Regardless of the advancement of synthetic bone substitutes,allograft-derived bone substitutes still dominate in the orthopaedic circle in the treatments of bone diseases.Nevertheless,the stringent devitalization proc...Regardless of the advancement of synthetic bone substitutes,allograft-derived bone substitutes still dominate in the orthopaedic circle in the treatments of bone diseases.Nevertheless,the stringent devitalization process jeopardizes their osseointegration with host bone and therefore prone to long-term failure.Hence,improving osseointegration and transplantation efficiency remains important.The alteration of bone tissue microenvironment(TME)to facilitate osseointegration has been generally recognized.However,the concept of exerting metal ionic cue in bone TME without compromising the mechanical properties of bone allograft is challenging.To address this concern,an interfacial tissue microenvironment with magnesium cationc cue was tailored onto the gamma-irradiated allograft bone using a customized magnesium-plasma surface treatment.The formation of the Mg cationic cue enriched interfacial tissue microenvironment on allograft bone was verified by the scanning ion-selective electrode technique.The cellular activities of human TERT-immortalized mesenchymal stem cells on the Mg-enriched grafts were notably upregulated.In the animal test,superior osseointegration between Mg-enriched graft and host bone was found,whereas poor integration was observed in the gamma-irradiated controls at 28 days post-operation.Furthermore,the bony in-growth appeared on magnesium-enriched allograft bone was significant higher.The mechanism possibly correlates to the up-regulation of integrin receptors in mesenchymal stem cells under modified bone TME that directly orchestrate the initial cell attachment and osteogenic differentiation of mesenchymal stem cells.Lastly,our findings demonstrate the significance of magnesium cation modified bone allograft that can potentially translate to various orthopaedic procedures requiring bone augmentation.展开更多
This paper presents a probabilistic approach for studying the reliability of cementless hip prostheses in the presence of mechanical uncertainties and its application to the investigation of the influence of bone-impl...This paper presents a probabilistic approach for studying the reliability of cementless hip prostheses in the presence of mechanical uncertainties and its application to the investigation of the influence of bone-implant interface properties. The non-linear deterministic model of the bone-implant coupled system and its finite element implementation are described, and the proposed reliability analysis is exposed. It is demonstrated that the distribution (uniform, truncated Gaussian and truncated lognormal distribution) of the two chosen parameters and the truncation lengths have a minor influence on the Hasofer-Lind index. This index logically increases as the failure threshold increases. FORM and SORM approximations are compared with the results obtained using a crude Monte-Carlo method for the estimation of failure probability. The performance of three Monte-Carlo methods is studied in terms of the necessary number of FE calculations. The method based on the Directional Simulation (DS) technique is efficient and less time-consuming. The validity and operational capacity of the proposed approach would not be compromised by an increase in the number of uncertain parameters.展开更多
BACKGROUND Today,biological fixation of uncemented press-fit acetabular components plays an important role in total hip arthroplasty.Long-term stable fixation of these implants depends on the osseointegration of the a...BACKGROUND Today,biological fixation of uncemented press-fit acetabular components plays an important role in total hip arthroplasty.Long-term stable fixation of these implants depends on the osseointegration of the acetabular cup bone tissue into the acetabular cup implant,and their ability to withstand functional loads.AIM To compare the strength of bone-implant osseointegration of four types of porous metal implants in normal and osteoporotic bone in rabbits.METHODS The study was performed in 50 female California rabbits divided into nonovariectomized(non-OVX)and ovariectomized groups(OVX)at 6 mo of age.Rabbits were sacrificed 8 wk after the implantation of four biomaterials[TTM,CONCELOC,Zimmer Biomet's Trabecular Metal(TANTALUM),and ATLANT]in a 5-mm diameter defect created in the left femur.A biomechanical evaluation of the femur was carried out by testing implant breakout force.The force was gradually increased until complete detachment of the implant from the bone occurred.RESULTS The breakout force needed for implant detachment was significantly higher in the non-OVX group,compared with the OVX group for all implants(TANTALUM,194.7±6.1 N vs 181.3±2.8 N;P=0.005;CONCELOC,190.8±3.6 N vs 180.9±6.6 N;P=0.019;TTM,186.3±1.8 N vs 172.0 N±11.0 N;P=0.043;and ATLANT,104.9±7.0 N vs 78.9 N±4.5 N;P=0.001).In the OVX group,The breakout forces in TANTALUM,TTM,and CONCELOC did not differ significantly(P=0.066).The breakout force for ATLANT in the OVX group was lower by a factor of 2.3 compared with TANTALUM and CONCELOC,and by 2.2 compared with TTM(P=0.001).In the non-OVX group,the breakout force for ATLANT was significantly different from all other implants,with a reduction in fixation strength by a factor of 1.9(P=0.001).CONCLUSION TANTALUM,TTM,and CONCELOC had equal bone-implant osseointegration in healthy and in osteoporotic bone.ATLANT had significantly decreased osseointegration(P=0.001)in healthy and in osteoporotic bone.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.81902189,81772354,82002303,31570980)Clinical Innovation Research Program of Guangzhou Regenerative Medicine and Health Guangdong Laboratory(2018GZR0201001)+6 种基金National Key Research and Development Plan(2018YFC1105103)Research Grant Council General Research Funds(RGC GRF)(17214516)Shenzhen Science and Technology Innovation Funding(JCYJ20160429190821781 and JCYJ2016429185449249)Science Technology Project of Guangzhou City(201804010185)Science and Technology Innovation Project of Foshan City(1920001000025)Scientific Research Foundation of PEKING UNIVERSITY SHENZHEN HOSPITAL KYQD(2021064)National Young Thousand-Talent Scheme to Zhang Zhi-Yong.
文摘Regardless of the advancement of synthetic bone substitutes,allograft-derived bone substitutes still dominate in the orthopaedic circle in the treatments of bone diseases.Nevertheless,the stringent devitalization process jeopardizes their osseointegration with host bone and therefore prone to long-term failure.Hence,improving osseointegration and transplantation efficiency remains important.The alteration of bone tissue microenvironment(TME)to facilitate osseointegration has been generally recognized.However,the concept of exerting metal ionic cue in bone TME without compromising the mechanical properties of bone allograft is challenging.To address this concern,an interfacial tissue microenvironment with magnesium cationc cue was tailored onto the gamma-irradiated allograft bone using a customized magnesium-plasma surface treatment.The formation of the Mg cationic cue enriched interfacial tissue microenvironment on allograft bone was verified by the scanning ion-selective electrode technique.The cellular activities of human TERT-immortalized mesenchymal stem cells on the Mg-enriched grafts were notably upregulated.In the animal test,superior osseointegration between Mg-enriched graft and host bone was found,whereas poor integration was observed in the gamma-irradiated controls at 28 days post-operation.Furthermore,the bony in-growth appeared on magnesium-enriched allograft bone was significant higher.The mechanism possibly correlates to the up-regulation of integrin receptors in mesenchymal stem cells under modified bone TME that directly orchestrate the initial cell attachment and osteogenic differentiation of mesenchymal stem cells.Lastly,our findings demonstrate the significance of magnesium cation modified bone allograft that can potentially translate to various orthopaedic procedures requiring bone augmentation.
文摘This paper presents a probabilistic approach for studying the reliability of cementless hip prostheses in the presence of mechanical uncertainties and its application to the investigation of the influence of bone-implant interface properties. The non-linear deterministic model of the bone-implant coupled system and its finite element implementation are described, and the proposed reliability analysis is exposed. It is demonstrated that the distribution (uniform, truncated Gaussian and truncated lognormal distribution) of the two chosen parameters and the truncation lengths have a minor influence on the Hasofer-Lind index. This index logically increases as the failure threshold increases. FORM and SORM approximations are compared with the results obtained using a crude Monte-Carlo method for the estimation of failure probability. The performance of three Monte-Carlo methods is studied in terms of the necessary number of FE calculations. The method based on the Directional Simulation (DS) technique is efficient and less time-consuming. The validity and operational capacity of the proposed approach would not be compromised by an increase in the number of uncertain parameters.
文摘BACKGROUND Today,biological fixation of uncemented press-fit acetabular components plays an important role in total hip arthroplasty.Long-term stable fixation of these implants depends on the osseointegration of the acetabular cup bone tissue into the acetabular cup implant,and their ability to withstand functional loads.AIM To compare the strength of bone-implant osseointegration of four types of porous metal implants in normal and osteoporotic bone in rabbits.METHODS The study was performed in 50 female California rabbits divided into nonovariectomized(non-OVX)and ovariectomized groups(OVX)at 6 mo of age.Rabbits were sacrificed 8 wk after the implantation of four biomaterials[TTM,CONCELOC,Zimmer Biomet's Trabecular Metal(TANTALUM),and ATLANT]in a 5-mm diameter defect created in the left femur.A biomechanical evaluation of the femur was carried out by testing implant breakout force.The force was gradually increased until complete detachment of the implant from the bone occurred.RESULTS The breakout force needed for implant detachment was significantly higher in the non-OVX group,compared with the OVX group for all implants(TANTALUM,194.7±6.1 N vs 181.3±2.8 N;P=0.005;CONCELOC,190.8±3.6 N vs 180.9±6.6 N;P=0.019;TTM,186.3±1.8 N vs 172.0 N±11.0 N;P=0.043;and ATLANT,104.9±7.0 N vs 78.9 N±4.5 N;P=0.001).In the OVX group,The breakout forces in TANTALUM,TTM,and CONCELOC did not differ significantly(P=0.066).The breakout force for ATLANT in the OVX group was lower by a factor of 2.3 compared with TANTALUM and CONCELOC,and by 2.2 compared with TTM(P=0.001).In the non-OVX group,the breakout force for ATLANT was significantly different from all other implants,with a reduction in fixation strength by a factor of 1.9(P=0.001).CONCLUSION TANTALUM,TTM,and CONCELOC had equal bone-implant osseointegration in healthy and in osteoporotic bone.ATLANT had significantly decreased osseointegration(P=0.001)in healthy and in osteoporotic bone.
