizzol_kec_dr_arafo.pdf: 688008 bytes, checksum: 35e9164526c1e0e9be53fc6134f7ea9a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este estudo avaliou a resposta do tecido mole, do espaço faríngeo e a estabilidade após avanço maxilo-mandibular com rotação anti-horária e reconstrução da ATM com próteses totais articulares do tipo TMJ Concepts system®. As mudanças cirúrgicas e pós-cirúrgicas foram analisadas utilizando-se telerradiografias laterais. Com o movimento cirúrgico, houve redução do ângulo do plano oclusal (14,9 ± 8,0°) e aumento do espaço aéreo faríngeo - PASnar (4,9mm). A região anterior da maxila moveu-se para a frente e para cima enquanto a porção posterior, para a frente e para baixo. A mandíbula avançou, e sofreu rotação no sentido anti-horário. No período pós-cirúrgico, a maxila apresentou alterações mínimas no plano horizontal, enquanto todas as medidas mandibulares permaneceram estáveis. A postura da cabeça (OPT/NS) mostrou flexão imediatamente após a cirurgia e extensão em longo prazo, enquanto a curvatura cervical (OPT/CVT) não apresentou mudanças. Os resultados cirúrgicos mostraram ainda aumento das distâncias entre a terceira vértebra cervical (C3) e o mento e desta com o hióide, permanecendo estáveis durante o período de observação. A distância entre o osso hióide e o plano mandibular reduziu durante e após a cirurgia. Já a resposta do tecido mole evidenciou diferentes razões entre tecido duro/mole nos pacientes com e sem genioplastia. As mudanças horizontais na morfologia do lábio superior após avanço, impacção da maxila, sutura em VY e sutura da base alar mostraram maior movimento do que as mudanças observadas em tecido duro. O avanço maxilo-mandibular com rotação anti-horária do plano oclusal associado a próteses totais de ATM (TMJ Concepts system®) mostrou-se estável durante o período de observação. O espaço aéreo faríngeo aumentou... / This study evaluated stability, soft tissue response and oropharyngeal airway space changes after maxillo-mandibular advancement and counter-clockwise rotation with TMJ reconstruction using TMJ Concepts system® total joint prostheses. Lateral cephalograms were analyzed to estimate surgical and post surgical changes. During surgery, the occlusal plane angle decreased 14.9 ± 8.0° and the retroglossal airway space (PASnar) increased 4.9mm. The anterior region of maxilla moved forward and upward while the posterior nasal spine moved downward and forward. The mandible changed forward and rotated in a counter-clockwise direction. At long-term follow-up evaluation the maxilla showed minor horizontal changes, while all mandibular measurements remained stable. Head posture (OPT/NS) showed flexure immediately after surgery and extension long-term post surgery, while cervical curvature (OPT/CVT) had no significant changes. Surgery increased the distances between the third cervical vertebrae (C3) and menton, and C3 and hyoid, remaining stable afterwards. The distance from the hyoid to the mandibular plane decreased during surgery and in the longest follow-up. Soft tissue response indicated different hard/soft tissue ratios between patients with or without genioplasties. Horizontal changes in upper lip morphology after maxillary advancement/impaction, VY closure, and alar base cinch sutures showed greater movement, than observed in hard tissue. TMJ Concepts total joint prostheses associated with maxillo-mandibular advancement and counter-clockwise rotation showed to be stable during the follow-up observation period. Immediate increase in oropharyngeal airway dimension, was influenced by post-surgical changes in head posture but remained stable over the follow-up period. Soft tissue changes showed a known predictable response.
4

The design and cadaveric assessment of a new artifial first metatarsophalangeal joint replacement for the great toe

Nevin, Craig January 1995 (has links)
The great toe is the part of the foot that most often requires surgical intervention. The first metatarsophalangeal joint (FMTPJ) is the most prominent joint of the great toe. Primary causes of FMTPJ failure are rheumatoid arthritis, osteoarthrosis and joint degeneration secondary to deformities such as hallux valgus, hallux rigidus or the trauma of previous surgery. FMTPJ prostheses are used to restore a measure of motion, correct deformities and relieve pain. FMTPJ replacement is most often indicated for elderly and less active patients but is contra-indicated for young, rheumatoid and active patients. The most common types of FMTPJ prostheses are made from silicone elastomer. Although these have been in use since the 1960's, there are many problems associated with these and all other types of FMTPJ prostheses. For example, recent research has shown that silicone elastomer metatarsophalangeal arthroplasties may cause severe, chronic silicone granulomatous disease. Also, previous studies of the pressure distribution under normal feet, and pathological feet before and after surgery, can be used to show that FMTPJ prostheses fail to restore normal weight-bearing. In this regard, FMTPJ arthroplasties perform little better than amputation. The reasons for the poor biomechanical performance of FMTPJ arthroplasty are not well documented. Existing theoretical models of FMTPJ function cannot be used to explain why almost all surgery of the first ray causes weight bearing to transfer to the lateral side of the foot. A new hypothesis of FMTPJ function was therefore formulated. It is known that the motions of the FMTPJ are linked to motions of the other bones of the foot and ankle because the strong fibrous tissues of the plantar aponeurosis connect the hallux to the calcaneus. However, it is hypothesised that the particular orientation of the bones at the final stages of the stance phase is crucial to the weight-bearing functions of the FMTPJ. A specification for a new prosthesis was therefore developed in accordance with the biomechanical principles contained in the hypothesis. Various potential designs of prosthesis were investigated, but a ball-and-socket configuration was selected because it appeared to allow the motions necessary to restore normal loading in the foot. Three slightly different prototype ball-and-socket FMTPJ prostheses were designed and manufactured. These prototypes were inserted into cadavers; which allowed the range of motion of the prototype prostheses to be assessed in relation to the constraints imposed by the strong fibrous attachments in the foot. Some of the rudimentary surgical techniques and the instruments required to insert and align the prostheses were developed. The various design features that had been incorporated in the different prototypes were assessed in terms of their relevance to ultimate performance of the arthroplasty. In order to verify the biomechanical design principles, cadaveric FMTP joints were tested for range of motion before and after inserting the prostheses. The results were compared to the range of motions obtained from a dry bone specimen, and to the most successful FMTPJ design to date- a double-stem silicone elastomer prosthesis. Finally, the results from all the tests were compared and discussed in relation to the original hypothesis about the function of the great toe. The results obtained from the new prosthesis were sufficiently encouraging to be able to recommend that the prototype be manufactured for further clinical trials. The new prosthesis was found to simulate the conditions that are necessary to re-establish normal weight-bearing patterns in the foot; such as an elevated centre of rotation for the proximal end of the first metatarsal bone, tension in the plantar aponeurosis, mobile bones in the arch, and weight-bearing by the first metatarsal. Previous prostheses used in FMTPJ arthroplasty are believed to be inadequate in that they do not restore at least one of these conditions, which ultimately lead to implant failure. Within the limits of cadaver trials, the new design has demonstrated that it has the potential to succeed.
5

Development of high performance tribological coatings for application onto hip joint prostheses

Knox, Paul January 2010 (has links)
In this thesis Graphit-iC™, an amorphous carbon coating developed by Teer Coatings Ltd. was modified and deposited onto CoCr and WHMWPE substrates in order to improve the wear properties. It was identified that depositing a hard coating onto soft substrate would cause high stresses and lead to coating delamination. Consequently the polyethylene substrates were ion implanted with nitrogen to reduce the hardness differential at the substrate-coating boundary. The coating was characterised using a pin on disc method in order to determine wear and friction. Hardness and fatigue was characterised using nano-indentation and the coating adhesion was measured using scratch testing. Application of the coatings resulted in a significant reduction in wear. Wear factors as low as 3.65x10¯18m³/Nm were achieved for coated CoCr substrates compared to 3.53x10¯15m³/Nm reported in the literature for uncoated CoCr. The coating resulted in friction coefficients between 0.12 and 0.19 with hardness ranging from 6.65 and 15.63GPa. Similarly coating UHMWPE resulted in a reduction in the wear factor to less than 9.6x10¯17m³/Nm. It was concluded that the deposition of amorphous carbon coatings can improve wear of hip joint prostheses, although consideration must be made for the adhesion of the coating to the substrate so that it does not contribute to an early failure of the device. Improved adhesion can be achieved by reducing the hardness differential between the coating and adhesion, either through softening the coating or by using interlayers.
6

Efeito do filme de carbono DLC aplicado por plasma como recobrimento em Polietileno de Ultra Densidade e Alto Peso Molecular (UHWPE) e planejamento virtual utilizando a técnica de elementos finitos em cirúrgias de próteses totais da ATM / The effect of DLC film applied by plasma coating deposition of Ultra High Molecular Weight Polyethylene (UHWPE) in total ATM prosthesis and it virtual planning using the FEA technique

Silva, Alecsandro de Moura [UNESP] 14 January 2016 (has links)
Submitted by ALECSANDRO DE MOURA SILVA null (alecsms@yahoo.com.br) on 2016-06-07T17:44:58Z No. of bitstreams: 1 Alecsandro final com ficha 02062016.pdf: 1266134 bytes, checksum: 8fb4b0e5bdde927d35075c9cf2dcb764 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-06-08T20:16:23Z (GMT) No. of bitstreams: 1 silva_am_dr_sjrp.pdf: 1266134 bytes, checksum: 8fb4b0e5bdde927d35075c9cf2dcb764 (MD5) / Made available in DSpace on 2016-06-08T20:16:23Z (GMT). No. of bitstreams: 1 silva_am_dr_sjrp.pdf: 1266134 bytes, checksum: 8fb4b0e5bdde927d35075c9cf2dcb764 (MD5) Previous issue date: 2016-01-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho teve por objetivo avaliar o efeito do filme de carbono (DLC) aplicado por plasma como recobrimento da liga de Ti -6Al-4V e do polietileno de alto peso molecular (UHMWPE) em prótese totais de ATM, com a finalidade de melhorar suas propriedades bio-tribológicas. Outro aspecto abordado neste trabalho a aplicação do planejamento virtual utilizando a técnica de elementos finitos (FEA), na apresentação de um caso clínico, colocando a importância do cirurgião de conhecer a fundo tanto o planejamento cirúrgico quanto o desenvolvimento da prótese customizadas (TMJ), e assim evitar possíveis falhas biomecânicas. Material: Para o desenvolvimento deste trabalho primeiramente foram utilizados 40 corpos de prova de Ti-6Al-V, dos quais 15 foram recobertas com um DLC e 15 por DLC-Ag pelo método de deposição químico (PECVD), e 10 foram mantidos sem recobrimento como controle. Além disso, foram confeccionados 30 corpos de prova de UHMWPE, dos quais, 15 foram recobertas por DLC pelo sistema de deposição físico (CVD) e 15 foram mantidas sem recobrimento como controle. Métodos: Foram avaliadas as características superfíciais das amostras, adesão em simulador de fadiga deslizante reproduzindo o trabalho condili fossapo 2000,000 de ciclos em banhocom ringuer lactato a 36 graus, a uma carga 200 N. As amostras com filmes foram submetidas a teste de citotoxicidade com células osteoblásticas. Resultados: As células se mostraram uma biocompatibilidade significativa com as amostras portando filme de DLC em substrato Ti6Al4v, se mostrando inerte ao polietileno. Neste estudo também foi apresentado um caso clinico, paciente com 12 anos de idade genero feminino, portadora de anquilose bilateral da ATM relatou já ter sido submetida a cirurgias repetidas sem sucesso, apresentando deformidade esqueletal classe II, em consequência da anquilose temporomandibular, abertura bucal limitada inicial (4,9 mm) e pos cirurgico reconstrução bilateral com prótese total de ATM customizada após o ato cirúrgico, mostrou se com uma abertura de (23 mm) após um ano, com melhora significativa para alimentação e apneia severa do sono. Conclusão: O Dlc em titânio dentro dos parâmetros que conseguimos de deposição, se apresenta como promissor para cobertura de peças protéticas a serem colocadas em seres humanos por sua baixa condutividade elétrica, ótima resposta biológica. / This study aimed to evaluate the effect of carbon film (DLC) applied by plasma as coating the Ti-6Al-4V alloy and ultra high molecular weight polyethylene (UHMWPE) in total TMJ prosthesis, in order to improve their bio-tribological properties. Another aspects addressed in this work are the application of virtual planning using the technique of finite element (FEA) and the presentation of a case, placing the importance of the surgeon to know the background both surgical planning and the development of customized prosthesis (TMJ) and thus avoid possible biomechanical faults. Material: For the development of this work were first used 40 specimens of Ti-6Al-V, of which 15 were coated with a DLC and 15 DLC-Ag by chemical deposition method (PECVD), and 10 were kept without coating as control. In addition, they made 30 UHMWPE specimens, of which 15 were coated with DLC by physical deposition system (CVD) and 15 were maintained without coating as a control. Methods: The surface characteristics of the samples were evaluated for adhesion sliding fatigue tester reproducing the work condili fossapo 2000.000 cycles in banhocom ringuer lactate at 36 degrees, to a load 200 N. The film samples were subjected to cytotoxicity testing in osteoblastic cells. Results: The cells showed a significant biocompatibility with samples carrying DLC film on Ti6Al4V substrate, showing inert to the polyethylene. This study also presented a clinical case patient with 12 years of female gender age, bearer of bilateral ankylosis of the TMJ reported having been subjected to repeated unsuccessful attempts, with deformity skeletal class II, as a result of temporomandibular ankylosis, limited mouth opening initial (4.9 mm) and post surgical bilateral reconstruction with customized ATM denture after surgery, showed up with an opening (23 mm) after one year, with a significant improvement for food and severe sleep apnea. Conclusion: Dlc titanium within the parameters we can deposition, is presented as promising to cover prosthetic pieces to be placed on humans for its low electrical conductivity, good biological response.
7

Développement et modélisation d'éléments de prothèse pour la main / Development and modelisation of elements of prosthesis for the hand

Girod, Loïc 14 October 2010 (has links)
Comme toute articulation fonctionnelle, l’articulation interphalangienne proximale(IPP) est la cible de lésions ou de pathologies pouvant compromettre les fonctions globales de la main. Les principaux objectifs d’une arthroplastie digitale sont de restituer la fonction et la stabilité de l’articulation et de réduire ou supprimer la douleur de manière durable. Le présent travail de thèse porte sur le développement et la modélisation de deux concepts prothétiques pour l’articulation IPP : une prothèse semi-contrainte en alliage de nickel-titane et une prothèse de resurfaçage. Outre le travail de dimensionnement, des essais de fatigue et d’usure sont conduits sur les deux implants. Des études complémentaires à chaque concept sont présentées. Celles-ci portent en premier lieu sur la mise en forme et les traitements thermiques de la prothèse semi-contrainte accompagnées d’une étude de relargage de nickel et une investigation sur les mécanismes mis en jeu. Enfin, une modélisation par éléments finis de l’interaction entre une prothèse articulaire et son environnement osseux est présentée de manière à évaluer la stabilité primaire des implants / As any functional joint, the proximal interphalangeal joint (PIP) is the target of hurts or of pathologies which can compromise the global functions of the hand. The main objectives of a digital arthroplasty are to restore the function and the stability of the joint and to reduce or suppress the pain in a long-lasting way. The present work of thesis concerns the development and the modeling of two concepts of PIP prostheses: a semiconstrained prosthesis made of nickel-titanium alloy and a resurfacing prosthesis. Besides the work of sizing, fatigue and wear tests are done on both implants. Additional studies are presented for each concept. First, we focus on the shaping and the heat treatments of the semi-constrained prosthesis accompanied with a study nickel ion release and an investigation on the involved mechanisms. Eventually, a finite element modeling of the interaction between the prosthesis and the surrounding bone is presented to estimate the primary stability of implants
8

Greffage de polymères biomimétiques sur implants articulaires en polyéthylène : contrôle du comportement tribologique / Grafting biomimetic polymers on polyethylene articular implants : control of the tribological behaviour

Wang, Na 15 April 2013 (has links)
Les maladies ostéoarticulaires représentent environ 10% de l'ensemble des pathologies identifiées en France chaque année. Pour l'instant aucun traitement permettant la réparation du tissu cartilagineux n'est vraiment disponible hormis la pose d'un implant articulaire. Mais, malgré de nombreux efforts pour développer de nouveaux matériaux pour les implants articulaires leur durée de vie in vivo s'avère souvent très décevante par rapport aux extrapolations faites à partir de simulations ex-vivo. Les discordances entre les durées de vie in vivo et ex vivo sont principalement imputées aux conditions d'essais ex vivo insuffisamment réalistes vis-à-vis des propriétés physico-chimiques des lubrifiants biologiques. Dans ce contexte, ce travail vise à agir sur la réactivité physicochimique des surfaces frottantes des implants articulaires en UHMWPE afin de maîtriser l'accrochage des molécules lubrifiantes de type phospholipidique (MPC) et ainsi d'augmenter leurs performances tribologiques. Les résultats montre que l'activation physicochimique des surfaces de UHMWPE par des couches de MPC peuvent diminuer l'usure des surfaces polymères d'implant mais cela nécessite un contrôle de la qualité de la couche MPC greffée (densité surfacique, épaisseur, accrochage chimique, adsorption physico-chimique) afin de garantir une bonne tenue mécanique et tribologique. D'autre part les résultats montrent que la présence de lubrifiant biologique (substitut du fluide synovial à base de liposomes) peut réduire l'usure des surfaces de UHWPE même si la couche de MPC est peu dense et peu épaisse / The osteoarticular diseases account for approximately 10% of all identified pathologies in France each year. Currently there is really no effective treatment available for repairing of the cartilage tissue except for the installation of articular implants. However, in spite of many efforts to develop new materials for articular implants, their lives in-vivo is often disappointing compared with the extrapolations from ex-vivo simulations. The discordances between the lives in-vivo and ex-vivo are mainly contributed to the experimental conditions of ex-vivo insufficiently realistic related to the physic-chemical properties of biological lubricants. In this context, this work aims to investigate physicochemical reactivity of friction surface of UHMWPE articular implants to control the attachment to the lubricating molecules of phospholipid types (MPC) and increase their tribological performance. The results showed that the physicochemical activation of UHMWPE surface with layers of MPC can reduce the surface wear of polymer implant but it requires some quality controls of the grafted MPC layer (surface density, thickness, chemical bonding, physical and chemical adsorption) to ensure good mechanical and tribological performance. In addition, the result also showed that the presence of organic lubricant (substitute synovial fluid containing liposomes) can reduce the surface wear of UHMPE even if the layer is sparse and thin
9

Experiences of abandonment and anonymity among arthroplastic surgery patients in the perioperative period : some issues concerning communication, pain and suffering

Sjöling, Mats, January 2005 (has links)
Diss. (sammanfattning) Umeå : Univ., 2005. / Härtill 4 uppsatser.

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