954 resultados para Subtalar joint, Cadaver study, Ankle instability, Ligament injury


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INTRODUCTION: Basketball is characterized with high injury rate. In the literature it's not defined whether or not there are differences between the sexes. OBJECTIVE: Characterize and analyze the incidence of athletic injuries in basketball players, comparing the sexes. MATERIALS AND METHODS: Fifteen under-23 category athletes of each sex were interviewed with the reported morbidity inquire. RESULTS: The age of the female and male teams, in average, was 18 ± 0.65 and 18.20 ± 1.57 years respectively. The male team had more injuries than the female one (respectively 2.6 ± 1.45 against 1.2 ± 1.18, p < 0.05). The joint damage was the most common injury in the male team, representing 58.97%, and the second most common in the female team (33.33%). The lower limbs were the most common injured sites (80.95% in the female and 69.23% in the male). The most frequent injury mechanism in the male team was the landing (43.59%), and in the female was the vertical jump (28.57%). In both teams the most injuries occurred during the training (61.9% in the female and 71.8% in the male). The absence was necessary in 47.62% (female) and 56.41% (male). Great part of the athletes didn't received any treatment (61.9% and 51.28% in the female and male team respectively). The return to the activities was mostly symptomatic, in both female and male team (85.71% and 84.62% respectively). CONCLUSION: The incidence of injuries in basketball is higher in the lower limbs. The male team is more likely to suffer injuries, and the main injury mechanisms were different between male and female team.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Introdução: vários fatores estão associados à lesão de isquemia fria (IF) e referfusão quente (RQ) no transplante hepático (TxH), tais como infiltrado de neutrófilos e linfo-plasmocitário, liberação de citoquinas inflamatórias e apoptose. Porém, pouco se conhece sobre o papel da IF/RQ em enxertos esteatóticos. Objetivo: avaliar o papel da lesão de IF/RQ no TxH em humanos comparando enxertos esteatóticos e não esteatóticos. Métodos: entre maio/02 e março/07 foram realizadas 84 biópsias pós reperfusão (2hs após RQ) e 18 pré reperfusão, totalizando-se 84 TxH em 82 pacientes. As biópsias foram agrupadas em 5 grupos, de acordo com o grau de macro e microesteatose: GEL – leve (<30%), GEM – moderada (30-59%), GEG - grave (≥60%), GEA - sem esteatose, GPR-pré-reperfusão. Nas 102 biópsias foram analisadas: porcentagens de macro e microesteatose, graus de exudato de neutrófilos (0-3) e infiltrado linfo-plasmocitário portal (0-3), índices de apoptose (métodos de Túnel e Caspase- 3) e de ICAM-1. As esteatoses macro (n=49) e microvesicular (n=74) foram individualmente analisadas e classificadas em graus leve (G1), moderado (G2) e grave (G3) e ausente (G4). Resultados: o índice de apoptose (TUNEL) foi: GEL=0.262±0.111, GEM=0.278±0.113, GEG=0.244±0.117, GEA=0,275±0.094 e GPR=0.181±0.123, p-0.07. No grupo macroesteatose índice de apoptose (TUNEL) foi: G1=0.284± 0.106, G2+3=0.160±0.109, G4=0,275±0.094, p-0.05; e no grupo microesteatose, G1=0.222±0.123, G2+3=0.293±0.108, G4=0.275±0.094, p-0.049. O GEG expressou o ICAM-1 em 83% dos casos de forma difusa. Não existiu diferença estatística entre os grupos ao analisarmos os índices de apoptose (caspase-3) e ICAM-1. Conclusão: o GEG e o grupo macroesteatose (moderado e grave) apresentaram significante redução no índice de apoptose, enquanto o grupo microesteatose (moderado e grave), significante aumento. E o GEG apresentou expressão de ICAM-1 difusamente, podendo ser estes marcadores envolvidos na lesão de I/R hepática dos enxertos esteatóticos.

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Gegenstand der Arbeit: Die distale Radiusfraktur ist der häufigste Bruch des Menschen. Neben etablierten Verfahren wie der dorsalen und palmaren Plattenosteosynthese gibt es seit Kurzem neuartige minimalinvasive Osteosynthesesysteme. Gegenstand der vorliegenden Arbeit ist die Untersuchung der biomechanischen Stabilität von zwei neuartigen Implantaten für die distale extraartikuläre Radiusfraktur. rnMethodik: Es handelt sich einerseits um das System XSCREW (Zimmer, Freiburg i. Br., Deutschland), eine kanülierte Schraube, die über den Processus styloideus eingeführt wird und mit bis zu neun Bohrdrähten im Knochen fixiert werden kann. Das Vergleichsimplantat DorsalNailPlate (HandInnovations, Miami, Florida, USA) ist ein Hybrid aus einer dorsalen Platte und einem Marknagel. Beide Systeme wurden an 8 paarigen frischen unfixierten Leichenradii unter Axialbelastung bis 100 N und Torsionsbelastung bis 1,5 Nm getestet. Die A3-Fraktur wurde durch eine standardisierte Keilosteotomie simuliert. Das Biomaterial wurde prä- und postinterventionell sowie nach einem Dauerbelastungstest unter 1000 Zyklen in Rotation mit 0,5 Hz untersucht. Ein Versagenstest mit steigendem Drehmoment beendete das Experiment. rnErgebnisse: Die XSCREW erreichte eine Axialsteifigkeit von 136 N/mm und eine Torsionssteifigkeit von 0,16 Nm/°. Die DNP erzielte hingegen axial 70 N/mm und torsional 0,06 Nm/°. Der Unterschied zwischen beiden Verfahren war nur für die Torsion eindeutig statistisch auffällig (p=0,012), jedoch nicht für die Axialsteifigkeit (p=0,054). Die ursprüngliche Axial- und Torsionssteifigkeit wurde durch die XSCREW signifikant besser wiederhergestellt als durch die DNP (p=0,012). Beide Verfahren erzielten nach der Intervention signifikant niedrigere Steifigkeiten als die intakten Knochen (p=0,012). Ein Präparat der DNP-Gruppe und vier Präparate der XSCREW-Gruppe überstanden den Dauerbelastungstest. Das Drehmoment bei Versagen war mit der XSCREW höher als mit der DNP, der Unterschied zwischen den Verfahren war signifikant (p=0,043). Die Schwachstellen beider Systeme lagen vorwiegend in der proximalen Verankerung im Knochen. Kirschner-Drähte bzw. Verriegelungsschrauben führten unter andauernder Belastung zu einer Spaltung der Kortikalis im Schaftbereich. Bedingt durch die Ausrichtung der distalen Verriegelungen können mit beiden Implantaten Schäden an der radiocarpalen bzw. radioulnaren Gelenkfläche entstehen. rnZusammenfassung: Die XSCREW ermöglicht insgesamt eine höhere mechanische Stabilität als die DNP. Beide Verfahren sind jedoch einer winkelstabilen palmaren Plattenosteosynthese insbesondere unter rotatorischer Dauerbelastung unterlegen und erreichen nicht die Stabilität eines anderen neuartigen minimalinvasiven Systems.

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BACKGROUND: Local anaesthetic blocks of the greater occipital nerve (GON) are frequently performed in different types of headache, but no selective approaches exist. Our cadaver study compares the sonographic visibility of the nerve and the accuracy and specificity of ultrasound-guided injections at two different sites. METHODS: After sonographic measurements in 10 embalmed cadavers, 20 ultrasound-guided injections of the GON were performed with 0.1 ml of dye at the classical site (superior nuchal line) followed by 20 at a newly described site more proximal (C2, superficial to the obliquus capitis inferior muscle). The spread of dye and coloration of nerve were evaluated by dissection. RESULTS: The median sonographic diameter of the GON was 4.2 x 1.4 mm at the classical and 4.0 x 1.8 mm at the new site. The nerves were found at a median depth of 8 and 17.5 mm, respectively. In 16 of 20 in the classical approach and 20 of 20 in the new approach, the nerve was successfully coloured with the dye. This corresponds to a block success rate of 80% (95% confidence interval: 58-93%) vs 100% (95% confidence interval: 86-100%), which is statistically significant (McNemar's test, P=0.002). CONCLUSIONS: Our findings confirm that the GON can be visualized using ultrasound both at the level of the superior nuchal line and C2. This newly described approach superficial to the obliquus capitis inferior muscle has a higher success rate and should allow a more precise blockade of the nerve.

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STUDY DESIGN.: Cadaver study. OBJECTIVE.: To determine bone strength in vertebrae by measuring peak breakaway torque or indentation force using custom-made pedicle probes. SUMMARY OF BACKGROUND DATA.: Screw performance in dorsal spinal instrumentation is dependent on bone quality of the vertebral body. To date no intraoperative measuring device to validate bone strength is available. Destructive testing may predict bone strength in transpedicular instrumentations in osteoporotic vertebrae. Insertional torque measurements showed varying results. METHODS.: Ten human cadaveric vertebrae were evaluated for bone mineral density (BMD) measurements by quantitative computed tomography. Peak torque and indentation force of custom-made probes as a measure for mechanical bone strength were assessed via a transpedicular approach. The results were correlated to regional BMD and to biomechanical load testing after pedicle screw implementation. RESULTS.: Both methods generated a positive correlation to failure load of the respective vertebrae. The correlation of peak breakaway torque to failure load was r = 0.959 (P = 0.003), therewith distinctly higher than the correlation of indentation force to failure load, which was r = 0.690 (P = 0.040). In predicting regional BMD, measurement of peak torque also performed better than that of indentation force (r = 0.897 [P = 0.002] vs. r = 0.777 [P = 0.017]). CONCLUSION.: Transpedicular measurement of peak breakaway torque is technically feasible and predicts reliable local bone strength and implant failure for dorsal spinal instrumentations in this experimental setting.

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Bennett fractures are unstable, and, with inadequate treatment, lead to osteoarthritis, weakness and loss of function of the first carpometacarpal joint. This study focuses on long-term functional and radiological outcomes after open reduction and internal fixation.

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Differential muscle weakness can cause a cavus foot deformity. Presenting complaints in the hindfoot may include ankle instability, secondary arthritis, or peroneal tendonitis. Presenting complaints in the forefoot may include stress fractures, callus formation over the lateral border of the foot, claw toes, first ray overload, and metatarsalgia. More general presenting complaints can include a drop-foot gait, decreased walking tolerance, and difficulty with shoe or orthotic fitting. To surgically correct the foot shape, soft tissue contractures need to be released, bone deformity corrected, and muscles balanced to optimize their strength and prevent recurrence of the deformity. This article reviews the diagnosis and management of the cavovarus foot secondary to longstanding muscle imbalance.

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BACKGROUND: Stable anatomical reconstruction of the joint surface in ankle fractures is essential to successful recovery. However, the functional outcome of fractures involving the posterior tibial plafond is often poor. We describe the morbidity and functional outcome for plate fixation of the displaced posterior malleolus using a posterolateral approach. MATERIALS AND METHODS: The posterolateral approach was used for osteosynthesis of the posterior malleolus in 45 consecutive patients (median age 54 years) with AO/Muller-classification type 44-A3 (n = 1), 44-B3 (n = 35), 44-C1 (n = 7), and 44-C2 (n = 2) ankle fractures. Thirty-three of the patients suffered complete fracture dislocation. Functional outcome at followup was measured using the modified Weber protocol and the standardized AAOS foot and ankle questionnaire. Radiological evaluation employed standardized anterior-posterior and lateral views. RESULTS: The fragment comprised a median of 24% (range, 10% to 48%) of the articular surface. Postoperative soft tissue problems were encountered in five patients (11%), one of whom required revision surgery. Two patients (4%) developed Stage I complex regional pain syndrome. Clinical and radiological followup at 25 months disclosed no secondary displacement of the fixed fragment. The median foot and ankle score was 93 (range, 58 to 100), shoe comfort score was 77 (range, 0 to 100). A median score of 7 (range, 5 to 16) was documented using the modified Weber protocol. CONCLUSION: The posterolateral approach allowed good exposure and stable fixation of a displaced posterior malleolar fragment with few local complications. The anatomical repositioning and stable fixation led to good functional and subjective outcome.

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The recently introduced rabbit blood shunt subarachnoid haemorrhage model is based on the two standard procedures of subclavian artery cannulation and transcutaneous cisterna magna puncture. An extracorporeal shunt placed in between the arterial system and the subarachnoid space allows examiner-independent SAH in a closed cranium. Despite its straightforwardness, it is worth examining some specific features and characteristics of the model. We outline technical considerations to successfully perform the model with minimal mortality and morbidity. In addition, we discuss outcome measures, advantages and limitations, and the applicability of the model for the study of early brain injury and delayed cerebral vasospasm after SAH.

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OBJECTIVE To compare biomechanical stiffness of cadaveric canine cervical spine constructs stabilized with bicortical stainless steel pins and polymethylmethacrylate (PMMA), monocortical stainless steel screws with PMMA, or monocortical titanium screws with PMMA. STUDY DESIGN Biomechanical cadaver study. ANIMALS Eighteen canine cervical vertebral columns (C2-C7) were collected from skeletally mature dogs (weighing 22-32 kg). METHODS Specimens were radiographed and examined by dual energy X-ray absorptiometry. Stiffness of the unaltered C4-C5 intervertebral motion unit was measured in extension, flexion and lateral bending using non-destructive 4-point bend testing. Specimens were then stabilized by (1) bicortical stainless steel pins/PMMA, (2) monocortical stainless steel screws/PMMA, or (3) monocortical titanium screws/PMMA. Mechanical testing was repeated and stiffness data from unaltered specimens and the 3 treatment groups were compared. RESULTS All 3 surgical methods significantly increased stiffness of the C4-C5 motion unit compared with the unaltered specimen (P < .001 for all treatments), but stiffness was not significantly different among the 3 fixation groups (P = .578). CONCLUSIONS In this model, monocortical screw fixation (with stainless steel or titanium screws) was biomechanically equivalent to bicortical fixation.

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In this research, the halved and tabled traditional timber scarf joint is analyzed. This joint consists in two end joint pieces usually subjected to tension. Initially, the study is discussed from an experimental point of view. In this way, 3 critical cross-sections are established (section of the notch, section of the horizontal plane and reduced section) and mechanical tests are performed to achieve the failure on each of critical sections by changing the geometry of the joint. The study is completed by developing a finite element model which allows verify experimental results and extend the analysis to other geometries. This model has to simulate the real behavior of the material which is being studied, so mechanical tests are performed to obtain the elastic constants and the coefficients of friction of the material. In the reduced section, an abrupt decrease of the effective cross-section takes place, and this effect is also experimentally analyzed. These tests indicate that a crack is initiated before the bending-tension failure occurs in the reduced section. The test material consists of wood of Pinus sylvestris L. coming from the “Valsaín´s Sawmill” (Segovia) with “premium quality” according to the nonstructural wood visual classification of sawmill. It is observed that initiation of a crack, in the mortise (bottom of reduced section), and shear stress concentration, at the initial part of the heel (beginning of horizontal plane), completely determine the mechanical behaviour of the joint, resulting in 3 failure modes: local compression failure in the section of the notch, shear failure in the horizontal plane, and failure of stresses concentration, mainly perpendicular to the grain tension, at the bottom of reduced section. The geometric optimization is obtained for halved and tabled traditional scarf joint, when the joint has made with similar properties of wood than tested specimens, for any height and width of the cross-section. It is considered the failure due to the initiation of a crack in reduced section, by applying a correction coefficient into the usual equation used to design the members subjected to both tension and bending. Therefore, it is possible to obtain, analytically, the design conditions to be met of the 3 critical cross-sections. According to the theoretical optimization, the tension strength of complete cross-section is reduced until 14%, when using this type of joint. The experimental optimization indicates even a greater reduction, until 6%. En el presente trabajo de investigación se analiza el comportamiento mecánico de las uniones tradicionales de empalme de llave, que consisten en dos piezas unidas por sus testas transmitiéndose entre ellas principalmente un esfuerzo de tracción. Inicialmente, el estudio se aborda desde un punto de vista experimental. De este modo, se establecen las 3 secciones críticas o de estudio (sección del encaje, sección rasante del cogote y sección reducida) y se realizan ensayos mecánicos, variando la geometría de la unión, para alcanzar la rotura en cada una de ellas. Se completa el estudio mediante la elaboración de un modelo por elementos finitos que permite verificar los resultados experimentales y ampliar el análisis a otras geometrías. Este modelo debe simular el comportamiento real del material objeto de estudio, por lo que se realizan ensayos para obtener las constantes elásticas y los coeficientes de rozamiento del mismo. También se analiza, experimentalmente, el efecto entalladura que reduce bruscamente la sección completa del tirante, estableciendo que el fallo por flexotracción en la sección reducida de la pieza, no llega a producirse por el inicio previo de una grieta. El material de ensayo consiste en madera de Pinus sylvestris L. (pino silvestre) procedente del Aserradero de Valsaín (Segovia) y de calidad “Extra” o “Primera” según la clasificación visual no estructural del aserradero. Se observa que el inicio de una grieta en la mortaja del rediente y la concentración de tensiones tangenciales en la parte inicial del cogote, determinan completamente el comportamiento mecánico de la unión, dando lugar a 3 modos distintos de rotura: fallo por compresión en la sección del encaje, fallo por cortante en la sección rasante y fallo por concentración de tensiones, principalmente tracciones perpendiculares, en el rebaje de la sección reducida. Se consigue optimizar geométricamente cualquier empalme de llave confeccionado con madera de características similares a la ensayada, para cualquier valor de la altura y de la anchura de la sección. Se considera el agotamiento en la sección reducida causado por el inicio de grieta, mediante la aplicación de un coeficiente corrector en la expresión habitual de agotamiento por flexotracción, en consecuencia, finalmente es posible obtener, de modo analítico, un valor del índice de agotamiento en cada una de las 3 secciones de estudio. La optimización teórica del empalme de llave indica que la capacidad resistente del tirante bruto se reduce al 14%, cuando se coloca este tipo de unión tradicional. Experimentalmente se obtiene, que, para la sección ensayada, la capacidad resistente del tirante bruto se reduce todavía más, llegando al 6%.

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Nos dias de hoje, a ligação adesiva de estruturas complexas que não poderiam ou não seriam tão fáceis de ser fabricadas numa só peça é cada vez mais usual. As juntas adesivas têm vindo a substituir muitos outros métodos de ligação, como por exemplo ligações aparafusadas, rebitas ou soldadas, devido às vantagens de facilidade na sua fabricação, resistência superior e capacidade de unir materiais diferentes. Por esta razão as juntas adesivas têm vindo a ser aplicadas cada vez mais em várias industrias como aeroespacial, aeronáutica, automóvel, naval e calçado. O tipo de adesivo a usar em determinada aplicação é principalmente escolhido consoante as suas características mecânicas e o tipo de resposta pretendida às solicitações impostas. Como exemplo de adesivo resistente e frágil existe o Araldite® AV138. Por outro lado, o adesivo Araldite® 2015 é menos resistente, mas apresenta maior ductilidade e flexibilidade. Além dos adesivos Araldite® comerciais, existem adesivos de poliuretano que combinam características de elevada resistência com características de grande ductilidade e flexibilidade, como por exemplo o Sikaforce® 7752. Esta dissertação tem como objetivo estudar experimentalmente e numericamente, através de modelos de dano coesivo (MDC), o comportamento de diferentes configurações de junta em T quando sujeitas a solicitações de arrancamento. Consideram-se os adesivos anteriormente mencionados para testar as juntas sob diferentes tipos de adesivos. A junta em T é constituída por 2 aderentes em L de alumínio e um aderente base também em alumínio, unidos por uma camada de adesivo. Experimentalmente é feito um estudo da resistência da junta com a variação da espessura dos aderentes em L (tP2). Com a análise numérica são estudadas as distribuições de tensões, evolução do dano, modos de rotura e resistência. Além disso, realizou-se um estudo numérico da existência ou não de adesivo de preenchimento na zona da curvatura dos aderentes em L nas tensões e na resistência da junta. Mostrouse que a variação da geometria nos aderentes em L, a presença de adesivo de preenchimento e o tipo de adesivo têm uma influência direta na resistência de junta. Os ensaios experimentais validaram os resultados numéricos e permitiram concluir que os MDC são uma técnica precisa para o estudo das geometrias das juntas em T.