Partial Meniscectomy Changes Fluid Pressurization in Articular Cartilage in Human Knees

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
M. Kazemi ◽  
L. P. Li ◽  
M. D. Buschmann ◽  
P. Savard
Keyword(s):  
Articular Cartilage ◽  
Knee Joint ◽  
Relaxation Times ◽  
Fluid Pressure ◽  
Partial Meniscectomy ◽  
Loading Conditions ◽  
Support Mechanism ◽  
Fluid Pressurization ◽  
Creep Loading ◽  
Intact Knee

Partial meniscectomy is believed to change the biomechanics of the knee joint through alterations in the contact of articular cartilages and menisci. Although fluid pressure plays an important role in the load support mechanism of the knee, the fluid pressurization in the cartilages and menisci has been ignored in the finite element studies of the mechanics of meniscectomy. In the present study, a 3D fibril-reinforced poromechanical model of the knee joint was used to explore the fluid flow dependent changes in articular cartilage following partial medial and lateral meniscectomies. Six partial longitudinal meniscectomies were considered under relaxation, simple creep, and combined creep loading conditions. In comparison to the intact knee, partial meniscectomy not only caused a substantial increase in the maximum fluid pressure but also shifted the location of this pressure in the femoral cartilage. Furthermore, these changes were positively correlated to the size of meniscal resection. While in the intact joint, the location of the maximum fluid pressure was dependent on the loading conditions, in the meniscectomized joint the location was predominantly determined by the site of meniscal resection. The partial meniscectomy also reduced the rate of the pressure dissipation, resulting in even larger difference between creep and relaxation times as compared to the case of the intact knee. The knee joint became stiffer after meniscectomy because of higher fluid pressure at knee compression followed by slower pressure dissipation. The present study indicated the role of fluid pressurization in the altered mechanics of meniscectomized knees.

Mechanical Response of Human Knee Joint to Sinusoidal Compression: Influence of Fluid Pressurization in Soft Tissues

2012 ◽  
Author(s):  
Yaghoub Dabiri ◽  
LePing Li
Keyword(s):  
Knee Joint ◽  
Soft Tissues ◽  
Mechanical Response ◽  
Fluid Pressure ◽  
Joint Modeling ◽  
Loading Frequency ◽  
Human Knee ◽  
Human Knee Joint ◽  
Fluid Pressurization

The mechanical response of the knee joint has been simulated using finite element methods with elastic material models [1–4]. Fluid pressurization in articular cartilage and menisci has not been considered in the anatomically accurate joint modeling until recently [5–7]. We have recently considered stress relaxation and creep behavior of human knees. The objective of the present study was to investigate the mechanics of the femoral cartilage under cyclical knee compression. We are particularly interested in the determination of loading versus unloading patterns for the fluid pressure and flow, as well as the influence of the loading frequency on the fluid pressurization.

scholarly journals The Scaffold–Articular Cartilage Interface: A Combined In Vitro and In Silico Analysis Under Controlled Loading Conditions

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Tony Chen ◽  
Moira M. McCarthy ◽  
Hongqiang Guo ◽  
Russell Warren ◽  
Suzanne A. Maher
Keyword(s):  
Articular Cartilage ◽  
Mechanical Loading ◽  
In Silico ◽  
Fluid Pressure ◽  
In Silico Analysis ◽  
Element Model ◽  
Loading Conditions ◽  
Optimal Method ◽  
Biphasic Finite Element

The optimal method to integrate scaffolds with articular cartilage has not yet been identified, in part because of our lack of understanding about the mechanobiological conditions at the interface. Our objective was to quantify the effect of mechanical loading on integration between a scaffold and articular cartilage. We hypothesized that increased number of loading cycles would have a detrimental effect on interface integrity. The following models were developed: (i) an in vitro scaffold–cartilage explant system in which compressive sinusoidal loading cycles were applied for 14 days at 1 Hz, 5 days per week, for either 900, 1800, 3600, or 7200 cycles per day and (ii) an in silico inhomogeneous, biphasic finite element model (bFEM) of the scaffold–cartilage construct that was used to characterize interface micromotion, stress, and fluid flow under the prescribed loading conditions. In accordance with our hypothesis, mechanical loading significantly decreased scaffold–cartilage interface strength compared to unloaded controls regardless of the number of loading cycles. The decrease in interfacial strength can be attributed to abrupt changes in vertical displacement, fluid pressure, and compressive stresses along the interface, which reach steady-state after only 150 cycles of loading. The interfacial mechanical conditions are further complicated by the mismatch between the homogeneous properties of the scaffold and the depth-dependent properties of the articular cartilage. Finally, we suggest that mechanical conditions at the interface can be more readily modulated by increasing pre-incubation time before the load is applied, as opposed to varying the number of loading cycles.

A Numerical Model of Mechanics of Osteoarthritis in Human Knee Joint

2012 ◽  
Author(s):  
Yaghoub Dabiri ◽  
LePing Li
Keyword(s):  
Articular Cartilage ◽  
Knee Joint ◽  
Fluid Pressure ◽  
Three Dimensional ◽  
Solid Matrix ◽  
Joint Mechanics ◽  
Human Knee ◽  
Human Knee Joint ◽  
Contact Loads ◽  
Model Fluid

Articular cartilage is composed of water entrapped in a solid matrix formed by proteoglycans and collagen fibers. Therefore, the mechanical behavior of this tissue is determined by all of these three components. In addition, the properties of articular cartilage vary along the depth and by location. In the human knee joint, the three dimensional geometry as well as the contact between the cartilaginous tissues plays essential roles in the joint mechanics. On the other hand, initiation and progression of osteoarthritis (OA) could be partly caused by contact loads. Consequently, the fibrillar and non-fibrillar matrices, the three dimensional geometry and the contact between the tissues should be considered as essential parameters in the study of the mechanics of osteoarthritis. However, previous studies on OA mechanics were mostly limited to explants geometries [1]. Also, the contact mechanics associated with the fluid pressure have not been considered in the previous OA models. In a recent knee model, fluid was considered in femoral cartilage but not in the menisci [2]. Additionally, the depth-dependent mechanical properties were not included in that model.

scholarly journals Study of the Mechanical Environment of Chondrocytes in Articular Cartilage Defects Repaired Area under Cyclic Compressive Loading

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Hai-Ying Liu ◽  
Hang-Tian Duan ◽  
Chun-Qiu Zhang ◽  
Wei Wang
Keyword(s):  
Articular Cartilage ◽  
Cyclic Loading ◽  
Response Curve ◽  
Fluid Pressure ◽  
Cartilage Defects ◽  
Loading Frequency ◽  
Liquid Pressure ◽  
Mechanical Environment ◽  
Finite Element Software ◽  
Maximum Value

COMSOL finite element software was used to establish a solid-liquid coupling biphasic model of articular cartilage and a microscopic model of chondrocytes, using modeling to take into account the shape and number of chondrocytes in cartilage lacuna in each layer. The effects of cyclic loading at different frequencies on the micromechanical environment of chondrocytes in different regions of the cartilage were studied. The results showed that low frequency loading can cause stress concentration of superficial chondrocytes. Moreover, along with increased frequency, the maximum value of stress response curve of chondrocytes decreased, while the minimum value increased. When the frequency was greater than 0.2 Hz, the extreme value stress of response curve tended to be constant. Cyclic loading had a large influence on the distribution of liquid pressure in chondrocytes in the middle and deep layers. The concentration of fluid pressure changed alternately from intracellular to peripheral in the middle layer. Both the range of liquid pressure in the upper chondrocytes and the maximum value of liquid pressure in the lower chondrocytes in the same lacunae varied greatly in the deep layer. At the same loading frequency, the elastic modulus of artificial cartilage had little effect on the mechanical environment of chondrocytes.

Articular cartilage thickness and glycosaminoglycan distribution in the young canine knee joint after remobilization of the immobilized limb

1994 ◽  
Vol 12 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Ilkka Kiviranta ◽  
Markku Tammi ◽  
Jukka Jurvelin ◽  
Jari Arokoski ◽  
Anna-Marja Säämänen ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Knee Joint ◽  
Cartilage Thickness

Articular cartilage in the knee joint of the African elephant,Loxodonta africana, Blumenbach 1797

2007 ◽  
Vol 269 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Gunter F. Egger ◽  
Kirsti Witter ◽  
Gerald Weissengruber ◽  
Gerhard Forstenpointner
Keyword(s):  
Articular Cartilage ◽  
Knee Joint ◽  
Loxodonta Africana ◽  
African Elephant
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