The Experts below are selected from a list of 93 Experts worldwide ranked by ideXlab platform

L'hocine Yahia - One of the best experts on this subject based on the ideXlab platform.

  • Reduced stress shielding with limited micromotions using a carbon fibre Composite biomimetic hip Stem: a finite element model.
    Proceedings of the Institution of Mechanical Engineers. Part H Journal of engineering in medicine, 2011
    Co-Authors: Christiane Caouette, L'hocine Yahia, Martin N Bureau
    Abstract:

    Total hip arthroplasty (THA) enjoys excellent rates of success in older patients, but younger patients are still at risk of aseptic loosening and bone resorption from stress shielding. One solution to the stress shielding problem is to use a hip Stem with mechanical properties matching those of cortical bone. The objective of the present study was to investigate numerically the biomechanical performance of such a biomimetic hip Stem based on a hydroxyapatite (HA)-coated carbon fibre Composite. A finite element model (FEM) of the biomimetic Stem was constructed. Contact elements were studied to model the bone-implant interface in a non-osseointegrated and osseointegrated state in the best way. Three static load cases representing slow walking, stair climbing, and gait in a healthy individual were considered. Stress shielding and bone-implant interface micromotions were evaluated and compared with the results of a similar FEM based on titanium alloy (Ti-6Al-4V). The Composite Stems allowed for reduced stress shielding when compared with a traditional Ti-6Al-4V Stem. Micromotions were slightly higher with the Composite Stem, but remained below 40 microm on most of the HA-coated surface. It is concluded that a biomimetic Composite Stem might offer a better compromise between stress shielding and micromotions than the Ti-6Al-4V Stem with the same external geometry.

  • bone remodeling in a new biomimetic polymer Composite hip Stem
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Habiba Bougherara, Martin N Bureau, L'hocine Yahia
    Abstract:

    Adaptive bone remodeling is an important factor that leads to bone resorption in the surrounding femoral bone and implant loosening. Taking into account this factor in the design of hip implants is of clinical importance, because it allows the prediction of the bone-density redistribution and enables the monitoring of bone adaptation after prosthetic implantation. In this article, adaptive bone remodeling around a new biomimetic polymer-Composite-based (CF/PA12) hip prosthesis is investigated to evaluate the amount of stress shielding and bone resorption. The design concept of this new prosthesis is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF)-reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Strain energy density theory coupled with 3D Finite Element models is used to predict bone density redistributions in the femoral bone before and after total hip replacement (THR) using both polymer-Composite and titanium (Ti) Stems. The result of numerical simulations of bone remodeling revealed that the CF/PA12 Composite Stem generates a better bone density pattern compared with the Ti-based Stem, indicating the effectiveness of the Composite Stem to reduce bone resorption caused by stress-shielding phenomenon. This may result in an extended lifetime of THR.

  • Bone remodeling in a new biomimetic polymer-Composite hip Stem
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Habiba Bougherara, Martin N Bureau, L'hocine Yahia
    Abstract:

    Adaptive bone remodeling is an important factor that leads to bone resorption in the surroudning femoral bone and implant loosening. Taking into account this factor in the design of hip implants is of clinical importance, since it allows the prediction of the bone-density redistribution and enables the monitoring of bone adaptation after prosthetic implantation. In this paper adaptive bone remodeling around a new biomimetic polymer-Composite based (CF/PA12) hip prosthesis is investigated in order to evaluate the amount of stress shielding and bone resorption. The design concept of this new prosthesis is based on a hollow sub-structure made of hydroxyapatite-coated, continuous carbon fiber (BF) reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Strain energy density theory coupled with 3-D Finite Element models are used to predict bone desity redistributions in the femoral bone before and after total hip replacement using both polymer-Composite and titanium Stems. The result of numerical simulations of bone remodeling revealed that the CF-PA12 Composite Stem generates an excellent bone density pattern compared to the titanium-based Stem, indicating the effectiveness of the Composite Stem to reduce bone resorption caused by stress shielding phenomenon. This may result in an extended lifetime of Total Hip Replacement (THR).Le remodelage osseux adaptatif est un ph\ue9nom\ue8ne important menant \ue0 une r\ue9sorption du tissu osseux dans lequel est implant\ue9e une tige f\ue9morale, ce qui en affecte la stabilit\ue9. La prise en compte de ce facteur dans la conception des proth\ue8ses de hanche rev\ueat une importance clinique particuli\ue8re en permettant de pr\ue9voir la redistribution de la densit\ue9 min\ue9rale osseuse et d\u2019\ue9valuer l\u2019adaptation osseuse cons\ue9cutive \ue0 la pose de la proth\ue8se. Le pr\ue9sent article traite de l\u2019\ue9valuation du remodelage adaptatif du tissu osseux entourant un nouveau mod\ue8le de proth\ue8se de hanche en polym\ue8re Composite FC/PA12 biomim\ue9tique que nous avons effectu\ue9e dans le but de quantifier la r\ue9sorption osseuse par d\ue9viation des contraintes (ph\ue9nom\ue8ne de court-circuitage des contraintes) attribuable \ue0 la proth\ue8se. Recouverte d\u2019hydroxyapatite de calcium, la tige f\ue9morale \ue9tudi\ue9e se compose d\u2019une structure externe creuse monopi\ue8ce en polyamide 12 (PA12) renforc\ue9 de fibre de carbone (FC) dont la cavit\ue9 interne est remplie de polym\ue8re mou. L\u2019utilisation du crit\ue8re de l\u2019\ue9nergie de d\ue9formation minimale et de mod\ue8les 3D d\u2019\ue9l\ue9ments finis nous a permis de pr\ue9dire la distribution de la densit\ue9 min\ue9rale du tissu osseux f\ue9moral avant et apr\ue8s la pose d\u2019une proth\ue8se totale de hanche (PTH) comportant une tige f\ue9morale en polym\ue8re Composite ou une tige en titane (Ti). Les r\ue9sultats des simulations num\ue9riques du remodelage osseux r\ue9v\ue8lent que la tige f\ue9morale en polym\ue8re Composite FC/PA12 permet le maintien d\u2019une meilleure densit\ue9 min\ue9rale osseuse que la tige en titane, ce qui t\ue9moigne de l\u2019efficacit\ue9 de la tige en polym\ue8re Composite \ue0 r\ue9duire la r\ue9sorption osseuse attribuable \ue0 la d\ue9viation des contraintes. Ce mod\ue8le de tige f\ue9morale pourrait donc prolonger la dur\ue9e de vie utile de la proth\ue8se totale de hanche.Peer reviewed: YesNRC publication: Ye

  • A Novel Approach for Bone Remodeling After Prosthetic Implantation
    Damage and Fracture Mechanics, 2009
    Co-Authors: Habiba Bougherara, Václav Klika, František Maršík, Ivo A. Mařík, L'hocine Yahia
    Abstract:

    The aim of the present study is to predict the functional adaptation of bone in response to changes in mechanical loading using a new biothermodynamic model for bone remodeling. In our approach, which fits into the framework of open syStems, changes in the density are governed by balance of mass and balance of entropy supplemented by additional mass and entropy sources. The governing equations of bone remodeling process are based on irreversible thermodynamics and kinetics of chemical reactions. The key feature of this model is its ability to simulate the coupling between the mechanical and biochemical parameters that control bone remodeling, in particular the effect of dynamical loading, frequency of load and nutrition. Besides, the model can be used to predict some skeletal diseases such as bone fractures and osteoporosis. In the present paper, a biothermodynamic model was applied to the design of prosthetic implants. Numerical computations of bone density distributions after Total Hip Replacement (THR) using 3D finite element analysis showed that the biomimetic Composite Stem exhibit a better density patterns compared to the conventional titanium Stem, indicating that the biomimetic prosthesis promotes higher remodeling rate and consequently less stress shielding. Furthermore, the model showed that the concentration of a new bone strongly depends on the history and intensity of loading and also on nutrition.

  • design of a biomimetic polymer Composite hip prosthesis
    Journal of Biomedical Materials Research Part A, 2007
    Co-Authors: Habiba Bougherara, Martin N Bureau, Melissa Campbell, Aurelian Vadean, L'hocine Yahia
    Abstract:

    A new biomimetic Composite hip prosthesis (Stem) was designed to obtain properties similar to those of the contiguous bone, in particular stiffness, to allow normal loading of the surrounding femoral bone. This normal loading would reduce excessive stress shielding, known to result in bone loss, and micromotions at the bone-implant interface, leading to aseptic prosthetic loosening. The design proposed is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF) reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Different Composite configurations were studied to match the properties of host tissue. Nonlinear three-dimensional analysis of the hip prosthesis was carried out using a three-dimensional finite element bone model based on the Composite femur. The performance of Composite-based hip and titanium alloy-based (Ti-6Al-4V) Stems embedded into femoral bone was compared. The effect of core stiffness and ply configuration was also analyzed. Results show that stresses in Composite Stem are lower than those in Ti Stem, and that the femoral bone implanted with Composite structure sustains more load than the one implanted with Ti Stem. Micromotions in the Composite Stem are significantly smaller than those in Ti Stem over the entire bone-implant surface because of the favorable interfacial stress distribution.

Habiba Bougherara - One of the best experts on this subject based on the ideXlab platform.

  • a preliminary biomechanical study of a novel carbon fibre hip implant versus standard metallic hip implants
    Medical Engineering & Physics, 2011
    Co-Authors: Habiba Bougherara, Rad Zdero, A Dubov, Suraj Shah, Shaheen Khurshid, Emil H Schemitsch
    Abstract:

    Total hip arthroplasty is a widespread surgical approach for treating severe osteoarthritis of the human hip. Aseptic loosening of standard metallic hip implants due to stress shielding and bone loss has motivated the development of new materials for hip prostheses. Numerically, a three-dimensional finite element (FE) model that mimicked hip implants was used to compare a new hip Stem to two commercially available implants. The hip implants simulated were a novel CF/PA12 carbon-fibre polyamide-based Composite hip Stem, the Exeter hip Stem (Stryker, Mahwah, NJ, USA), and the Omnifit Eon (Stryker, Mahwah, NJ, USA). A virtual axial load of 3 kN was applied to the FE model. Strain and stress distributions were computed. Experimentally, the three hip Stems had their distal portions rigidly mounted and had strain gauges placed along the surface at 3 medial and 3 lateral locations. Axial loads of 3 kN were applied. Measurements of axial stiffness and strain were taken and compared to FE analysis. The overall linear correlation between FE model versus experimental strains showed reasonable results for the lines-of-best-fit for the Composite (Pearson R(2)=0.69, slope=0.82), Exeter (Pearson R(2)=0.78, slope=0.59), and Omnifit (Pearson R(2)=0.66, slope=0.45), with some divergence for the most distal strain locations. From FE analysis, the von Mises stress range for the Composite Stem was much lower than that in the Omnifit and Exeter implants by 200% and 45%, respectively. The preliminary experiments showed that the Composite Stem stiffness (1982 N/mm) was lower than the metallic hip Stem stiffnesses (Exeter, 2460 N/mm; Omnifit, 2543 N/mm). This is the first assessment of stress, strain, and stiffness of the CF/PA12 carbon-fibre hip Stem compared to standard commercially-available devices.

  • A preliminary biomechanical study of a novel carbon–fibre hip implant versus standard metallic hip implants
    Medical Engineering & Physics, 2011
    Co-Authors: Habiba Bougherara, Rad Zdero, A Dubov, Suraj Shah, Shaheen Khurshid, Emil H Schemitsch
    Abstract:

    Total hip arthroplasty is a widespread surgical approach for treating severe osteoarthritis of the human hip. Aseptic loosening of standard metallic hip implants due to stress shielding and bone loss has motivated the development of new materials for hip prostheses. Numerically, a three-dimensional finite element (FE) model that mimicked hip implants was used to compare a new hip Stem to two commercially available implants. The hip implants simulated were a novel CF/PA12 carbon-fibre polyamide-based Composite hip Stem, the Exeter hip Stem (Stryker, Mahwah, NJ, USA), and the Omnifit Eon (Stryker, Mahwah, NJ, USA). A virtual axial load of 3 kN was applied to the FE model. Strain and stress distributions were computed. Experimentally, the three hip Stems had their distal portions rigidly mounted and had strain gauges placed along the surface at 3 medial and 3 lateral locations. Axial loads of 3 kN were applied. Measurements of axial stiffness and strain were taken and compared to FE analysis. The overall linear correlation between FE model versus experimental strains showed reasonable results for the lines-of-best-fit for the Composite (Pearson R(2)=0.69, slope=0.82), Exeter (Pearson R(2)=0.78, slope=0.59), and Omnifit (Pearson R(2)=0.66, slope=0.45), with some divergence for the most distal strain locations. From FE analysis, the von Mises stress range for the Composite Stem was much lower than that in the Omnifit and Exeter implants by 200% and 45%, respectively. The preliminary experiments showed that the Composite Stem stiffness (1982 N/mm) was lower than the metallic hip Stem stiffnesses (Exeter, 2460 N/mm; Omnifit, 2543 N/mm). This is the first assessment of stress, strain, and stiffness of the CF/PA12 carbon-fibre hip Stem compared to standard commercially-available devices.

  • bone remodeling in a new biomimetic polymer Composite hip Stem
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Habiba Bougherara, Martin N Bureau, L'hocine Yahia
    Abstract:

    Adaptive bone remodeling is an important factor that leads to bone resorption in the surrounding femoral bone and implant loosening. Taking into account this factor in the design of hip implants is of clinical importance, because it allows the prediction of the bone-density redistribution and enables the monitoring of bone adaptation after prosthetic implantation. In this article, adaptive bone remodeling around a new biomimetic polymer-Composite-based (CF/PA12) hip prosthesis is investigated to evaluate the amount of stress shielding and bone resorption. The design concept of this new prosthesis is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF)-reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Strain energy density theory coupled with 3D Finite Element models is used to predict bone density redistributions in the femoral bone before and after total hip replacement (THR) using both polymer-Composite and titanium (Ti) Stems. The result of numerical simulations of bone remodeling revealed that the CF/PA12 Composite Stem generates a better bone density pattern compared with the Ti-based Stem, indicating the effectiveness of the Composite Stem to reduce bone resorption caused by stress-shielding phenomenon. This may result in an extended lifetime of THR.

  • Bone remodeling in a new biomimetic polymer-Composite hip Stem
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Habiba Bougherara, Martin N Bureau, L'hocine Yahia
    Abstract:

    Adaptive bone remodeling is an important factor that leads to bone resorption in the surroudning femoral bone and implant loosening. Taking into account this factor in the design of hip implants is of clinical importance, since it allows the prediction of the bone-density redistribution and enables the monitoring of bone adaptation after prosthetic implantation. In this paper adaptive bone remodeling around a new biomimetic polymer-Composite based (CF/PA12) hip prosthesis is investigated in order to evaluate the amount of stress shielding and bone resorption. The design concept of this new prosthesis is based on a hollow sub-structure made of hydroxyapatite-coated, continuous carbon fiber (BF) reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Strain energy density theory coupled with 3-D Finite Element models are used to predict bone desity redistributions in the femoral bone before and after total hip replacement using both polymer-Composite and titanium Stems. The result of numerical simulations of bone remodeling revealed that the CF-PA12 Composite Stem generates an excellent bone density pattern compared to the titanium-based Stem, indicating the effectiveness of the Composite Stem to reduce bone resorption caused by stress shielding phenomenon. This may result in an extended lifetime of Total Hip Replacement (THR).Le remodelage osseux adaptatif est un ph\ue9nom\ue8ne important menant \ue0 une r\ue9sorption du tissu osseux dans lequel est implant\ue9e une tige f\ue9morale, ce qui en affecte la stabilit\ue9. La prise en compte de ce facteur dans la conception des proth\ue8ses de hanche rev\ueat une importance clinique particuli\ue8re en permettant de pr\ue9voir la redistribution de la densit\ue9 min\ue9rale osseuse et d\u2019\ue9valuer l\u2019adaptation osseuse cons\ue9cutive \ue0 la pose de la proth\ue8se. Le pr\ue9sent article traite de l\u2019\ue9valuation du remodelage adaptatif du tissu osseux entourant un nouveau mod\ue8le de proth\ue8se de hanche en polym\ue8re Composite FC/PA12 biomim\ue9tique que nous avons effectu\ue9e dans le but de quantifier la r\ue9sorption osseuse par d\ue9viation des contraintes (ph\ue9nom\ue8ne de court-circuitage des contraintes) attribuable \ue0 la proth\ue8se. Recouverte d\u2019hydroxyapatite de calcium, la tige f\ue9morale \ue9tudi\ue9e se compose d\u2019une structure externe creuse monopi\ue8ce en polyamide 12 (PA12) renforc\ue9 de fibre de carbone (FC) dont la cavit\ue9 interne est remplie de polym\ue8re mou. L\u2019utilisation du crit\ue8re de l\u2019\ue9nergie de d\ue9formation minimale et de mod\ue8les 3D d\u2019\ue9l\ue9ments finis nous a permis de pr\ue9dire la distribution de la densit\ue9 min\ue9rale du tissu osseux f\ue9moral avant et apr\ue8s la pose d\u2019une proth\ue8se totale de hanche (PTH) comportant une tige f\ue9morale en polym\ue8re Composite ou une tige en titane (Ti). Les r\ue9sultats des simulations num\ue9riques du remodelage osseux r\ue9v\ue8lent que la tige f\ue9morale en polym\ue8re Composite FC/PA12 permet le maintien d\u2019une meilleure densit\ue9 min\ue9rale osseuse que la tige en titane, ce qui t\ue9moigne de l\u2019efficacit\ue9 de la tige en polym\ue8re Composite \ue0 r\ue9duire la r\ue9sorption osseuse attribuable \ue0 la d\ue9viation des contraintes. Ce mod\ue8le de tige f\ue9morale pourrait donc prolonger la dur\ue9e de vie utile de la proth\ue8se totale de hanche.Peer reviewed: YesNRC publication: Ye

  • A Novel Approach for Bone Remodeling After Prosthetic Implantation
    Damage and Fracture Mechanics, 2009
    Co-Authors: Habiba Bougherara, Václav Klika, František Maršík, Ivo A. Mařík, L'hocine Yahia
    Abstract:

    The aim of the present study is to predict the functional adaptation of bone in response to changes in mechanical loading using a new biothermodynamic model for bone remodeling. In our approach, which fits into the framework of open syStems, changes in the density are governed by balance of mass and balance of entropy supplemented by additional mass and entropy sources. The governing equations of bone remodeling process are based on irreversible thermodynamics and kinetics of chemical reactions. The key feature of this model is its ability to simulate the coupling between the mechanical and biochemical parameters that control bone remodeling, in particular the effect of dynamical loading, frequency of load and nutrition. Besides, the model can be used to predict some skeletal diseases such as bone fractures and osteoporosis. In the present paper, a biothermodynamic model was applied to the design of prosthetic implants. Numerical computations of bone density distributions after Total Hip Replacement (THR) using 3D finite element analysis showed that the biomimetic Composite Stem exhibit a better density patterns compared to the conventional titanium Stem, indicating that the biomimetic prosthesis promotes higher remodeling rate and consequently less stress shielding. Furthermore, the model showed that the concentration of a new bone strongly depends on the history and intensity of loading and also on nutrition.

Martin N Bureau - One of the best experts on this subject based on the ideXlab platform.

  • Reduced stress shielding with limited micromotions using a carbon fibre Composite biomimetic hip Stem: a finite element model.
    Proceedings of the Institution of Mechanical Engineers. Part H Journal of engineering in medicine, 2011
    Co-Authors: Christiane Caouette, L'hocine Yahia, Martin N Bureau
    Abstract:

    Total hip arthroplasty (THA) enjoys excellent rates of success in older patients, but younger patients are still at risk of aseptic loosening and bone resorption from stress shielding. One solution to the stress shielding problem is to use a hip Stem with mechanical properties matching those of cortical bone. The objective of the present study was to investigate numerically the biomechanical performance of such a biomimetic hip Stem based on a hydroxyapatite (HA)-coated carbon fibre Composite. A finite element model (FEM) of the biomimetic Stem was constructed. Contact elements were studied to model the bone-implant interface in a non-osseointegrated and osseointegrated state in the best way. Three static load cases representing slow walking, stair climbing, and gait in a healthy individual were considered. Stress shielding and bone-implant interface micromotions were evaluated and compared with the results of a similar FEM based on titanium alloy (Ti-6Al-4V). The Composite Stems allowed for reduced stress shielding when compared with a traditional Ti-6Al-4V Stem. Micromotions were slightly higher with the Composite Stem, but remained below 40 microm on most of the HA-coated surface. It is concluded that a biomimetic Composite Stem might offer a better compromise between stress shielding and micromotions than the Ti-6Al-4V Stem with the same external geometry.

  • bone remodeling in a new biomimetic polymer Composite hip Stem
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Habiba Bougherara, Martin N Bureau, L'hocine Yahia
    Abstract:

    Adaptive bone remodeling is an important factor that leads to bone resorption in the surrounding femoral bone and implant loosening. Taking into account this factor in the design of hip implants is of clinical importance, because it allows the prediction of the bone-density redistribution and enables the monitoring of bone adaptation after prosthetic implantation. In this article, adaptive bone remodeling around a new biomimetic polymer-Composite-based (CF/PA12) hip prosthesis is investigated to evaluate the amount of stress shielding and bone resorption. The design concept of this new prosthesis is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF)-reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Strain energy density theory coupled with 3D Finite Element models is used to predict bone density redistributions in the femoral bone before and after total hip replacement (THR) using both polymer-Composite and titanium (Ti) Stems. The result of numerical simulations of bone remodeling revealed that the CF/PA12 Composite Stem generates a better bone density pattern compared with the Ti-based Stem, indicating the effectiveness of the Composite Stem to reduce bone resorption caused by stress-shielding phenomenon. This may result in an extended lifetime of THR.

  • Bone remodeling in a new biomimetic polymer-Composite hip Stem
    Journal of Biomedical Materials Research Part A, 2010
    Co-Authors: Habiba Bougherara, Martin N Bureau, L'hocine Yahia
    Abstract:

    Adaptive bone remodeling is an important factor that leads to bone resorption in the surroudning femoral bone and implant loosening. Taking into account this factor in the design of hip implants is of clinical importance, since it allows the prediction of the bone-density redistribution and enables the monitoring of bone adaptation after prosthetic implantation. In this paper adaptive bone remodeling around a new biomimetic polymer-Composite based (CF/PA12) hip prosthesis is investigated in order to evaluate the amount of stress shielding and bone resorption. The design concept of this new prosthesis is based on a hollow sub-structure made of hydroxyapatite-coated, continuous carbon fiber (BF) reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Strain energy density theory coupled with 3-D Finite Element models are used to predict bone desity redistributions in the femoral bone before and after total hip replacement using both polymer-Composite and titanium Stems. The result of numerical simulations of bone remodeling revealed that the CF-PA12 Composite Stem generates an excellent bone density pattern compared to the titanium-based Stem, indicating the effectiveness of the Composite Stem to reduce bone resorption caused by stress shielding phenomenon. This may result in an extended lifetime of Total Hip Replacement (THR).Le remodelage osseux adaptatif est un ph\ue9nom\ue8ne important menant \ue0 une r\ue9sorption du tissu osseux dans lequel est implant\ue9e une tige f\ue9morale, ce qui en affecte la stabilit\ue9. La prise en compte de ce facteur dans la conception des proth\ue8ses de hanche rev\ueat une importance clinique particuli\ue8re en permettant de pr\ue9voir la redistribution de la densit\ue9 min\ue9rale osseuse et d\u2019\ue9valuer l\u2019adaptation osseuse cons\ue9cutive \ue0 la pose de la proth\ue8se. Le pr\ue9sent article traite de l\u2019\ue9valuation du remodelage adaptatif du tissu osseux entourant un nouveau mod\ue8le de proth\ue8se de hanche en polym\ue8re Composite FC/PA12 biomim\ue9tique que nous avons effectu\ue9e dans le but de quantifier la r\ue9sorption osseuse par d\ue9viation des contraintes (ph\ue9nom\ue8ne de court-circuitage des contraintes) attribuable \ue0 la proth\ue8se. Recouverte d\u2019hydroxyapatite de calcium, la tige f\ue9morale \ue9tudi\ue9e se compose d\u2019une structure externe creuse monopi\ue8ce en polyamide 12 (PA12) renforc\ue9 de fibre de carbone (FC) dont la cavit\ue9 interne est remplie de polym\ue8re mou. L\u2019utilisation du crit\ue8re de l\u2019\ue9nergie de d\ue9formation minimale et de mod\ue8les 3D d\u2019\ue9l\ue9ments finis nous a permis de pr\ue9dire la distribution de la densit\ue9 min\ue9rale du tissu osseux f\ue9moral avant et apr\ue8s la pose d\u2019une proth\ue8se totale de hanche (PTH) comportant une tige f\ue9morale en polym\ue8re Composite ou une tige en titane (Ti). Les r\ue9sultats des simulations num\ue9riques du remodelage osseux r\ue9v\ue8lent que la tige f\ue9morale en polym\ue8re Composite FC/PA12 permet le maintien d\u2019une meilleure densit\ue9 min\ue9rale osseuse que la tige en titane, ce qui t\ue9moigne de l\u2019efficacit\ue9 de la tige en polym\ue8re Composite \ue0 r\ue9duire la r\ue9sorption osseuse attribuable \ue0 la d\ue9viation des contraintes. Ce mod\ue8le de tige f\ue9morale pourrait donc prolonger la dur\ue9e de vie utile de la proth\ue8se totale de hanche.Peer reviewed: YesNRC publication: Ye

  • design of a biomimetic polymer Composite hip prosthesis
    Journal of Biomedical Materials Research Part A, 2007
    Co-Authors: Habiba Bougherara, Martin N Bureau, Melissa Campbell, Aurelian Vadean, L'hocine Yahia
    Abstract:

    A new biomimetic Composite hip prosthesis (Stem) was designed to obtain properties similar to those of the contiguous bone, in particular stiffness, to allow normal loading of the surrounding femoral bone. This normal loading would reduce excessive stress shielding, known to result in bone loss, and micromotions at the bone-implant interface, leading to aseptic prosthetic loosening. The design proposed is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF) reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Different Composite configurations were studied to match the properties of host tissue. Nonlinear three-dimensional analysis of the hip prosthesis was carried out using a three-dimensional finite element bone model based on the Composite femur. The performance of Composite-based hip and titanium alloy-based (Ti-6Al-4V) Stems embedded into femoral bone was compared. The effect of core stiffness and ply configuration was also analyzed. Results show that stresses in Composite Stem are lower than those in Ti Stem, and that the femoral bone implanted with Composite structure sustains more load than the one implanted with Ti Stem. Micromotions in the Composite Stem are significantly smaller than those in Ti Stem over the entire bone-implant surface because of the favorable interfacial stress distribution.

  • Design of a biomimetic polymer‐Composite hip prosthesis
    Journal of biomedical materials research. Part A, 2007
    Co-Authors: Habiba Bougherara, Martin N Bureau, Melissa Campbell, Aurelian Vadean, L'hocine Yahia
    Abstract:

    A new biomimetic Composite hip prosthesis (Stem) was designed to obtain properties similar to those of the contiguous bone, in particular stiffness, to allow normal loading of the surrounding femoral bone. This normal loading would reduce excessive stress shielding, known to result in bone loss, and micromotions at the bone-implant interface, leading to aseptic prosthetic loosening. The design proposed is based on a hollow substructure made of hydroxyapatite-coated, continuous carbon fiber (CF) reinforced polyamide 12 (PA12) Composite with an internal soft polymer-based core. Different Composite configurations were studied to match the properties of host tissue. Nonlinear three-dimensional analysis of the hip prosthesis was carried out using a three-dimensional finite element bone model based on the Composite femur. The performance of Composite-based hip and titanium alloy-based (Ti-6Al-4V) Stems embedded into femoral bone was compared. The effect of core stiffness and ply configuration was also analyzed. Results show that stresses in Composite Stem are lower than those in Ti Stem, and that the femoral bone implanted with Composite structure sustains more load than the one implanted with Ti Stem. Micromotions in the Composite Stem are significantly smaller than those in Ti Stem over the entire bone-implant surface because of the favorable interfacial stress distribution.

Dwight T. Davy - One of the best experts on this subject based on the ideXlab platform.

  • Effects of mechanical testing device variables on polymer Composite femoral Stem strains
    Biomaterials, 1996
    Co-Authors: Anneliese Dorothy Heiner, Stanley A. Brown, Dwight T. Davy
    Abstract:

    Polymer Composite femoral Stems do not have a well-established in vitro mechanical testing method. The objective of this study was to examine mechanical testing devices for pressfit Composite Stems, using finite element analysis. The goals were to examine the effects of testing device design variables (geometry, material, interface friction, embedding height and applied load angle) and to reproduce the maximum strains of the Stem implanted in a femur. The Stem strains were affected by design changes to the testing device. The maximum normal and interlaminar shear strains of the Composite Stem in the femur were not as well reproduced by the testing device as were the maximum in-plane tensile strains. Decreasing the embedding height increased the Stem strains and shifted the Stem failure location from the neck to the embedding height. Testing a femoral Stem using a testing device with a low embedding height may be inappropriate when trying to induce neck failure, since failure may occur at the embedding height instead of in the neck. A single-material testing device of birchwood, an orthotropic material with a longitudinal stiffness in the range of bone, best simulated a femur in this study.

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  • Effects of mechanical testing device variables on polymer Composite femoral Stem strains
    Biomaterials, 1996
    Co-Authors: Anneliese Dorothy Heiner, Stanley A. Brown, Dwight T. Davy
    Abstract:

    Polymer Composite femoral Stems do not have a well-established in vitro mechanical testing method. The objective of this study was to examine mechanical testing devices for pressfit Composite Stems, using finite element analysis. The goals were to examine the effects of testing device design variables (geometry, material, interface friction, embedding height and applied load angle) and to reproduce the maximum strains of the Stem implanted in a femur. The Stem strains were affected by design changes to the testing device. The maximum normal and interlaminar shear strains of the Composite Stem in the femur were not as well reproduced by the testing device as were the maximum in-plane tensile strains. Decreasing the embedding height increased the Stem strains and shifted the Stem failure location from the neck to the embedding height. Testing a femoral Stem using a testing device with a low embedding height may be inappropriate when trying to induce neck failure, since failure may occur at the embedding height instead of in the neck. A single-material testing device of birchwood, an orthotropic material with a longitudinal stiffness in the range of bone, best simulated a femur in this study.

  • Finite element design of a mechanical testing method for polymer Composite femoral Stems
    1995
    Co-Authors: Anneliese Dorothy Heiner
    Abstract:

    ["Polymer Composite femoral Stems do not have a standardized in vitro mechanical testing method. The testing device for metallic Stems, which simulates proximal resorption of the femur, is inappropriate for Composite Stems, which they are expected to reduce or prevent proximal resorption. The objective of this study was to determine a mechanical testing method for pressfit Composite Stems, using finite element analysis (FEA). The goal was to reproduce the strains of the Stem implanted in a femur. Three simplified models used for preliminary studies were beam-on-elastic-foundation, two-dimensional plus sideplates FEA, and axisymmetric FEA. These models showed that Stem stresses were affected by design changes to the testing device, and gave some results equivalent to those found with the more complex models. The effects on the Composite Stem of varying the testing device were studied using full 3-D FEA models. The Stem strains were affected by design changes to the testing device. The maximum normal and interlaminar shear strains of the Composite Stem in the testing device were either lower than or about equal to the maximum strains of the Composite Stem in the femur. A single-material testing device made of birchwood was chosen as the b est testing device from the parametric study. Birchwood is an orthotropic material with a longitudinal stiffness in the range of bone. This testing device improved the Stem strains which lead to Composite interlaminar failure, relative to the other testing devices studied. The viability of the testing device, as measured by stresses on the bone cement or testing device and by interface motion, was also affected by changes to the testing device and Stem material. Changing from a metallic Stem to a Composite Stem increased the bone cement stresses by about twofold. Some testing device configurations had cement stresses that were close to or above static cement strengths. The birchwood testing device had high interface motion. Other Stem materials were compared to the Composite Stem. The strains on a metallic Stem and the Composite Stem were not always affected in the same way by changes to the testing device. An isotropic Stem was a better simplification of the Composite Stem than was a transversely isotropic Stem."]