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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

Scaphoid variation and an anatomical basis for variable carpal mechanics

Fogg, Quentin A. January 2004 (has links)
The morphology and function of the wrist is poorly understood. Improved understanding of carpal anatomy may facilitate improved understanding of carpal mechanics and may enhance the clinical management of wrist dysfunction. Many detailed investigations of wrist structure have been reported, many of which have focussed on the scaphoid and its ligamentous supports. The results of these studies are not readily collated to provide an accurate description of the scaphoid and its supports. This study attempted to provide a detailed description of the anatomy of the scaphoid and its supporting structures. A detailed nomenclature was proposed to facilitate accurate description of the scaphoid and related structures. Gross observation enabled separation of the sample population of scaphoids into two groups. Morphometric analyses were used to determine any significant differences between the groups (type one and type two). The histological sections were then used to facilitate accurate gross identification of ligaments and computed tomographs were used to investigate the in situ variation of scaphoid orientation. The investigations suggest that two distinct populations of scaphoid existed within the sample population. The scaphoids varied in bone morphology, arrangement and degree of ligamentous support and position relative to the capitate. Articular facet shape and size differed between scaphoid types. The orientation and number of ligaments supporting the scaphoid were suggestive of variable scaphoid motion. The variation in ligamentous patterns was supported by histological investigation. Computed tomographs through the longitudinal axis of the scaphoid suggested a variable position of the scaphoid relative to the capitate. The variation of these structures was discussed in relation to the kinematic findings of others. A theoretical model of variable scaphoid function was proposed based on the anatomical findings. The data presented and the reviewed kinematic data may be extrapolated to suggest two models of scaphoid motion. The scaphoids may be divided into rotating/translating scaphoids and flexing/extending scaphoids. This must be confirmed by a combined anatomical and mechanical study. The clinical implications of different scaphoid structure and function may be profound. The ability to identify such differences in situ may facilitate varied clinical management for the various types of wrist suggested. / Thesis (Ph.D.)--Department of Anatomical Sciences, 2004.
2

Diagnóstico de necrose avascular em pacientes com pseudoartrose do escafoide : correlação dos exames de imagem pré-operatórios e achados intraoperatórios com o anatomopatológico / Scaphoid fracture nonunion : correlation of radiographic imaging (routine, CT, MRI), proximal fragment histologic viability evaluation, and estimation of viability at surgery

Bervian, Michel Roberto, 1979- 25 August 2018 (has links)
Orientador: Bruno Livani / Texto em português e inglês / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-25T16:03:28Z (GMT). No. of bitstreams: 1 Bervian_MichelRoberto_M.pdf: 4068927 bytes, checksum: bf1a7a79c46ef107971e898469875605 (MD5) Previous issue date: 2014 / Resumo: Objetivo: Realizar exames de imagem pré-operatórios, verificar a vascularização do segmento proximal do escafoide no intraoperatório e estabelecer correlações diagnósticas destes com o exame anatomopatológico. Justificativa: O diagnóstico pré-operatório do estado vascular do segmento proximal do escafoide é importante para o planejamento e direcionamento da escolha da técnica cirúrgica a ser utilizada. Métodos: Estudo experimental, prospectivo, caracterizado por ensaio não controlado. Os pacientes foram avaliados em relação à necrose do segmento proximal do escafoide em exames pré-operatórios (radiografia, tomografia computadorizada e ressonância nuclear magnética) e, no intraoperatório, no qual a condição vascular do segmento proximal do escafoide foi avaliada após sua perfuração, que demonstrou a presença ou não de sangramento. A ausência de sangramento estabelece como condição um segmento de necrose avascular ou esclerótico. Foi colhido material do segmento proximal e enviado para exame anatomopatológico, e os achados foram classificados em quatro tipos principais: viabilidade óssea, grau intermediário com maior ou menor viabilidade óssea e necrose completa. Foi utilizado o teste de qui-quadrado para testar a associação entre os achados dos exames de imagem e exame intraoperatório quando comparados com o exame de anatomopatológico. Resultados: Foram avaliados 19 pacientes do gênero masculino com diagnóstico de pseudoartrose do escafoide. Os resultados demonstraram que existe associação significativa entre a alteração radiográfica e a necrose óssea p<0,05 (0,026). A tomografia não apresentou associação significativa com o diagnóstico anatomopatológico da necrose do osso escafoide p>0,05 (0,125). A ressonância nuclear magnética mostrou que o hipossinal marcado em T1 apresentou correlação significativa com o diagnóstico anatomopatológico de necrose no segmento proximal do escafoide em todos os pacientes p<0,05 (0,002). Em 90% dos ossos considerados escleróticos na avaliação intraoperatória a necrose foi confirmada pelo exame anatomopatológico, e a associação foi significativa p<0,05 (0,003). Conclusão: Na pseudoartrose do escafoide, imagens de ressonância nuclear magnética com hipossinal de baixa intensidade marcado em T1 e ausência de sangramento no intraoperatório são fortes indicativos de necroseOsteonecrose do segmento proximal / Abstract: Background: The purpose of this study was to correlate the preoperative imaging, vascularity of the proximal pole, and histology of the proximal pole bone of established scaphoid fracture nonunions. Methods: This was a prospective observational study. Patients were evaluated preoperatively for necrosis of the proximal scaphoid fragment by radiography, computed tomography (CT) and magnetic resonance imaging (MRI). Vascular status of the proximal scaphoid was determined intraoperatively, demonstrating the presence or absence of puncate bone bleeding. Samples were harvested from the proximal scaphoid fragment and sent for pathological examination. We determined the association between the imaging and intraoperative examination and histological findings. Results: We evaluated 19 male patients diagnosed with scaphoid nonunion. CT evaluation showed no correlation to scaphoid proximal fragment necrosis. MRI showed a marked low signal intensity on T1-weighted, and the diagnosis of necrosis in the proximal scaphoid fragment was confirmed by the histology in all patients. Intraoperative assessment showed that 90% of bones had absence of intraoperative puncate bone bleeding, which was confirmed as necrosis by microscopic examination. Correlation between preoperative imaging, intraoperative findings and pathology was found in 41% of cases, with 26% for bone necrosis and 15% for viable bone. Conclusions: In scaphoid nonunion MRI images with marked low signal intensity on T1-weighted and the absence of intraoperative puncate bone bleeding are strong indicatives of osteonecrosis of the proximal fragment / Mestrado / Fisiopatologia Cirúrgica / Mestre em Ciências
3

Scaphoid fractures : Studies on diagnosis and treatment

Vinnars, Bertil January 2008 (has links)
<p>Scaphoid fracture is most common in young individuals of working age. Without adequate diagnosis and treatment, long-term results are poor. Operative treatment is being recommended increasingly often instead of a long time in cast, although there is no evidence-based support for its superiority.</p><p>The present thesis focuses on diagnostic problems and therapeutic consequences of acute scaphoid fractures and of scaphoid reconstruction when other treatments have failed.</p><p>Simultaneous plain radiographs and computed tomography were done in 97 injured wrists. Structural assessments of plain radiography images were highly predictive with respect to the risk of having a displaced or comminute fracture as diagnosed on computed tomography. Any finding of a gap or step-off > 0.5 mm, the presence of an intermediate fragment or a dorsal lunate tilt of ≥ 15° identified 81 % of fractures that were displaced or comminuted when investigated with computed tomography.</p><p>Eighty-three patients were randomly allocated to and received either nonoperative treatment in cast or operative treatment with the aim of assessing long-term outcome of the two treatment options. Fifty-two of the patients were occupationally active. From an occupational perspective with an early return to work, surgical treatment was superior in individuals with manual employment, and from a health economic perspective conservative treatment was superior in non-manual workers.</p><p>Patients treated for scaphoid fractures generally do well up to 13 years after the injury based on limb-specific outcome scores. No benefits were identified with operative treatment compared to non-operative treatment in cast. On the contrary, there was an increased risk for osteoarthritis in the scaphotrapezial joint in those who were operated.</p><p>The patient-rated long-term results of silicone implant arthroplasty were good, with pain relief and reasonable hand function in many patients up to 20 years after surgery.</p>
4

Scaphoid fractures : Studies on diagnosis and treatment

Vinnars, Bertil January 2008 (has links)
Scaphoid fracture is most common in young individuals of working age. Without adequate diagnosis and treatment, long-term results are poor. Operative treatment is being recommended increasingly often instead of a long time in cast, although there is no evidence-based support for its superiority. The present thesis focuses on diagnostic problems and therapeutic consequences of acute scaphoid fractures and of scaphoid reconstruction when other treatments have failed. Simultaneous plain radiographs and computed tomography were done in 97 injured wrists. Structural assessments of plain radiography images were highly predictive with respect to the risk of having a displaced or comminute fracture as diagnosed on computed tomography. Any finding of a gap or step-off &gt; 0.5 mm, the presence of an intermediate fragment or a dorsal lunate tilt of ≥ 15° identified 81 % of fractures that were displaced or comminuted when investigated with computed tomography. Eighty-three patients were randomly allocated to and received either nonoperative treatment in cast or operative treatment with the aim of assessing long-term outcome of the two treatment options. Fifty-two of the patients were occupationally active. From an occupational perspective with an early return to work, surgical treatment was superior in individuals with manual employment, and from a health economic perspective conservative treatment was superior in non-manual workers. Patients treated for scaphoid fractures generally do well up to 13 years after the injury based on limb-specific outcome scores. No benefits were identified with operative treatment compared to non-operative treatment in cast. On the contrary, there was an increased risk for osteoarthritis in the scaphotrapezial joint in those who were operated. The patient-rated long-term results of silicone implant arthroplasty were good, with pain relief and reasonable hand function in many patients up to 20 years after surgery.
5

Tratamento da pseudoartrose do escafoide = estudo comparativo entre o uso do exerto ósseo da extremidade distal do rádio vascularizado e não vascularizado / Treatment of scaphoid nonunion : comparative study of the use of vascularized and nonvascularized bone graft from the dorsal distal tip of the radius

Ribak, Samuel 09 March 2010 (has links)
Orientador: Maurício Etchebehere / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-16T21:07:49Z (GMT). No. of bitstreams: 1 Ribak_Samuel_D.pdf: 49523344 bytes, checksum: ed945eca0e5edfae363666a01c273fde (MD5) Previous issue date: 2010 / Resumo: Avaliaram-se os aspectos clínicos, funcionais e radiográficos de 86 pacientes portadores de pseudoartroses do escafoide. Comparam-se 46 pacientes submetidos à técnica de enxerto ósseo vascularizado dorsal do rádio distal, baseado na artéria suprarretinacular intercompartimental 1,2* (Grupo I), e 40 pacientes submetidos à cirurgia pela técnica de enxerto ósseo convencional não vascularizado da mesma região, rádio distal (Grupo II), objetivando definir o melhor procedimento quanto à consolidação e função. A amostra foi composta por 25 pseudoartroses no terço médio e 21 no polo proximal nos pacientes do Grupo I, e 22 no terço médio, duas no polo distal e 16 no polo proximal nos pacientes do Grupo II. No transoperatório, 30 escafoides foram considerados não vascularizados nos pacientes do Grupo I, e 20 nos pacientes do Grupo II. A estabilização do escafóide foi realizada por três fios de Kirschner e, no pós-operatório, todos os pacientes foram submetidos à imobilização com tala gessada antebraquiopalmar por quatro semanas. O tempo de seguimento médio pósoperatório foi de 24.4 meses (Grupo I), e de 21.7 meses (Grupo II). Conseguiu-se consolidação de 89.1% nos pacientes do Grupo I e tempo médio de consolidação de 9.7 semanas. Nos pacientes do Grupo II, houve consolidação em 72.5%, com tempo médio de 12 semanas. Os resultados funcionais do Grupo I foram satisfatórios em 72% dos pacientes e 57,5% no Grupo II. Concluímos que a técnica de enxerto ósseo vascularizado apresenta, quanto ao índice de consolidação e função, resultados superioresaos do procedimento não vascularizado, sendo mais eficiente quando a condição do polo proximal do escafoide é esclerótica / Abstract: The clinical, functional and radiographic aspects of 86 patients presenting with scaphoid nonunion were evaluated in this study. Forty-six patients undergoing the technique of vascularized bone graft from the dorsal distal radius, based on the 1, 2 intercompartmental supraretinacular artery (Group I), and 40 patients undergoing the technique of usual nonvascularized bone graft of the same area (distal radius) (Group II), are compared with the purpose of determining the best procedure concerning healing and function. Our sample comprised nonunions in 25 middle-third and 21 proximal-pole patients (Group I), and in 22 middlethird, 2 distal-pole, and 16 proximal-pole patients (Group II). Transoperatively, 30 scaphoids in Group I patients and 20 in Group II patients were considered sclerotic. Scaphoid stabilization was achieved with three K-wires and, postoperatively, and immobilization consisted of a short-arm cast for all patients for four weeks. The average postoperative follow-up time was 24.4 months for Group I, and 21.7 months for Group II. Healing was achieved in 89.1% of Group I patients, with an average healing time of 9.7 weeks. Within Group II, healing was achieved in 72.5% of patients, with an average healing time of 12 weeks. The functional results were satisfactory in 72% of Group I patients and 57.5% of Group II patients. We therefore conclude, from the healing and function indices, that the vascularized bone graft technique produces superior results than the nonvascularized bone graft procedure, being more efficient when the proximal pole of the scaphoid is sclerotic / Doutorado / Fisiopatologia Cirúrgica / Doutor em Ciências

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