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Cynthia E. Dunning - One of the best experts on this subject based on the ideXlab platform.
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the effect of Stem Material and surface treatment on the torsional stability at the metal cement interface of upper limb joint replacement syStems
Journal of Biomedical Materials Research Part B, 2014Co-Authors: Yara K Hosein, Graham J.w. King, Cynthia E. DunningAbstract:Stem surface treatment and Material are two design factors that may affect the onset of implant loosening. For upper limb applications, no known in vitro studies have addressed the role of these two factors on cemented implant stability. Therefore, the purpose of this study was to compare the torsional stability of cemented titanium and cobalt chrome Stems with varying surface treatments in vitro. Thirty implant Stems of circular cross-section (O = 8mm) were machined from cobalt chrome (n = 15) and titanium (n = 15). For each type, Stems were subdivided into three groups for application of clinically relevant surface treatments: smooth, sintered beads, or plasma spray. Stems were potted in bone cement, allowed 24 h to cure, and placed in a Materials testing machine. Stems were tested under cyclic torsion (1-30 Nm), using a staircase loading protocol. Failure was defined as either the first rapid increase in Stem rotation without resistance, or attaining a maximum torque of 30 Nm. Implant Stems with non-smooth surfaces offered greater resistance to torsion (p < 0.05), with the plasma spray treatment outlasting the beaded and smooth Stems (p < 0.05). Titanium offered superior interface strength (p < 0.05) but reduced resistance to motion (p < 0.05) when compared to cobalt chrome. Therefore, these design features should be considered during upper limb implant design.
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The effect of Stem Material and surface treatment on the torsional stability at the metal–cement interface of upper limb joint replacement syStems
Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2014Co-Authors: Yara K Hosein, Graham J.w. King, Cynthia E. DunningAbstract:Stem surface treatment and Material are two design factors that may affect the onset of implant loosening. For upper limb applications, no known in vitro studies have addressed the role of these two factors on cemented implant stability. Therefore, the purpose of this study was to compare the torsional stability of cemented titanium and cobalt chrome Stems with varying surface treatments in vitro. Thirty implant Stems of circular cross-section (O = 8mm) were machined from cobalt chrome (n = 15) and titanium (n = 15). For each type, Stems were subdivided into three groups for application of clinically relevant surface treatments: smooth, sintered beads, or plasma spray. Stems were potted in bone cement, allowed 24 h to cure, and placed in a Materials testing machine. Stems were tested under cyclic torsion (1-30 Nm), using a staircase loading protocol. Failure was defined as either the first rapid increase in Stem rotation without resistance, or attaining a maximum torque of 30 Nm. Implant Stems with non-smooth surfaces offered greater resistance to torsion (p < 0.05), with the plasma spray treatment outlasting the beaded and smooth Stems (p < 0.05). Titanium offered superior interface strength (p < 0.05) but reduced resistance to motion (p < 0.05) when compared to cobalt chrome. Therefore, these design features should be considered during upper limb implant design.
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The Effect of Distal Ulnar Implant Stem Material and Length on Bone Strains
The Journal of Hand Surgery, 2007Co-Authors: Rebecca L. Austman, Brendon J. B. Beaton, Cheryl E. Quenneville, Graham J.w. King, Karen D. Gordon, Cynthia E. DunningAbstract:Purpose Implant design parameters can greatly affect load transfer from the implant Stem to the bone. We have investigated the effect of length or Material of distal ulnar implant Stems on the surrounding bone strains. Methods Eight cadaveric ulnas were instrumented with 12 strain gauges and secured in a customized jig. Strain data were collected while loads (5–30 N) were applied to the medial surface of the native ulnar head. The native ulnar head was removed, and a stainless steel implant with an 8-cm–long finely threaded Stem was cemented into the canal. After the cement had cured, the 8-cm Stem was removed, leaving a threaded cement mantle in the canal that could accept shorter threaded Stems of interest. The loading protocol was then repeated for stainless steel Stems that were 7, 5, and 3 cm in length, as well as for a 5-cm–long titanium alloy (TiAl 6 V 4 ) Stem. Other stainless steel Stem lengths between 3 and 7 cm were tested at intervals of 0.5 cm, with only a 20 N load applied. Results No Stem length tested matched the native strains at all gauge locations. No significant differences were found between any Stem length and the native bone at the 5th and 6th strain gauge positions. Strains were consistently closer to the native bone strains with the titanium Stem than the stainless steel Stem for each gauge pair that was positioned on the bone overlying the Stem. The 3-cm Stem results were closer to the native strains than the 7-cm Stem for all loads at gauges locations that were on top of the Stem. Conclusions The results from this study suggest that the optimal Stem characteristics for distal ulnar implants from a load transfer point of view are possessed by shorter (approximately 3 to 4 cm) titanium Stems.
Yara K Hosein - One of the best experts on this subject based on the ideXlab platform.
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the effect of Stem Material and surface treatment on the torsional stability at the metal cement interface of upper limb joint replacement syStems
Journal of Biomedical Materials Research Part B, 2014Co-Authors: Yara K Hosein, Graham J.w. King, Cynthia E. DunningAbstract:Stem surface treatment and Material are two design factors that may affect the onset of implant loosening. For upper limb applications, no known in vitro studies have addressed the role of these two factors on cemented implant stability. Therefore, the purpose of this study was to compare the torsional stability of cemented titanium and cobalt chrome Stems with varying surface treatments in vitro. Thirty implant Stems of circular cross-section (O = 8mm) were machined from cobalt chrome (n = 15) and titanium (n = 15). For each type, Stems were subdivided into three groups for application of clinically relevant surface treatments: smooth, sintered beads, or plasma spray. Stems were potted in bone cement, allowed 24 h to cure, and placed in a Materials testing machine. Stems were tested under cyclic torsion (1-30 Nm), using a staircase loading protocol. Failure was defined as either the first rapid increase in Stem rotation without resistance, or attaining a maximum torque of 30 Nm. Implant Stems with non-smooth surfaces offered greater resistance to torsion (p < 0.05), with the plasma spray treatment outlasting the beaded and smooth Stems (p < 0.05). Titanium offered superior interface strength (p < 0.05) but reduced resistance to motion (p < 0.05) when compared to cobalt chrome. Therefore, these design features should be considered during upper limb implant design.
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The effect of Stem Material and surface treatment on the torsional stability at the metal–cement interface of upper limb joint replacement syStems
Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2014Co-Authors: Yara K Hosein, Graham J.w. King, Cynthia E. DunningAbstract:Stem surface treatment and Material are two design factors that may affect the onset of implant loosening. For upper limb applications, no known in vitro studies have addressed the role of these two factors on cemented implant stability. Therefore, the purpose of this study was to compare the torsional stability of cemented titanium and cobalt chrome Stems with varying surface treatments in vitro. Thirty implant Stems of circular cross-section (O = 8mm) were machined from cobalt chrome (n = 15) and titanium (n = 15). For each type, Stems were subdivided into three groups for application of clinically relevant surface treatments: smooth, sintered beads, or plasma spray. Stems were potted in bone cement, allowed 24 h to cure, and placed in a Materials testing machine. Stems were tested under cyclic torsion (1-30 Nm), using a staircase loading protocol. Failure was defined as either the first rapid increase in Stem rotation without resistance, or attaining a maximum torque of 30 Nm. Implant Stems with non-smooth surfaces offered greater resistance to torsion (p < 0.05), with the plasma spray treatment outlasting the beaded and smooth Stems (p < 0.05). Titanium offered superior interface strength (p < 0.05) but reduced resistance to motion (p < 0.05) when compared to cobalt chrome. Therefore, these design features should be considered during upper limb implant design.
Efendi Mabruri - One of the best experts on this subject based on the ideXlab platform.
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Fenomena Temper Embrittlement Pada Baja Martensitik AISI 410 Untuk Aplikasi Stem Gate Valve 20” Class 150 Grade WCB [Temper Embrittlement Phenomena of AISI 410 Martensitic Steel for Stem Gate Valve 20” Class 150 Grade WCB ]
Metalurgija, 2016Co-Authors: Galih Senopati, Cahya Sutowo, Efendi MabruriAbstract:Temper embrittlement is a phenomenon that will decrease the toughness of steel due to tempering process at a certain temperature range. This phenomenon has been found in martensitic steel. This research is investigated the failure in Stem gate valve of crude oil pipeline syStem. The Stem gate valve Material is made of stainless steel AISI 410. Several examinations were done to study cause of failure in Stem gate valve such as visual inspection, chemical composition test using OES (optical emission spectrometer) and EDS (energy dispersive spectrometry), metallography observation by using optical microscopy (OM) and SEM (scanning electron microscopy), fractography using SEM, and Rockwell hardness test. Chemical composition test result on Stem gate valve showed 13,65-13,67 wt.% Cr. The content of Cr in Stem Material is out from the required composition of AISI standard with the requirement of Cr amount 13,5 wt.%. Fractography result on the surface of failure Stem area by SEM was observed intergranular crack followed by secondary crack. Its indicated that Stem gate valve failure was caused by temper embrittlement due to tempering process. Abstrak Temper embrittlement merupakan fenomena penurunan kekuatan dari Material baja yang disebabkan oleh proses tempering pada rentang temperatur tertentu. Beberapa kasus temper embrittlement ditemukan pada baja martensitik. Pada studi kali ini dilakukan pengamatan terhadap Stem gate valve pada siStem perpipaan minyak mentah yang mengalami patah. Stem gate valve tersebut terbuat dari baja tahan karat martensitik tipe AISI 410. Kemudian dilakukan beberapa pengujian untuk mengetahui proses terjadinya patah pada Stem gate valve yang meliputi pemeriksaan visual, analisa komposisi kimia dengan OES (optical emission spectrometer) dan EDS (energy dispersive spectrometry), pengamatan metalografi dengan OM (optical microscopy) dan SEM (scanning electron microscopy), fraktografi dengan SEM, serta uji keras Rockwell. Hasil pemeriksaan pada Stem gate valve menunjukkan komposisi Cr adalah 13,65-13,67 % berat atau melebihi batas atas standar AISI 410 yaitu 13,5 %berat. Dari pengamatan struktur mikro diketahui Material Stem gate valve dalam kondisi telah dilakukan proses tempering dan teramati adanya secondary crack. Dari pengamatan fraktografi diketahui jenis retakan pada permukaan Stem yang patah adalah retakan antar butir (intergranular crack) yang mengindikasikan terjadinya proses temper embrittlement pada saat proses tempering Material Stem gate valve.
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fenomena temper embrittlement pada baja martensitik aisi 410 untuk aplikasi Stem gate valve 20 class 150 grade wcb temper embrittlement phenomena of aisi 410 martensitic steel for Stem gate valve 20 class 150 grade wcb
Metalurgija, 2016Co-Authors: Galih Senopati, Cahya Sutowo, Efendi MabruriAbstract:Temper embrittlement is a phenomenon that will decrease the toughness of steel due to tempering process at a certain temperature range. This phenomenon has been found in martensitic steel. This research is investigated the failure in Stem gate valve of crude oil pipeline syStem. The Stem gate valve Material is made of stainless steel AISI 410. Several examinations were done to study cause of failure in Stem gate valve such as visual inspection, chemical composition test using OES (optical emission spectrometer) and EDS (energy dispersive spectrometry), metallography observation by using optical microscopy (OM) and SEM (scanning electron microscopy), fractography using SEM, and Rockwell hardness test. Chemical composition test result on Stem gate valve showed 13,65-13,67 wt.% Cr. The content of Cr in Stem Material is out from the required composition of AISI standard with the requirement of Cr amount 13,5 wt.%. Fractography result on the surface of failure Stem area by SEM was observed intergranular crack followed by secondary crack. Its indicated that Stem gate valve failure was caused by temper embrittlement due to tempering process. Abstrak Temper embrittlement merupakan fenomena penurunan kekuatan dari Material baja yang disebabkan oleh proses tempering pada rentang temperatur tertentu. Beberapa kasus temper embrittlement ditemukan pada baja martensitik. Pada studi kali ini dilakukan pengamatan terhadap Stem gate valve pada siStem perpipaan minyak mentah yang mengalami patah. Stem gate valve tersebut terbuat dari baja tahan karat martensitik tipe AISI 410. Kemudian dilakukan beberapa pengujian untuk mengetahui proses terjadinya patah pada Stem gate valve yang meliputi pemeriksaan visual, analisa komposisi kimia dengan OES (optical emission spectrometer) dan EDS (energy dispersive spectrometry), pengamatan metalografi dengan OM (optical microscopy) dan SEM (scanning electron microscopy), fraktografi dengan SEM, serta uji keras Rockwell. Hasil pemeriksaan pada Stem gate valve menunjukkan komposisi Cr adalah 13,65-13,67 % berat atau melebihi batas atas standar AISI 410 yaitu 13,5 %berat. Dari pengamatan struktur mikro diketahui Material Stem gate valve dalam kondisi telah dilakukan proses tempering dan teramati adanya secondary crack. Dari pengamatan fraktografi diketahui jenis retakan pada permukaan Stem yang patah adalah retakan antar butir (intergranular crack) yang mengindikasikan terjadinya proses temper embrittlement pada saat proses tempering Material Stem gate valve.
J A Simoes - One of the best experts on this subject based on the ideXlab platform.
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relationship of design features of Stemmed tibial knee prosthesis with stress shielding and end of Stem pain
Materials & Design, 2009Co-Authors: Antonio Completo, Pedro Talaia, Fernando Fonseca, J A SimoesAbstract:Abstract Materials and design are important issues within general product development and even more in biomedical product. Knee prosthesis is a product that still lacks of adequate design solutions. Stress shielding and stress concentrations related to the end-of-Stem pain are frequent clinical evidences that are intimately related to the design of the prosthesis and Stems used in revision total knee arthroplasty, to the femoral and tibial components. Stress shielding and stress concentrations were assessed through finite element analyses of different tibial Stem designs. Stress shielding was determined considering the relative minimal principal cancellous bone stresses between implanted and intact tibiae models. Scintigraphy and radiographs of painful implanted knees were assessed to correlate clinical findings with the finite element stresses. This study showed that Stem design, geometry and Material change the mechanical behavior of bone around tibial tray and Stem in revision TKA. For the analyzed bone regions, underneath tibial tray and around the Stem, the geometry of Stem had a more pronounced bone effect comparatively to the Stem Material. The results of this study support that short Stems produce a minor effect in bone relatively to long Stem in terms of stress shielding and stress concentration at tip region. No significant stress shielding differences was observed between Co–Cr and titanium Stems. Overall, all Stems provoked high stress concentrations in bone at the tip of the Stem. Scintigraphy of a painful implanted knee showed local osteoblastic activity and radiographs evidence bone ossification at the distal tip of the Stem due the stress concentration. The results show that long Stems induce very high distal stresses and are more prone to induce pain. A new concept of long Stem with a distal polymeric (flexible Material) tip reduces the magnitude of stresses at the end of the Stem and therefore can theoretically contribute to reduce pain.
Graham J.w. King - One of the best experts on this subject based on the ideXlab platform.
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the effect of Stem Material and surface treatment on the torsional stability at the metal cement interface of upper limb joint replacement syStems
Journal of Biomedical Materials Research Part B, 2014Co-Authors: Yara K Hosein, Graham J.w. King, Cynthia E. DunningAbstract:Stem surface treatment and Material are two design factors that may affect the onset of implant loosening. For upper limb applications, no known in vitro studies have addressed the role of these two factors on cemented implant stability. Therefore, the purpose of this study was to compare the torsional stability of cemented titanium and cobalt chrome Stems with varying surface treatments in vitro. Thirty implant Stems of circular cross-section (O = 8mm) were machined from cobalt chrome (n = 15) and titanium (n = 15). For each type, Stems were subdivided into three groups for application of clinically relevant surface treatments: smooth, sintered beads, or plasma spray. Stems were potted in bone cement, allowed 24 h to cure, and placed in a Materials testing machine. Stems were tested under cyclic torsion (1-30 Nm), using a staircase loading protocol. Failure was defined as either the first rapid increase in Stem rotation without resistance, or attaining a maximum torque of 30 Nm. Implant Stems with non-smooth surfaces offered greater resistance to torsion (p < 0.05), with the plasma spray treatment outlasting the beaded and smooth Stems (p < 0.05). Titanium offered superior interface strength (p < 0.05) but reduced resistance to motion (p < 0.05) when compared to cobalt chrome. Therefore, these design features should be considered during upper limb implant design.
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The effect of Stem Material and surface treatment on the torsional stability at the metal–cement interface of upper limb joint replacement syStems
Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2014Co-Authors: Yara K Hosein, Graham J.w. King, Cynthia E. DunningAbstract:Stem surface treatment and Material are two design factors that may affect the onset of implant loosening. For upper limb applications, no known in vitro studies have addressed the role of these two factors on cemented implant stability. Therefore, the purpose of this study was to compare the torsional stability of cemented titanium and cobalt chrome Stems with varying surface treatments in vitro. Thirty implant Stems of circular cross-section (O = 8mm) were machined from cobalt chrome (n = 15) and titanium (n = 15). For each type, Stems were subdivided into three groups for application of clinically relevant surface treatments: smooth, sintered beads, or plasma spray. Stems were potted in bone cement, allowed 24 h to cure, and placed in a Materials testing machine. Stems were tested under cyclic torsion (1-30 Nm), using a staircase loading protocol. Failure was defined as either the first rapid increase in Stem rotation without resistance, or attaining a maximum torque of 30 Nm. Implant Stems with non-smooth surfaces offered greater resistance to torsion (p < 0.05), with the plasma spray treatment outlasting the beaded and smooth Stems (p < 0.05). Titanium offered superior interface strength (p < 0.05) but reduced resistance to motion (p < 0.05) when compared to cobalt chrome. Therefore, these design features should be considered during upper limb implant design.
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The Effect of Distal Ulnar Implant Stem Material and Length on Bone Strains
The Journal of Hand Surgery, 2007Co-Authors: Rebecca L. Austman, Brendon J. B. Beaton, Cheryl E. Quenneville, Graham J.w. King, Karen D. Gordon, Cynthia E. DunningAbstract:Purpose Implant design parameters can greatly affect load transfer from the implant Stem to the bone. We have investigated the effect of length or Material of distal ulnar implant Stems on the surrounding bone strains. Methods Eight cadaveric ulnas were instrumented with 12 strain gauges and secured in a customized jig. Strain data were collected while loads (5–30 N) were applied to the medial surface of the native ulnar head. The native ulnar head was removed, and a stainless steel implant with an 8-cm–long finely threaded Stem was cemented into the canal. After the cement had cured, the 8-cm Stem was removed, leaving a threaded cement mantle in the canal that could accept shorter threaded Stems of interest. The loading protocol was then repeated for stainless steel Stems that were 7, 5, and 3 cm in length, as well as for a 5-cm–long titanium alloy (TiAl 6 V 4 ) Stem. Other stainless steel Stem lengths between 3 and 7 cm were tested at intervals of 0.5 cm, with only a 20 N load applied. Results No Stem length tested matched the native strains at all gauge locations. No significant differences were found between any Stem length and the native bone at the 5th and 6th strain gauge positions. Strains were consistently closer to the native bone strains with the titanium Stem than the stainless steel Stem for each gauge pair that was positioned on the bone overlying the Stem. The 3-cm Stem results were closer to the native strains than the 7-cm Stem for all loads at gauges locations that were on top of the Stem. Conclusions The results from this study suggest that the optimal Stem characteristics for distal ulnar implants from a load transfer point of view are possessed by shorter (approximately 3 to 4 cm) titanium Stems.