scholarly journals In vitro three dimensional biomechanical comparison of two internal fixation methods in equine adult radii

2007 ◽  
Author(s):  
John Charles Janicek
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charles Savoldelli ◽  
Elodie Ehrmann ◽  
Yannick Tillier

AbstractWith modern-day technical advances, high sagittal oblique osteotomy (HSOO) of the mandible was recently described as an alternative to bilateral sagittal split osteotomy for the correction of mandibular skeletal deformities. However, neither in vitro nor numerical biomechanical assessments have evaluated the performance of fixation methods in HSOO. The aim of this study was to compare the biomechanical characteristics and stress distribution in bone and osteosynthesis fixations when using different designs and placing configurations, in order to determine a favourable plating method. We established two finite element models of HSOO with advancement (T1) and set-back (T2) movements of the mandible. Six different configurations of fixation of the ramus, progressively loaded by a constant force, were assessed for each model. The von Mises stress distribution in fixations and in bone, and bony segment displacement, were analysed. The lowest mechanical stresses and minimal gradient of displacement between the proximal and distal bony segments were detected in the combined one-third anterior- and posterior-positioned double mini-plate T1 and T2 models. This suggests that the appropriate method to correct mandibular deformities in HSOO surgery is with use of double mini-plates positioned in the anterior one-third and posterior one-third between the bony segments of the ramus.


2020 ◽  
Vol 17 (4) ◽  
pp. 258
Author(s):  
Farzin Sarkarat ◽  
Atiye Ahmady ◽  
Farzam Farahmand ◽  
Ali Fateh ◽  
Roozbeh Kahali ◽  
...  

Author(s):  
Hollensteiner Marianne ◽  
Sandriesser Sabrina ◽  
Krauss Hilmar ◽  
Greinwald Markus ◽  
Fabian Stuby ◽  
...  

1996 ◽  
Vol 09 (03) ◽  
pp. 106-10 ◽  
Author(s):  
E. Egger ◽  
J. Huhta ◽  
M. Histand ◽  
C. Mallinckrodt ◽  
R. Nye

SummaryA long oblique osteotomy model of canine femoral fractures was created to compare six methods of internal fixation. The following methods were tested: three cerclage wires, three lag screws, eight-hole dynamic compression plate attached with six cerclage wires, eight-hole dynamic compression plate attached with six cortical screws, eight-hole dynamic compression plate attached with six cortical screws superimposed over three cerclage wires, and an eight-hole dynamic compression plate attached with six cortical screws superimposed over three lag screws. The repaired femurs were mounted in a mechanical testing machine in an orientation designed to mimic physiological loading. Axial compression was applied which resulted in the test specimens experiencing simultaneous compressive and bending forces. The effects of the method of osteotomy repair, bone temperature, and bone diameter were analyzed. The maximum load and the stiffness of the composite fixation and bones were determined. There were not any statistically significant differences in stiffness among the groups. All fixation methods, in which plates were attached with screws, resulted in significantly greater maximum load values than treatment techniques where plates were not used. None of the fixation methods attained a mean maximum load greater than 58% of the mean maximum load of the control femurs.Six methods of commonly used internal fixation methods are compared. A method of in vitro positioning of test femurs to mimic in vivo orientation is presented. Maximum load capabilities of fixation do not significantly increase with the addition of interfragmentary compression to plate fixation.


2003 ◽  
Vol 12 (5) ◽  
pp. 474-479 ◽  
Author(s):  
Teija Lund ◽  
Thomas Nydegger ◽  
Gabor Rathonyi ◽  
Lutz-Peter Nolte ◽  
Dietrich Schlenzka ◽  
...  

2015 ◽  
Vol 44 (8) ◽  
pp. 984-988 ◽  
Author(s):  
Y. Oguz ◽  
E.R. Watanabe ◽  
J.M. Reis ◽  
R. Spin-Neto ◽  
M.A. Gabrielli ◽  
...  

Author(s):  
P.L. Moore

Previous freeze fracture results on the intact giant, amoeba Chaos carolinensis indicated the presence of a fibrillar arrangement of filaments within the cytoplasm. A complete interpretation of the three dimensional ultrastructure of these structures, and their possible role in amoeboid movement was not possible, since comparable results could not be obtained with conventional fixation of intact amoebae. Progress in interpreting the freeze fracture images of amoebae required a more thorough understanding of the different types of filaments present in amoebae, and of the ways in which they could be organized while remaining functional.The recent development of a calcium sensitive, demembranated, amoeboid model of Chaos carolinensis has made it possible to achieve a better understanding of such functional arrangements of amoeboid filaments. In these models the motility of demembranated cytoplasm can be controlled in vitro, and the chemical conditions necessary for contractility, and cytoplasmic streaming can be investigated. It is clear from these studies that “fibrils” exist in amoeboid models, and that they are capable of contracting along their length under conditions similar to those which cause contraction in vertebrate muscles.


Author(s):  
J. P. Revel

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.


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