The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform

Michael Tanzer - One of the best experts on this subject based on the ideXlab platform.

  • characterization of bone ingrowth and interface mechanics of a new Porous 3d printed biomaterial an animal study
    Journal of Bone and Joint Surgery-british Volume, 2019
    Co-Authors: Michael Tanzer, P J Chuang, C G Ngo, L Song, Kevor Tenhuisen
    Abstract:

    Aims The purpose of this study was to evaluate the biological fixation of a 3D printed Porous Implant, with and without different hydroxyapatite (HA) coatings, in a canine model. Materials and Meth...

  • cervical fusion cage computationally optimized with Porous architected titanium for minimized subsidence
    Journal of The Mechanical Behavior of Biomedical Materials, 2018
    Co-Authors: Ahmed Moussa, Michael Tanzer, Damiano Pasini
    Abstract:

    Anterior cervical discectomy with fusion is a common surgical treatment that can relieve patients suffering from cervical spondylosis. This surgery is most commonly performed with the use of a cervical cage. One serious complication of the fusion cages commercially available in the market is subsidence of the cage with loss of the normal alignment of the spine and recurrent pain. This work presents the proof-of-concept of a fusion cage made of a graded Porous titanium with microarchitecture minimizing the risk of subsidence associated with fully-solid Implants. The optimized properties of the Porous Implant are obtained through a scheme combining multiscale mechanics and density-based topology optimization. Asymptotic homogenization is used to capture the effective properties of the Porous material, which uses a tetrahedron based cell as building block. The stress levels and normal strains obtained under various loading conditions on the C7 superior surface of the vertebrae are used as indicators of subsidence. The results suggest a reduced risk of subsidence for the optimized Implant versus the fully-solid Implant. Under the most severe condition of combined loading, a collective improvement of the average von Mises stress up to 14% can be observed on the posterior, left, and right lateral regions of the C7 superior surface. Similarly, for the average normal strain, the optimized cage exhibits a more favourable distribution with a top gain of 21.7% at given locations.

  • fully Porous 3d printed titanium femoral stem to reduce stress shielding following total hip arthroplasty
    Journal of Orthopaedic Research, 2017
    Co-Authors: Sajad Arabnejad, Burnett Johnston, Michael Tanzer, Damiano Pasini
    Abstract:

    Current hip replacement femoral Implants are made of fully solid materials which all have stiffness considerably higher than that of bone. This mechanical mismatch can cause significant bone resorption secondary to stress shielding, which can lead to serious complications such as peri-prosthetic fracture during or after revision surgery. In this work, a high strength fully Porous material with tunable mechanical properties is introduced for use in hip replacement design. The Implant macro geometry is based off of a short stem taper-wedge Implant compatible with minimally invasive hip replacement surgery. The Implant micro-architecture is fine-tuned to locally mimic bone tissue properties which results in minimum bone resorption secondary to stress shielding. We present a systematic approach for the design of a 3D printed fully Porous hip Implant that encompasses the whole activity spectrum of Implant development, from concept generation, multiscale mechanics of Porous materials, material architecture tailoring, to additive manufacturing, and performance assessment via in vitro experiments in composite femurs. We show that the fully Porous Implant with an optimized material micro-structure can reduce the amount of bone loss secondary to stress shielding by 75% compared to a fully solid Implant. This result also agrees with those of the in vitro quasi-physiological experimental model and the corresponding finite element model for both the optimized fully Porous and fully solid Implant. These studies demonstrate the merit and the potential of tuning material architecture to achieve a substantial reduction of bone resorption secondary to stress shielding. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1774-1783, 2017.

  • the otto aufranc award demineralized bone matrix around Porous Implants promotes rapid gap healing and bone ingrowth
    Clinical Orthopaedics and Related Research, 2012
    Co-Authors: Michael Tanzer, Dennis J Bobyn, Kristian M Bobyn, Louisphilippe Lefebvre
    Abstract:

    Background Noncemented revision arthroplasty is often complicated by the presence of bone Implant gaps that reduce initial stability and biologic fixation. Demineralized bone matrix has osteoinductive properties and therefore the potential to enhance gap healing and Porous Implant fixation.

Scott J Hollister - One of the best experts on this subject based on the ideXlab platform.

  • structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process
    Journal of Biomedical Materials Research Part A, 2007
    Co-Authors: Chiaying Lin, Tobias Wirtz, Frank Lamarca, Scott J Hollister
    Abstract:

    A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyping process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic characterizations and the mechanical properties were investigated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scanning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used Porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97+/-0.90 GPa, which is comparable with the reported Porous tantalum modulus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new Porous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a Porous Implant for spine fusion.

  • structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process
    Journal of Biomedical Materials Research Part A, 2007
    Co-Authors: Tobias Wirtz, Frank Lamarca, Scott J Hollister
    Abstract:

    A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyp- ing process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic charac- terizations and the mechanical properties were investi- gated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scan- ning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used Porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97 6 0.90 GPa, which is comparable with the reported Porous tantalum modu- lus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new po- rous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a Porous Implant for spine fusion. 2007 Wiley Periodicals, Inc. J Biomed Mater Res 83A: 272-279, 2007

Damiano Pasini - One of the best experts on this subject based on the ideXlab platform.

  • cervical fusion cage computationally optimized with Porous architected titanium for minimized subsidence
    Journal of The Mechanical Behavior of Biomedical Materials, 2018
    Co-Authors: Ahmed Moussa, Michael Tanzer, Damiano Pasini
    Abstract:

    Anterior cervical discectomy with fusion is a common surgical treatment that can relieve patients suffering from cervical spondylosis. This surgery is most commonly performed with the use of a cervical cage. One serious complication of the fusion cages commercially available in the market is subsidence of the cage with loss of the normal alignment of the spine and recurrent pain. This work presents the proof-of-concept of a fusion cage made of a graded Porous titanium with microarchitecture minimizing the risk of subsidence associated with fully-solid Implants. The optimized properties of the Porous Implant are obtained through a scheme combining multiscale mechanics and density-based topology optimization. Asymptotic homogenization is used to capture the effective properties of the Porous material, which uses a tetrahedron based cell as building block. The stress levels and normal strains obtained under various loading conditions on the C7 superior surface of the vertebrae are used as indicators of subsidence. The results suggest a reduced risk of subsidence for the optimized Implant versus the fully-solid Implant. Under the most severe condition of combined loading, a collective improvement of the average von Mises stress up to 14% can be observed on the posterior, left, and right lateral regions of the C7 superior surface. Similarly, for the average normal strain, the optimized cage exhibits a more favourable distribution with a top gain of 21.7% at given locations.

  • fully Porous 3d printed titanium femoral stem to reduce stress shielding following total hip arthroplasty
    Journal of Orthopaedic Research, 2017
    Co-Authors: Sajad Arabnejad, Burnett Johnston, Michael Tanzer, Damiano Pasini
    Abstract:

    Current hip replacement femoral Implants are made of fully solid materials which all have stiffness considerably higher than that of bone. This mechanical mismatch can cause significant bone resorption secondary to stress shielding, which can lead to serious complications such as peri-prosthetic fracture during or after revision surgery. In this work, a high strength fully Porous material with tunable mechanical properties is introduced for use in hip replacement design. The Implant macro geometry is based off of a short stem taper-wedge Implant compatible with minimally invasive hip replacement surgery. The Implant micro-architecture is fine-tuned to locally mimic bone tissue properties which results in minimum bone resorption secondary to stress shielding. We present a systematic approach for the design of a 3D printed fully Porous hip Implant that encompasses the whole activity spectrum of Implant development, from concept generation, multiscale mechanics of Porous materials, material architecture tailoring, to additive manufacturing, and performance assessment via in vitro experiments in composite femurs. We show that the fully Porous Implant with an optimized material micro-structure can reduce the amount of bone loss secondary to stress shielding by 75% compared to a fully solid Implant. This result also agrees with those of the in vitro quasi-physiological experimental model and the corresponding finite element model for both the optimized fully Porous and fully solid Implant. These studies demonstrate the merit and the potential of tuning material architecture to achieve a substantial reduction of bone resorption secondary to stress shielding. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1774-1783, 2017.

Tobias Wirtz - One of the best experts on this subject based on the ideXlab platform.

  • structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process
    Journal of Biomedical Materials Research Part A, 2007
    Co-Authors: Chiaying Lin, Tobias Wirtz, Frank Lamarca, Scott J Hollister
    Abstract:

    A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyping process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic characterizations and the mechanical properties were investigated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scanning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used Porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97+/-0.90 GPa, which is comparable with the reported Porous tantalum modulus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new Porous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a Porous Implant for spine fusion.

  • structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process
    Journal of Biomedical Materials Research Part A, 2007
    Co-Authors: Tobias Wirtz, Frank Lamarca, Scott J Hollister
    Abstract:

    A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyp- ing process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic charac- terizations and the mechanical properties were investi- gated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scan- ning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used Porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97 6 0.90 GPa, which is comparable with the reported Porous tantalum modu- lus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new po- rous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a Porous Implant for spine fusion. 2007 Wiley Periodicals, Inc. J Biomed Mater Res 83A: 272-279, 2007

Frank Lamarca - One of the best experts on this subject based on the ideXlab platform.

  • structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process
    Journal of Biomedical Materials Research Part A, 2007
    Co-Authors: Chiaying Lin, Tobias Wirtz, Frank Lamarca, Scott J Hollister
    Abstract:

    A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyping process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic characterizations and the mechanical properties were investigated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scanning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used Porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97+/-0.90 GPa, which is comparable with the reported Porous tantalum modulus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new Porous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a Porous Implant for spine fusion.

  • structural and mechanical evaluations of a topology optimized titanium interbody fusion cage fabricated by selective laser melting process
    Journal of Biomedical Materials Research Part A, 2007
    Co-Authors: Tobias Wirtz, Frank Lamarca, Scott J Hollister
    Abstract:

    A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyp- ing process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic charac- terizations and the mechanical properties were investi- gated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scan- ning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used Porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97 6 0.90 GPa, which is comparable with the reported Porous tantalum modu- lus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new po- rous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a Porous Implant for spine fusion. 2007 Wiley Periodicals, Inc. J Biomed Mater Res 83A: 272-279, 2007