The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Orhun K. Muratoglu - One of the best experts on this subject based on the ideXlab platform.
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lower prosthesis specific 10 year revision rate with crosslinked than with non crosslinked Polyethylene in primary total knee arthroplasty
Acta Orthopaedica, 2015Co-Authors: Richard De Steiger, Orhun K. Muratoglu, Michelle Lorimer, Alana Cuthbert, Stephen E GravesAbstract:Background and purpose — While highly crosslinked Polyethylene has shown reduced in vivo wear and lower rates of revision for total hip arthroplasty, there have been few long-term studies on its use in total knee arthroplasty (TKA). We compared the rate of revision of non-crosslinked Polyethylene to that of crosslinked Polyethylene in patients who underwent TKA for osteoarthritis.Patients and methods — We examined data from the Australian Orthopaedic Association National Joint Replacement Registry on 302,214 primary TKA procedures with non-crosslinked Polyethylene and 83,890 procedures with crosslinked Polyethylene, all of which were performed for osteoarthritis. The survivorship of the different Polyethylenes was estimated using the Kaplan-Meier method and was compared using proportional hazard models.Results — The 10-year cumulative revision rate for non-crosslinked Polyethylene was 5.8% (95% CI: 5.7–6.0) and for crosslinked Polyethylene it was 3.5% (95% CI: 3.2–3.8) (> 6.5-year HR = 2.2 (1.5–3.1); p < ...
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comparison of hip simulator wear of 2 different highly cross linked ultra high molecular weight Polyethylene acetabular components using both 32 and 38 mm femoral heads
Journal of Arthroplasty, 2007Co-Authors: Daniel M Estok, Brian R Burroughs, Orhun K. Muratoglu, William H HarrisAbstract:Abstract Much evidence suggests that ultra high molecular weight Polyethylene (UHMWP) irradiated to 9.5 Mrad has lower wear than UHMWP given 5 Mrad. Curiously, highly cross-linked Polyethylenes gain weight during hip simulator testing. We postulated that ( a ) UHMWP irradiated to 9.5 Mrad would wear less than UHMWP irradiated to 5 Mrad UHMWP, ( b ) articulation against 38-mm heads would accentuate this difference, and ( c ) weight gain of highly cross-linked material reflects the inadequacy of load soak controls. We compared 9.5 versus 5 Mrad Polyethylene in hip simulator wear tests, with both load soak corrections and with novel "motion soak" corrections. The 9.5-Mrad material wore less than 5-Mrad material for 32- and 38-mm heads. Motion soak corrections were more accurate than load soak corrections.
Avram A Edidin - One of the best experts on this subject based on the ideXlab platform.
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radiation and chemical crosslinking promote strain hardening behavior and molecular alignment in ultra high molecular weight Polyethylene during multi axial loading conditions
Biomaterials, 1999Co-Authors: Steven M Kurtz, Lisa A Pruitt, C W Jewett, Jude R Foulds, Avram A EdidinAbstract:The mechanical behavior and evolution of crystalline morphology during large deformation of eight types of virgin and crosslinked ultra high molecular weight Polyethylene (UHMWPE) were studied using the small punch test and transmission electron microscopy (TEM). We investigated the hypothesis that both radiation and chemical crosslinking hinder molecular mobility at large deformations, and hence promote strain hardening and molecular alignment during the multiaxial loading of the small punch test. Chemical crosslinking of UHMWPE was performed using 0.25% dicumyl peroxide (GHR 8110, GUR 1020 and 1050), and radiation crosslinking was performed using 150 kGy of electron beam radiation (GUR 1150). Crosslinking increased the ultimate load at failure and decreased the ultimate displacement of the Polyethylenes during the small punch test. Crosslinking also increased the near-ultimate hardening behavior of the Polyethylenes. Transmission electron microscopy was used to characterize the crystalline morphology of the bulk material, undeformed regions of the small punch test specimens, and deformed regions of the specimens oriented perpendicular and parallel to the punch direction. In contrast with the virgin Polyethylenes, which showed only subtle evidence of lamellar alignment, the crosslinked Polyethylenes exhibited enhanced crystalline lamellae orientation after the small punch test, predominantly in the direction parallel to the punch direction or deformation axis. Thus, the results of this study support the hypothesis that crosslinking promotes strain hardening during multiaxial loading because of increased resistance to molecular mobility at large deformations effected by molecular alignment. The data also illustrate the sensitivity of large deformation mechanical behavior and crystalline morphology to the method of crosslinking and resin of Polyethylene.
William H Harris - One of the best experts on this subject based on the ideXlab platform.
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comparison of hip simulator wear of 2 different highly cross linked ultra high molecular weight Polyethylene acetabular components using both 32 and 38 mm femoral heads
Journal of Arthroplasty, 2007Co-Authors: Daniel M Estok, Brian R Burroughs, Orhun K. Muratoglu, William H HarrisAbstract:Abstract Much evidence suggests that ultra high molecular weight Polyethylene (UHMWP) irradiated to 9.5 Mrad has lower wear than UHMWP given 5 Mrad. Curiously, highly cross-linked Polyethylenes gain weight during hip simulator testing. We postulated that ( a ) UHMWP irradiated to 9.5 Mrad would wear less than UHMWP irradiated to 5 Mrad UHMWP, ( b ) articulation against 38-mm heads would accentuate this difference, and ( c ) weight gain of highly cross-linked material reflects the inadequacy of load soak controls. We compared 9.5 versus 5 Mrad Polyethylene in hip simulator wear tests, with both load soak corrections and with novel "motion soak" corrections. The 9.5-Mrad material wore less than 5-Mrad material for 32- and 38-mm heads. Motion soak corrections were more accurate than load soak corrections.
Stephen E Graves - One of the best experts on this subject based on the ideXlab platform.
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lower prosthesis specific 10 year revision rate with crosslinked than with non crosslinked Polyethylene in primary total knee arthroplasty
Acta Orthopaedica, 2015Co-Authors: Richard De Steiger, Orhun K. Muratoglu, Michelle Lorimer, Alana Cuthbert, Stephen E GravesAbstract:Background and purpose — While highly crosslinked Polyethylene has shown reduced in vivo wear and lower rates of revision for total hip arthroplasty, there have been few long-term studies on its use in total knee arthroplasty (TKA). We compared the rate of revision of non-crosslinked Polyethylene to that of crosslinked Polyethylene in patients who underwent TKA for osteoarthritis.Patients and methods — We examined data from the Australian Orthopaedic Association National Joint Replacement Registry on 302,214 primary TKA procedures with non-crosslinked Polyethylene and 83,890 procedures with crosslinked Polyethylene, all of which were performed for osteoarthritis. The survivorship of the different Polyethylenes was estimated using the Kaplan-Meier method and was compared using proportional hazard models.Results — The 10-year cumulative revision rate for non-crosslinked Polyethylene was 5.8% (95% CI: 5.7–6.0) and for crosslinked Polyethylene it was 3.5% (95% CI: 3.2–3.8) (> 6.5-year HR = 2.2 (1.5–3.1); p < ...
Steven M Kurtz - One of the best experts on this subject based on the ideXlab platform.
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radiation and chemical crosslinking promote strain hardening behavior and molecular alignment in ultra high molecular weight Polyethylene during multi axial loading conditions
Biomaterials, 1999Co-Authors: Steven M Kurtz, Lisa A Pruitt, C W Jewett, Jude R Foulds, Avram A EdidinAbstract:The mechanical behavior and evolution of crystalline morphology during large deformation of eight types of virgin and crosslinked ultra high molecular weight Polyethylene (UHMWPE) were studied using the small punch test and transmission electron microscopy (TEM). We investigated the hypothesis that both radiation and chemical crosslinking hinder molecular mobility at large deformations, and hence promote strain hardening and molecular alignment during the multiaxial loading of the small punch test. Chemical crosslinking of UHMWPE was performed using 0.25% dicumyl peroxide (GHR 8110, GUR 1020 and 1050), and radiation crosslinking was performed using 150 kGy of electron beam radiation (GUR 1150). Crosslinking increased the ultimate load at failure and decreased the ultimate displacement of the Polyethylenes during the small punch test. Crosslinking also increased the near-ultimate hardening behavior of the Polyethylenes. Transmission electron microscopy was used to characterize the crystalline morphology of the bulk material, undeformed regions of the small punch test specimens, and deformed regions of the specimens oriented perpendicular and parallel to the punch direction. In contrast with the virgin Polyethylenes, which showed only subtle evidence of lamellar alignment, the crosslinked Polyethylenes exhibited enhanced crystalline lamellae orientation after the small punch test, predominantly in the direction parallel to the punch direction or deformation axis. Thus, the results of this study support the hypothesis that crosslinking promotes strain hardening during multiaxial loading because of increased resistance to molecular mobility at large deformations effected by molecular alignment. The data also illustrate the sensitivity of large deformation mechanical behavior and crystalline morphology to the method of crosslinking and resin of Polyethylene.