1,721,006 research outputs found
Diagnosis and treatment of flexible flatfoot: results of 2019 flexible flatfoot survey from the European Paediatric Orthopedic Society
No full textThe aim of the study was to evaluate flexible flatfoot (FFF) diagnostic and current therapeutic modalities, as well as treatment expectations, among members of the European Paediatric Orthopaedic Society (EPOS). A 59-questions survey on FFF diagnosis and treatment preferences was distributed to EPOS members. The survey consisted of six sections (1) general clinical parameters; (2) foot aspects; (3) X-ray angles (or lines); (4) expectations; (5) standard clinical assessment; and (6) management options. Descriptive statistics were performed. A total of 93 responses were analysed. In general, clinical parameters, age (91.4% of cases), laxity (81.7%), diffuse pain (84.9%), and pain at the ankle joint (81.7%) were rated as 'average' and 'crucial importance' by the vast majority of respondents. Meary's angle (47.3% of cases), talonavicular coverage (35.5%), and lateral talocalcaneal angle (35.5%) were assessed as main radiological tools in the FFF evaluation. Among respondents, 61.3% rated 'improved ability to walk longer without symptoms' as of 'crucial importance'. Eighty-two percent of the respondents felt less than 10% of patients with FFF are candidates for corrective surgery. Arthroereisis (29.3%) was the most common surgical procedure (16.4% for subtalar and 12.9% for extra-articular arthroereisis, respectively), followed by lateral column lengthening (17.9%) and medializing calcaneal osteotomy (12.3%). There is great variation among respondents in diagnostic and treatment preferences in the management of children with FFF. The results of the EPOS 2019 FFF survey clearly show that large-scale, multicentric, international studies are necessary to elucidate which diagnostic and treatment practices lead to the best outcomes
Biomechanical study of adolescent idiopathic scoliosis with spine energetic equilibrium and soft tissues poromechanics
No full textCe travail de thèse s’inscrit dans le défi sociétal de la santé et est construit sur une approche originale interdisciplinaire en mécanobiologie. La pathologie étudiée est la scoliose idiopathique, déformation rachidienne structurelle la plus courante touchant 2 à 3% des enfants de 10 ans ou plus. Environ 10% va progresser pendant la croissance et nécessiter un traitement spécifique pouvant aller jusqu’à une chirurgie très invasive. L’aide au diagnostic, la prise en charge du patient et son suivi sont des étapes clés dans lesquelles la proposition d’une quantification objective des phénomènes liés aux altérations pathologiques soutenue par des modèles prédictifs peut apporter une contribution significative. La modélisation mécanique du rachis trouve ses limitations dans le caractère multi-échelles en espace et en temps des tissus biologiques impliqués dans la scoliose. De nombreuses études se sont attachées à comprendre les phénomènes biomécaniques à l’échelle d’un segment vertébral ou bien l’épidémiologie à l’échelle du rachis. Ces approches constituent l’essentiel des travaux disponibles, cependant, il n’existe pas de travaux combinant les deux échelles spatiales, qui sont difficilement modélisables numériquement. L'évolution temporelle de la scoliose est quant à elle principalement étudiée dans la littérature du point de vue clinique et rarement du point de vue mécanique. La méthodologie proposée dans cette thèse s'attache à prendre en compte certaines caractéristiques multi-échelles de la scoliose en s’efforçant de contourner les obstacles par l'élaboration d'un nouveau cadre théorique. L'hypothèse centrale de cette approche est que la position d’équilibre quasi-statique du rachis scoliotique dérive de la minimisation d’une énergie potentielle totale incluant les énergies de déformation des structures déformables ainsi que les efforts internes et externes. Cette modélisation a été paramétrée par des opérateurs de type tenseurs effectifs. La détermination de solutions d’équilibre a été effectuée par minimisation numérique, celle des tenseurs effectifs a été menée par l’implémentation d’une méthode numérique inverse originale par son adaptation au domaine du vivant et incluant notamment une méthode de pénalisation. Cette résolution a été réalisée à partir d’un modèle mécanique global filaire et tridimensionnel du rachis. A une sous-échelle incluant le segment vertébral, une approche poroélastique a été proposée. Cette partie du travail a permis de discuter de la notion d’échelle de temps multiples et d’établir des liens entre les échelles spatiales par le biais des torseurs d’efforts internes. L’approche heuristique a été construite par des échanges avec les informations cliniques (radiographies biplanaires), ceci en collaboration avec le service d’orthopédie pédiatrique du CHU Toulouse. La résolution d’un problème inverse sur un rachis très peu déformé a montré que les résultats obtenus étaient similaires à ceux de la littérature, validant la pertinence de ce modèle. Par ailleurs, les résolutions menées à partir d’une cohorte de patients (scolioses stables ou instables) ont permis de mettre évidence des indices évolutifs associés à l’adaptation mécanique des segments vertébraux. Ainsi, les temps de résolution des modèles numériques étant optimisés, il est possible d’envisager à court terme l’utilisation de cette nouvelle méthodologie en contexte clinique pour aider au diagnostic précoce des scolioses instables, à la rééducation adaptée et la planification chirurgicale. En perspective, grâce au modèle développé dans cette thèse, l’exploration de l’altération des propriétés de transports dans les segments pathologiques permettra d’étudier la dégénérescence discale et ainsi s’intéresser aux causes du développement de la scoliose. Ce type de recherches pourra être effectué par l’enrichissement de la méthodologie par des modèles de transports réactifs étayés par les observations cliniques.The research developed during this Ph.D thesis falls within the societal challenge on health and is based on an innovative interdisciplinary methodology in the field of mechanobiology. The studied pathology is the adolescent idiopathic scoliosis, which is the most common spine structural deformity, affecting 2 to 3% of children from 10 years old. About 10% will progress during growth and require specific treatment, which may include invasive surgery. Improvements in diagnosis techniques and patients follow-up are key objectives for which the quantification of phenomena involved in the pathology evolution supported by predictive models can bring new insight in scoliosis care. Because scoliotic spine is a multiscale problem in space and time, mechanical modeling is challenging. Many studies have focused on understanding biomechanical phenomena at the vertebral segment scale or epidemiology at the spine scale. These researches constitute the majority of the work available to date, however, to our knowledge, there is no work combining the two spatial scales, which is challenging to model numerically. The scoliosis temporal evolution is mainly studied from clinical perpectives and rarely using mechanical approaches. The methodology proposed within the framework of this thesis aimed at taking into account some of the scoliosis multiscale characteristics and attempted to circumvent these obstacles. The main assumption was that the quasi-static equilibrium position of the scoliotic spine was derived from the minimization of a total potential energy including the deformation energies of the deformable structures as well as internal and external forces. This energy model was parameterized by operators such as effective tensors. The determination of the equilibrium solution was carried out by numerical minimization. The evaluation of effective tensors was carried out by the implementation of inverse numerical techniques including penalization methods. This approach is original in the context of a clinical problem. The resolution has been performed using a global three-dimensional wireframe mechanical model of the spine. At the vertebral segment subscale, a poroelastic model has been proposed. This part of the work discussed the multiple timescale involved in scoliosis and put forward links between spatial scales through internal stress tensors. This heuristic approach was built on a constant exchange with experts in the field (pediatric orthopedics department of the Toulouse University Hospital) and validated with clinical data (biplanar radiographs). The resolution of an inverse problem on a slightly deformed spine showed that the results obtained were similar to those extracted from the literature, hence validating the relevance of this model. The resolutions carried out from a cohort of patients (stable or unstable scoliosis) highlighted evolutionary indices associated with the mechanical adaptation of the vertebral segments. Thus, the low computational cost of the optimized digital models enable us to consider, in the near future, the use of this innovative methodology in a clinical context to help in the early diagnosis of unstable scoliosis, in the choice of an appropriate rehabilitation and in the surgical planning. In perspective, based on the current model, the exploration of the alteration of transport properties in segments under pathological mechanical loading will allow us to study disc degeneration and therefore to explore scoliosis causes. To reach this objective, the current two scales approach will be enriched with reactive transport models supported by clinical observations
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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