Biomechanische Untersuchung der Primärstabilität von zwei winkelstabilen Implantaten für die valgisierende Osteotomie am Tibiakopf (HTO)

Whitelegg's Octopus - Oc50 - with Dive Bomber - DB15 - photographed 1972

Balancing incompatible endoprosthetic design goals: a combined ingrowth and bone remodeling simulation

Item does not contain fulltextIn order to design a good cementless femoral implant many requirements need to be fulfilled. For instance, the range of micromotions at the bone-implant interface should not exceed a certain threshold and a good ratio between implant-bone stiffness that does not cause bone resorption, needs to be ensured. Stiff implants are known to evoke lower interface micromotions but at the same time they may cause extensive resorption of the surrounding bone. Composite stems with reduced stiffness give good remodeling results but implant flexibility is likely to evoke high micromotions proximally. Finding a good balance between these incompatible design goals is very challenging. The current study proposes a finite element methodology that employs subsequent ingrowth and remodeling simulations and can be of assistance when designing new implants. The results of our simulations for the Epoch stem were in a good agreement with the clinical data. The proposed implant design made of porous tantalum with an inner CoCrMo core performed slightly better with respect to the Epoch stem and considerably better with respect to a Ti alloy stem. Our combined ingrowth and remodeling simulation can be a useful tool when designing a new implant that well balances mentioned incompatible design goals

Análise da influência da bandagem funcional de tornozelo no tempo de reação do fibular longo em sujeitos saudáveis Analysis of ankle taping influence in the peroneal reaction time in healthy subjects

OBJETIVOS: O objetivo deste estudo foi analisar a influência da bandagem funcional de tornozelo no tempo de reação do fibular longo de indivíduos sadios. MÉTODOS: A amostra foi composta por oito indivíduos do gênero masculino, fisicamente ativos, sem histórias prévias de lesões de tornozelo e, com os resultados negativos aos testes de instabilidade articular de tornozelo. Foram usados como instrumentos da pesquisa, a bandagem funcional de tornozelo tipo bota fechada, para realizar o teste uma plataforma capaz de inclinar 30o no plano frontal simulando a entorse lateral do tornozelo e um eletromiógrafo de oito canais (Bortec Electronics Incorporation, Canadá) para aquisições dos sinais eletromiográficos. Os sinais EMG foram coletados juntamente com o sinal da plataforma (sincronismo). A coleta dos dados foi realizada em dois momentos, primeiramente sem a bandagem e logo após com a bandagem. RESULTADOS: Os indivíduos tinham idade média de 23,3 anos (± 2,8), massa corpórea de 74,4kg (± 9,4), estatura de 1,7m (± 0,4) e IMC de 23,7kg/m2 (± 2,4). O estudo encontrou diferença estatisticamente significativa p = 0,018 na situação da bandagem funcional de tornozelo com diminuição do tempo de reação do fibular longo. CONCLUSÃO: Acreditamos que esta melhora se deva ao íntimo contato da bandagem com os receptores cutâneos do tornozelo, aumentando a ativação do reflexo fibular, com consequente ganho proprioceptivo e, assim, aumentando a habilidade dos sujeitos em responder a situações súbitas de entorses. O estudo demonstrou diminuição no tempo de reação do fibular longo de indivíduos sadios com o uso da bandagem funcional de tornozelo quando submetidos à inclinação lateral súbita do tornozelo.<br>OBJECTIVE: The aim of this study was to analyze the influence of the ankle functional tape on long fibular reaction time in health subjects. METHODS: The sample was composed of eight physically active male subjects, without ankle injury history and with negative results on ankle joint instabilities tests. The instruments used in this research were an ankle functional tape(closed boot type), a platform capable to 30° frontal inclination and an eight-channel electromyograph (Bortec Electronics Incorporation, Canada) for the electrical signals acquisition. The EMG signals were collected concomitantly to the platform (synchronism). Data were collected in two moments: firstly without tape and immediately after, with the tape. RESULTS: The subject average age was 23.3 years (± 2.8), body mass of 74.4 kg (± 9.4), height of 1.7 m (± 0.4) and BMI of 23.7 kg/m2. The research found statistically significant difference of p = 0.018 when the subjects were using the functional ankle tape, with a decreasing of reaction time in long fibular. CONCLUSION: We believe that this increase is related to the close contact of the functional tape with the ankle cutaneous receptors, increasing the fibular reflex activation, with a consequent proprioceptive gain and hence increasing the subjects' ability to respond to sudden ankle sprains. The study showed decrease in long fibular reaction time of health subjects while using this kind of ankle tape when submitted to a sudden lateral ankle inclination