Esporotricose se constitui em micose intermediária, resultante do adentrar do fungo Sporothrix schenkii na pele ou no panículo. Trata-se de uma micose com características zoonóticas (sapro e antropozoonose). Objetivou-se: determinar a ocorrência de esporotricose-infecção ou esporotricose-doença, em felinos domésticos (domiciliados e querenciados), em animais de gatis de benemerência e daqueles felinos selvagens ou exóticos, mantidos em cativeiro, a partir do isolamento do fungo Sporothrix schenckii de decalques de garras em meio de cultivo. A amostragem foi composta por 132 felinos domésticos, selvagens ou exóticos. Da totalidade dos animais, 120 (91,0%) eram felinos domésticos, 11 (8,3%) selvagens e um exótico (0,7%). Segundo o sexo, 89 (67,4%) eram machos e os 43 (32,6%) restantes eram fêmeas. A maioria dos animais (80,3%) não apresentavam precisa definição racial, sendo que a média de idade foi de, aproximadamente, 71,8 meses. Vinte e um (17,5%) felinos eram querenciados. Da totalidade dos animais, 89 (67,4%) mantinham contato com outros animais da mesma espécie. Foi possível isolar o Sporothrix schenckii, das garras de um dos felinos investigados, com quadro generalizado de esporotricose. Os agentes, patógenos em potencial, Microsporum canis e Malassezia pachydermatis foram isolados, respectivamente, em 12,1% e 5,3% dos animais. Isolaram-se fungos anemófilos, reputados como contaminantes: Penicillium sp 28 (52,9%), Aspergillus sp 13 (24,5%), Rhodotorula sp cinco (9,4%), Candida sp cinco (9,4%), Trichoderma sp um (1,9%) e Acremonium sp um (1,9%). Pela magnitude de ocorrência (0,7%) de S. schenckii nas garras de felinos, o pressuposto potencial dos gatos, ora investigados, como possível fonte de infecção, na cidade de São Paulo, se mostrou bastante baixo. / Sporotrichosis is a subcutaneous mycosis, acquired through the skin and panniculus by the insertion of the Sporothrix schenckii fungus. It\'s a zoonotic mycosis (sapro and anthropozoonozis). The goals of this study were: to determine the occurrence of sporotrichosis infection or sporotrichosis disease in domestic felines (indoor and outdoor) cattery and wild or exotic in captivity, through the S. schenckii isolation from nail imprinting in culture media. The sample comprised 132 domestic, wild or exotic felines. From the total, 120 (91.0%) were domestic cats, 11(8.3%) wild and one exotic (0.7%). They were 89 (67.4%) males and 43 (32.6%) females. Most of animals (80.3%) were non-breed and the average age was 71.8 months. Twenty one (17,5%) felines lived outdoor. From the total 89 (67.4%) animals have had regular contact with other of the same species. It was possible to isolate the Sporothrix schenckii from the nails of an investigated one, with generalized sporotrichosis condition. The potencial pathogen, Microsporum canis and Malassezia pachydermatis agents, were isolated in 12.1% and 5.3% respectively. Air fungus, considered as contaminants, were isolated: Penicillium sp 28 (52,9%), Aspergillus sp 13 (24,5%), Rhodotorula sp five (9,4%), Candida sp five (9,4%), Trichoderma sp one (1,9%) e Acremonium sp one (1,9%). The low occurrence of S. schenckii (0.7%) in the feline nails, in this investigation, shows it with a small probability as a source of infection in the city of São Paulo.

INTRODUÇÃO: Onicomicose é a infecção fúngica das unhas e é considerada a onicopatia mais frequente em adultos. Representa até 50% das lesões ungueais, sendo necessária confirmação diagnóstica com exame complementar que demostre a presença do fungo na unha, sendo o exame micológico direto e a cultura para fungos os mais utilizados. A dermatoscopia é um exame não invasivo, rápido e de baixo custo cujos padrões para onicomicose relatados na literatura em estudos retrospectivos chegam a 100% de sensibilidade e especificidade. Deste modo realizamos um estudo prospectivo para comparar a dermatoscopia frente ao exame micológico. MÉTODOS: Estudo prospectivo, transversal avaliando 109 pacientes e 202 unhas com suspeita diagnóstica de onicomicose. Os padrões dermatoscópicos encontrados foram descritos através de fotografias digitais. A sensibilidade e especificidade dos padrões de onicomicose distal-lateral foram determinados de acordo com o resultado do exame micológico. RESULTADOS: Foram significativos (p < 0,05) para o diagnóstico de onicomicose distal lateral e tiveram sensibilidade/especificidade calculadas os padrões: borda recortada (80,2% / 65,3%), borda linear (12,6% / 42,9%), estrias irregulares (81,1% / 65,3%), estrias finas/regulares (9,9% / 59,2%); e as cores branco (93,7% / 18,4%), amarelo (63,1% / 71,4%) e laranja (10,8% / 100%). Após análise multivariada stepwise forward os padrões de estrias irregulares, borda linear e cor amarela mantiveram significância estatística (p < 0,05). DISCUSSÃO: Os achados deste trabalho prospectivo estão de acordo com a literatura mostrando que há correlação entre o exame micológico e a dermatoscopia. Todavia, não ratifica a sensibilidade e especificidade de 100% encontrada em estudo retrospectivo para os padrões de borda recortada e borda linear. Também não demonstrado na literatura, as cores amarela, branca e laranja foram também estatisticamente significativas para o diagnóstico. CONCLUSÃO: A dermatoscopia correlaciona bem com a história natural da infecção fúngica e com o exame micológico, sendo um exame promissor para o diagnóstico de onicomicose. Sugerimos que futuros estudos comparem a dermatoscopia com exames considerados padrão-ouro (ex: microscopia de fluorescência e PCR) para detectar exames falso negativos / BACKGROUND: Onychomycosis is defined as a fungal infection of the nail and is considered the most common onychopathy in adults. It represents up to 50% of nail diseases and demonstration of the fungal pathogen is necessary for diagnostic confirmation. Direct mycological examination and fungal culture are commonly used for this purpose. Dermoscopy is a noninvasive, fast and inexpensive exam, reaching 100% diagnostic sensitivity and specificity for onychomycosis in retrospective studies. Thus, we conducted a prospective study to compare dermoscopy with mycological examination. METHODS Prospective, cross-sectional study with 109 patients and 202 nails evaluated. Dermoscopic patterns were described using digital photography and their sensitivity and specificity for distal-lateral onychomycosis were determined. RESULTS: Statistically significant (p < 0.05) patterns and colors for the diagnosis of distal-lateral onychomycosis and respective sensitivity / specificity: jagged edge (80.2% / 65.3%), linear edge (12.6% / 42 , 9%), longitudinal irregular streaks (81.1% / 65.3%), longitudinal fine / regular streaks (9.9% / 59.2%); white color (93.7% / 18.4%), yellow color (63.1% / 71.4%) and orange color (10.8% / 100%). After a stepwise forward multivariate analysis irregular streaks, linear edge and yellow color remained statistically significant (p < 0.05). DISCUSSION: Findings of this prospective study are in agreement with the literature showing that there is correlation between mycological examination and dermoscopy. However, this study does not agree with 100% sensitivity and specificity found in retrospective studies for jagged edge and linear edge patterns. In addition, white, yellow and orange colors were also statistically significant for the diagnosis of onychomycosis. CONCLUSION: Dermoscopy correlates well with the natural history of fungal nail infection and mycological examination, and we consider it a promising method for the diagnosis of onychomycosis. We suggest that future studies compare dermoscopy with a gold standard exam (ex: fluorescence microscopy, PCR) to detect false negative cases

Onicomicose é uma infecção crônica das unhas provocadas por fungos. É a doença mais comum das unhas em todo o mundo e constitui cerca de metade de todas as alterações ungueais em indivíduos imunocompetentes e imunossuprimidos. Nos últimos anos, vários estudos tem demonstrado aumento na prevalência de onicomicose. Esse aumento pode ser atribuído a diversos fatores, incluindo o aumento da expectativa de vida, e propagação do vírus da imunodeficiência humana (HIV). Nesse sentido, o número de pacientes renais crônicos vem aumentando em todo mundo. No entanto, a literatura relata poucos estudos sobre a prevalência e as características das onicomicoses nestes pacientes. Diante disso, nossos objetivos foram determinar a prevalência, etiologia e perfil de suscetibilidade das onicomicoses provenientes de pododáctilos de pacientes dialíticos (DL), receptores de transplante renal (RTR) e pacientes grupo controle. Foram examinados 510 pacientes, sendo 336 provenientes da Unidade de Transplante Renal (149 DL e 187 RTR), e 174 pacientes do Ambulatório de Clínica Geral, sem histórico de doença associada à imunossupressão (Grupo controle). Os isolados foram identificados por testes fenotípicos e moleculares. O perfil de suscetibilidade foi realizado pelo método de microdiluição em caldo frente aos fármacos fluconazol, itraconazol, voriconazol e terbinafina. A prevalência de onicomicose foi de 23,4% nos pacientes DL e 23,0% nos RTR, significativamente maior que no grupo controle (13,2%). Nos pacientes DL, onicomicose foi associada com diabetes, mas não com o tempo de diálise e sexo. Nos pacientes RTR, onicomicose foi mais prevalente em homens, mas não houve associação com duração do transplante, diabetes e protocolo de tratamento imunossupressor. Trichophyton rubrum foi a agente mais prevalente (45,9%), seguido por T. mentagrophytes (24,5%) e Candida parapsilosis (18%). Todos antifúngicos foram eficazes frente aos isolados de dermatófitos, sendo terbinafina o mais eficiente. Os isolados de C. parapsilosis foram todos sensíveis aos quatro antifúngicos de acordo com os atuais \"end-points\". Nossos achados permitiram concluir que pacientes renais (DL e RTR) tem risco aumentado de desenvolver onicomicose. Nossos dados também revelaram que a etiologia e a suscetibilidade das espécies isoladas são comparáveis aos encontrados em outros grupos de pacientes não renais descritos na literatura. / Onychomycosis is a chronic fungal infection of the nail. It is the most common disorder of nails worldwide and constitutes about 50% of all nail changes of the immunosuppressed and healthy patients. In recent years, several reports have shown increased prevalence of onychomycosis. This increase can be attributed to several factors, including increased life expectancy, and to the human immunodeficiency virus (HIV) epidemics. In this regard, the number of chronic renal patients is also increasing worldwide. However, the literature reports few studies on onychomycosis in these patients. Therefore, our objectives were to determine the prevalence, etiology and susceptibility profile of onychomycosis of the toenail of patients undergoing hemodialysis treatment (HD), kidney transplant recipients (KTR) and control patients. Were examined 510 patients, 336 attending the Renal Transplantation Unit (187 KTR e 149 HD) and 174 patients attending an internal medicine outpatient service with diseases other than renal disease (control group). The isolates were identified by phenotypic and molecular tests. Antifungal susceptibility tests were performed using a broth microdilution method against the antifungal drugs voriconazole, itraconazole, fluconazole and terbinafine. The prevalence of onychomycosis in HD patients (23.4%) and KTR (23.0%) was significantly higher than control group (13.2%). In HD patients, onychomycosis was associated with diabetes but not duration of dialysis and gender. In KTR, onychomycosis was more prevalent in males, but not associated with duration of transplantation, diabetes or immunosuppressive protocols. Trichophyton rubrum was the most prevalent species (45.9%) followed by T. mentagrophytes (24.5%) and Candida parapsilosis (18%). While all antifungals were efficient against the dermatophyte isolates, terbinafine was the most effective. All C. parapsilosis isolates were sensitive to the antifungals according to the current end-points. In conclusion, this study shows that HD patients and KTR are at high risk of contracting onychomycosis. Our data also show that the etiology and susceptibility of the species are comparable with those found in other groups of non-renal patients described in the literature.

Avaliou-se a influência da exposição ao flúor (F) através da água de beber, da velocidade de crescimento das unhas, da idade e do gênero na concentração deste elemento nas unhas das mãos e dos pés. Em adição, verificou-se a correlação entre as concentrações de F na saliva total, saliva do ducto da parótida e unhas das mãos e dos pés. Participaram do estudo 300 indivíduos, das faixas etárias de 3-7,14-20, 30-40 e 50-60 anos, residentes de cinco comunidades brasileiras, sendo duas no Estado de São Paulo (Pirajuí e Bauru, com água não fluoretada e 0,7 mgF/L na água de abastecimento, respectivamente) e três no Estado da Paraíba (Cajazeirinhas, Brejo dos Santos e Brejo das Freiras, com 0,2, 0,7 e 1,7 mgF/L na água de consumo, respectivamente). Foram coletadas duas ou três (apenas em Bauru) amostras de água de beber, além de duas amostras de: unhas dos pés, unhas das mãos, saliva total e saliva do ducto da parótida de cada indivíduo. O F nas amostras foi analisado com eletrodo íon-específico. Os dados obtidos foram analisados estatisticamente através de análise de variância e regressão linear (p<0,05). A exposição ao F através da água de beber, a velocidade de crescimento das unhas, a idade e o gênero influenciaram a concentração de F nas unhas das mãos e dos pés, sendo que o fator de exposição ao F através da água foi o que exerceu maior influência pelo modelo de regressão linear adotado. As unhas dos pés (R2=0,46) se mostraram melhores indicadoras de exposição ao F do que as das mãos (R2=0,24). Foi encontrada uma correlação negativa significativa entre velocidade de crescimento das unhas e concentração de F nas mesmas. Houve correlação positiva significativa entre concentração de F nas unhas das mãos e dos pés com: saliva total (r=0,36 e r=0,41) e saliva do ducto da parótida (r=0,25 e r=0,53), respectivamente. Também se observou correlação positiva entre saliva total e do ducto da parótida (r=0,24), bem como entre concentração de F na água e saliva total (r=0,41) e saliva do ducto (r=0,65). Todos os fatores testados influenciaram os níveis de F nas unhas e, portanto, devem ser levados em consideração quando se utiliza este marcador biológico. / The influence of fluoride (F) concentration in the drinking water, nails growth rate, age and gender upon the F content in fingernail and toenail were evaluated. In addition, the correlations among the F concentrations in whole saliva, parotid ductal saliva and finger/toenails were verified. Three hundred volunteers of 3-7, 14-20, 30-40, 50-60 years participated. They were residents of five Brazilian communities, two in Sao Paulo State (Pirajuí and Bauru, non-fluoridated and 0.7 mgF/L artificially fluoridated drinking water, respectively) and three in Paraiba State (Cajazeirinhas, Brejo dos Santos and Brejo das Freiras, 0.2, 0.7 and 1.73 mgF/L naturally fluoridated drinking water, respectively). Two or three samples of drinking water, and two samples of fingernails, toenails, whole saliva and ductal saliva were collected from each volunteer, with one-week interval period between the collections. F in water, whole saliva, ductal saliva and nails was determined using the ion-sensitive electrode. Data were analyzed by ANOVA and linear regression (p<0.05). The F exposure from the drinking water, nails growth rate, age and gender influenced the levels of F in fingernails and toenails. Considering the model of multivariate linear regression adopted, F exposure from the water influenced the most. Toenails (R2=0.46) seemed to be better indicators of F than fingernails (R2=0.24). It was found a significant negative correlation between nails growth rate and their content of F. Positive correlations were found between F concentration in fingernails and toenails and: F concentration in whole saliva (r=0.36 and r=0.41) and in parotid ductal saliva (r=0.25 and r=0.53), respectively. Moreover, it was observed a positive correlation between whole and parotid saliva (r=0.24), as well as between F concentration in the drinking water and whole (r=0.41) and parotid saliva (r=0.65). All factors that influenced nails F concentration must be taken into account when using them as biological markers.

INTRODUÇÃO: Onicomicose é a infecção fúngica das unhas e é considerada a onicopatia mais frequente em adultos. Representa até 50% das lesões ungueais, sendo necessária confirmação diagnóstica com exame complementar que demostre a presença do fungo na unha, sendo o exame micológico direto e a cultura para fungos os mais utilizados. A dermatoscopia é um exame não invasivo, rápido e de baixo custo cujos padrões para onicomicose relatados na literatura em estudos retrospectivos chegam a 100% de sensibilidade e especificidade. Deste modo realizamos um estudo prospectivo para comparar a dermatoscopia frente ao exame micológico. MÉTODOS: Estudo prospectivo, transversal avaliando 109 pacientes e 202 unhas com suspeita diagnóstica de onicomicose. Os padrões dermatoscópicos encontrados foram descritos através de fotografias digitais. A sensibilidade e especificidade dos padrões de onicomicose distal-lateral foram determinados de acordo com o resultado do exame micológico. RESULTADOS: Foram significativos (p < 0,05) para o diagnóstico de onicomicose distal lateral e tiveram sensibilidade/especificidade calculadas os padrões: borda recortada (80,2% / 65,3%), borda linear (12,6% / 42,9%), estrias irregulares (81,1% / 65,3%), estrias finas/regulares (9,9% / 59,2%); e as cores branco (93,7% / 18,4%), amarelo (63,1% / 71,4%) e laranja (10,8% / 100%). Após análise multivariada stepwise forward os padrões de estrias irregulares, borda linear e cor amarela mantiveram significância estatística (p < 0,05). DISCUSSÃO: Os achados deste trabalho prospectivo estão de acordo com a literatura mostrando que há correlação entre o exame micológico e a dermatoscopia. Todavia, não ratifica a sensibilidade e especificidade de 100% encontrada em estudo retrospectivo para os padrões de borda recortada e borda linear. Também não demonstrado na literatura, as cores amarela, branca e laranja foram também estatisticamente significativas para o diagnóstico. CONCLUSÃO: A dermatoscopia correlaciona bem com a história natural da infecção fúngica e com o exame micológico, sendo um exame promissor para o diagnóstico de onicomicose. Sugerimos que futuros estudos comparem a dermatoscopia com exames considerados padrão-ouro (ex: microscopia de fluorescência e PCR) para detectar exames falso negativos / BACKGROUND: Onychomycosis is defined as a fungal infection of the nail and is considered the most common onychopathy in adults. It represents up to 50% of nail diseases and demonstration of the fungal pathogen is necessary for diagnostic confirmation. Direct mycological examination and fungal culture are commonly used for this purpose. Dermoscopy is a noninvasive, fast and inexpensive exam, reaching 100% diagnostic sensitivity and specificity for onychomycosis in retrospective studies. Thus, we conducted a prospective study to compare dermoscopy with mycological examination. METHODS Prospective, cross-sectional study with 109 patients and 202 nails evaluated. Dermoscopic patterns were described using digital photography and their sensitivity and specificity for distal-lateral onychomycosis were determined. RESULTS: Statistically significant (p < 0.05) patterns and colors for the diagnosis of distal-lateral onychomycosis and respective sensitivity / specificity: jagged edge (80.2% / 65.3%), linear edge (12.6% / 42 , 9%), longitudinal irregular streaks (81.1% / 65.3%), longitudinal fine / regular streaks (9.9% / 59.2%); white color (93.7% / 18.4%), yellow color (63.1% / 71.4%) and orange color (10.8% / 100%). After a stepwise forward multivariate analysis irregular streaks, linear edge and yellow color remained statistically significant (p < 0.05). DISCUSSION: Findings of this prospective study are in agreement with the literature showing that there is correlation between mycological examination and dermoscopy. However, this study does not agree with 100% sensitivity and specificity found in retrospective studies for jagged edge and linear edge patterns. In addition, white, yellow and orange colors were also statistically significant for the diagnosis of onychomycosis. CONCLUSION: Dermoscopy correlates well with the natural history of fungal nail infection and mycological examination, and we consider it a promising method for the diagnosis of onychomycosis. We suggest that future studies compare dermoscopy with a gold standard exam (ex: fluorescence microscopy, PCR) to detect false negative cases

<p>Primates and many other animals that move in an arboreal environment often cling, sometimes for long periods, on vertical supports. Primates, however, face a special challenge in that almost all primates bear nails on the tips of their digits rather than claws. Squirrels and other arboreal animals possess claws and/or adhesive pads on their digits in order to hold their weight on vertical substrates. Assuming the ancestral primate was arboreal and lost claws prior to the radiation of primates this paradox has important implications and raises a significant question about living primates and early primate evolution: how can primates maintain vertical postures without claws and how did early primates meet this challenge? Primate vertically clinging and grasping postures (VCG) have been studied in the wild and theoretical models of VCG postures have been described. This dissertation builds on this work, by studying the biomechanics of VCG postures in primates. Based on mechanical models, it was hypothesized VCG posture in primates will vary in three ways. </p><p>Hypothesis 1: Species with different morphological features associated with different locomotor modes will vertically cling and grasp in different ways. </p><p>Hypothesis 2: As substrate size increases, primates will place their arms to the side of the support and adjust posture and muscle recruitment in order to maintain a necessary tangential to normal force ratio to resist gravity. </p><p>Hypothesis 3: On substrates of the same relative size, larger animals should be less effective at maintaining VCG postures due to scaling relationships between muscle strength and body mass. </p><p>The sample consisted of multiple individuals from eight strepsirrhine species at the Duke Lemur Center. The sample varied in locomotor mode--habitual vertical clinging and leaping (VCL) compared to less specialized arboreal quadrupeds--and body mass--100 to 4,000 grams. Subjects were videorecorded while holding VCG postures on substrates of increasing size. Substrate preference data were calculated based on frequency and duration of VCG postures on each substrate. Qualitative kinematic data were recorded for a maximum of thirty trials per individual, per substrate. Angular data were calculated for forelimbs and hindlimbs from these videos for ten trials per individual per substrate. In addition, kinetic data from an imbedded force transducer were collected for two species that vary in locomotor mode, but not body mass. </p><p>There are several significant and relevant results from this study that address both primate functional anatomy and locomotor evolution. Hypothesis one was supported by hand and hindlimb joint postures, shown to be highly sensitive to locomotor mode. VCL primates exhibited deeply flexed limbs and more hand grasping (wrapping around the substrate) versus parallel hand postures and use of bowed finger postures compared to less specialized primates. Kinetically, species were shown to bear the majority of their weight in their hindlimbs relative to their forelimbs. The forelimb joints and foot showed little variation by habitual locomotor mode. Hypothesis two found support in that species tend to prefer smaller substrates, clinging less frequently for shorter durations as substrate size increases. Hand posture changed as size increased, as primates (except for the slow lorises) in this study grasped with their pollex on smaller substrates, but the pollex disengaged in grasping on larger substrates. Hypothesis three was not supported; body mass did not influence VCG postures. </p><p>Taken together, the finding that the forelimb held a wide range of postures on each substrate size for all species and played a limited role in weight-bearing suggests the forelimb free to move (to adjust posture and or forage). The hindlimb plays a more specific role in weight-bearing and is more sensitive to variations in primate anatomy. Additionally, these findings lead to hypotheses concerning the relatively short pollexes of primates, and that the ancestral primate was smaller than 100g and preferred small substrates as found in a fine-branch niche.</p> / Dissertation

In a 6-week rat model it was demonstrated that a small dose of peri-implant zoledronic acid (ZA) increased local bone formation 3-fold compared with controls. Ancillary in vitro studies using 14C-labeled ZA implant doses demonstrated biphasic elution profiles for implants coated with hydroxyapatite; complete ZA release occurred within one to three weeks in serum compared with only 60% ZA release after 12 weeks in water. Implants without hydroxyapatite coating showed more burst-type release profiles and full ZA elution within 24 hours of hydration in serum or water. Canine studies at 6 weeks using implants with 14C-labeled ZA showed that the compound remained localized, with the greatest ZA concentration immediately adjacent to the implant. Although there was evidence of skeletal ZA distribution via diffusion into the circulation, the levels were two orders of magnitude less than at the implant site.

An intramedullary nail is a trauma treatment device used for fracture fixation of long bones. These devices are subject to failure, including lag screw cut-out and failure at the lag screw insertion hole from high stress concentrations in that region. Clinical developments for such devices are frequently based on a trial and error method, which often results in failure before improvement. However, the finite element method can be used for the development of trauma treatment devices, and their interaction with bone, by providing a large data set at a relatively low cost. Also, parameters can be changed to assess the relative benefits of one device to another. A novel finite element model has been developed that can be used for the analysis of intramedullary nails inserted into long bones. A commercially available finite element package, ANSYS, has been used to implement the modelling strategy. The finite element modelling technique has been applied to fractures of the proximal femur, but the model is generic, and can be developed to deal with any form of intramedullary device where contact between the bone and implant is important. The finite element strategy can be used in pre-clinical trials to test a new device, or for the design optimisation of existing devices. The finite element model consists of the device surrounded by a thin layer of bone, which forms a 'base' model component that is re-usable. This 'base' component can be mathematically connected to any long bone model, forming an integrated implant and bone construct. The construct can be used to assess which device is best suited to a particular fracture, for example. Contact elements have been used to allow stresses to develop as contact is achieved within the implant and bone construct. Pre-assignment of contact points is not required. Verification of the finite element model is achieved by comparison to available data from experiments carried out on constructs of bone and device that use intramedullary femoral nails. In this thesis the finite element model has been applied to two areas of proximal femoral nailing. The finite element model is used to analyse the distal end of a Gamma nail, and shows that analyses that do not consider contact may not lead to accurate predictions of stresses. The model has been developed for using configurations with one and two distal locking screws. The most distal locking screw is more critical under axial loading, and the more proximal screw is more important for bending loads. The use of 'softer' screws distributes the load more evenly between them. The finite element model has been used to investigate the mechanical environment of a fracture callus for a femoral neck fracture, and a subtrochanteric fracture. The use of one and two lag screws, fracture gap size and material properties of the nail have been investigated for a stiffening callus. Results show that the use of two lag screws for a neck fracture provides a more rigid support at the early stages of fracture healing, and minimises stress-shielding once the callus has healed. For subtrochanteric fractures there is a critical point at which the fracture callus is able to carry any load. A Titanium nail significantly reduces the peak stress at the lag screw insertion hole, and titanium lag screws share the load more evenly between them. Each two-lag-screw configuration used transfers a similar load into the fracture callus. A configuration using a larger lag screw above a smaller has a significantly higher stress at the upper lag screw insertion hole. Critically, the load shared between two lag screws changes as the fracture callus stiffens and an assessment should be made at different stages of fracture healing to optimise the use of a device.

Thesis (Ph.D.) -- University of Western Sydney, 2001. / Bibliography : leaves 201-208.

Thesis (Ph. D.)--Oregon State University, 2004. / Typescript (photocopy). Includes bibliographical references. Also available via the World Wide Web.