Background: There is a relation between Hounsfield units obtained from computed tomography (CT) scans and bone density. The density of the bones can be used to establish its mechanical properties and therefore to assess the bone mechanical condition using CT images. Objectives: To identify the effect of the transfemoral amputation and the use of external lower limb prosthesis in the bone properties, by comparing Young’s modulus. Study Design: Young’s modulus comparison. Methods: Comparison of bone density between the healthy femur and the amputated bone of 20 unilateral transfemoral amputees was done by generating three histograms of the Hounsfield units at different parts of the femur. The histograms were created based on images obtained by CT and the Hounsfield units were translated to Young’s modulus to establish the comparison. Results: The results show a significant difference ( p-value <0.05) between the mean value of Young’s modulus of healthy and amputated bone. Conclusions: There is clearly a direct association between the use of external prosthesis and the bone demineralization due the stress shielding phenomenon. The Young’s modulus comparison using information from CT images can be a suitable tool to analyze the bone demineralization due to the use of exoprosthesis.
Background: Many finite element investigations have been made in the field of lower limb prosthetics; however, friction between bone and soft tissues as a boundary condition has not been considered. Objectives: To establish whether the change in the contact boundary condition between bone and soft tissues in a transfemoral amputee affects the stress-strain state on the residual limb. Study Design: Finite element analysis comparison. Methods: Finite element models of four transfemoral amputees were developed. In these models the socket, soft tissues and femur were included and two simulations were made for each model, in one of them the interaction between bone and soft tissues was defined as tied (there is no relative displacement between surfaces) and in the other it was defined as a friction boundary condition. Results: The von Mises stress and strain peaks are higher when the friction definition is used than for tied contact definition. The distribution pattern of stresses and strains also change when the contact definition varies from tied to friction. Conclusions: It was concluded that the friction between bone and soft tissues have a significant impact on the results of finite element models of lower limb prosthetic systems, and therefore in its predictive capabilities.
Clinical relevanceUnderstanding the bone-soft tissue interaction can lead to more realistic and accurate finite element models used to predict the stress-strain state in the residual limb of prosthetic users and therefore predict the occurrence of deep tissue injuries.
SALNH) y es el resultado del interés promovido en la sociedad para diseñar un conjunto de recomendaciones, simples, exhaustivas y sobre todo aplicables a la región acerca de la creación, cuidado y manejo de los accesos vasculares para pacientes en hemodiálisis; para ello se seleccionó la información con mayor sustento científico y que mejor se adapta a las necesidades de los pacientes. Este documento intenta poner al alcance de todos los profesionales de la salud y los pacientes las mejores opciones sobre el acceso vascular (AV) para hemodiálisis, desde su planeación, creación y vigilancia hasta la resolución de las complicaciones potenciales.
Pone foco en las infancias precarizadas de distintas generaciones; surge de la obligación de hacer visibles esos rostros otros, que dan cuenta de la humanidad de niños y niñas que han sido atravesadas por distintas formas de muerte y violencia (Butler, 2006;Levinas, 2001).Los modos y prácticas de precarización de las infancias, entendidas como vidas reducidas tanto en su dignidad como en sus capacidades humanas (Nussbaum, 2013), si bien producen siempre un efecto deshumanizante, varían en sus formas de materialización en las distintos territorios, espacialidades y temporalidades. El proyecto se realizó en un territorio rural, de población mestiza, afro e indígena, como es Urabá (noroccidente de Colombia, departamento de Antioquia), incluyendo sus centros poblados, que en las últimas décadas han vivido un proceso intenso de migración forzada de campesinos y otros migrantes -emigración e inmigración-, producido por la irrupción de grupos armados, tanto ilegales (narcotráfico, organizaciones delincuenciales) como legales, en el marco del conflicto armado colombiano. Según un informe de la Justicia Especial para la Paz (2022):El caso 04 estudia los hechos victimizantes ocurridos en diez municipios de Urabá: Turbo,
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