Limits...
Connecting mechanics and bone cell activities in the bone remodeling process: an integrated finite element modeling.

Hambli R - Front Bioeng Biotechnol (2014)

Bottom Line: The model was able to predict final human proximal femur adaptation similar to the patterns observed in a human proximal femur.The results obtained reveal complex spatio-temporal bone adaptation.The proposed FEM model gives insight into how bone cells adapt their architecture to the mechanical and biological environment.

View Article: PubMed Central - PubMed

Affiliation: Prisme Institute, Polytechnique Orleans, PRISME/MMH , Orleans , France ; I3MTO, Université d'Orléans , Orleans , France.

ABSTRACT
Bone adaptation occurs as a response to external loadings and involves bone resorption by osteoclasts followed by the formation of new bone by osteoblasts. It is directly triggered by the transduction phase by osteocytes embedded within the bone matrix. The bone remodeling process is governed by the interactions between osteoblasts and osteoclasts through the expression of several autocrine and paracrine factors that control bone cell populations and their relative rate of differentiation and proliferation. A review of the literature shows that despite the progress in bone remodeling simulation using the finite element (FE) method, there is still a lack of predictive models that explicitly consider the interaction between osteoblasts and osteoclasts combined with the mechanical response of bone. The current study attempts to develop an FE model to describe the bone remodeling process, taking into consideration the activities of osteoclasts and osteoblasts. The mechanical behavior of bone is described by taking into account the bone material fatigue damage accumulation and mineralization. A coupled strain-damage stimulus function is proposed, which controls the level of autocrine and paracrine factors. The cellular behavior is based on Komarova et al.'s (2003) dynamic law, which describes the autocrine and paracrine interactions between osteoblasts and osteoclasts and computes cell population dynamics and changes in bone mass at a discrete site of bone remodeling. Therefore, when an external mechanical stress is applied, bone formation and resorption is governed by cells dynamic rather than adaptive elasticity approaches. The proposed FE model has been implemented in the FE code Abaqus (UMAT routine). An example of human proximal femur is investigated using the model developed. The model was able to predict final human proximal femur adaptation similar to the patterns observed in a human proximal femur. The results obtained reveal complex spatio-temporal bone adaptation. The proposed FEM model gives insight into how bone cells adapt their architecture to the mechanical and biological environment.

No MeSH data available.


Related in: MedlinePlus

FE of the proximal femur and boundary conditions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4126454&req=5

Figure 2: FE of the proximal femur and boundary conditions.

Mentions: To illustrate the capabilities of the mechanobiological bone adaptation model developed, remodeling of a 2D proximal femur was performed. The 2D model is based on the geometry of a real femur, taken from a radiograph of a coronal section of the proximal femur (Jacobs et al., 1995). An FE model was constructed including the trabecular and cortical bones and a representation of the acetabulum allowing for the free femur head articulation (Figure 2). The purpose of the model is to show the adaptation of the proximal femur only (trabecular and cortical bone). Hence, the acetabulum appears as an exterior element, which participates in load bearing, but is not part of the adaptation process in the algorithm.


Connecting mechanics and bone cell activities in the bone remodeling process: an integrated finite element modeling.

Hambli R - Front Bioeng Biotechnol (2014)

FE of the proximal femur and boundary conditions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126454&req=5

Figure 2: FE of the proximal femur and boundary conditions.
Mentions: To illustrate the capabilities of the mechanobiological bone adaptation model developed, remodeling of a 2D proximal femur was performed. The 2D model is based on the geometry of a real femur, taken from a radiograph of a coronal section of the proximal femur (Jacobs et al., 1995). An FE model was constructed including the trabecular and cortical bones and a representation of the acetabulum allowing for the free femur head articulation (Figure 2). The purpose of the model is to show the adaptation of the proximal femur only (trabecular and cortical bone). Hence, the acetabulum appears as an exterior element, which participates in load bearing, but is not part of the adaptation process in the algorithm.

Bottom Line: The model was able to predict final human proximal femur adaptation similar to the patterns observed in a human proximal femur.The results obtained reveal complex spatio-temporal bone adaptation.The proposed FEM model gives insight into how bone cells adapt their architecture to the mechanical and biological environment.

View Article: PubMed Central - PubMed

Affiliation: Prisme Institute, Polytechnique Orleans, PRISME/MMH , Orleans , France ; I3MTO, Université d'Orléans , Orleans , France.

ABSTRACT
Bone adaptation occurs as a response to external loadings and involves bone resorption by osteoclasts followed by the formation of new bone by osteoblasts. It is directly triggered by the transduction phase by osteocytes embedded within the bone matrix. The bone remodeling process is governed by the interactions between osteoblasts and osteoclasts through the expression of several autocrine and paracrine factors that control bone cell populations and their relative rate of differentiation and proliferation. A review of the literature shows that despite the progress in bone remodeling simulation using the finite element (FE) method, there is still a lack of predictive models that explicitly consider the interaction between osteoblasts and osteoclasts combined with the mechanical response of bone. The current study attempts to develop an FE model to describe the bone remodeling process, taking into consideration the activities of osteoclasts and osteoblasts. The mechanical behavior of bone is described by taking into account the bone material fatigue damage accumulation and mineralization. A coupled strain-damage stimulus function is proposed, which controls the level of autocrine and paracrine factors. The cellular behavior is based on Komarova et al.'s (2003) dynamic law, which describes the autocrine and paracrine interactions between osteoblasts and osteoclasts and computes cell population dynamics and changes in bone mass at a discrete site of bone remodeling. Therefore, when an external mechanical stress is applied, bone formation and resorption is governed by cells dynamic rather than adaptive elasticity approaches. The proposed FE model has been implemented in the FE code Abaqus (UMAT routine). An example of human proximal femur is investigated using the model developed. The model was able to predict final human proximal femur adaptation similar to the patterns observed in a human proximal femur. The results obtained reveal complex spatio-temporal bone adaptation. The proposed FEM model gives insight into how bone cells adapt their architecture to the mechanical and biological environment.

No MeSH data available.


Related in: MedlinePlus