Search results for "Dislocation"
showing 10 items of 118 documents
Tibial tubercle osteotomy: effect of different osteotomy planes on contact surface area and tubercle anteriorization
2022
In 1983, Fulkerson introduced a technique of tibial tubercle osteotomy performed according to an inclined plane with respect to frontal plane. Due to obliquity of the osteotomy plane, this procedure allows both anterior and medial transfer of the tibial tubercle. The purpose of the study was to investigate the influence of the different degrees of the oblique plane of osteotomy on anterior displacement and the contact surface area of tibial tubercle. Synthetic bones were used for the study. An osteotomy of the tibial tubercle (TT) was performed in each specimen. Specifically, 3 different degrees of osteotomy planes relative to the reference frontal plane were examined: 20°, 30° and 40°. On …
Lesión compleja del codo pediátrico: fractura de cóndilo externo asociada a luxación posteromedial de codo.
2020
espanolAntecedentes y objetivo: La fractura de condilo externo asociada a una luxacion posteromedial de codo es una entidad muy rara, de la cual existen muy pocos casos publicados. Nuestro objetivo es presentar un caso complejo tratado en nuestro centro, el diagnostico, el tratamiento elegido, y el seguimiento a las 9 semanas. Caso clinico: varon de 5 anos con una luxacion posteromedial de codo asociada a una fractura de condilo externo, diagnosticada mediante TC y tratada de forma quirurgica mediante un abordaje anterior sobre el codo, reduccion abierta y osteosintesis con agujas de Kirschner. Resultados: los resultados clinicos y radiologicos a las 9 semanas son excelentes, presentando un…
Cathodoluminescence and photoluminescence study of plastically deformed ZnTe bulk single crystals
2001
Samples of zinc telluride bulk single crystals, which were deformed in uniaxial compression, have been studied by photoluminescence (PL) and cathodoluminescence (CL). As a particular feature the deformed samples present a PL emission band peaked at 603 nm, whose intensity increases as the plastic deformation does. This band is related to the density of dislocations produced during the interaction of slip systems. This hypothesis is supported by CL images. which reveal the activation of the successive slip systems corresponding to different levels of deformation.
Observation of a charge delocalization from Se vacancies inBi2Se3: A positron annihilation study of native defects
2016
By means of positron annihilation lifetime spectroscopy, we have investigated the native defects present in ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$, which belongs to the family of topological insulators. We experimentally demonstrate that selenium vacancy defects $({\text{V}}_{\text{Se1}})$ are present in ${\mathrm{Bi}}_{2}{\mathrm{Se}}_{3}$ as-grown samples, and that their charge is delocalized as temperature increases. At least from 100 K up to room temperature both ${\text{V}}_{\text{Se1}}^{0}$ and ${\text{V}}_{\text{Se1}}^{+}$ charge states coexist. The observed charge delocalization determines the contribution of ${\text{V}}_{\text{Se1}}$ defects to the $n$-type conductivity of ${\mathrm{…
On the dynamics of dislocation patterning
1997
Recent computer simulations on dislocation patterning have provided remarkable results in accordance with empirical laws. Moreover, several analytical models on dislocation dynamics have provided qualitative insight on dislocation patterning. However, a model, based on partial differential equations, which gives a dynamical evolution of dislocation patterns in function of measurable variables still missing. Here, we give a re-formulation of a model proposed some years ago. From this formulation, we obtained that the onset of a dislocation instability is related to the applied stress. The analytical and numerical results reported are partial and studies on this direction are under developmen…
Elastic moduli, dislocation core energy and melting of hard disks in two dimensions
2000
Elastic moduli and dislocation core energy of the triangular solid of hard disks of diameter $\sigma$ are obtained in the limit of vanishing dislocation- antidislocation pair density, from Monte Carlo simulations which incorporates a constraint, namely that all moves altering the local connectivity away from that of the ideal triangular lattice are rejected. In this limit, we show that the solid is stable against all other fluctuations at least upto densities as low as $\rho \sigma^2 = 0.88$. Our system does not show any phase transition so diverging correlation lengths leading to finite size effects and slow relaxations do not exist. The dislocation pair formation probability is estimated …
Bemerkungen zu K.-D. Thomann: „100 Jahre Zeitschrift für Orthopädie“
2008
The historical review of 100 years of the Zeitschrift fur Orthopadie could create the impression that the Nazi era did not have any significant impact on orthopedics in Germany. In this commentary it is shown that the Prevention of Heredopathic Offspring Act of 1933 resulted in an uncritical overemphasis on hereditary factors. This decisively influenced concepts of, research into and therapy for hip dislocation, both in Germany and other countries.
Posterior subtalar dislocation.
2009
A subtalar dislocation of the foot is an uncommon injury, and cases of posterior subtalar dislocation are even rarer. This injury is characterized by a simultaneous dislocation of talocalcaneal and talonavicular joints while tibiotalar and calcaneocuboid articulations remain intact. Subtalar dislocation is commonly accompanied by fractures of the malleoli, talus, or fifth metatarsal and by a rotational component of the subtalar joint. Subtalar dislocation can occur in any direction and produces significant deformity. This article presents a case of pure posterior subtalar dislocation in an 80-year-old man who presented with pain and deformity in his left ankle following a motorcycle acciden…
A new method to evaluate the influence of the glenosphere positioning on stability and range of motion of a reverse shoulder prosthesis
2019
Abstract Purpose Shoulder instability and reduced range of motion are two common complications of a total reverse shoulder arthroplasty. In this work, a new approach is proposed to estimate how the glenoid component positioning can influence the stability and the range of motion of a reverse shoulder prosthesis. Materials and methods A standard reverse shoulder prosthesis has been analysed. To perform virtual simulation of the shoulder-prosthesis assembly, all the components of the prosthesis have been acquired via a 3D laser scanner and the solid models of the shoulder bones have been reconstructed through CT images. Loads on the shoulder joint have been estimated using anatomical models d…
Comments to the paper "do we really need new medical information about the Turin Shroud?".
2015
Abstract Following the interesting arguments raised in a recent letter to the editor, about a paper recently published in this journal, the authors are happy to take a cue from them to clarify some facts that have not been sufficiently treated for space. After a description of the methods used, arguments regarding a blunt trauma on the right shoulder with consequent dislocation, the position of the hands on the pubis with brachial plexus injury, and the wrist nailing that caused retracted thumbs are discussed in detail.