A Biphasic Finite Element Model of In Vitro Plowing Tests of the Temporomandibular Joint Disc

2009 ◽  
Vol 37 (6) ◽  
pp. 1152-1164 ◽  
Author(s):  
R. L. Spilker ◽  
J. C. Nickel ◽  
L. R. Iwasaki
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Temporomandibular Joint ◽  
Element Model ◽  
Temporomandibular Joint Disc ◽  
Biphasic Finite Element

A 3D Biphasic Finite Element Model of the Human Knee Joint for the Study of Tibiofemoral Contact and Fluid Pressurization

2013 ◽  
Author(s):  
Hongqiang Guo ◽  
Suzanne A. Maher ◽  
Robert L. Spilker
Keyword(s):  
Finite Element ◽  
Fluid Flow ◽  
Knee Joint ◽  
Contact Problem ◽  
Finite Element Model ◽  
Soft Tissues ◽  
Fluid Pressure ◽  
Element Model ◽  
Human Knee Joint ◽  
Biphasic Finite Element

Biphasic theory which considers soft tissue, such as articular cartilage and meniscus, as a combination of a solid and a fluid phase has been widely used to model their biomechanical behavior [1]. Though fluid flow plays an important role in the load-carrying ability of soft tissues, most finite element models of the knee joint consider cartilage and the meniscus as solid. This simplification is due to the fact that biphasic contact is complicated to model. Beside the continuity conditions for displacement and traction that a single-phase contact problem consists of, there are two additional continuity conditions in the biphasic contact problem for relative fluid flow and fluid pressure [2]. The problem becomes even more complex when a joint is being modeled. The knee joint, for example, has multiple contact pairs which make the biphasic finite element model of this joint far more complex. Several biphasic models of the knee have been developed [3–9], yet simplifications were included in these models: (1) the 3D geometry of the knee was represented by a 2D axisymmetric geometry [3, 5, 6, 9]; (2) no fluid flow was allowed between contact surfaces of the soft tissues [4, 8] which is inconsistent with the equation of mass conservation across the contact interface [10]; (3) zero fluid pressure boundary conditions were inaccurately applied around the contact area [7].

8A35 Study on constructing a finite element model of temporomandibular joint.

2012 ◽  
Vol 2012.24 (0) ◽  
pp. _8A35-1_-_8A35-2_
Author(s):  
Suguru ICHIKAWA ◽  
Mamoru MURATA ◽  
Yasukazu NISHI ◽  
Akira NAKAJIMA ◽  
Kazuyoshi HOSHINO ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Temporomandibular Joint ◽  
Element Model

Impact of spinal rod stiffness on porcine lumbar biomechanics: Finite element model validation and parametric study

2017 ◽  
Vol 231 (12) ◽  
pp. 1071-1080
Author(s):  
Martin Brummund ◽  
Vladimir Brailovski ◽  
Yvan Petit ◽  
Yann Facchinello ◽  
Jean-Marc Mac-Thiong
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Variable Stiffness ◽  
Transverse Process ◽  
Threshold Value ◽  
Element Model ◽  
Three Dimensional Finite Element

A three-dimensional finite element model of the porcine lumbar spine (L1–L6) was used to assess the effect of spinal rod stiffness on lumbar biomechanics. The model was validated through a comparison with in vitro measurements performed on six porcine spine specimens. The validation metrics employed included intervertebral rotations and the nucleus pressure in the first instrumented intervertebral disc. The numerical results obtained suggest that rod stiffness values as low as 0.1 GPa are required to reduce the mobility gradient between the adjacent and instrumented segments and the nucleus pressures across the porcine lumbar spine significantly. Stiffness variations above this threshold value have no significant effect on spine biomechanics. For such low-stiffness rods, intervertebral rotations in the instrumented zone must be monitored closely in order to guarantee solid fusion. Looking ahead, the proposed model will serve to examine the transverse process hooks and variable stiffness rods in order to further smooth the transition between the adjacent and instrumented segments, while preserving the stability of the instrumented zone, which is needed for fusion.

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