Problems that screw cannot be inserted may occur in screw-rod fixation techniques such as Harms technique. We compared the biomechanical stability imparted to the C-2 vertebrae by four designed posterior screw and rod fixation techniques for the management of odontoid fractures. A three-dimensional finite element model of the odontoid fracture was established by subtracting several unit structu...

BACKGROUND Finite element analysis results will show significant differences if the model used is performed under various material properties, geometries, loading modes or other conditions. This study adopted an FE model, taking into account the possible asymmetry inherently existing in the spine with respect to the sagittal plane, with a more geometrically realistic outline to analyze and comp...

STUDY DESIGN Retrospective review. OBJECTIVE To determine if lumbarized sacra at the L5-6 level (functional L4-5) are a contraindication to a lateral transpsoas approach. SUMMARY OF BACKGROUND DATA Transitional vertebrae at the lumbosacral junction present mechanical and morphologic changes, though these changes have not been characterized with respect to the feasibility of a lateral transp...

Complementary to axial, lateral displacement and strain can provide important information on the biological soft tissues. In this paper, the effects of key parameters (i.e., lateral displacement, pitch, beamwidth, beam overlap and interpolation) on lateral displacement estimation were investigated, in simulations and homogeneous phantom experiments, using lateral rigid motion only to study its ...

As for homogeneous lenses, for axial gradients the analysis of the Seidel and chromatic aberration coefficients can be very useful in lens design. However, at present few commercial optical design programs list the Seidel aberrations of GRIN lenses and none of them lists the chromatic aberrations. In order to facilitate the computer implementation of the chromatic aberrations of axial GRIN lens...

The adhesion and friction coupling of hierarchical carbon nanotube arrays was investigated with a hierarchical multiscale modeling approach. At device level, vertically aligned carbon nanotube (VA-CNT) arrays with laterally distributed segments on top were analyzed via finite element methods to determine the macroscopic adhesion and friction force coupling. At the nanoscale, molecular dynamics ...

INTRODUCTION: Conventional wisdom dictates that fusion rates increase with increasing construct stiffness. Traditional pedicle screw systems generally rely upon stiff components and rigid interconnections. For ease of insertion, some "semi-rigid" systems include polyaxial connections. A favorable bio logical outcome (fusion) is only weakly related to instrumentation type and it is increasingly ...

A dam spillway is a hydraulic structure that appropriately and safely diverts the outflow to downstream, so that the dam stability and passing of flood flows can be guaranteed. Compared to straight crest spillway, an Ogee spillway with curvature in plan in a fixed-width can pass more flow. Therefore under the low hydraulic heads and the need for a smaller place in plane, they are considered as ...

MRI cardiac tagging has been established as the gold standard in assessing intramyocardial displacement and strain. Yet, despite the high imaging quality of cardiac MRI, tagging techniques are limited by low spatial and temporal resolution. It has been recently shown that axial displacement and strain could be estimated and utilizing Bscan ultrasonography [1]. We compared and correlated intramy...

BACKGROUND The lateral radiograph-based system described by Tsuyama is used widely to classify ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. However, OPLL is a complex 3-dimensional (3-D) lesion, not a simple and uniplanar one, which is often difficult to identify on a lateral radiograph. Furthermore, its reliability among spine surgeons has not been investig...