Univ.-Prof. DI Dr. Dieter Pahr

Dieter Pahr studied mechanical engineering at the Technical University of Vienna and received his doctorate in 2003 with the dissertation "Experimental and numerical investigations of perforated FRP laminates" under the supervision of Prof. Rammerstorfer. After receiving the venia docendi for "Computational Solid Mechanics" under the supervision of Prof. Zysset in 2008 with the habilitation thesis "Computational multi-scale modelling of synthetic and natural composites ", he became an Associate Professor of "Computational Biomechanics".

Since 2013 he has also been CEO of Dr. Pahr Ingenieurs e.U., a spin-off from the TU Vienna. In 2016 Dieter Pahr was appointed as a professor for musculoskeletal biomechanics at the Karl-Landsteiner Private University in Krems an der Donau, where he heads the division biomechanics where he founded a laboratory for biomechanics and is responsible for training in biomedical physics for medical students. In 2020 he was nominated as professor for computational biomechanics at the TU Vienna at the Institute for Lightweight Design and Structural Biomechanics. His double professorship at the TU Vienna and at KL Krems aims to put engineering at the service of human health. His research covers the areas of prevention, treatment, and aftercare of diseases of the musculoskeletal system with the help of simulation methods, imaging methods, experimental investigations, and 3D printing.

+43 2732 720 90 330

+43 2732 720 90 5330

biomech@kl.ac.at

Publications

2022
- Conference Paper
  - Amraish, N. & Pahr, D.H., 2022. New insights into high-resolution strain fields of trabecular bone using digital image correlation. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Aryeetey, O.J., Frank, M., Lorenz, A. & Pahr, D.H., 2022. Fracture toughness determination of muscle tissue based on AQLV model derived viscous dissipated energy. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Bachmann, S., Pahr, D.H. & Synek, A., 2022. Homogenized-FE-based inverse bone remodeling: modified optimization criterion and evaluation on the distal radius. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Berger, L., Pahr, D.H. & Synek, A., 2022. Articular contact vs. embedding: the effect of boundary conditions on volar plate fixation at the distal radius. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Frank, M., Aryeetey, O.J., Estermann, S.-J. & Pahr, D.H., 2022. Adaptive quasi-linear model – universal material parameters of liver tissue for different load cases?. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Haslinger, K., Frank, M., Pahr, D.H. & Thurner, P.J., 2022. Novel method to obtain mechanical properties of isolated trabeculae under compression in wet condition. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Nägl, K., Reisinger, A. & Pahr, D.H., 2022. Biomechanical failure behaviour of 3D printed femoral bones compared to artificial and human bones. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Reisinger, A., Frank, M., Thurner, P. & Pahr, D.H., 2022. Damage in single trabeculae under tension identified by inverse rheological modelling. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Stefanek, P., Synek, A., Dall´Ara, E. & Pahr, D.H., 2022. Validation of linear and materially nonlinear μFE predicted displacement fields of bone biopsies using DVC. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
  - Voumard, B., Stefanek, P., Pretterklieber, M., Pahr, D.H. & Zysset, P., 2022. Influence of ageing on micromechanical properties of the femoral neck using the inverse method. In 27th Congress of the European Society of Biomechanics. 26.-29.06.2022. Porto, Portugal.
    Link
- Journal Article
  - Bachmann, S., Dunmore, C.J., Skinner, M.M., Pahr, D.H. & Synek, A., 2022. A computational framework for canonical holistic morphometric analysis of trabecular bone. Scientific reports, 12(1), S.5187.
  - Cepic, L.Zupancic, Frank, M., Reisinger, A., Pahr, D.H., Zechner, W. & Schedle, A., 2022. Biomechanical finite element analysis of short-implant-supported, 3-unit, fixed CAD/CAM prostheses in the posterior mandible. International journal of implant dentistry, 8(1), S.8.
  - Cepic, L.Zupancic, Frank, M., Reisinger, A., Sagl, B., Pahr, D.H., Zechner, W. & Schedle, A., 2022. Experimental validation of a micro-CT finite element model of a human cadaveric mandible rehabilitated with short-implant-supported partial dentures. Journal of the Mechanical Behavior of Biomedical Materials, 126.
  - Jaksa, L., Pahr, D.H., Kronreif, G. & Lorenz, A., 2022. Calibration Dependencies and Accuracy Assessment of a Silicone Rubber 3D Printer. Inventions, 7(2).
  - Silva-Henao, J.D., Synek, A., Pahr, D.H. & Reisinger, A., 2022. Selection of animal bone surrogate samples for orthopaedic screw testing based on human radius CT-derived bone morphology. Medical Engineering and Physics, 103, S.103786.
  - Sinzinger, F., van Kerkvoorde, J., Pahr, D.H. & Moreno, R., 2022. Predicting the trabecular bone apparent stiffness tensor with spherical convolutional neural networks. Bone reports, 16, S.101179.
  - Steiner, L., Synek, A. & Pahr, D.H., 2022. Femoral Bone Strength Prediction Using Isotopological B-Spline-Transformed Meshes. Biomechanics, 2(1).
  - Streicher, J., Reisinger, A., Warnung, L. & Pahr, D.H., 2022. 3D-Printing Offers Dry Replication and New Insight into Unique Museum Specimens. FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 36 Suppl 1.
2021
- Conference Paper
  - Amraish, N., Reisinger, A. & Pahr, D.H., 2021. Measurement of linear strain fields by means of digital image correlation. In 26th Congress of the European Society of Biomechanics. 11.-14.07.2021. Milan, Italy.
  - Aryeetey, O.J., Frank, M. & Pahr, D.H., 2021. Reduced parameter adaptive quasi-linear viscoelastic (AQLV) model of soft biological tissue. In 26th Congress of the European Society of Biomechanics. 11.-14.07.2021. Milan, Italy.
  - Bachmann, S., Synek, A. & Pahr, D.H., 2021. Presentation: A novel method for quantitative and statistical comparison of local differences in bone morphometry. In CMBBE 2021: 17th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering. 07.-09.09.2021. Online.
    Link
  - Estermann, S.-J., Förster-Streffleur, S., Hirtler, L., Streicher, J., Pahr, D.H. & Reisinger, A., 2021. Viscoelastic properties of human liver: influence of Thiel preservation and comparison with animal tissue. In 26th Congress of the European Society of Biomechanics. 11.-14.07.2021. Milan, Italy.
  - Frank, M., Aryeetey, O.J. & Pahr, D.H., 2021. Usage of the Abaqus – Adaptive quasi-linear viscoelastic model for arbitrary load prediction. In 26th Congress of the European Society of Biomechanics. 11.-14.07.2021. Milan, Italy.
  - Haendel, M., Stelzer, S., Einwoegerer, T., Grebe, A., Gunz, P., Neubauer, S., Pahr, D.H., Simon, U. & Teschler-Nicola, M., 2021. Presentation: Digitisation and reconstruction of the burial of newborn twins from the Gravettian site Krems-Wachtberg. In UISPP. 02.-07.09.2021. Meknès (Online).
    Link
  - Silva-Henao, J.D., Pahr, D.H. & Reisinger, A., 2021. Bone sample selection for screw mechanical testing based on peri-implant CT morphometry. In 26th Congress of the European Society of Biomechanics. 2021. Milan, Italy.
  - Stipsitz, M., Zysset, P.K. & Pahr, D.H., 2021. Influence of stress redistributions in μFEA on the predicted failure load of radius segments. In 26th Congress of the European Society of Biomechanics. 11.-14.07.2021. Milan, Italy.
  - Synek, A., Baumbach, S.F. & Pahr, D.H., 2021. Presentation: Towards optimization of volar plate fixations of distal radius fractures: Using finite element analyses to reduce the number of screws. In 29th Annual Meeting of the European Orthopaedic Research Society. 15.-17.09.2021. Rome, Italy.
  - Synek, A., Baumbach, S.F. & Pahr, D.H., 2021. Towards optimization of plate fracture fixations at the distal radius: Using FEA to reduce the number of screws. In 26th Congress of the European Society of Biomechanics. 11.-14.07.2021. Milan, Italy.
- Journal Article
  - Amini, M., Reisinger, A., Hirtler, L. & Pahr, D.H., 2021. Which experimental procedures influence the apparent proximal femoral stiffness? A parametric study. BMC Musculoskeletal Disorders, 22(1), S.815.
  - Amraish, N., Reisinger, A. & Pahr, D.H., 2021. A novel specimen shape for measurement of linear strain fields by means of digital image correlation. Scientific reports, 11(1), S.17515.
  - Aryeetey, O.J., Frank, M., Lorenz, A., Estermann, S.-J., Reisinger, A. & Pahr, D.H., 2021. A parameter reduced adaptive quasi-linear viscoelastic model for soft biological tissue in uniaxial tension. Journal of the Mechanical Behavior of Biomedical Materials, S.104999.
  - Estermann, S.-J., Förster-Streffleur, S., Hirtler, L., Streicher, J., Pahr, D.H. & Reisinger, A., 2021. Comparison of Thiel preserved, fresh human, and animal liver tissue in terms of mechanical properties. Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft, 236, S.151717.
  - Estermann, S.-J., Pahr, D.H. & Reisinger, A., 2021. Material design of soft biological tissue replicas using viscoelastic micromechanical modelling. Journal of the mechanical behavior of biomedical materials, 125, S.104875.
  - Frank, M., Grabos, A., Reisinger, A., Burr, D.B., Pahr, D.H., Allen, M.R. & Thurner, P.J., 2021. Effects of anti-resorptive treatment on the material properties of individual canine trabeculae in cyclic tensile tests. Bone, S.115995.
  - Jaksa, L., Pahr, D.H., Kronreif, G. & Lorenz, A., 2021. Development of a Multi-Material 3D Printer for Functional Anatomic Models. International Journal of Bioprinting, 7(4), S.420.
  - Jeyakumar, V., Amraish, N., Niculescu-Morsza, E., Bauer, C., Pahr, D.H. & Nehrer, S., 2021. Decellularized Cartilage Extracellular Matrix Incorporated Silk Fibroin Hybrid Scaffolds for Endochondral Ossification Mediated Bone Regeneration. International journal of molecular sciences, 22(8).
  - Reisinger, A., Pahr, D.H., Frank, M. & Thurner, P.J., 2021. Effects of Osteoporosis on Bone Morphometry and Material Properties of Individual Human Trabeculae in the Femoral Head. JBMR Plus, n/a(n/a), S.e10503.
  - Steiner, L., Synek, A. & Pahr, D.H., 2021. Femoral strength can be predicted from 2D projections using a 3D statistical deformation and texture model with finite element analysis. Medical engineering & physics, 93, S.72-82.
  - Stipsitz, M., Zysset, P.K. & Pahr, D.H., 2021. Prediction of the Inelastic Behaviour of Radius Segments: Damage-based Nonlinear Micro Finite Element Simulation vs Pistoia Criterion. Journal of biomechanics, 116, S.110205.
  - Synek, A., Baumbach, S.F. & Pahr, D.H., 2021. Towards optimization of volar plate fixations of distal radius fractures: Using finite element analyses to reduce the number of screws. Clinical biomechanics, 82, S.105272.
2020
- Conference Paper
  - Pahr, D.H., Stefanek, P. & Stipsitz, M., 2020. Presentation: Non-linear micro FE in Bone Biomechanics. In Scientific Meeting of the Austrian Chapter of ESB 2020. 30.11.2020. Online.
  - Reisinger, A., Estermann, S.-J., Frank, M., Förster-Streffleur, S., Streicher, J., Hirtler, L., Thurner, P. & Pahr, D.H., 2020. Presentation: Viscosity Identification in Bone and Soft Tissue Mechanics . In Scientific Meeting of the Austrian Chapter of ESB 2020. 30.11.2020. Online.
- Journal Article
  - Amraish, N., Reisinger, A. & Pahr, D.H., 2020. Robust Filtering Options for Higher-Order Strain Fields Generated by Digital Image Correlation. Applied Mechanics, 1(4), S.174-192.
  - Benca, E., Amini, M. & Pahr, D.H., 2020. Effect of CT imaging on the accuracy of the finite element modelling in bone. European radiology experimental, 4(1), S.51.
  - Estermann, S.-J., Pahr, D.H. & Reisinger, A., 2020. Hyperelastic and viscoelastic characterization of hepatic tissue under uniaxial tension in time and frequency domain. Journal of the Mechanical Behavior of Biomedical Materials, 112, S.104038.
  - Estermann, S.-J., Pahr, D.H. & Reisinger, A., 2020. Quantifying tactile properties of liver tissue, silicone elastomers, and a 3D printed polymer for manufacturing realistic organ models. Journal of the Mechanical Behavior of Biomedical Materials, 104, S.103630.
    Link
  - Georgiou, L., Dunmore, C.J., Bardo, A., Buck, L.T., Hublin, J.-J., Pahr, D.H., Stratford, D., Synek, A., Kivell, T.L. & Skinner, M.M., 2020. Evidence for habitual climbing in a Pleistocene hominin in South Africa. Proceedings of the National Academy of Sciences of the United States of America, 117(15), S.8416-8423.
  - Iori, G., Peralta, L., Reisinger, A., Heyer, F., Wyers, C., van den Bergh, J., Pahr, D.H. & Raum, K., 2020. Femur strength predictions by nonlinear homogenized voxel finite element models reflect the microarchitecture of the femoral neck. Medical engineering & physics, 79, S.60-66.
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  - Iori, G., Schneider, J., Reisinger, A., Heyer, F., Peralta, L., Wyers, C., Gluer, C.C., van den Bergh, J.P., Pahr, D.H. & Raum, K., 2020. Cortical thinning and accumulation of large cortical pores in the tibia reflect local structural deterioration of the femoral neck. Bone, 137, S.115446.
    Link
  - Pahr, D.H. & Reisinger, A., 2020. A Review on Recent Advances in the Constitutive Modeling of Bone Tissue. Current osteoporosis reports.
  - Reisinger, A., Frank, M., Thurner, P.J. & Pahr, D.H., 2020. A two-layer elasto-visco-plastic rheological model for the material parameter identification of bone tissue. Biomechanics and modeling in mechanobiology.
  - Skinner, M.M., Georgiou, L., Stratford, D., Dunmore, C.J., Bardo, A., Buck, L.T., Hublin, J.-J., Pahr, D.H., Synek, A. & Kivell, T.L., 2020. Reply to Haeusler et al.: Internal structure of the femur provides robust evidence for locomotor and taxonomic diversity at Sterkfontein. Proceedings of the National Academy of Sciences of the United States of America.
    Link
  - Steiner, L., Synek, A. & Pahr, D.H., 2020. Comparison of different microCT-based morphology assessment tools using human trabecular bone. Bone reports, 12, S.100261.
  - Stipsitz, M., Zysset, P.K. & Pahr, D.H., 2020. Efficient materially nonlinear µFE solver for simulations of trabecular bone failure. Biomechanics and modeling in mechanobiology, 19, S.861-874.
  - Synek, A., Lu, S.-C., Nauwelaerts, S., Pahr, D.H. & Kivell, T.L., 2020. Metacarpophalangeal joint loads during bonobo locomotion: model predictions versus proxies. Interface: Journal of the Royal Society, 17(164), S.20200032.
2019
- Conference Paper
  - Amini, M., Reisinger, A. & Pahr, D.H., 2019. Effect of selected scan parameters on qct-based bmd estimations of a femur. In European Society of Biomechanics. Vienna: TU Verlag, S. 134.
    Link
  - Amraish, N., Reisinger, A. & Pahr, D.H., 2019. Accuracy and precision of full field surface strain measurements. In European Society of Biomechanics. Vienna: TU Verlag, S. 223.
  - Estermann, S.-J., Müller-Guttenbrunn, C., Pahr, D.H. & Reisinger, A., 2019. Comparison of tactile properties of liver tissue and potential 3D printing materials via macroindentation. In 11. Kongress der Deutschen Gesellschaft für Biomechanik (DGfB). Berlin, S. 199.
  - Estermann, S.-J., Müller-Guttenbrunn, C., Pahr, D.H. & Reisinger, A., 2019. Presentation: Macroindentation of liver tissue and 3d printing materials for comparison of tactile properties. In European Society of Biomechanics. Vienna: TU Verlag, S. 230.
  - Frank, M., Reisinger, A., Pahr, D.H. & Thurner, P.J., 2019. Tensile mechanical properties of human individual trabeculae of non- and osteopororotic fracture donors . In European Society of Biomechanics. Vienna: TU Verlag, S. 685.
  - Iori, G., Schneider, J., Heyer, F., Wyers, C., Gluer, C.C., van den Bergh, J., Pahr, D.H. & Raum, K., 2019. Cortical bone thinning at the tibia reflects femoral neck structural deterioration. In European Society of Biomechanics. Vienna: TU Verlag, S. 274.
  - Kluess, D., Soodmand, E., Lorenz, A., Pahr, D.H., Schwarze, M., Cichon, R., Varady, P.A., Herrmann, S., Buchmeier, B., Schröder, C., Lehner, S. & Kebbach, M., 2019. Ein Finite-Elemente-Ringversuch zur Biomechanik des humanen Femur zwischen sieben teilnehmenden Laboren mit experimenteller Validierung. In 11. Kongress der Deutschen Gesellschaft für Biomechanik (DGfB). Berlin, S. 118.
  - Lorenz, A., Freidhager, C., Leichtle, U.G. & Pahr, D.H., 2019. Krümmungsbasierte Detektion anatomischer Landmarken und Achsen am menschlichen Kniegelenk . In 11. Kongress der Deutschen Gesellschaft für Biomechanik (DGfB). Berlin, S. 91.
  - Lorenz, A., Steiner, L., Freidhager, C., Leichtle, U.G. & Pahr, D.H., 2019. Comparison of different methods for automatic landmark detection from 2D images, 3D images or 3D surface meshes. In European Society of Biomechanics. Vienna: TU Verlag, S. 165.
  - Pahr, D.H., Synek, A., Stipsitz, M. & Steiner, L., 2019. Micro FE in bone biomechanics – Recent advances . In 11. Kongress der Deutschen Gesellschaft für Biomechanik (DGfB). Berlin, S. 117.
  - Reisinger, A., Frank, M., Thurner, P. & Pahr, D.H., 2019. Elasto-visco-plastic material parameters of single trabeculae identified by rheological modelling. In European Society of Biomechanics. Vienna: TU Verlag, S. 182.
    Link
  - Sinzinger, F., Pahr, D.H. & Moreno, R., 2019. Predicting the trabecular bone stiffness tensor with spherical convolutional neural networks. In European Society of Biomechanics. Vienna: TU Verlag, S. 164.
  - Steiner, L. & Pahr, D.H., 2019. Statistical deformation model based estimation of 3D models from 2D projections can be used to predict human femoral strength. In European Society of Biomechanics. Vienna: TU Verlag, S. 634.
  - Stelzer, S., Einwögerer, T., Grebe, A., Gunz, P., Händel, M., Neubauer, S., Pahr, D.H., Simon, U. & Teschler-Nicola, M., 2019. Digitisation of an Upper Palaeolithic infant burial from Krems-Wachtberg. In European Society for the study of Human Evolution. Liège/Belgium.
  - Stipsitz, M., Zysset, P. & Pahr, D.H., 2019. Failure behavior of trabecular bone based on materially nonlinear micro fe simulations. In European Society of Biomechanics. Vienna: TU Verlag, S. 270.
    Link
  - Synek, A., Lu, S.-C., Kivell, T.L., Nauwelaerts, S. & Pahr, D.H., 2019. Metacarpophalangeal joint loads of bonobos during different locomotor modes: Proxies vs. Model predictions. In European Society of Biomechanics. Wien: TU Verlag, S. 25.
  - Synek, A., Lu, S.-C., Vereecke, E., Kivell, T.L. & Pahr, D.H., 2019. Identifying optimal tendon path parameters of a musculoskeletal human finger model. In European Society of Biomechanics. Vienna: TU Verlag, S. 447.
    Link
  - Teschler-Nicola, M., Mandl, K., Becker, S., Stelzer, S., Pahr, D.H. & Weiss-Krejci, E., 2019. A "perforated" human hyoid bone - Bone artefact or thyroglossal duct cyst. In 6th International Anthropological Congress of Dr Aleš Hrdlička. 03.-05.09.2019. Czech Republic.
- Journal Article
  - Amini, M., Reisinger, A. & Pahr, D.H., 2019. Influence of processing parameters on mechanical properties of a 3D-printed trabecular bone microstructure. Journal of biomedical materials research. Part B, Applied biomaterials, 108(1), S.38-47.
  - Benca, E., Synek, A., Amini, M., Kainberger, F., Hirtler, L., Windhager, R., Mayr, W. & Pahr, D.H., 2019. QCT-based finite element prediction of pathologic fractures in proximal femora with metastatic lesions. Scientific reports, 9, S.10305.
  - Georgiou, L., Kivell, T.L., Pahr, D.H., Buck, L.T. & Skinner, M.M., 2019. Trabecular architecture of the great ape and human femoral head. Journal of anatomy, 234(5), S.679-693.
    Link
  - Iori, G., Schneider, J., Reisinger, A., Heyer, F., Peralta, L., Wyers, C., Grasel, M., Barkmann, R., Gluer, C.C., van den Bergh, J.P., Pahr, D.H. & Raum, K., 2019. Large cortical bone pores in the tibia are associated with proximal femur strength. PloS one, 14, S.e0215405.
  - Kluess, D., Soodmand, E., Lorenz, A., Pahr, D.H., Schwarze, M., Cichon, R., Varady, P.A., Herrmann, S., Buchmeier, B., Schröder, C., Lehner, S. & Kebbach, M., 2019. A round-robin finite element analysis of human femur mechanics between seven participating laboratories with experimental validation. Comput Methods Biomech Biomed Engin, 22, S.1020-1031.
    Link
  - Synek, A., Dunmore, C.J., Kivell, T.L., Skinner, M.M. & Pahr, D.H., 2019. Inverse remodelling algorithm identifies habitual manual activities of primates based on metacarpal bone architecture. Biomechanics and modeling in mechanobiology, 18, S.399-410.
  - Synek, A., Lu, S.-C., Vereecke, E.E., Nauwelaerts, S., Kivell, T.L. & Pahr, D.H., 2019. Musculoskeletal models of a human and bonobo finger: parameter identification and comparison to in vitro experiments. PeerJ, 7, S.e7470.
2018
- Journal Article
  - Georgiou, L., Kivell, T.L., Pahr, D.H. & Skinner, M.M., 2018. Trabecular bone patterning in the hominoid distal femur. PeerJ, 6, S.e5156.
  - Lu, S.C., Vereecke, E.E., Synek, A., Pahr, D.H. & Kivell, T.L., 2018. A novel experimental design for the measurement of metacarpal bone loading and deformation and fingertip force. PeerJ, 6, S.e5480.
  - Panyasantisuk, J., Dall'Ara, E., Pretterklieber, M., Pahr, D.H. & Zysset, P.K., 2018. Mapping anisotropy improves QCT-based finite element estimation of hip strength in pooled stance and side-fall load configurations. Medical Engineering & Physics, 59, S.36-42.
    Link
2017
- Journal Article
  - Benca, E., Reisinger, A., Patsch, J.M., Hirtler, L., Synek, A., Stenicka, S., Windhager, R., Mayr, W. & Pahr, D.H., 2017. Effect of simulated metastatic lesions on the biomechanical behavior of the proximal femur. Journal of Orthopaedic Research, 35, S.2407-2414.

Research Projects

Medi3D Print II
Medi3DPrint-2
- Project Number: 10020
- Project Lead: Gernot Kronreif, ACMIT - Austrian Center for Medical Innovation and Technology
- Project Partner: Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 36 months starting from 01.01.2022
Cortmech-Damage
Determination of material properties of bone tissue with an adapted two‑layer elasto‑visco‑plastic-damage rheological model
- Project Lead: Andreas Reisinger, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Project Partner: Technische Universität Wien / Institute for Lightweight Design and Structural Biomechanics
- Duration: 5 months starting from 01.09.2021
Background
Trabecular bone tissue can be properly modeled as an elasto‑visco‑plastic material. However, loading-unloading experiments of individual trabeculae revealed a decrease of the elastic modulus with increasing strain. As such, goal of the current study is to scale the elastic part of a previously developed 2-layer elasto‑visco‑plastic rheological model with a damage variable (from 0-1), which is dependent on plastic strain. This adaptation will enable an improved description of bone tissue material properties. Additionally, new tensile tests will be performed on cortical bone specimens obtained from the shaft of human femurs to compare the usage of the proposed model for cortical and trabecular bone tissue. Additional specimens will be obtained from the femoral neck of healthy and osteoporotic donors to determine if there is a change of material properties of bone tissue with respect to osteoporosis. Previously, it has been shown that there is no significant change of the material properties of individual trabeculae in osteoporosis. Goal of the current study is to investigate if that holds also for cortical bone tissue in the femoral neck. Knowledge of this information is not only essential in computer simulations, which require reliable material input parameters, but also for a better understanding of the effect of osteoporosis on the material itself.
ELSA
Gait-based evaluation of early rehabilitation after ACL reconstruction
- Project Number: LSC18_018
- Project Lead: Andrea Zauner-Dungl, Karl Landsteiner University of Health Sciences / Institute of Physiotherapy and Rehabilitation (University Hospital Krems)
- Project Partner: FH St. Pölten / Institute of Health Sciences, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 45 months starting from 15.01.2020
Background
A postsurgical treatment after ACL reconstruction is necessary for early return-to-sport as well as to minimize the occurrence of long-term complications. However, the required amount of postsurgical physiotherapeutic supervision remains unclear, as studies concerning less supervision (home-based program) showed sufficient clinical outcomes in home-based groups. Gait plays a major role in rehabilitation process, therefore affordable and simple applicable devices are needed for clinical practice, as 3D gait analysis (gold standard) is expensive. Wearable systems like IMUs (Inertial Measurement Unit) are already used for clinical investigation. Still, there is a lack of appropriate methods and scores for gait assessment, concerning rehabilitation after ACL reconstruction. The aim of the current study is the gait-based assessment of the early rehabilitation progress after ACLre construction.
For this purpose, a specific ACL rehabilitation score is developed, including multiple aspects of gait as well as clinical parameters. The quality of the score derived by data of a simple, clinically applicable, IMU-based gait analysis device (G-Walk) is evaluated in comparison to a standard 3D gait analysis system. Based on the developed score, the outcome of two different ACL rehabilitation programs (home-based versus standardized) will be determined. Therefore, a clinical study is conducted. Two groups of patients with different postsurgical treatment after ACL reconstruction will be formed. Gait assessments will be carried out 6-7 weeks, 9-10 weeks and 12-13 weeks postsurgical using a simple IMU-based gait analysis system (G-Walk) as well as standard 3D gait analysis system for validation purpose. Pre-existing gait data of healthy people will serve as a control. A new ACL habilitation score will be developed, including clinical parameters (e.g. range of motion, IKDC, Lysholm), standard gait parameters (regarding kinematics, kinetics and spatiotemporal characteristics) as well as more sophisticated gait parameters like symmetry, variability, complexity or local stability. Statistical analysis will be performed to determine the influence of the rehabilitation programs and the adequacy of the score determined from IMU data compared to 3D gait analysis data. The results of the proposed study will not only give information about the impact of physiotherapeutic supervision on the early normalization of gait and if home-based programs can confidently be recommended for specific patients. It will also provide a clinically applicable method for gait assessment which can be integrated in the routinely follow-up procedure after ACL reconstruction and used to answer related scientific questions. Furthermore, the proposed method can lay the basis for the development of similar scores in different fields of rehabilitation or therapy assessment.
Measurement of mechanical strains
Measurement of mechanical strains on the surface of biological tissues
- Project Number: SC18-006
- Project Lead: Dieter Pahr, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 26 months starting from 01.07.2019
Background
Bone is a fascinating, living, and smart load-bearing tissue. It supports the body, facilitates locomotion and acts as protector to inner organs. Understanding of bone mechanical properties helps in developing treatments and clinical applications suitable for more complex and personalized solutions.
In general, biological tissues are inhomogeneous and anisotropic. To understand mechanical behaviour of biological tissues, a complete description of this behaviour over the whole geometry and shape of the sample is necessary. Bone and soft tissues mechanical properties have been widely investigated with different approaches, such as in vitro experiments and numerical models. Experimentally, strain gauges (SGs) are considered as gold-standard for strain measurements on the bone surface due to their high accuracy. However, measurements with the SGs allow only for discrete points to be evaluated and do not provide full-field strain distribution on the surface of the sample. In addition, SGs require detailed surface preparation. A poor preparation can result in extremely inaccurate results. Transducers and extensometers have been used as well to measure the global strain in bone. All the previous three strain measurement techniques induce perturbation in the results due to their contribution to the load-bearing capacity, lead into a systematic underestimate of the actual strain distribution.
During the last years, optical measurement techniques based on digital image correlation (DIC) paired with computational power allowed contactless measurement of whole surfaces. Thus, they overcome the limitation of contacting the surface and availability of single measurement points.
DIC depend on tracking the displacement of recognized features (speckles) on the sample surface. DIC tracks the displacement between deformed and un-deformed digital images of the surface. Based on the digital images, a full-field displacement map is calculated from which a full-field strain map is derived. The accuracy of DIC depends on the quality of the speckles, measurement conditions (light and speckle size and distribution), as well as various software (facet and grid size) and hardware parameters (optics and camera resolution), which must be optimized. Despite the versatile advantages of DIC approach in obtaining full-field strain measurements on the surface of interest, DIC has not been fully exploited yet for measurements on biological samples, and in particular, on bone.
The aims of this study are: (i) extensively investigate the accuracy and precision of the DIC method based on standardized metallic and polymeric samples under zero-load by evaluating the speckle pattern size and distribution, (ii) validation of the accuracy and precision of DIC measuring system against a precise extensometer; (iii) evaluate 3D full-field strain distribution on the surface of biological tissue like bone and tendon samples; (iv) provide practical guidelines on how to harness the benefits of DIC application to measure strain fields on biological hard and soft tissues.
FAM-3D
Functional anatomical 3D-models
- Project Number: K3-F-807/002-2018
- Project Lead: Nikolaus Dellantoni, ACMIT - Austrian Center for Medical Innovation and Technology
- Project Partner: Karl Landsteiner University of Health Sciences / Division Biomechanics, Niederoesterreichische Landesgesundheitsagentur (NOE LGA) / X-ray Institute for Diagnostics, Interventional Radiology and Nuclear Medicine
- Duration: 45 months starting from 01.04.2019
Colon-Plug
Colon-Plug
- Project Number: 874254
- Project Lead: Dieter Pahr, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Project Partner: Teaching ordination / Prim. Univ.-Prof. Dr. Georg Bischof
- Duration: 12 months starting from 01.03.2019
Reproducing biological tissues
Reproducing biological tissues in terms of their mechanical properties by means of 3D printing
- Project Number: SC17-016
- Project Lead: Dieter Pahr, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 34 months starting from 01.12.2018
Background
3D printing, also known as additive manufacturing (AM) or rapid prototyping, has become a highly versatile tool with a broad range of applications, such as manufacturing, art, design, and medicine. In the field of biomedical engineering AM has not only gained wide popularity in tissue engineering for printing scaffolds and in biomechanics for patient-specific prostheses, but it has also been proposed as an instrument for fabricating realistic 3D models. For example, individual modelling of patient-specific conditions via AM poses an excellent opportunity for surgeons to practice procedures beforehand. Studies have shown that in doing so operation time is reduced and the physician's confidence is increased, resulting in shorter times of radiation exposure and lower costs. Although 3D modelling approaches for pre-surgical planning have been reported previously, a closer look, concerning the mechanical properties of the printed materials, is still required. Currently, these models lack accurate representation of the tissue biomechanics. This demands a procedure for fine-tuning the mechanical properties of the 3D printed materials to closely match the in vivo conditions. In this project, 3D printing is applied to the task of producing materials that closely imitate biological tissues, and organ-like structures, in terms of their mechanical properties. The printed tissues can be patient-specific for pre-surgical planning, as well as standardized for applications in research dealing with advancing novel operating techniques, implant technology, and other medical devices. One of the incentives is to thereby limit the demand of donor organs and reduce variability of the organs used in research. Due to the fact that the capabilities of 3D printing are currently rapidly increasing, this research can also be seen as the groundwork for even more applications concerning printed organs that might be possible with future technology. The key objectives of this project are:
the establishment of a testing protocol for acquiring characteristic biomechanical parameters of different tissues, the development of software tools for attaining these parameters in 3D printed structures (based on suitable material combinations and spatial distribution thereof, plus post-processing procedures), the printing of these tissue replicas alongside the validation of their mechanical properties via comparison with the actual tissue characteristics. All instructions for manufacturing these models are to be contained in a so-called “toolbox”.
Digitisation as a chance for restoration and visualisation
Digitisation as a chance for restoration and visualisation – A pilot study on the 30,000 year old double burial of newborns from Krems-Wachtberg
- Project Number: FTI17-010
- Project Lead: Dieter Pahr, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Project Partner: Museum of Natural History Vienna / Department of Anthropology, Danube University Krems / Collection Studies and Management, Austrian Academy of Science / Institute for Oriental and European Archaeology
- Duration: 47 months starting from 01.11.2018
Background
The discovery of the more than 30,000 years old ritual double burial of two neonates at the Krems-Wachtberg site in 2005 has evoked much attention not only by the media and the general public, but also from the international scientific community as findings of sub adults of ancient humans are, on a global scale, extremely rare occasions. After the discovery and exposure the ritual burial was carefully recovered as a block, and the fragile specimens were stored to keep its original excellent condition. In 2015 the recovered block was excavated, documenting each single step with state-of-the art methods.
Digitisation is now aimed for to enable analyses, restoration and also visualisation. Currently, the only non-destructive way to make a digital copy and visualize the remains is high-resolution micro-computed tomography imaging. It allows 3D reconstruction of the surface as well as the inner micro-structure - making it possible to “uncover the invisible”. Such a device has been installed at the division for Biomechanics of KL University as part of the Core Facility at Campus Krems. This will overcome the current restrictions of analysis and allows a digitisation of the findings for future analysis.
Together with the available light scanning data from the excavation the whole assembly can be reconstructed. Apart from 3-dimensional reconstruction it will be possible to restorate the chaîne operatoire of activities which were part of this burial process, as well as the post-sedimentary formation processes (4D = modelling the development through time).
In addition to the reconstruction of the burial, up-to-date documentation and archiving of the data is of utmost importance to lay a basis for further research. Thus, one of the main objectives of this pilot project is to set up a catalogue of criteria for a long term, open-source data repository which provides access to all the data regarding the excavation and findings for larger groups of scientists beyond disciplinary borders.
Digitisation of the Krems-Wachtberg double burial is challenging in all respects and requires a variety of experts to deal with the many aspects that are inherent in such a spectacular discovery. For the first time, it is possible to investigate this outstanding find from Krems-Wachtberg under the leadership of Lower Austrian research institutions. As one of its main targets, the proposed project will contribute to a further professionalization in Collection Management and Museology – one of the areas of Lower Austrian FTI strategy – and it will significantly improve the visibility of cultural heritage in Lower Austria by latest technical developments that allow for scientific exploitation on an international level.
HIPStar
Obesity-specific joint center estimation in gait analysis
- Project Number: P 30923-B30
- Project Lead: Brian Horsak, FH St. Pölten / Institute of Health Sciences
- Project Partner: Karl Landsteiner University of Health Sciences / Division Biomechanics, Medical University of Vienna / Department of Pediatrics and Adolescent Medicine, Orthopaedic Hospital Vienna-Speising
- Duration: 36 months starting from 01.10.2018
Background
Gait analysis aims at gathering quantitative information about the mechanics of the musculo-skeletal system during locomotion. Typically, in gait analysis, variables such as kinematics, joint moments, and powers are determined. This information is used to evaluate pathological gait patterns. Errors in locating the three-dimensional (3D) position of the hip joint center (HJC) can strongly affect the calculation of 3D gait analysis variables. This consequentially leads to incorrect interpretations. The problem of inaccuracy in HJC location increases significantly in patients where bony landmarks are difficult to identify, such as in overweight or obese populations. Nevertheless, gait analysis remains as the state of the art method for clinicians and for researchers. Often medical imaging-based methods are recommended to identify the 3D HJC localization. However, some of those methods expose patients to radiation or are expensive and time-consuming. Therefore, non-invasive predictive methods, based on experimental data, or functional models were introduced in recent years to estimate the position of the HJC. Researcher has attempted to evaluate which of these methods best determine the HJC most accurately in various populations. Among those, only a few studies recruited children or clinically diagnosed patients. Surprisingly, there is no study, which recruited overweight or obese children and adolescents. However, all currently non-invasive available methods are strongly affected by the amount of subcutaneous fat present (wobbling mass), which can introduce great inaccuracies. Therefore, a study to identify how well existing HJC estimation methods work for this very specific population is strongly recommended. In addition, new methods such as 3D free-hand ultrasound techniques (3DUS) may bear great potential for accurate and non-invasive estimation techniques. These methods, are still experimental and have not yet been tested in overweight populations.
The primary aim of this study is to evaluate the accuracy of current non-invasive HJC estimation methods for clinical 3D gait analysis to magnetic resonance imaging (MRI) in a population of overweight or obese children and adolescents. Based on the results obtained in this study, we will (i) provide recommendations, for which methods serve best to estimate the HJC position; (ii) develop soft tissue compensation algorithms and strategies that allow for a more accurate estimation of the HJC; (iii) in addition, we will evaluate the use of 3DUS as a promising alternative in HJC estimation.
BEST MgAlloy
Biocompatible elements - simulations and tests for Mg alloys
- Project Number: KF3-F-639/004-2017
- Project Lead: Jelena Horky, AIT Austrian Institute of Technology / Center for Health & Bioresources
- Project Partner: Aerospace & Advanced Composites GmbH, FH Wiener Neustadt, AC2T research GmbH, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 42 months starting from 01.04.2018
Background
Biodegradable magnesium-based implants are increasingly coming into focus for temporary use in medical applications, such as plates, nails, pins or screws for osteosynthesis of broken bones. The great advantage of this is the elimination of a second operation for explanting any permanent metallic fixations.
Endobone
Developmental tissue engineering model of endochondral ossification for bone regeneration
- Project Number: LSC16_024
- Project Lead: Stefan Nehrer, Danube University Krems / Department of Regenerative Medicine
- Project Partner: Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 48 months starting from 01.01.2018
Background
Bone engraftment techniques to treat large bone defects involve implantation of allogenic bone grafts as a replacement tissue but are constrained on poor integration and functional anastomosis for ingrowth of vasculature from the host tissue. In proportionate many unresolved factors are to be addressed in advancing the clinical outcome for treating fracture non-unions, osteonecrosis, osteoporosis. Tissue engineering strategies hold promise in promoting bone regeneration. Nevertheless, the common approach in bone tissue engineering is by stimulating the osteogenesis route for regenerating bone which still remains an ineffective approach. Mimicking the natural process of bone formation through a developmental mechanism for formation of long bones called endochondral ossification has been envisioned from the commencement of research in the field of bone tissue engineering. In the current proposal, we propose a strategy for bone regeneration with naturally derived biomaterials incorporating extracellular matrix derived from cartilage (CD-ECM) as a template. We hypothesize that bone regeneration through a cartilaginous intermediate template onto solid biomaterials will produce a neotissue that mimics the native bone in its structure and functionality. To test this hypothesis we will compare bone regeneration from the proposed model to the gold-standard bone allografts used in clinics. CD-ECM incorporated biomaterials embedding hypertrophic chondrocytes are evaluated for their mineralized matrix formation in vitro with biochemical analysis and histological evaluation. Further, by non-destructive analysis micro-computed tomography (µCT) monitoring generated 3D segmented images and biomechanical testing of the scaffolds are evaluated together with computational finite element modelling simulations to determine the stiffness, strength of the engineered bone. The CD-ECM incorporated biomaterials are then implanted with or without hypertrophic chondrocytes ectopically in a mouse model for de novo mineralized matrix formation. The bone formation is further assessed by biochemical, µCT, biomechanical, computational modelling. This interdisciplinary approach would aid in a developmental engineering process instructing bioresponsive scaffolds to recapitulate native bone repair mechanisms.
Medi3D Print
3D print of biological materials
- Project Lead: Gernot Kronreif, ACMIT - Austrian Center for Medical Innovation and Technology
- Project Partner: Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 39 months starting from 01.01.2018
Background
3D printing is entering medicine and can help in many ways. In addition to accurately fitting implants and orthoses, 3D printing can be used in surgical preparation to gain a better understanding of the planned surgery. Increasingly, the printing of organs is becoming more important. In this research project materials are to be printed with the help of the Polyjet process which come as close as possible to real biological tissues from the haptic but also with regard to the biomechanical behavior. The printing technology developed in this way enables the production of patient-specific organ models based on CT and MRI data, which can be used for preoperative planning prior to complicated procedures. Furthermore, for the further development of surgical techniques and implants mechanically equivalent organs or specimens can be produced, which make dispensing with the use of body donations for these concerns. The printed organs are standardizable and have no undesirable variability, as is the case with body donation.
Novel biomechanical test setup
Development of a novel biomechanical test setup together with bone strength simulation models to improve the diagnoses and treatment of osteoporosis
- Project Number: SC16_009
- Project Lead: Dieter Pahr, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 37 months starting from 01.10.2017
Background
Osteoporosis (OP) is a silent bone disease resulting in loss of bone density, decreased bone strength and ultimately fracture. It is underrated, underdiagnosed and undertreated. Every third women and every fifth men over 50 are concerned. OP is responsible for more than 4 million fractures annually in the EU, with hip fracture as the most common type. This translates into more than €40 billions of health care costs, out of which less than 5% is spent on prevention. Beside diabetes, cardiovascular diseases, and cancer it’s one of the important health care challenges in the next decades. Especially in Lower Austria this puts an estimated €200 million of annual burden on the healthcare system only. The early diagnostics of OP is vital for fracture prevention. This in return increases the life quality of the patient, and decreases the healthcare and social costs. Bone density is used as predictor of osteoporotic fracture risk. It is measured with DEXA and diagnosed with a derived T-score. However, recent studies showed the inaccuracy and insufficiency of such densitometry measures. For example, more than 50% of OP fractures occur in the patients who are considered as “low risk” by this method, and 15% of patients are falsely treated for being at "high risk". An improvement of this situation needs (a) better screening techniques, (b) more screening, and (c) improved diagnosis scores. The goal of this project is to improve osteoporosis diagnostic tools. Bone fracture happens because of overloading and/or reduced resistance against loading due to bone loss. Finite element analysis (FEA) simulation is a non-invasive numerical method which is able to estimate individual bone strength in-vivo based on DEXA or Quantitative Computed Tomography (QCT) images. Geometrical, structural, and material properties are computed from images and combined with typical physiological loading conditions including the magnitude, direction, and frequency of the loading. The accuracy of the model is inherited from a good knowledge of all these parameters. FEA -based bone strength has the potential to effectively improve diagnosis, assessment, and monitoring of osteoporosis. But despite the significant progress made in the last decade, these predictions still need considerable improvements through enhancements in imaging, mechanical testing, and simulation techniques to justify their clinical use.
M3dRES
Additive Manufacturing for Medical Research
- Project Number: FFG858060
- Project Lead: Francesco Moscato, Medical University of Vienna / Center for Medical Physics and Biomedical Engineering
- Project Partner: ACMIT - Austrian Center for Medical Innovation and Technology, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Duration: 60 months starting from 01.05.2017
Background
The M3dRES project aims at establishing a unique infrastructure devoted to 3d-printing for medical research in a strongly interdisciplinary environment.
M3dRES provides essential tools for the personalized patient treatment, for the enhancement of medical imaging, for the acceleration of tissue engineering and regenerative medicine, and for the modernization of current medical education.
OsteoSim
Computer simulation models for the early detection of osteoporosis
- Project Number: FFG850746
- Project Lead: Dieter Pahr, Karl Landsteiner University of Health Sciences / Division Biomechanics
- Project Partner: Danube University Krems / Department of Regenerative Medicine, Braincon GmbH&CoKG, Technische Universität Wien / Institute for Lightweight Design and Structural Biomechanics
- Duration: 36 months starting from 01.12.2015
Background
Osteoporosis is a common age disease of the bone. The cause of osteoporosis is usually a hormonal change. Older women are predominantly affected, but men are also increasingly suffering from this disease. The widespread of osteoporosis is gradually becoming a health economic problem. Osteoporosis gradually reduces bone density. As a result, the entire skeleton is weakened biomechanically and it is more likely to suffer from bone fractures. In clinical practice, the diagnosis of osteoporosis or, in general, the estimation of a fracture risk on the basis of bone density measurement (BMD measurement) is carried out. According to WHO, a T <-2.5 standard deviation is the critical threshold for the diagnosis of osteoporosis. Unfortunately, results of studies (eg, Rotterdam study3) show that in a group with non-vertebral fractures, only 44 percent of women and 21 percent of men had a value below -2.5. The final goal is to combine both medical reports from osteoporosis and osteoarthrosis together with new, validated assessment models, which gives better results than the T-score. As a secondary goal, relationships and possible interactions of both diseases are shown. This is to be achieved by four research tasks: new models of osteoporosis, standardization of radiographs, combined findings - correlations osteoporosis and osteoarthrosis, validation of new osteoporosis assessment models.

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2019

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2018

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Research Projects

Medi3D Print II

Cortmech-Damage

Background

ELSA

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Measurement of mechanical strains

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FAM-3D

Colon-Plug

Reproducing biological tissues

Background

Digitisation as a chance for restoration and visualisation

Background

HIPStar

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BEST MgAlloy

Background

Endobone

Background

Medi3D Print

Background

Novel biomechanical test setup

Background

M3dRES

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OsteoSim

Background

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