Biomedical Engineering Reference
In-Depth Information
FEA and the isotropic remodeling theory developed by Huiskes and coworkers [48].
They checked the influence of the strain energy threshold on the simulation of
the remodeling process. Finally, they estimated that the difference between several
thresholds implied a 4% of bone mass loss.
Kerner
et al
. [69] carried out bone remodeling simulations of patient-specific
3D FE models of bone specimens obtaining their bone densitometry (DEXA).
This work again showed the potential of these techniques to study the interaction
between the implant and the bone, getting prediction of bone loss in accordance to
the DEXA measurements on the specimens.
Prendergast and Taylor [70] used anatomical finite element models to preclinically
test the effect of hip prosthesis design. They performed these simulations using
a bone remodeling theory based on damage accumulation. They studied the
importance of two features of intramedullary prosthesis design on bone adaptation:
elastic modulus and the presence of a prosthesis collar. They concluded, as Huiskes
et al
. [61] did, that a low elasticity modulus reduced the bone loss, whereas the
presence of a collar had no significant effect.
The isotropic bone remodeling theory developed by Beaupre
et al
. [45] was also
applied with 2D FEA to simulate bone adaptation around porous-coated implants
[71] in the proximal femur and tibia. The predicted bone density distribution around
implanted prostheses was consistent with clinical and experimental findings
of other researchers. Similar works were performed in this sense, with this
same remodeling theory, to predict bone apparent density alteration around
non-cemented acetabular components in 2D models [72].
Weinans
et al
. [73] studied the influence of different parameters on stress
shielding that are normally used in these computer simulations, such as loading
conditions and bone material properties. They analyzed four different loading con-
ditions and two different bone density-elastic modulus relationships, obtaining
differences up to 20% in specific regions due to changes in loading condi-
tions and of 10% after changing the relationship between apparent density and
elastic modulus. From these results, they concluded that although bone remod-
eling is different for each individual, there is no important difference between
individuals.
Doblar´eandGarcıa [23] developed an anisotropic bone remodeling theory, which
was used to analyze the influence of anisotropy on bone remodeling after a THR
with an Exeter hip prosthesis [24]. They predicted that bone anisotropy changes
after replacement, tending to a more isotropic distribution (see Figure 4.2).
Cegonino
et al
. [74] also analyzed the mechanical stability and bone remodeling
adaptation of several distal femoral fractures treated with an intramedullary nail
(DFN: distal femoral nail) and with an extramedullary plate (LISS: less invasive
stabilization system). Both types of implants achieve a correct stabilization of
the fracture, while the LISS plate causes more resorption in the distal region,
specifically in the fracture site, due to the bridge effect of the plate in this
region.
More recently, Perez
et al
. [75] applied a bone remodeling model [24] in order
to predict the bone remodeling of a resurfacing prosthesis with different cement
