scholarly journals Wear and migration of highly cross-linked and conventional cemented polyethylene cups with cobalt chrome or Oxinium femoral heads: A randomized radiostereometric study of 150 patients

2011 ◽  
Vol 29 (8) ◽  
pp. 1222-1229 ◽  
Author(s):  
Thomas Kadar ◽  
Geir Hallan ◽  
Arild Aamodt ◽  
Kari Indrekvam ◽  
Mona Badawy ◽  
...  
Keyword(s):  
Femoral Heads ◽  
And Migration ◽  
Cobalt Chrome

Wear Performance of 28 Millimeter Femoral Heads with the Harris Galante Cup: Comparison of Alumina and Cobalt Chrome

2003 ◽  
pp. 177-182
Author(s):  
Ch. Hendrich ◽  
S. Goebel ◽  
Ch. Roller ◽  
S. Kirschner ◽  
J. M. Martell
Keyword(s):  
Wear Performance ◽  
Femoral Heads ◽  
Cobalt Chrome

Five-year comparison of wear using oxidised zirconium and cobalt–chrome femoral heads in total hip arthroplasty

2015 ◽  
Vol 97-B (7) ◽  
pp. 883-889 ◽  
Author(s):  
S. S. Jassim ◽  
S. Patel ◽  
N. Wardle ◽  
J. Tahmassebi ◽  
R. Middleton ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Total Hip ◽  
Femoral Heads ◽  
Cobalt Chrome

scholarly journals Bearing-Foreign Material Deposition on Retrieved Co-Cr Femoral Heads: Composition and Morphology

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Nishant M. Tikekar ◽  
Anneliese D. Heiner ◽  
Thomas E. Baer ◽  
Karen M. Kruger ◽  
John J. Callaghan ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Optical Profilometry ◽  
Foreign Material ◽  
X Ray ◽  
Material Deposition ◽  
Dislocation Reduction ◽  
Femoral Heads ◽  
Acetabular Shell ◽  
Hip Arthroplasties ◽  
Cobalt Chrome

Bearing-foreign material deposition onto a femoral head can occur from contact with an acetabular shell due to dislocation, reduction, or subluxation. The purpose of this study was to comprehensively characterize deposit regions on retrieved cobalt-chrome femoral heads from metal-on-polyethylene total hip arthroplasties that had experienced such adverse events. The morphology, topography, and composition of deposition regions were characterized using macrophotography, optical profilometry, scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. The deposit areas were relatively large, they were much rougher than the surrounding undamaged clean areas, and they displayed several distinct morphologies. Titanium alloy elements were the predominant constituents. Calcium and phosphorous were also detected within the deposit areas, in a composition that could nucleate abrasive hydroxyapatite. In addition, tungsten-rich particles, likely present as tungsten carbide, were observed on top of the titanium deposits. The increased roughness associated with these deposition features would be expected to accelerate damage and wear of the opposing liner and hence accelerate the development of osteolysis.

Comparison of in vivo wear between polyethylene liners articulating with ceramic and cobalt-chrome femoral heads

2000 ◽  
Vol 82-B (7) ◽  
pp. 948-951 ◽  
Author(s):  
C. J. Sychterz ◽  
C. A. Engh ◽  
A. M. Young ◽  
R. H. Hopper ◽  
C. A. Engh
Keyword(s):  
Femoral Heads ◽  
Cobalt Chrome

Demonstration of Retinal Glycogen with Silver Methenamine

1971 ◽  
Vol 29 ◽  
pp. 564-565
Author(s):  
A. W. Sedar ◽  
G. H. Bresnick
Keyword(s):  
Lactic Acid ◽  
Chromic Acid ◽  
Periodic Acid ◽  
Müller Cell ◽  
External Limiting Membrane ◽  
Electron Microscope Level ◽  
Reactive Process ◽  
Inner Limiting Membrane ◽  
Muller Cell ◽  
And Migration

After experimetnal damage to the retina with a variety of procedures Müller cell hypertrophy and migration occurs. According to Kuwabara and others the reactive process in these injuries is evidenced by a marked increase in amount of glycogen in the Müller cells. These cells were considered originally supporting elements with fiber processes extending throughout the retina from inner limiting membrane to external limiting membrane, but are known now to have high lactic acid dehydrogenase activity and the ability to synthesize glycogen. Since the periodic acid-chromic acid-silver methenamine technique was shown to demonstrate glycogen at the electron microscope level, it was selected to react with glycogen in the fine processes of the Müller cell that ramify among the neural elements in various layers of the retina and demarcate these cells cytologically. The Rhesus monkey was chosen as an example of a well vascularized retina and the rabbit as an example of a avascular retina to explore the possibilities of the technique.

Structure and migration of planar defects in crystals observed in atomic scale

1978 ◽  
Vol 36 (1) ◽  
pp. 284-285 ◽  
Author(s):  
H. Hashimoto ◽  
Y. Sugimoto ◽  
Y. Takai ◽  
H. Endoh
Keyword(s):  
Electron Microscope ◽  
Rotation Angle ◽  
Crystal Surface ◽  
Electron Gun ◽  
Atomic Scale ◽  
Present Observation ◽  
Twist Boundary ◽  
Optical Magnification ◽  
Zinc Crystal ◽  
And Migration

As was demonstrated by the present authors that atomic structure of simple crystal can be photographed by the conventional 100 kV electron microscope adjusted at “aberration free focus (AFF)” condition. In order to operate the microscope at AFF condition effectively, highly stabilized electron beams with small energy spread and small beam divergence are necessary. In the present observation, a 120 kV electron microscope with LaB6 electron gun was used. The most of the images were taken with the direct electron optical magnification of 1.3 million times and then magnified photographically.1. Twist boundary of ZnSFig. 1 is the image of wurtzite single crystal with twist boundary grown on the surface of zinc crystal by the reaction of sulphur vapour of 1540 Torr at 500°C. Crystal surface is parallel to (00.1) plane and electron beam is incident along the axis normal to the crystal surface. In the twist boundary there is a dislocation net work between two perfect crystals with a certain rotation angle.

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