Estimating lumbar passive stiffness behaviour from subject-specific finite element models and in vivo 6DOF kinematics

The effects of degeneration and surgery on cervical spine mechanics are commonly evaluated through in vitro testing and finite element models derived from these tests. The objectives of the current study were to estimate the load applied to the C2 vertebra during in vivo functional flexion-extension and to evaluate the effects of anterior cervical arthrodesis on spine kinetics. Spine and head kinematics from 16 subjects (six arthrodesis patients and ten asymptomatic controls) were determined during functional flexion-extension using dynamic stereo X-ray and conventional reflective markers. Subject-specific inverse dynamics models, including three flexor muscles and four extensor muscles attached to the skull, estimated the force applied to C2. Total force applied to C2 was not significantly different between arthrodesis and control groups at any 10 deg increment of head flexion-extension (all p values ≥ 0.937). Forces applied to C2 were smallest in the neutral position, increased slowly with flexion, and increased rapidly with extension. Muscle moment arms changed significantly during flexion-extension, and were dependent upon the direction of head motion. The results suggest that in vitro protocols and finite element models that apply constant loads to C2 do not accurately represent in vivo cervical spine kinetics.

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Subject-specific finite element models can accurately predict strain levels in long bones

Journal of Biomechanics ◽

10.1016/j.jbiomech.2007.02.010 ◽

2007 ◽

Vol 40 (13) ◽

pp. 2982-2989 ◽

Cited By ~ 208

Author(s):

Enrico Schileo ◽

Fulvia Taddei ◽

Andrea Malandrino ◽

Luca Cristofolini ◽

Marco Viceconti

Keyword(s):

Finite Element ◽

Finite Element Models ◽

Long Bones ◽

Subject Specific

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An accurate estimation of bone density improves the accuracy of subject-specific finite element models

Journal of Biomechanics ◽

10.1016/j.jbiomech.2008.05.017 ◽

2008 ◽

Vol 41 (11) ◽

pp. 2483-2491 ◽

Cited By ~ 184

Author(s):

Enrico Schileo ◽

Enrico Dall’Ara ◽

Fulvia Taddei ◽

Andrea Malandrino ◽

Tom Schotkamp ◽

...

Keyword(s):

Finite Element ◽

Bone Density ◽

Accurate Estimation ◽

Finite Element Models ◽

Subject Specific

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Corrigendum to “How accurately can subject-specific finite element models predict strains and strength of human femora? Investigation using full-field measurements” [J. Biomech. 49 (2016) 802–806]

Journal of Biomechanics ◽

10.1016/j.jbiomech.2018.12.032 ◽

2019 ◽

Vol 84 ◽

pp. 290-292

Author(s):

Lorenzo Grassi ◽

Sami P. Väänänen ◽

Matti Ristinmaa ◽

Jukka S. Jurvelin ◽

Hanna Isaksson

Keyword(s):

Finite Element ◽

Field Measurements ◽

Finite Element Models ◽

Full Field ◽

Subject Specific

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Subject-Specific Finite Element Modeling of the Tibiofemoral Joint Based on CT, Magnetic Resonance Imaging and Dynamic Stereo-Radiography Data in Vivo

Journal of Biomechanical Engineering ◽

10.1115/1.4026228 ◽

2014 ◽

Vol 136 (4) ◽

Cited By ~ 16

Author(s):

Robert E. Carey ◽

Liying Zheng ◽

Ameet K. Aiyangar ◽

Christopher D. Harner ◽

Xudong Zhang

Keyword(s):

Magnetic Resonance Imaging ◽

Finite Element ◽

Magnetic Resonance ◽

Contact Area ◽

Resonance Imaging ◽

Model Predictions ◽

Subject Specific ◽

Skeletal Kinematics ◽

Tibiofemoral Kinematics

In this paper, we present a new methodology for subject-specific finite element modeling of the tibiofemoral joint based on in vivo computed tomography (CT), magnetic resonance imaging (MRI), and dynamic stereo-radiography (DSX) data. We implemented and compared two techniques to incorporate in vivo skeletal kinematics as boundary conditions: one used MRI-measured tibiofemoral kinematics in a nonweight-bearing supine position and allowed five degrees of freedom (excluding flexion-extension) at the joint in response to an axially applied force; the other used DSX-measured tibiofemoral kinematics in a weight-bearing standing position and permitted only axial translation in response to the same force. Verification and comparison of the model predictions employed data from a meniscus transplantation study subject with a meniscectomized and an intact knee. The model-predicted cartilage-cartilage contact areas were examined against “benchmarks” from a novel in situ contact area analysis (ISCAA) in which the intersection volume between nondeformed femoral and tibial cartilage was characterized to determine the contact. The results showed that the DSX-based model predicted contact areas in close alignment with the benchmarks, and outperformed the MRI-based model: the contact centroid predicted by the former was on average 85% closer to the benchmark location. The DSX-based FE model predictions also indicated that the (lateral) meniscectomy increased the contact area in the lateral compartment and increased the maximum contact pressure and maximum compressive stress in both compartments. We discuss the importance of accurate, task-specific skeletal kinematics in subject-specific FE modeling, along with the effects of simplifying assumptions and limitations.

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