PD Dr. Jonas Widmer
PD Dr. Jonas Widmer completed his doctorate at ETH Zurich in 2016-2020 in the field of experimental and computer-aided biomechanics in the field of spinal surgery and habilitates at the Medical Faculty of the University of Zurich in 2024. Since November 2020, PD Dr. Jonas Widmer has headed the Spine Biomechanics Group at Balgrist University Hospital.
In addition to his academic activities, he works at 25Segments in the research and development of various new spinal implants and is co-founder and part-time CTO of Moving Spine AG, a company that develops medical devices in the field of dynamic spinal stabilization.
PUBLICATIONS
ORIGINAL PAPERS
Wunderli, S. L.; Widmer, J.; Amrein, N.; Foolen, J.; Silvan, U.; Leupin, O.; Snedeker, J. G. Minimal Mechanical Load and Tissue Culture Conditions Preserve Native Cell Phenotype and Morphology in Tendon-a Novel Ex Vivo Mouse Explant Model. Journal of Orthopaedic Research 2018, 36 (5), 1383–1390. https://doi.org/10.1002/jor.23769.
Bernal, L. M. B.; Schmidt, I. T.; Vulin, N.; Widmer, J.; Snedeker, J. G.; Cattin, P. C.; Zam, A.; Rauter, G. Optimizing controlled laser cutting of hard tissue (bone). at - Automatisierungstechnik 2018, 66 (12), 1072–1082. https://doi.org/10.1515/auto-2018-0072.
Scheibler, A.-G.; Götschi, T.; Widmer, J.; Holenstein, C.; Steffen, T.; Camenzind, R. S.; Snedeker, J. G.; Farshad, M. Feasibility of the Annulus Fibrosus Repair with in Situ Gelating Hydrogels – A Biomechanical Study. PLOS ONE 2018, 13 (12), e0208460. https://doi.org/10.1371/journal.pone.0208460.
Cornaz, F.; Fasser, M.-R.; Spirig, J. M.; Snedeker, J. G.; Farshad, M.; Widmer, J. 3D Printed Clamps Improve Spine Specimen Fixation in Biomechanical Testing. J Biomech 2019, 98, 109467. https://doi.org/10.1016/j.jbiomech.2019.109467.
Widmer, J.; Fornaciari, P.; Senteler, M.; Roth, T.; Snedeker, J. G.; Farshad, M. Kinematics of the Spine Under Healthy and Degenerative Conditions: A Systematic Review. Ann Biomed Eng 2019, 47 (7), 1491–1522. https://doi.org/10.1007/s10439-019-02252-x.
Cornaz, F.; Widmer, J.; Snedeker, J. G.; Spirig, J. M.; Farshad, M. Cross-Links in Posterior Pedicle Screw-Rod Instrumentation of the Spine: A Systematic Review on Mechanical, Biomechanical, Numerical and Clinical Studies. Eur Spine J 2020, 30 (1), 34–49. https://doi.org/10.1007/s00586-020-06597-z.
Widmer, J.; Fasser, M.-R.; Croci, E.; Spirig, J.; Snedeker, J. G.; Farshad, M. Individualized Prediction of Pedicle Screw Fixation Strength with a Finite Element Model. Computer Methods in Biomechanics and Biomedical Engineering 2020, 23 (4), 155–167. https://doi.org/10.1080/10255842.2019.1709173.
Schoenenberger, A. D.; Tempfer, H.; Lehner, C.; Egloff, J.; Mauracher, M.; Bird, A.; Widmer, J.; Maniura-Weber, K.; Fucentese, S. F.; Traweger, A.; Silvan, U.; Snedeker, J. G. Macromechanics and Polycaprolactone Fiber Organization Drive Macrophage Polarization and Regulate Inflammatory Activation of Tendon in Vitro and in Vivo. Biomaterials 2020, 249, 120034. https://doi.org/10.1016/j.biomaterials.2020.120034.
Widmer, J.; Cornaz, F.; Scheibler, G.; Spirig, J. M.; Snedeker, J. G.; Farshad, M. Biomechanical Contribution of Spinal Structures to Stability of the Lumbar Spine—Novel Biomechanical Insights. The Spine Journal 2020, 20(10), 1705–1716. https://doi.org/10.1016/j.spinee.2020.05.541.
Caprara, S.; Carrillo, F.; Snedeker, J. G.; Farshad, M.; Senteler, M. Automated Pipeline to Generate Anatomically Accurate Patient-Specific Biomechanical Models of Healthy and Pathological FSUs. Front. Bioeng. Biotechnol.2021, 9. https://doi.org/10.3389/fbioe.2021.636953.
Caprara, S.; Fasser, M.-R.; Spirig, J. M.; Widmer, J.; Snedeker, J. G.; Farshad, M.; Senteler, M. Bone Density Optimized Pedicle Screw Instrumentation Improves Screw Pull-out Force in Lumbar Vertebrae. Computer Methods in Biomechanics and Biomedical Engineering 2021, 25 (4), 464–474. https://doi.org/10.1080/10255842.2021.1959558.
Fasser, M.-R.; Jokeit, M.; Kalthoff, M.; Gomez Romero, D. A.; Trache, T.; Snedeker, J. G.; Farshad, M.; Widmer, J. Subject-Specific Alignment and Mass Distribution in Musculoskeletal Models of the Lumbar Spine. Front Bioeng Biotechnol 2021, 9, 721042. https://doi.org/10.3389/fbioe.2021.721042.
Farshad, M.; Frey, A.; Jentzsch, T.; Betz, M.; Widmer, J.; Spirig, J. M. Reducing the Kyphosis Effect of Anterior Short Thoracolumbar/Lumbar Scoliosis Correction with an Autograft Fulcrum Effect. BMC Musculoskeletal Disorders 2021, 22 (1), 216. https://doi.org/10.1186/s12891-021-04083-1.
Cornaz, F.; Widmer, J.; Farshad-Amacker, N. A.; Spirig, J. M.; Snedeker, J. G.; Farshad, M. Intervertebral Disc Degeneration Relates to Biomechanical Changes of Spinal Ligaments. The Spine Journal 2021. https://doi.org/10.1016/j.spinee.2021.04.016.
Götschi, T.; Widmer, J.; Cornaz, F.; Kimenai, J.; Spirig, J. M.; Snedeker, J. G.; Farshad, M. Region- and Degeneration Dependent Stiffness Distribution in Intervertebral Discs Derived by Shear Wave Elastography. Journal of Biomechanics 2021, 121, 110395. https://doi.org/10.1016/j.jbiomech.2021.110395.
Spirig, J. M.; Winkler, E.; Cornaz, F.; Fasser, M.-R.; Betz, M.; Snedeker, J. G.; Widmer, J.; Farshad, M. Biomechanical Performance of Bicortical versus Pericortical Bone Trajectory (CBT) Pedicle Screws. Eur Spine J2021. https://doi.org/10.1007/s00586-021-06878-1.
Cornaz, F.; Widmer, J.; Farshad-Amacker, N. A.; Spirig, J. M.; Snedeker, J. G.; Farshad, M. Biomechanical Contributions of Spinal Structures with Different Degrees of Disc Degeneration. Spine 2021, Publish Ahead of Print. https://doi.org/10.1097/BRS.0000000000003883.
Cornaz, F.; Widmer, J.; Fasser, M.-R.; Snedeker, J. G.; Matsukawa, K.; Spirig, J. M.; Farshad, M. Is a Cross-Connector Beneficial for Single Level Traditional or Cortical Bone Trajectory Pedicle Screw Instrumentation? PLOS ONE 2021, 16 (6), e0253076. https://doi.org/10.1371/journal.pone.0253076.
Roth, T.; Rahm, S.; Jungwirth-Weinberger, A.; Süess, J.; Sutter, R.; Schellenberg, F.; Taylor, W. R.; Snedeker, J. G.; Widmer, J.; Zingg, P. Restoring Range of Motion in Reduced Acetabular Version by Increasing Femoral Antetorsion – What about Joint Load? Clinical Biomechanics 2021, 87, 105409. https://doi.org/10.1016/j.clinbiomech.2021.105409.
Cornaz, F.; Burkhard, M.; Fasser, M.-R.; Spirig, J. M.; Snedeker, J. G.; Farshad, M.; Widmer, J. 3D Printed Clamps for Fixation of Spinal Segments in Biomechanical Testing. Journal of Biomechanics 2021, 125, 110577. https://doi.org/10.1016/j.jbiomech.2021.110577.
Widmer, J.; Cornaz, F.; Farshad-Amacker, N. A.; Snedeker, J. G.; Spirig, med. J. M.; Farshad, M. Hydrostatic Integrity of the Intervertebral Disc Assessed by MRI. Journal of Biomechanics 2021, 127, 110661. https://doi.org/10.1016/j.jbiomech.2021.110661.
Burkhard, M. D.; Cornaz, F.; Spirig, J. M.; Wanivenhaus, F.; Loucas, R.; Fasser, M.-R.; Widmer, J.; Farshad, M. Posterior Spinal Instrumentation and Decompression with or without Cross-Link? North American Spine Society Journal (NASSJ) 2021, 8, 100093. https://doi.org/10.1016/j.xnsj.2021.100093.
Cornaz, F.; Farshad, M.; Widmer, J. Location of Pedicle Screw Hold in Relation to Bone Quality and Loads. Frontiers in Bioengineering and Biotechnology 2022, 10.
Fasser, M.-R.; Kuravi, R.; Bulla, M.; Snedeker, J. G.; Farshad, M.; Widmer, J. A Novel Approach for Tetrahedral-Element-Based Finite Element Simulations of Anisotropic Hyperelastic Intervertebral Disc Behavior. Frontiers in Bioengineering and Biotechnology 2022, 10.
Widmer, J.; Aubin, C.-E.; van Lenthe, G. H.; Matsukawa, K. Editorial: Innovations to Improve Screw Fixation in Traumatology and Orthopedic Surgery. Frontiers in Bioengineering and Biotechnology 2022, 10.
Balzer, I.; Mühlemann, M.; Jokeit, M.; Rawal, I. S.; Snedeker, J. G.; Farshad, M.; Widmer, J. A Deep Learning Pipeline for Automatized Assessment of Spinal MRI. Computer Methods and Programs in Biomedicine Update2022, 2, 100081. https://doi.org/10.1016/j.cmpbup.2022.100081.
Tsagkaris, C.; Widmer, J.; Wanivenhaus, F.; Redaelli, A.; Lamartina, C.; Farshad, M. The Sitting vs Standing Spine. North American Spine Society Journal (NASSJ) 2022, 9, 100108. https://doi.org/10.1016/j.xnsj.2022.100108.
Cornaz, F.; Fasser, M.-R.; Snedeker, J. G.; Spirig, J. M.; Farshad, M.; Widmer, J. The Biomechanical Fundamentals of Crosslink-Augmentation in Posterior Spinal Instrumentation. Sci Rep 2022, 12 (1), 7621. https://doi.org/10.1038/s41598-022-11719-2.
Jokeit, M.; Kim, J. H.; Snedeker, J. G.; Farshad, M.; Widmer, J. Mesh-Based 3D Reconstruction from Bi-Planar Radiographs; 2022.
Haupt, S.; Cornaz, F.; Falkowski, A. L.; Widmer, J.; Farshad, M. Biomechanical Considerations of the Posterior Surgical Approach to the Lumbar Spine. The Spine Journal 2022. https://doi.org/10.1016/j.spinee.2022.08.006.
Cornaz, F.; Haupt, S.; Farshad, M.; Widmer, J. Real-Time Assessment of Anteroposterior Stability of Spinal Segments. Eur Spine J 2022, 31 (9), 2368–2376. https://doi.org/10.1007/s00586-022-07286-9.
Fasser, M.-R.; Gerber, G.; Passaplan, C.; Cornaz, F.; Snedeker, J. G.; Farshad, M.; Widmer, J. Computational Model Predicts Risk of Spinal Screw Loosening in Patients. Eur Spine J 2022, 31 (10), 2639–2649. https://doi.org/10.1007/s00586-022-07187-x.
Farshad, M.; Cornaz, F.; Spirig, J. M.; Sutter, R.; Farshad-Amacker, N. A.; Widmer, J. Spondylophyte Classification Based on Biomechanical Effects on Segmental Stiffness. The Spine Journal 2022, 22 (11), 1903–1912. https://doi.org/10.1016/j.spinee.2022.06.001.
Lindenmann, S.; Tsagkaris, C.; Farshad, M.; Widmer, J. Kinematics of the Cervical Spine Under Healthy and Degenerative Conditions: A Systematic Review. Ann Biomed Eng 2022, 50 (12), 1705–1733. https://doi.org/10.1007/s10439-022-03088-8.
Farshad, M.; Hagel, V.; Spirig, J. M.; Fasser, M.-R.; Widmer, J.; Burkhard, M. D.; Calek, A.-K. Biomechanics of Transforaminal Endoscopic Approaches. Spine (Phila Pa 1976) 2022, 47 (24), 1753–1760. https://doi.org/10.1097/BRS.0000000000004471.
Heggli, I.; Laux, C. J.; Mengis, T.; Karol, A.; Cornaz, F.; Herger, N.; Aradi‐Vegh, B.; Widmer, J.; Burkhard, M. D.; Farshad‐Amacker, N. A.; Pfammatter, S.; Wolski, W. E.; Brunner, F.; Distler, O.; Farshad, M.; Dudli, S. Modic Type 2 Changes Are Fibroinflammatory Changes with Complement System Involvement Adjacent to Degenerated Vertebral Endplates. JOR Spine 2022. https://doi.org/10.1002/jsp2.1237.
Tsagkaris, C.; Kalachanis, K.; Widmer, J.; Farshad, M. Spine Biomechanics in the Work of Aristotle (384 – 322 BC). Surg Innov 2022, 155335062211480. https://doi.org/10.1177/15533506221148012.
Tsagkaris, C.; Calek, A.-K.; Fasser, M.-R.; Spirig, J. M.; Caprara, S.; Farshad, M.; Widmer, J. Bone Density Optimized Pedicle Screw Insertion. Frontiers in Bioengineering and Biotechnology 2023, 11.
Burkhard, M. D.; Cornaz, F.; Spirig, J. M.; Wanivenhaus, F.; Fasser, M.-R.; Widmer, J.; Farshad, M. Residual Motion of Cortical versus Pedicle Screw Constructs after Decompression, Interbody Fusion and Cross-Link Augmentation. Eur Spine J 2023, 32 (4), 1401–1410. https://doi.org/10.1007/s00586-023-07596-6.
Burkhard, M. D.; Spirig, J. M.; Wanivenhaus, F.; Cornaz, F.; Fasser, M.-R.; Widmer, J.; Farshad, M. Residual Motion of Different Posterior Instrumentation and Interbody Fusion Constructs. Eur Spine J 2023, 32 (4), 1411–1420. https://doi.org/10.1007/s00586-023-07597-5.
Farshad, M.; Tsagkaris, C.; Widmer, J.; Fasser, M.-R.; Cornaz, F.; Calek, A.-K. Vertebropexy as a Semi-Rigid Ligamentous Alternative to Lumbar Spinal Fusion. Eur Spine J 2023, 32 (5), 1695–1703. https://doi.org/10.1007/s00586-023-07647-y.
Haupt, S.; Cornaz, F.; Falkowski, A. L.; Farshad, M.; Widmer, J. The Biomechanical Consequence of Posterior Interventions at the Thoracolumbar Spine on the Passively Stabilized Flexed Posture. Journal of Biomechanics2023, 153, 111599. https://doi.org/10.1016/j.jbiomech.2023.111599.
Burkhard, M. D.; Calek, A.-K.; Fasser, M.-R.; Cornaz, F.; Widmer, J.; Spirig, J. M.; Wanivenhaus, F.; Farshad, M. Biomechanics after Spinal Decompression and Posterior Instrumentation. Eur Spine J 2023, 32 (6), 1876–1886. https://doi.org/10.1007/s00586-023-07694-5.
Calek, A.-K.; Tsagkaris, C.; Fasser, M.-R.; Widmer, J.; Hagel, V.; Farshad, M. Biomechanical Limitations of Partial Pediculectomy in Endoscopic Spine Surgery. The Spine Journal 2023, 23 (7), 1088–1095. https://doi.org/10.1016/j.spinee.2023.02.005.
Calek, A.-K.; Altorfer, F.; Fasser, M.-R.; Widmer, J.; Farshad, M. Interspinous and Spinolaminar Synthetic Vertebropexy of the Lumbar Spine. Eur Spine J 2023, 32 (9), 3183–3191. https://doi.org/10.1007/s00586-023-07798-y.
Spirig, J. M.; Fasser, M.-R.; Widmer, J.; Wanivenhaus, F.; Laux, C. J.; Farshad, M.; Passaplan, C. Intraoperative Anteroposterior and Oblique Fluoroscopic Views for Detection of Mediolateral Pedicle Screw Misplacement in the Lumbar Spine: A Randomized Cadaveric Study. The Spine Journal 2023, 0 (0). https://doi.org/10.1016/j.spinee.2023.10.006.
Calek, A.-K.; Widmer, J.; Fasser, M.-R.; Farshad, M. Lumbar Vertebropexy after Unilateral Total Facetectomy. The Spine Journal 2023, 23 (11), 1730–1737. https://doi.org/10.1016/j.spinee.2023.07.005.
Calek, A.-K.; Cornaz, F.; Suter, M.; Fasser, M.-R.; Baumgartner, S.; Sager, P.; Farshad, M.; Widmer, J. Load Distribution on Intervertebral Cages with and without Posterior Instrumentation. Spine J 2023, S1529-9430(23)03485-X. https://doi.org/10.1016/j.spinee.2023.10.017.