• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 16
  • 9
  • 1
  • 1
  • Tagged with
  • 26
  • 26
  • 26
  • 17
  • 17
  • 17
  • 14
  • 11
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 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

Studies on tibial shaft fractures

Larsson, Kenneth. January 1983 (has links)
Thesis (doctoral)--University of Uppsala, 1983. / Includes bibliographical references (p. 36-41).
2

Studies on segmental displacement after Le Fort I and bilateral sagittal split osteotomies stabilized by rigid internal fixation

Wall, Gert. January 2001 (has links)
Thesis (doctoral)--Malmö University, Sweden, 2001. / Added t.p. with thesis statement inserted. Includes bibliographical references.
3

Studies on segmental displacement after Le Fort I and bilateral sagittal split osteotomies stabilized by rigid internal fixation

Wall, Gert. January 2001 (has links)
Thesis (doctoral)--Malmö University, Sweden, 2001. / Added t.p. with thesis statement inserted. Includes bibliographical references.
4

Análise topográfica através de análise metalográfica de placa e parafuso do sistema 2,4mm com sistema de travamento em três diferentes quantidades de ciclos de autoclavagem / Topographical analysis via metallographic analysis of plate and screw system of 2.4 mm locking system in three different cycles of autoclaving

Santos, Saulo Ellery, 1983- 03 January 2012 (has links)
Orientador: Roger William Fernandes Moreira, Marcelo Marotta Araujo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-20T05:38:06Z (GMT). No. of bitstreams: 1 Santos_SauloEllery_D.pdf: 17593176 bytes, checksum: 114d3bc8c68cd4b332a698a936817b96 (MD5) Previous issue date: 2012 / Resumo: Sistemas de fixação interna estável são utilizados em cirurgia óssea, sejam elas de fraturas ou osteotomias programadas, podem ser submetido a múltiplos procedimentos de esterilização procedimentos antes da implantação em um ambiente de acolhimento. Durante a sua utilização eventualmente o cirurgião depara-se com intercorrências cirúrgicas como quebra da placa durante a dobragem ou quebra de parafusos durante sua inserção e isso de fato ocorre na prática clínica. O objetivo do autor neste estudo foi avaliar se o processo repetido de autoclavagens influencia nas características de dureza e microscópicas das placas e parafusos do sistema 2,4mm "locking". A amostra foi dividas em placas: grupo I (0) controle, grupo II submetido a 20 processos de autoclavagem e grupo III submetido a 60 processos de autoclavagem. Os parafusos foram divididos da mesma forma: grupo I (0), grupo II (20) e grupo III (60). Após o preparo do corpo de provas foram realizados os testes de dureza e avaliação em microscopia da microestrutura. Encontrou-se uma média de valores de dureza de 180,2; 183,8 e 171,8 Vickers respectivamente para os grupos I, II e III das placas (p=0,497) e os valores médios de 328,8; 340,8 e 355,3 Vickers respectivamente para os grupos I, II e III dos parafusos (p=0,283). Na análise microscópica tanto dos parafusos quanto das placas observou-se imagens em 500x que revelaram a microestrutura do material, com grânulos em conformações diferentes, de acordo com a margem analisada, observam-se ainda formação de maclas, principalmente na margem interna, o que pode ser decorrente de força de pressão/cisalhamento durante processo de usinagem, mas sem diferenças entre os grupos. Baseado nos resultados obtidos nas amostras estudadas, observou-se que o processo repetido de autoclavagens não alterou significativamente as características de dureza e microscópicas do material analisado / Abstract: Stable internal fixation systems are used in bone surgery, either fractures or osteotomies, It can be submitted to multiple procedures sterilization procedures before implantation. During its use eventually the surgeon is confronted with surgical complications such as rupture of the plate during bending or breakage of screws during insertion, and this in fact occurs in clinical practice. The aim of study was to evaluate if the repeated autoclaving influences the characteristics of hardness and microscopic of plates and screws of 2.4 mm system "locking". The sample was divided into plates: group I (0) control, group II was subjected to 20 sterilization processes and group III underwent 60 procedures for autoclaving. The screws were divided equally: group I (0), group II (20) and group III (60). After preparing the sample, and were carried out hardness testing and evaluation in the microscopy of microstructure. We found a mean hardness value of 180.2, 183.8 and 171.8 Vickers respectively for the groups I, II and III of the plates (p = 0.497) and mean values of 328.8, 340.8 and 355.3 Vickers respectively for the groups I, II and III of the screws (p = 0.283). Microscopic analyzes of both screws and the plates was observed images 500x revealed that the microstructure of the material, with granules in different conformations in accordance with the margin analyzed, there are still forming twinned, especially in the inset, which may be due to pressure force / shear during the machining process, but no differences between groups was observed. Based on the results obtained in all samples, it was observed that the repeated autoclaving does not significantly alter the characteristics of the material hardness and microscopic examination / Doutorado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Doutor em Clínica Odontológica
5

Displaced femoral neck fractures : a prospective randomized study of clinical outcome, nutrition and costs /

Johansson, Torsten, January 2002 (has links)
Diss. (sammanfattning) Linköping : Univ., 2002. / Härtill 4 uppsatser.
6

A bone reaming system using micromachined pressure sensor.

January 2001 (has links)
Ho, Wai-to Antony. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 100-102). / Abstracts in English and Chinese. / Abstract --- p.I / Acknowledgement --- p.III / Table of Content --- p.IV / List of Figures --- p.VI / List of Tables --- p.X / List of Charts --- p.XI / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter 1.1 --- Biomedical sensing --- p.1 / Chapter 1.2 --- Bone Fracture --- p.2 / Chapter 1.3 --- Bone Fracture Treatment --- p.3 / Chapter 1.4 --- Objectives --- p.4 / Chapter CHAPTER 2: --- LITERATURE SURVEY --- p.5 / Chapter 2.1 --- Bone Structure --- p.5 / Chapter 2.2 --- Biomechanics in Bone Fracture --- p.10 / Chapter 2.3 --- Mathematical Model on Bending and Fracture --- p.11 / Chapter 2.4 --- Intramedullary nailing --- p.12 / Chapter 2.5 --- Reaming technique for intramedullary nailing --- p.14 / Chapter 2.6 --- More on reaming technique --- p.16 / Chapter 2.7 --- Existing pressure-monitoring system of reaming operation --- p.18 / Chapter 2.8 --- Biomedical sensation --- p.19 / Chapter CHAPTER 3: --- SYSTEM DESIGN: RE-ENGINEERING OF A BONE REAMING SYSTEM --- p.23 / Chapter 3.1 --- Mechanical Design-Bone Reaming Guide Rod --- p.23 / Chapter 3.2 --- Guide Rod --- p.24 / Chapter 3.2.1 --- Guide Rod: Head --- p.25 / Chapter 3.2.2 --- Guide Rod: Rod Body --- p.32 / Chapter 3.2.3 --- Guide Rod: Tail --- p.41 / Chapter 3.3 --- Connection System --- p.43 / Chapter 3.3.1 --- Connection System: Components --- p.44 / Chapter 3.3.2 --- Connection System: Connection Mechanism --- p.50 / Chapter 3.3.3 --- Connection System: Disconnection Mechanism --- p.53 / Chapter 3.4 --- Signal Transmission Mechanism --- p.54 / Chapter 3.5 --- Plastic Case --- p.57 / Chapter 3.6 --- Selection of Microsensor --- p.59 / Chapter CHAPTER 4: --- SIGNAL CONDITIONING & PROCESSING --- p.62 / Chapter 4.1 --- Signal Conditioning and Processing --- p.62 / Chapter 4.2 --- Voltage Regulation --- p.62 / Chapter 4.3 --- Instrumentation Amplification --- p.64 / Chapter 4.4 --- Noise Filtering --- p.66 / Chapter 4.5 --- Signal Processing Software --- p.66 / Chapter CHAPTER 5: --- EXPERIMENTAL SETUP --- p.68 / Chapter 5.1 --- Experiments --- p.68 / Chapter 5.2 --- MEMS Pressure Sensor --- p.68 / Chapter 5.3 --- Voltage Regulation Experiment --- p.70 / Chapter 5.4 --- Noise Filtering Experiment --- p.70 / Chapter 5.5 --- Rotating Bearing Signal Transmission System --- p.74 / Chapter 5.6 --- Guide Rod System Calibration Experiment --- p.76 / Chapter 5.6.1 --- Calibration Experiment-Stationary --- p.79 / Chapter 5.6.2 --- Calibration Experiment-Dynamic --- p.79 / Chapter CHAPTER 6: --- EXPERIMENTAL RESULTS --- p.80 / Chapter 6.1 --- Results --- p.80 / Chapter 6.2 --- MEMS Pressure Sensor --- p.80 / Chapter 6.3 --- Voltage Regulation Experiment --- p.81 / Chapter 6.4 --- Noise Filtering Experiment --- p.82 / Chapter 6.5 --- Rotating Bearing Signal Transmission System --- p.83 / Chapter 6.5.1 --- Non-rotating experiment --- p.83 / Chapter 6.5.2 --- Rotating experiment --- p.84 / Chapter 6.5.2.1 --- Rotating experiment -Unprocessed --- p.84 / Chapter 6.5.2.2 --- Rotating experiment -Noise Filtering --- p.86 / Chapter 6.6 --- Guide Rod System Calibration Experiment --- p.89 / Chapter 6.6.1 --- Calibration experiment-Stationary System Calibration --- p.89 / Chapter 6.6.2 --- Rotating experiment-Rotating Speed Calibration --- p.91 / Chapter 6.6.2.1 --- Influence of rotation motion on fluidic pressure --- p.91 / Chapter 6.6.2.2 --- Calibration Experiment --- p.94 / Chapter CHAPTER 7: --- CONCLUSION --- p.98 / Chapter CHAPTER 8: --- REFERENCE --- p.100 / Appendix --- p.103
7

Avaliação in vitro do uso de uma miniplaca convencional e locking, de 4 e 7 furos, para tratamento das fraturas de ângulo mandibular

Ribeiro Júnior, Paulo Domingos [UNESP] 06 May 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:31:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-06Bitstream added on 2014-06-13T19:20:06Z : No. of bitstreams: 1 ribeirojunior_pd_dr_araca.pdf: 475855 bytes, checksum: 25027ddf9644c9757d0a760d4ed4ca58 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Este estudo avaliou in vitro a influência do tipo de miniplaca (convencional ou locking) e do número de parafusos instalados no segmento ósseo distal e proximal para a promoção da estabilidade óssea e resistência da osteossínteses pelo método Champy, utilizada para o tratamento de fraturas de ângulo mandibular. Sessenta hemi-mandíbulas de poliuretano, com consistência similar ao osso mandibular, foram divididas em 4 grupos (n=15) e seccionadas na região de ângulo mandibular simulando uma fratura. Os segmentos ósseos foram fixados por diferentes tipos de miniplacas usando sistema 2.0- mm e parafusos monocorticais de 2.0 x 6.0mm. Nos grupos 1 e 2, dois parafusos convencionais (G1) ou locking (G2) foram instalados em cada segmento ósseo usando respectivamente miniplacas retas convencionais e locking; Nos grupos 3 e 4, três parafusos convencionais (G3) ou locking (G4) foram instados no segmento ósseo proximal e quatro parafusos convencionais (G3) ou locking (G4) foram instalados no segmento distal, usando uma miniplaca convencional (G3) e locking (G4) de sete furos, reta. As hemi-mandíbulas foram submetidas a um teste de compressão utilizando uma máquina universal de ensaio INSTRON até que houvesse um distanciamento entre os segmentos ósseos de 4 mm, seja no sentido horizontal ou vertical. Os dados registrados foram submetidos à avaliação estatística pelo método ANOVA e teste de Tukey utilizando um nível de significância de 1%. As miniplacas locking ofereceram maior resistência ao teste de compressão do que as miniplacas convencionais (p<0.01). Porém, não existiu diferença entre o uso de miniplacas de 7 ou 4 furos (p>0.01). Apesar de não estatisticamente significante os resultados numéricos sugeriram que as miniplacas locking longas oferecem maior resistência ao teste de compressão que as miniplacas locking curtas. / This study evaluated in vitro the influence of the type of miniplate (conventional or locking) and the number of screws installed in the proximal and distal segments on the stability and resistance of Champy’s osteosynthesis in mandibular angle fractures. Sixty polyurethane hemimandibles with bone-like consistency were randomly assigned to 4 groups (n=15) and sectioned in the mandibular angle region to simulate fracture. The bone segments were fixed by different osteosynthesis methods using 2.0-mm miniplates and 2.0 x 6 mm monocortical screws: Groups 1 and 2- Two conventional (G1) or locking (G2) screws were installed in each bone segment using either a conventional (G1) or a locking (G2) straight miniplate; Groups 3 and 4- Three conventional (G3) or locking (G4) screws were installed in the proximal segment and four conventional (G3) or locking (G4) screws were installed in the distal segment using a either a conventional (G3) or a locking (G4) 7-hole straight miniplate. The hemimandibles were loaded in compressive strength in an Instron machine until a 4-mm displacement occurred between the segments either vertically or horizontally. Data were analyzed statistically by ANOVA and Tukey’s test at 1% significance level. The locking plate/screw systems provided significantly greater resistance to displacement under compressive load than the conventional plate/screw systems (p<0.01). However, no statistically significant difference was found between 7-hole and 4-hole miniplates (p>0.01). In conclusion, the locking miniplates offered more resistance than conventional miniplates and long locking miniplates provided greater (number results) bone stability compared to short ones.
8

Surgical treatment of patients with displaced femoral neck fractures : aspects on outcome and selection criteria /

Blomfeldt, Richard, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.
9

The hip fracture epidemic : prevention and treatment strategies /

Stankewich, Charles J. January 1998 (has links)
Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [102]-108).
10

Comparação biomecânica e da redução óssea do Clamp and Rod Internal Fixation e placa de reconstrução bloqueada em fraturas de acetábulo / Comparação biomecânica e da redução óssea de Clamp and Rod Internal Fixation (CRIF) e placa de reconstrução bloqueada em fraturas de acetábulo

Bregadioli, Thales 19 April 2017 (has links)
Este estudo objetivou comparar, biomecanicamente, por meio dos ensaios de flexão destrutível e ciclagem, bem como a qualidade da redução óssea, após avaliação do molde da superfície articular de osteotomias centrais do acetábulo de cão fixadas com Clamp and Rod Internal Fixation (CRIF) 2,7 mm ou placa de reconstrução bloqueada 2,7 mm. Os implantes foram divididos em dois grupos, denominados grupo CRIF (GC) e grupo Placa (GP). Foram utilizadas nove pelves de cadáveres de cão com peso corporal entre 15 e 35 kg, posteriormente as pelves foram subdivididas em 18 hemipelves e distribuídas aleatoriamente para testar os dois implantes, um contralateral ao outro em uma mesma pelve. Para realização dos testes, foi simulado uma fratura central no acetábulo, por meio de osteotomia linear, realizada com auxílio de serra oscilatória e em seguida, fixadas segundo os padrões AO/SIF, sendo utilizados três parafusos craniais e dois caudais a osteotomia. Após comparação biomecânica de resistência máxima à flexão o GP (22,38&#177;8,44 N.m) demonstrou superioridade estatística em relação ao GC (15,60&#177;5,76 N.m), (p=0,02408). Na comparação do molde da superfície articular após 30 ciclos o GP (0,27 &#177; 0,24mm) demonstrou valores menores para lacuna da linha articular que o GC (0,49 &#177; 0,29mm), sendo o GP estatisticamente superior, (p=0,04784). Em conclusão, a aplicação da placa de reconstrução bloqueada é simples e deve ser considerada para redução de fraturas do acetábulo que necessitem de reconstrução anatômica. / The aim of this study was to compare the accuracy of reduction and biomechanical characteristics of acetabular osteotomies repaired with 2.7-mm Clamp and Rod Internal Fixation (CRIF) constructs or 2.7-mm locking reconstruction plates in cyclic and load to failure flexion tests. Nine dog cadavers with body weight between 15 and 35 kg were included in this study. All 18 hemipelves were randomly assigned into two groups named after the implants tested, group CRIF (GC) and group Plate (GP). All pelves were used to test both groups with each hemipelvis belonging to a different implant group. Acetabular osteotomies were created with an oscillatory saw and then fixed according to the AO/ASIF standards, using either 5-hole, 2.7-mm locking reconstruction plates with three locked screws cranial and two caudal to the osteotomy line, or CRIF constructs with 5 clamps, three located cranial and two caudal to the osteotomy line. Load to failure at GP (22.38 &#177; 8.44N.m) was significantly higher than GC (15.60 &#177; 5.76N.m), (p = 0.02408). Imprinted cast of acetabular reduction gap after 30 cycles was statistically smaller at GP (0.27 &#177; 0.24mm) than GC (0.49 &#177; 0.29mm) (p = 0.04784). We concluded that the appliance of locking reconstruction plates is simple and should be considered for acetabular fractures, that require perfect anatomical reconstruction.

Page generated in 0.0985 seconds