Estudio comparativo de la fijación con o sin cemento en Prótesis Total de Rodilla

Revisamos retrospectivamente una serie de 86 pacientes portadores de 110 prótesis totales modulares de rodilla colocadas como tratamiento de la gonartrosis. Se analizan los resultados obtenidos en los pacientes a los que se le realizó una fijación híbrida cementada (componente femoral no cementado y componente tibial y patelar cementado) respecto a los que se le realizó una prótesis de anclaje biológico sin ningún tipo de cementación. El análisis de la función clínica, movilidad de la rodilla, estudio radiológico y complicaciones de ambas series no demuestran diferencias significativas entre ambos grupos con un periodo de seguimiento de 45 meses (r=12-60).We have retrospectively review 86 patients with 110 total knee arthroplasty for the treatment of osteoarthrosis. We have analyzed the results obtained in a group of patients with partial fixation with cement and another group fixated without any cement. Clinical and radiological results and complications in both groups were similar without significant differences with an average follow-up of 45 months (12-60)

El enclavamiento encerrojado de Grosse-Kempf en el tratamiento de las fracturas diafisarias del fémur

Se presentan 50 fracturas diafisarias de fémur tratadas mediante enclavamiento endomedular encerrojado de Grosse-Kempf. Realizamos un estudio retrospectivo utilizando para la valoración del resultado la escala de Thorensen, que considera la existencia de callos viciosos radiológicos, la flexión de rodilla, la dismetría y la presencia de dolor e inflamación. El resultado a los 20 meses del tratamiento (12-27) es excelente en 32 casos, bueno en 13, regular en 4 y malo en 1. Creemos que este método de enclavamiento constituye un buen procedimiento para el tratamiento de este tipo de fracturas, especialmente de las fracturas conminutas de las zonas 2, 3, 4 y 5 de Wiss. La mayoría de los resultados regulares y malos son debidos a fallos en la técnica quirúrgica.We present 50 femoral shaft fractures treated by Grosse-Kempf intramedullary nailing. A retrospective study was performed by using the Thorensen scale for the evaluation of results. This scale takes into account different parameters such as radiological malposition, range of motion of the knee, shortening of the femur, pain, and swelling. Twenty months after treatment (range: 12-27), the results were excellent in 32 cases, good in 13, fair in 4 and poor in one. Grosse-Kempf nailing seems to be a good method for treating this type of fractures, particularly in conminuted fractures localized in the 2, 3, 4 and 5 Wiss's zones. The majority of fair and poor results are caused by errors in the surgical technique

Experiencia a medio plazo con prótesis total de rodilla semiconstreñida

Revisamos 25 prótesis totales de rodilla semiconstreñidas tipo Endo-Model Waldemar- Link implantadas en 23 pacientes con una edad media de 69,5 años y un seguimiento medio de 32 meses. Para la evaluación de los resultados clínicos hemos utilizado el protocolo de la Academia Americana en el que se incluyen los parámetros de: dolor, capacidad para la marcha, facilidad para subir y bajar escaleras, necesidad o no de bastones y flexoextensión de la articulación, tanto antes como después de la intervención. Asimismo hemos realizado un estudio radiológico de las prótesis en el que se ha valorado el centraje de los componentes protésicos en dos planos AP y L y las imágenes líticas periprotésicas. Los resultados obtenidos han sido satisfactorios observando en la totalidad de los pacientes una disminución del dolor y un aumento de su capacidad funcional. En ningún caso se han observado infecciones profundas de la prótesis. Se ha comprobado un aumento en el arco de flexión en las prótesis en que la punta del vástago femoral estaba desviada hacia la cortical anterior, sin que esto se acompañase de un déficit en la extensión.We have reviewed 25 total knee prosthesis (Endo-Model type, Waldemar-Link) performed in 23 patients with an age average of 69,5 years-old and a average follow-up of 32 months. The clinical assessment applied was the AAOS protocol including the parameters of: pain, ability to go up and down the stairs, to need of sticks, flexion and extension of the joint, before and after the operation. In the radiological study we have evaluated the correct alignment of the components in two planes A-P and L, and the periprosthetic lucencies. The results obtained have been satisfying in all the patients with a diminution of the pain and better function of the joint. No deep infection was observed and the flexion was better in prosthesis with anterior deviation of the femoral rod in the lateral plane

Coste energético en gonartrosis y prótesis total de rodilla

Se efectúa un estudio fisiológico del ejercicio en 15 pacientes con gonartrosis no intervenida, 15 portadores de PTR modular Press-fit y 15 portadores de PTR semicostreñida Link mediante el método de calorimetría indirecta con espirometría de circuito cerrado, comprobándose la influencia del dolor y la marcha en el consumo de oxígeno, siendo significativamente más bajo en los pacientes pendientes de colocación de una prótesis de rodilla y obteniendo mejor resultado clí- nico y energético en las prótesis totales de rodilla semiconstreñidas en relación a las modulares.By mean of calorimetric indirect method with spirometry of closed circle we carry out a physiologic study of the exercise in fifteen patients with arthritis of the knee, fifteen with total knee arthroplasty type Press-fit and fifteen with total knee arthroplasty type endomodel of Waldemar-Link. There was an influence of pain and gait in oxigen consume, being significantly lower in patients with arthritis of the knee without knee arthroplasty. The best clinic and energetic results were found in patients with knee arthroplasty type Waldemar-Link

Estudio de la marcha en pacientes tratados ortopédicamente de fractura unilateral del calcáneo

Veinticinco pacientes afectos de fractura unilateral desplazada articular de calcá- neo fueron tratados mediante inmovilización con yeso, siendo los resultados a los 6 años (rango: 3-10), excelentes en 5 pacientes, buenos en 4, regulares en 7 y malos en 9. De este grupo se excluyeron los afectos de patología local o general asociada, siendo útiles para el estudio de la marcha 12 pacientes a los que se les hizo deambular sobre plataformas dinamométricas para registrar la fuerza de reacción al suelo, demostrando una disminución de la fuerza vertical de apoyo y despegue (F1 y F3) y un aumento estadísticamente significativo del tiempo de apoyo total durante la marcha. Abogamos por la restitución anatómica del calcáneo como medio para mejorar la capacidad funcional del paciente.Twenty-five patients with unilateral displaced joint calcaneus fracture were treated by cast being the results after 6 years (range: 3-10), excellent in 5 patients, good in 4 patients, poor in 7 and bad in 9. We excluded for the study the patients with associated local or general pathology being useful for our study 12 patients. These patients walked on a dynamometric platform in order to analyse floor reaction forces, proving a diminuí ion of vertical support and takeoff forces (Fl and F2), and statistically significant a increase of total support phase during gait

Nuclear astrophysics with radioactive ions at FAIR

The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process, β-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Elastic scattering and total reaction cross sections for the (8)B, (7)Be, and (6)Li+(12)C systems

Angular distributions for the elastic scattering of (8)B, (7)Be, and (6)Li on a (12)C target have been measured at E(lab) = 25.8, 18.8, and 12.3 MeV, respectively. The analyses of these angular distributions have been performed in terms of the optical model using Woods-Saxon and double-folding type potentials. The effect of breakup in the elastic scattering of (8)B + (12)C is investigated by performing coupled-channels calculations with the continuum discretized coupled-channel method and cluster-model folding potentials. Total reaction cross sections were deduced from the elastic-scattering analysis and compared with published data on elastic scattering of other weakly and tightly bound projectiles on (12)C, as a function of energy. With the exception of (4)He and (16)O, the data can be described using a universal function for the reduced cross sections.Conselho Nacional de Pesquisa e Desenvolvimento (CNPq)Conselho Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)National Science Foundation NSF[PHY-0652591]National Science Foundation NSF[PHY-0969456]CONACYT (Mexico

Role of direct mechanism in two-nucleon T=0 transfer reactions in light nuclei using the (Li 6,α) probe

Background: Two-nucleon transfer reactions provide a unique tool to understand the correlation between nucleon pairs. Two-nucleon (pp, nn, and np) transfer reactions can occur via isoscalar (T=0, S=1) or isovector (T=1, S=0) processes. In particular, the isoscalar pair transfer can be induced by the (α,d) or (Li6,α) probes. In the past, most of the isoscalar np-transfer studies were performed with the (α,d) reaction, but this probe is strongly momentum mismatched with respect to other two-nucleon transfer reactions. Purpose: We aim to investigate the interplay between direct and sequential reaction mechanisms from the analysis of experimental (Li6,α) angular distributions in light targets. Method: Differential cross sections of (Li6,α) reactions at a beam energy of 20 MeV were measured with C12 and F19 targets. The interplay between direct and sequential transfer mechanisms in the experimental angular distributions was investigated with coupled-reaction-channels calculations. Results: The experimental angular distributions of isoscalar np transfer were compared with theoretical calculations assuming a direct or a sequential reaction mechanism. Direct np-transfer calculations describe successfully most of the angular distributions. The sequential transfer mechanism is about two orders of magnitude smaller than the direct process. Conclusions: The present results suggest a significant np correlation in the C12(Li6,α)N∗14 and F19(Li6,α)Ne∗21 reactions. Despite the relatively low cross section for the reactions with the asymmetric F19 target, the direct transfer mechanism remains dominant over the sequential process. Further studies including measurements with other asymmetric sd-shell nuclei will be required to fully understand the isoscalar and isovector np-transfer mechanism in this nuclear region.Fil: Zamora, J.C.. Universidade de Sao Paulo; BrasilFil: Ferreira, J.L.. Universidade Federal Fluminense; BrasilFil: Barioni, A.. Universidade Federal de Sao Paulo; BrasilFil: Cardozo, E.N.. Universidade Federal Fluminense; BrasilFil: Abriola, Daniel Hugo. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Arazi, Andres. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Assunção, M.. Universidade Federal de Sao Paulo; BrasilFil: de Barbará, Ezequiel. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Cardona, Maria Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Guimarães, V.. Universidade de Sao Paulo; BrasilFil: Hojman, Daniel Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Martí, Guillermo Virginio. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Mendes, D.R.. Universidade Federal Fluminense; BrasilFil: Pacheco, Alberto Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Pires, K.C.C.. Universidade de Sao Paulo; BrasilFil: Ramos, D.. Comisión Nacional de Energía Atómica. Gerencia del Área de Investigación y Aplicaciones No Nucleares. Gerencia Física (Centro Atómico Constituyentes). Proyecto Tandar; ArgentinaFil: Santos, O.C.B.. Universidade de Sao Paulo; BrasilFil: Lubian, J.. Universidade Federal Fluminense; Brasi