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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

Posicionamento do componente acetabular na artroplastia total do quadril com e sem o auxílio de um sistema de navegação computadorizado: estudo comparativo prospectivo randomizado / Acetabular component positioning in total hip arthroplasty with and without a computer-assisted system: a prospective, randomised and controlled study

Gurgel, Henrique Melo de Campos 06 July 2011 (has links)
Em um estudo prospectivo e randomizado sobre o posicionamento do componente acetabular na artroplastia total do quadril, 20 quadris foram operados com o auxílio da navegação livre de métodos de imagem e 20 quadris foram operados através do método convencional. Todas as cirurgias foram realizadas pelo mesmo cirurgião com o paciente em decúbito lateral. A avaliação do posicionamento foi feita através da medição tomográfica pós-operatória dos ângulos de anteversão e inclinação cirúrgicos e análise da zona de segurança. Os resultados obtidos foram similares em todas as comparações: anteversão média de 17,4o no grupo navegado e 14,5o no grupo convencional (p=0,215), inclinação média de 41,7o no grupo navegado e 42,2o no grupo convencional (p=0,633), desvio médio do objetivo da anteversão (15o) de 5,5o no grupo navegado e 6,6o no grupo convencional (p=0,429), desvio médio do objetivo da inclinação (40o) de 3o no grupo navegado e 3,2o no grupo convencional (p=0,783) e localização dentro da zona de segurança de 90% no grupo navegado e 80% no grupo convencional (p=0,661). A avaliação tomográfica pós-operatória do posicionamento acetabular na artroplastia total de quadril realizada com o paciente em decúbito lateral foi semelhante ao se comparar a técnica navegada com a técnica convencional / In a prospective and randomised study of the acetabular component position in total hip arthroplasty, 20 hips were operated using imageless navigation and 20 hips were operated using the conventional method. The same surgeon performed all the operations with the patient in the lateral position. The correct position of the acetabular component was evaluated with computed tomography performed after the surgeries, measuring the operative anteversion angle and the operative inclination angle and determining the cases inside the safe zone. The results were similar in all the analyses: a mean anteversion of 17.4o in the navigated group and 14.5o in the conventional group (p=0.215), a mean inclination of 41.7o in the navigated group and 42.2o in the conventional group (p=0.633), a mean deviation from the desired anteversion (15o) of 5.5o in the navigated group and 6.6o in the conventional group (p=0.429), a mean deviation from the desired inclination (40o) of 3o in the navigated group and 3.2o in the conventional group (p=0.783), and location inside the safe zone of 90% in the navigated group and 80% in the conventional group (p=0.661). The acetabular component positions tomography analyses in total hip arthroplasty, performed with the patient in the lateral position, were similar whether using imageless navigation or performing it conventionally
2

Failure analysis of ultra-high molecular weight polyethyelene acetabular cups

Burger, Nicolaas Daniel Lombard. January 2005 (has links)
Thesis (PhD.(Mechanical Engineering))--University of Pretoria, 2005. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.
3

A validation study of the newly developed Calce method for determining age-at-death using the acetabulum

Shapero, Stephen Paul 22 January 2016 (has links)
Age-at-death estimation is a key component of creating a biological profile in forensic and bioarchaeological contexts, and the development of methods that utilize different skeletal elements or observe traits in a new manner are an important part of progress in the study of forensic anthropology. Use of the acetabulum for identifying age-at-death is among new methods being developed, and the recently published method by Calce (2012) was the focus of the present study. The present author analyzed a sample of 489 modern American individuals drawn from the William M. Bass Donated Skeletal Collection housed at the University of Tennessee and assigned each individual to a phase described by Calce (2012). The results of the present study show that use of this method correctly classified age-at-death 62.2% of the time. The performance of this method is low compared to the results of the initial study where Calce (2012) found the method to be 81% accurate. This suggests that the acetabulum is not as beneficial as an age-at-death indicator as previously considered, and that more research on the utility of the acetabulum as an age indicator is required.
4

Posicionamento do componente acetabular na artroplastia total do quadril com e sem o auxílio de um sistema de navegação computadorizado: estudo comparativo prospectivo randomizado / Acetabular component positioning in total hip arthroplasty with and without a computer-assisted system: a prospective, randomised and controlled study

Henrique Melo de Campos Gurgel 06 July 2011 (has links)
Em um estudo prospectivo e randomizado sobre o posicionamento do componente acetabular na artroplastia total do quadril, 20 quadris foram operados com o auxílio da navegação livre de métodos de imagem e 20 quadris foram operados através do método convencional. Todas as cirurgias foram realizadas pelo mesmo cirurgião com o paciente em decúbito lateral. A avaliação do posicionamento foi feita através da medição tomográfica pós-operatória dos ângulos de anteversão e inclinação cirúrgicos e análise da zona de segurança. Os resultados obtidos foram similares em todas as comparações: anteversão média de 17,4o no grupo navegado e 14,5o no grupo convencional (p=0,215), inclinação média de 41,7o no grupo navegado e 42,2o no grupo convencional (p=0,633), desvio médio do objetivo da anteversão (15o) de 5,5o no grupo navegado e 6,6o no grupo convencional (p=0,429), desvio médio do objetivo da inclinação (40o) de 3o no grupo navegado e 3,2o no grupo convencional (p=0,783) e localização dentro da zona de segurança de 90% no grupo navegado e 80% no grupo convencional (p=0,661). A avaliação tomográfica pós-operatória do posicionamento acetabular na artroplastia total de quadril realizada com o paciente em decúbito lateral foi semelhante ao se comparar a técnica navegada com a técnica convencional / In a prospective and randomised study of the acetabular component position in total hip arthroplasty, 20 hips were operated using imageless navigation and 20 hips were operated using the conventional method. The same surgeon performed all the operations with the patient in the lateral position. The correct position of the acetabular component was evaluated with computed tomography performed after the surgeries, measuring the operative anteversion angle and the operative inclination angle and determining the cases inside the safe zone. The results were similar in all the analyses: a mean anteversion of 17.4o in the navigated group and 14.5o in the conventional group (p=0.215), a mean inclination of 41.7o in the navigated group and 42.2o in the conventional group (p=0.633), a mean deviation from the desired anteversion (15o) of 5.5o in the navigated group and 6.6o in the conventional group (p=0.429), a mean deviation from the desired inclination (40o) of 3o in the navigated group and 3.2o in the conventional group (p=0.783), and location inside the safe zone of 90% in the navigated group and 80% in the conventional group (p=0.661). The acetabular component positions tomography analyses in total hip arthroplasty, performed with the patient in the lateral position, were similar whether using imageless navigation or performing it conventionally
5

Less Is More: Three Traits to Reveal a More Accurate Aging Method

Unknown Date (has links)
Recently a new strategy for age-at-death estimation has been developed. In Stephanie Calce’s 2012 article, ‘A New Method to Estimate Adult Age-at-death Using the Acetabulum,’ she redesigns the previous attempts made by Rissech et al. (2006). Her technique simplifies Rissech et al. seven traits by condensing them into three easily identifiable traits. The aim of this paper is to determine that Calce’s original intent to create a more user-friendly and comprehensible scoring method was successful. My focus is to reveal if Calce’s technique is effective between different populations or whether interpopulation variation renders it an unstable approach to age estimation. I tested Calce’s forensic method of aging human skeleton’s on a random sample of skeletons of known age from the Hamann-Todd collection. In the test, Calce’s method proved to work well. As it is simpler than previously proposed methods, investigators should consider adopting it under appropriate circumstances. / Includes bibliography. / Thesis (M.A.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection
6

A new computed tomography method for evaluation of orthopedic implants applied to the acetabular cup

Olivecrona, Lotta, January 2010 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2010.
7

Assessment of acetabular cup position with computed tomography /

Olivecrona, Henrik, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
8

Mortalität, Komplikationen und langfristiges funktionales Ergebnis älterer Patienten mit geriatrischer Acetabulumfraktur

Wollmerstädt, Johannes 10 August 2021 (has links)
In den letzten Jahrzehnten sind Niedrig-Energie Traumata mit Brüchen des Acetabulums aufgrund der zunehmend alternden Bevölkerung häufiger geworden. Durch mehrere Autoren konnte dieser Anstieg belegt werden. (Herath et al. 2014; Rinne et al. 2017; Laird und Keating 2005; Ferguson et al. 2010) Im Unterschied zu jüngeren Patienten, bei denen es meist nach Verkehrsunfällen zu Frakturen des Acetabulums kommt, sind sie in der älteren Bevölkerung meist Resultat eines Niedrig-Energie-Traumas. Hier führt bereits das Fallen aus Standhöhe zu einer Fraktur. (Laird und Keating 2005; Gary et al. 2015) Genau wie Frakturen des proximalen, hüftnahen Femurs, können geriatrische Frakturen des Acetabulums aufgrund der folgenden Immobilisation und möglichen Komplikationen zu erhöhter Morbidität und Mortalität führen. Die Literatur legt nahe das operative Therapien eine frühere Mobilisation ermöglichen, Schmerzen reduzieren und die stationäre Aufenthaltsdauer verkürzen. Dadurch wird von weniger Komplikationen ausgegangen. (Pagenkopf et al. 2006; Vanderschot 2007) Andererseits könnte operative Therapie zu mehr Langzeitkomplikationen in Form von sekundärer Hüftgelenksarthrose führen. (Walley et al. 2017) Die vorliegende Arbeit möchte langfristige Mortalität und Ergebnis, hinsichtlich Schmerzen und Mobilität, nach geriatrischer Acetabulumfraktur ermitteln und einen Vergleich zwischen operativer und konservativer Therapie anstellen.:1. Einleitung 1.1. Epidemiologie 1.2. Anatomie und Ätiologie 1.3. Klassifikation 1.4. Diagnostik 1.5. Therapie 1.5.1. Konservative Therapie 1.5.1. Operative Therapie 1.6. Komplikationen 1.7. Rationale dieser Studie 2. Publikation 3. Zusammenfassung der Arbeit 4. Literaturverzeichnis 5. Anlagen 6. Darstellung des eigenen Beitrags 7. Erklärung über die eigenständige Abfassung der Arbeit 8. Danksagung
9

A cadaver‑based biomechanical model of acetabulum reaming for surgical virtual reality training simulators

Pelliccia, Luigi, Lorenz, Mario, Heyde, Christoph-Eckhard, Kaluschke, Maximilian, Klimant, Philipp, Knopp, Sebastian, Schleifenbaum, Stefan, Rotsch, Christian, Weller, René, Werner, Michael, Zachmann, Gabriel, Zajonz, Dirk, Hammer, Niels 08 February 2022 (has links)
Total hip arthroplasty (THA) is a highly successful surgical procedure, but complications remain, including aseptic loosening, early dislocation and misalignment. These may partly be related to lacking training opportunities for novices or those performing THA less frequently. A standardized training setting with realistic haptic feedback for THA does not exist to date. Virtual Reality (VR) may help establish THA training scenarios under standardized settings, morphology and material properties. This work summarizes the development and acquisition of mechanical properties on hip reaming, resulting in a tissue-based material model of the acetabulum for force feedback VR hip reaming simulators. With the given forces and torques occurring during the reaming, Cubic Hermite Spline interpolation seemed the most suitable approach to represent the nonlinear forcedisplacement behavior of the acetabular tissues over Cubic Splines. Further, Cubic Hermite Splines allowed for a rapid force feedback computation below the 1 ms hallmark. The Cubic Hermite Spline material model was implemented using a three-dimensional-sphere packing model. The resulting forces were delivered via a human–machine-interaction certified KUKA iiwa robotic arm used as a force feedback device. Consequently, this novel approach presents a concept to obtain mechanical data from high-force surgical interventions as baseline data for material models and biomechanical considerations; this will allow THA surgeons to train with a variety of machining hardness levels of acetabula for haptic VR acetabulum reaming.
10

Estudo em cadáveres sobre a associação entre os ângulos tomográficos do impacto fêmoro-acetabular e a histologia da lesão do lábio acetabular / Cadaveric study on the association between femoroacetabular impingement tomographic angles and the histology of labral tears

Ejnisman, Leandro 20 January 2016 (has links)
INTRODUÇÃO: O impacto fêmoro-acetabular (IFA) é considerado importante causa de dor do quadril no jovem, podendo evoluir para osteoartrite do quadril. O objetivo deste estudo foi investigar se há associação entre achados da tomografia computadorizada (TC) em cadáveres e lesões do lábio acetabular avaliadas histologicamente. MÉTODOS: Foram realizadas TCs de bacia de 20 cadáveres não formolizados. Os ângulos habituais relacionados ao IFA foram mensurados por um radiologista (ângulo alfa, versão femoral, versão acetabular, ângulo centro-borda e ângulo de Tönnis). O cadáver foi considerado portador de IFA tipo came quando apresentou um ângulo alfa maior que 50º. O cadáver foi considerado portador de IFA tipo pincer quando apresentou versão acetabular menor que 0º, ângulo centro-borda maior que 40º, ou ângulo de Tönnis menor que 0º. Os cadáveres foram então dissecados, o acetábulo foi ressecado, e três fragmentos foram obtidos da peça correspondendo às porções anterior, superior e posterior do rebordo acetabular. Após preparo histológico habitual, as lesões labiais foram avaliadas por um patologista. Quando presente, a lesão foi classificada segundo Seldes. RESULTADOS: A média de idade dos cadáveres foi de 50,2 anos ± 7,4. Foram estudados 13 homens e 7 mulheres. Dezesseis (80%) dos cadáveres foram considerados portadores de impacto tipo came. Oito (40%) cadáveres foram considerados portadores de impacto tipo pincer. Mulheres apresentaram maior proporção de IFA tipo pincer (21,4% dos homens apresentaram IFA tipo pincer e 83,3% das mulheres, p = 0,01). Histologicamente, 16 (80%) dos espécimes apresentaram lesão microscópica em pelos menos um fragmento. Ao dividirmos as regiões, os fragmentos anteriores apresentaram lesão labial em 65% dos casos, os fragmentos superiores 50% e os fragmentos posteriores em 25%. Segundo a classificação de Seldes, 60,7% das lesões foram do tipo 1, 28,6% foram do tipo 2, e 10,7% foram mistas. Indivíduos com lesão labial apresentaram um ângulo alfa maior (53,3º nos casos com lesão e 49,3º nos casos sem lesão, p = 0,01). Alterações tipo pincer não apresentaram associação com presença de lesões labiais (p > 0,05). Não foi encontrada associação entre pincer ou came e a classificação da lesão labial segundo Seldes (p > 0,05). CONCLUSÕES: Cadáveres com maior ângulo alfa apresentaram maior prevalência de lesão labial. Os demais ângulos analisados não apresentaram associação com a lesão labial. Nenhuma associação foi encontrada entre tipo de IFA e tipo de lesão labial segundo Seldes / INTRODUCTION: Femoroacetabular impingement (FAI) is an important cause of hip pain in the young patient, which may progress to hip arthritis. The purpose of this study was to investigate the relationship between computed tomographic findings in cadavers and histological labral findings. METHODS: Twenty fresh cadavers were submitted to a computed tomography (CT) scan. Standard FAI angles were measured, including alpha angle, femoral version, acetabular version, center-edge, and Tönnis angle. A cam lesion was defined as an alpha angle greater than 50º. A pincer lesion was defined as acetabular version less than 0º, or center-edge angle greater than 40º, or Tönnis angle less than 0º. Cadavers were dissected, the acetabulum was resected, and three fragments of each acetabuli were obtained corresponding to the anterior, superior and posterior acetabular rim. Following routine histological preparation, the histological slides were evaluated for possible labral tears. Tears were classified by Seldes type. RESULTS: The cadavers\' mean age was 50.2 years (SD: 7.4), 13 were males, 7 females. Sixteen (80%) specimens had a cam lesion. Eight (40%) specimens had a pincer lesion. Females were more likely to present a pincer lesion (21.4% males versus 83.3% females, p = 0.01). Histologically, 16 (80%) specimens had a labral tear in at least one region. When divided by region; anterior labra had lesions in 65% of cases; superior labra in 50% and posterior labra in 25%. According to Seldes classification, 60.7% of labral tears were type 1, 28.6% were type 2, and 10.7% were mixed. Patients who had a labral tear had significantly higher alpha angles (53.3º versus 49.3º, p = 0.01). Pincer lesions were not associated with labral tears (p > 0.05). We found no association between pincer or cam lesions and Seldes classification (p > 0.05). CONCLUSIONS: Cadavers presenting with higher alpha angles had higher prevalence of labral tears. Other FAI angles had no association with labral tears. No association was found between FAI type and Seldes classification

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