The Experts below are selected from a list of 4428 Experts worldwide ranked by ideXlab platform
Michael R Zernich - One of the best experts on this subject based on the ideXlab platform.
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Intergranular Corrosion-Fatigue Failure of cobalt-alloy femoral stems : a Failure analysis of two implants
Journal of Bone and Joint Surgery American Volume, 1994Co-Authors: Jeremy L. Gilbert, Christine A. Buckley, Joshua J. Jacobs, Kim C. Bertin, Michael R ZernichAbstract:Two modular hip implants with a cobalt-alloy head and a cobalt-alloy stem were retrieved after a fracture had occurred in the neck region of the femoral component, eighty-five and seventy months after implantation. Both implants failed less than one millimeter distal to the taper junction between the head and the stem (outside of the taper). The fracture surfaces of the implant were investigated with the use of scanning electron microscopy, to determine the nature of the Failure process. The fractures occurred at the grain boundaries of the microstructure and appeared to be the result of three factors: porosity at the grain boundaries; intergranular corrosive attack, initiated both at the head-neck taper and at the free surface; and cyclic Fatigue-loading of the stem. The corrosive attack of the free surface was initiated, in part, by the egression of surface grains and by the ingression of fluid into the intergranular regions. Sectioned surfaces showed extensive intergranular corrosive attack in the prosthetic neck localized in the region of the head-neck taper junction and penetrating deeply into the microstructure.
Gunnar Flivik - One of the best experts on this subject based on the ideXlab platform.
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Fatigue fracture in dual modular revision total hip arthroplasty stems Failure analysis and computed tomography diagnostics in two cases
Journal of Arthroplasty, 2014Co-Authors: Pontus Norman, Srinivasan Iyengar, Ingrid Svensson, Gunnar FlivikAbstract:We report on two patients with fracture of a modular, tapered and distally fixed, uncemented titanium revision hip stem, not previously described. A Failure analysis revealed that the cause of the fractures was the development of Fatigue cracks in the mid-stem cobalt-chromium modular junction ending in Corrosion-Fatigue Failure. No material defects or stress risers were found in any of the implants. The diameter of the mid-stem modular junction might be undersized for use in heavy and active patients. We also report a new way of detecting an undisplaced fracture at the modular junction, using the scout image from a computed tomography (CT) scan; a technique that can be used when plain radiographs are inconclusive.
Jeremy L. Gilbert - One of the best experts on this subject based on the ideXlab platform.
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Intergranular Corrosion-Fatigue Failure of cobalt-alloy femoral stems : a Failure analysis of two implants
Journal of Bone and Joint Surgery American Volume, 1994Co-Authors: Jeremy L. Gilbert, Christine A. Buckley, Joshua J. Jacobs, Kim C. Bertin, Michael R ZernichAbstract:Two modular hip implants with a cobalt-alloy head and a cobalt-alloy stem were retrieved after a fracture had occurred in the neck region of the femoral component, eighty-five and seventy months after implantation. Both implants failed less than one millimeter distal to the taper junction between the head and the stem (outside of the taper). The fracture surfaces of the implant were investigated with the use of scanning electron microscopy, to determine the nature of the Failure process. The fractures occurred at the grain boundaries of the microstructure and appeared to be the result of three factors: porosity at the grain boundaries; intergranular corrosive attack, initiated both at the head-neck taper and at the free surface; and cyclic Fatigue-loading of the stem. The corrosive attack of the free surface was initiated, in part, by the egression of surface grains and by the ingression of fluid into the intergranular regions. Sectioned surfaces showed extensive intergranular corrosive attack in the prosthetic neck localized in the region of the head-neck taper junction and penetrating deeply into the microstructure.
Pontus Norman - One of the best experts on this subject based on the ideXlab platform.
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Fatigue fracture in dual modular revision total hip arthroplasty stems Failure analysis and computed tomography diagnostics in two cases
Journal of Arthroplasty, 2014Co-Authors: Pontus Norman, Srinivasan Iyengar, Ingrid Svensson, Gunnar FlivikAbstract:We report on two patients with fracture of a modular, tapered and distally fixed, uncemented titanium revision hip stem, not previously described. A Failure analysis revealed that the cause of the fractures was the development of Fatigue cracks in the mid-stem cobalt-chromium modular junction ending in Corrosion-Fatigue Failure. No material defects or stress risers were found in any of the implants. The diameter of the mid-stem modular junction might be undersized for use in heavy and active patients. We also report a new way of detecting an undisplaced fracture at the modular junction, using the scout image from a computed tomography (CT) scan; a technique that can be used when plain radiographs are inconclusive.
Joshua J. Jacobs - One of the best experts on this subject based on the ideXlab platform.
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Intergranular Corrosion-Fatigue Failure of cobalt-alloy femoral stems : a Failure analysis of two implants
Journal of Bone and Joint Surgery American Volume, 1994Co-Authors: Jeremy L. Gilbert, Christine A. Buckley, Joshua J. Jacobs, Kim C. Bertin, Michael R ZernichAbstract:Two modular hip implants with a cobalt-alloy head and a cobalt-alloy stem were retrieved after a fracture had occurred in the neck region of the femoral component, eighty-five and seventy months after implantation. Both implants failed less than one millimeter distal to the taper junction between the head and the stem (outside of the taper). The fracture surfaces of the implant were investigated with the use of scanning electron microscopy, to determine the nature of the Failure process. The fractures occurred at the grain boundaries of the microstructure and appeared to be the result of three factors: porosity at the grain boundaries; intergranular corrosive attack, initiated both at the head-neck taper and at the free surface; and cyclic Fatigue-loading of the stem. The corrosive attack of the free surface was initiated, in part, by the egression of surface grains and by the ingression of fluid into the intergranular regions. Sectioned surfaces showed extensive intergranular corrosive attack in the prosthetic neck localized in the region of the head-neck taper junction and penetrating deeply into the microstructure.
