Magnesium-based implants are re-emerging as a substantial amendment to standard orthopaedic implants.A brief introduction of magnesium(Mg)as a biodegradable material and basic magnetic resonance imaging(MRI)principles...Magnesium-based implants are re-emerging as a substantial amendment to standard orthopaedic implants.A brief introduction of magnesium(Mg)as a biodegradable material and basic magnetic resonance imaging(MRI)principles are discussed.This review aims to highlight the current performance of these implants during examinations with MRI.We also aim to summarise comparisons between Mg-based implants with current standards to emphasise the promotion of biodegradable implants in clinical practice.A comprehensive search of current literature on Mg-based implants and the utilisation of MRI in the studies was performed.Additionally,recorded artefact behaviour of Mg-based implants during MRI was investigated.A total of nine studies were included in which MRI was employed to image Mg-based implants.Of those studies,four of the nine discuss artefact production caused by the implants.MRI successfully imaged regions of interest over all and produced fewer artefacts than other materials used in the studies.MRI was employed in contrast angiography,bone growth observation,bone infection healing,and blood perfusion.Imaging capabilities of an implant material are vital to translating products into clinical application.Positive findings presented in this review suggest and support the use of Mg-based implants due to their successful visual compatibility with MRI techniques.展开更多
An increasing prevalence of bone-related injuries and aging geriatric populations continue to drive the orthopaedic implant market.A hierarchical analysis of bone remodelling after material implantation is necessary t...An increasing prevalence of bone-related injuries and aging geriatric populations continue to drive the orthopaedic implant market.A hierarchical analysis of bone remodelling after material implantation is necessary to better understand the relationship between implant and bone.Osteocytes,which are housed and communicate through the lacuno-canalicular network(LCN),are integral to bone health and remodelling processes.Therefore,it is essential to examine the framework of the LCN in response to implant materials or surface treatments.Biodegradable materials offer an alternative solution to permanent implants,which may require revision or removal surgeries.Magnesium alloys have resurfaced as promising materials due to their bone-like properties and safe degradation in vivo.To further tailor their degradation capabilities,surface treatments such as plasma electrolytic oxidation(PEO)have demonstrated to slow degradation.For the first time,the influence of a biodegradable material on the LCN is investigated by means of non-destructive 3D imaging.In this pilot study,we hypothesize noticeable variations in the LCN caused by altered chemical stimuli introduced by the PEO-coating.Utilising synchrotron-based transmission X-ray microscopy,we have characterised morphological LCN differences around uncoated and PEO-coated WE43 screws implanted into sheep bone.Bone specimens were explanted after 4,8,and 12 weeks and regions near the implant surface were prepared for imaging.Findings from this investigation indicate that the slower degradation of PEO-coated WE43 induces healthier lacunar shapes within the LCN.However,the stimuli perceived by the uncoated material with higher degradation rates induces a greater connected LCN better prepared for bone disturbance.展开更多
Magnesium(Mg)-based implants have re-emerged in orthopaedic surgery as an alternative to permanent implants.Literature reveals little information on how the degradation of biodegradable implants may introduce safety i...Magnesium(Mg)-based implants have re-emerged in orthopaedic surgery as an alternative to permanent implants.Literature reveals little information on how the degradation of biodegradable implants may introduce safety implications for patient follow-up using medical imaging.Magnetic resonance imaging(MRI)benefits post-surgery monitoring of bone healing and implantation sites.Previous studies demonstrated radiofrequency(RF)heating of permanent implants caused by electromagnetic fields used in MRI.Our investigation is the first to report the effect of the degradation layer on RF-induced heating of biodegradable orthopaedic implants.WE43 orthopaedic compression screws underwent in vitro degradation.Imaging techniques were applied to assess the corrosion process and the material composition of the degraded screws.Temperature measurements were performed to quantify implant heating with respect to the degradation layer.For comparison,a commercial titanium implant screw was used.Strongest RF induced heating was observed for non-degraded WE43 screw samples.Implant heating had shown to decrease with the formation of the degradation layer.No statistical differences were observed for heating of the non-degraded WE43 material and the titanium equivalent.The highest risk of implant RF heating is most pronounced for Mg-based screws prior to degradation.Amendment to industry standards for MRI safety assessment is warranted to include biodegradable materials.展开更多
Magnesium(Mg)implants have shown to cause image artefacts or distortions in magnetic resonance imaging(MRI).Yet,there is a lack of information on how the degradation of Mg-based implants influences the image quality o...Magnesium(Mg)implants have shown to cause image artefacts or distortions in magnetic resonance imaging(MRI).Yet,there is a lack of information on how the degradation of Mg-based implants influences the image quality of MRI examinations.In this study,Mg-based implants are analysed in vitro,ex vivo,and in the clinical setting for various magnetic field strengths with the aim to quantify metallic artefact behaviour.In vitro corroded Mg-based screws and a titanium(Ti)equivalent were imaged according to the ASTM F2119.Mg-based and Ti pins were also implanted into rat femurs for different time points and scanned to provide insights on the influence of soft and hard tissue on metallic artefact.Additionally,MRI data of patients with scaphoid fractures treated with CE-approved Mg-based compression screws(MAGNEZIX®)were analysed at various time points post-surgery.The artefact production of the Mg-based material decreased as implant material degraded in all settings.The worst-case imaging scenario was determined to be when the imaging plane was selected to be perpendicular to the implant axis.Moreover,the Mg-based implant outperformed the Ti equivalent in all experiments by producing lower metallic artefact(p<0.05).This investigation demonstrates that Mg-based implants generate significantly lower metallic distortion in MRI when compared to Ti.Our positive findings suggest and support further research into the application of Mg-based implants including post-operative care facilitated by MRI monitoring of degradation kinetics and bone/tissue healing processes.展开更多
基金This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 811226.
文摘Magnesium-based implants are re-emerging as a substantial amendment to standard orthopaedic implants.A brief introduction of magnesium(Mg)as a biodegradable material and basic magnetic resonance imaging(MRI)principles are discussed.This review aims to highlight the current performance of these implants during examinations with MRI.We also aim to summarise comparisons between Mg-based implants with current standards to emphasise the promotion of biodegradable implants in clinical practice.A comprehensive search of current literature on Mg-based implants and the utilisation of MRI in the studies was performed.Additionally,recorded artefact behaviour of Mg-based implants during MRI was investigated.A total of nine studies were included in which MRI was employed to image Mg-based implants.Of those studies,four of the nine discuss artefact production caused by the implants.MRI successfully imaged regions of interest over all and produced fewer artefacts than other materials used in the studies.MRI was employed in contrast angiography,bone growth observation,bone infection healing,and blood perfusion.Imaging capabilities of an implant material are vital to translating products into clinical application.Positive findings presented in this review suggest and support the use of Mg-based implants due to their successful visual compatibility with MRI techniques.
基金This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 811226.Author Flenner gratefully acknowledges the financial support from the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-Project number 192346071,SFB 986(project Z2).
文摘An increasing prevalence of bone-related injuries and aging geriatric populations continue to drive the orthopaedic implant market.A hierarchical analysis of bone remodelling after material implantation is necessary to better understand the relationship between implant and bone.Osteocytes,which are housed and communicate through the lacuno-canalicular network(LCN),are integral to bone health and remodelling processes.Therefore,it is essential to examine the framework of the LCN in response to implant materials or surface treatments.Biodegradable materials offer an alternative solution to permanent implants,which may require revision or removal surgeries.Magnesium alloys have resurfaced as promising materials due to their bone-like properties and safe degradation in vivo.To further tailor their degradation capabilities,surface treatments such as plasma electrolytic oxidation(PEO)have demonstrated to slow degradation.For the first time,the influence of a biodegradable material on the LCN is investigated by means of non-destructive 3D imaging.In this pilot study,we hypothesize noticeable variations in the LCN caused by altered chemical stimuli introduced by the PEO-coating.Utilising synchrotron-based transmission X-ray microscopy,we have characterised morphological LCN differences around uncoated and PEO-coated WE43 screws implanted into sheep bone.Bone specimens were explanted after 4,8,and 12 weeks and regions near the implant surface were prepared for imaging.Findings from this investigation indicate that the slower degradation of PEO-coated WE43 induces healthier lacunar shapes within the LCN.However,the stimuli perceived by the uncoated material with higher degradation rates induces a greater connected LCN better prepared for bone disturbance.
基金This project has received funding from the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Skłodowska-Curie Grant Agreement No 811226.
文摘Magnesium(Mg)-based implants have re-emerged in orthopaedic surgery as an alternative to permanent implants.Literature reveals little information on how the degradation of biodegradable implants may introduce safety implications for patient follow-up using medical imaging.Magnetic resonance imaging(MRI)benefits post-surgery monitoring of bone healing and implantation sites.Previous studies demonstrated radiofrequency(RF)heating of permanent implants caused by electromagnetic fields used in MRI.Our investigation is the first to report the effect of the degradation layer on RF-induced heating of biodegradable orthopaedic implants.WE43 orthopaedic compression screws underwent in vitro degradation.Imaging techniques were applied to assess the corrosion process and the material composition of the degraded screws.Temperature measurements were performed to quantify implant heating with respect to the degradation layer.For comparison,a commercial titanium implant screw was used.Strongest RF induced heating was observed for non-degraded WE43 screw samples.Implant heating had shown to decrease with the formation of the degradation layer.No statistical differences were observed for heating of the non-degraded WE43 material and the titanium equivalent.The highest risk of implant RF heating is most pronounced for Mg-based screws prior to degradation.Amendment to industry standards for MRI safety assessment is warranted to include biodegradable materials.
基金funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 811226.
文摘Magnesium(Mg)implants have shown to cause image artefacts or distortions in magnetic resonance imaging(MRI).Yet,there is a lack of information on how the degradation of Mg-based implants influences the image quality of MRI examinations.In this study,Mg-based implants are analysed in vitro,ex vivo,and in the clinical setting for various magnetic field strengths with the aim to quantify metallic artefact behaviour.In vitro corroded Mg-based screws and a titanium(Ti)equivalent were imaged according to the ASTM F2119.Mg-based and Ti pins were also implanted into rat femurs for different time points and scanned to provide insights on the influence of soft and hard tissue on metallic artefact.Additionally,MRI data of patients with scaphoid fractures treated with CE-approved Mg-based compression screws(MAGNEZIX®)were analysed at various time points post-surgery.The artefact production of the Mg-based material decreased as implant material degraded in all settings.The worst-case imaging scenario was determined to be when the imaging plane was selected to be perpendicular to the implant axis.Moreover,the Mg-based implant outperformed the Ti equivalent in all experiments by producing lower metallic artefact(p<0.05).This investigation demonstrates that Mg-based implants generate significantly lower metallic distortion in MRI when compared to Ti.Our positive findings suggest and support further research into the application of Mg-based implants including post-operative care facilitated by MRI monitoring of degradation kinetics and bone/tissue healing processes.
