AIM 2014-2-final-dubravko.indd

120
A Comparative Study of the Proposed Models for the Components of the National Health Information System
doi: 10.5455/aim.2014.22.120-122
ORIGINAL PAPER
ACTA INFORM MED. 2014 APR 22(2): 120-122
Received: 17 December 2013 • Accepted: 28 Januar 2014
© AVICENA 2014
Proposed Use of the Computer as a Tool
to Aid Analysis of Properties of Materials
in Fixators of Spine
Antonio Santos1, Fernando Moreira2
Departamento de Biotecnologia, Universidade Federal de São Carlos, São Carlos, São Paulo, Brasil1
Departamento de Biotecnologia, Universidade Federal de São Carlos, São Carlos, São Paulo, Brasil2
Corresponding author: Antonio Santos. Departamento de Biotecnologia, Universidade Federal de São Carlos, São Carlos, São Paulo, Brasil. E-mail: ams@
sc.usp.br1.
ABSTRACT
Withobjectiveofanalyzingthemechanicalbehavioroftheinternalfixatorsofspineandofthebonystructure,thepiecesandthegroup
weremade(itstructuresbonyxinternalfixator)withtheaidasoftwareofsolidmodeling.Thematerialsusedintherehearsalshadbeen
thetitanium,nowinthemarketandacastoroilpolyurethanedestinedtothedevelopmentofyouimplantbony.
Key words:castoroil,internalfixators,simulatedandstructuresbony..
1. IN T RODUC T ION
From beginning to end of life, the skeletal system
adjusts to maintain the structural integrity of bones,
which in daily life is subject to various conditions of
mechanical loading. Consequently, the structural response, in part, due to the past history of loads imposed on the skeleton, the need for this, and the anticipation of future demands (1).
In orthopedic practice, often faced with situations
where there is continuity of bone changes (segmental
bone loss or fractures), especially because of the highenergy trauma, tumors, infections and congenital
malformations (2).
There is a continuous deformation depending on
the time of load application. The main element in
the ability of the vertebra to support load is spongy.
The cortical bone contributes 10% of the compressive
strength and bone with 50% (3).
The fixators of the spine for correction of conditions
is to make the injured segment disk using screws and
rods appropriate way to extend a force to be applied.
Currently the fixators, have been used not only for
stabilization of fractures, but also stretches pain and
bone compressor, conveyor segments or fragments
of bone and reducing fracture (4). However, little is
known about the mechanical behavior of these structures and what is the correlation between the choice
of the system and assembly, the type of disease being
treated and the complications that can set the (5).
The increase in applications and the number of
handset models available and studies the influence
of effort on bone demanded investigation of the mechanical characteristics of these devices, and different
ORIGINAL PAPER / ACTA INFORM MED. 2014 APR 22(2): 120-122
mounting, in order to adapt them to clinical applications desired (6). Most of the fasteners found on the
market for clinical tract, have been used in studies of
simulations is made of titanium (7).
In Brazil, the study of biomechanics of the column
began in 1987 (8). There are three types of biomechanical studies of the spine: tests of strength, endurance
and stability (9).
Strength tests are made by applying a progressive
force majeure, until there is structural failure. The fatigue is done by repeated application of a load until
structural failure occurs and the stability is given
from the application of different loads with different
meanings (10).
With a view to facilitate the analysis of specific
points of three-dimensional models created the finite element method (FEM), which is the subdivision
of the problem in small regions (elements) where the
field behavior of interest may approximate the functions simple, such as polynomials or harmonic functions. One reason for this simplification is the reduction of unknowns in the system of equations and consequently reducing the computational time.
In 1984, the Group of Analytical Chemistry and
Polymer Technology, University of São Paulo, campus
of São Carlos, through the Professor. Dr. Gilberto
Chierice, began research for the development of a
new polyurethane polyol derived from the castor (11).
Chemical or biological stability, density, and appropriate weight, strength and elasticity, and low cost
are essential qualities for the appointment of a biomaterial, but all these factors must be combined with the
biocompatibility, which is the primary requirement
Proposed Use of the Computer as a Tool to Aid Analysis of Properties of Materials in Fixators of Spine
for a material that can enter into contact with living
tissue without damaging it (12).
2. MATERIALS AND METHODS
METHODS
2. M AT2.EMATERIALS
R I ALS A N DAND
M ET
HODS
2. MATERIALS
AND
METHODS
The modeling
of the internal
fixators
of the spine
121
locked to prevent movement of the whole.
Material
Modulusofelasticity(GPa)
CoefficientPoisson
Table 1 Properties of Materials
1,37
Bone1
TableModulus
1 Properties
Materials
of of0,30
The modeling of the internal fixators of the spine (rods, shoes,
Coefficient
shoes,
screws)
andofwill
bone
structure
(cylMaterial
elasticity
Modulus
of
2
The
modeling
ofnuts,
the
internal
fixators
thebe
spine
(rods,
nuts,(rods,
screws)
and bone
structure
(cylinder)
made
up inshoes,
Table 1 Properties0,33
of Materials
103,4
Titanium
Poisson
Coefficient
inder)
will
be
made
up
in
modeling
software
(Figure
(GPa)
Material
elasticity
modeling
software
(Figure
1).structure
nuts,
screws)
and
(cylinder)
willspine
be made
in
Modulus
of
The
modeling
ofbone
the
internal fixators
of the
(rods,upshoes,
0,7
0,37
Polyurethane3
Poisson
Coefficient
1).
(GPa)
modeling
software
(Figure
elasticity
1 Material
nuts, screws)
and
bone 1).
structure (cylinder) will be made up in
Bone
1,37
0,30
Poisson
Table1Properties
of
Materials
(GPa)
modeling software (Figure 1).
Bone1
1,37
0,30
Titanium2 1
103,4
0,33
Bone
1,37
0,30
0,33
Polyurethane
0,7 103,4
0,37loads
Table
2 Titanium
shows3 2the different
values of the
to
3
2
Polyurethane
0,7
0,37
be applied
in the internal
fixation
Titanium
103,4of the vertebral
0,33
[13]Literature
valuesand
Ko, 3C.C.
et al. (1992)
Polyurethane
0,7 castor) (13,
0,37
column
(titanium
polyurethane
14,
[14]Literature
values
Clelland
al. et
(1991)
[13]Literature
values
Ko, et
C.C.
al. (1992)
15).
[14]Literature
values
Clelland
etG.D.
al.
[12]Literature
values
Silvestre
Filho,
[13]Literature
values
Ko,
C.C.
et (1991)
al.(2004)
(1992)
values
Silvestre
Filho,
(2004)
TESTS[12]Literature
LOAD(N)
[14]Literature
values
Clelland
et al.G.D.
(1991)
[12]Literature values Silvestre Filho, G.D. (2004)
Figure 1 – Fixators x Bone Structure
Structure
After modeling the
whole,1the
geometric data
will be
transferred
Figure
– Fixators
x Bone
Structure
Figure1–
Fixators
Structure
Figure
1 –x Bone
Fixators
x Bone
After
modeling
the whole,
the geometric
data
will be
After
modeling
the whole,
the geometric
data
transferred
to the
simulation
software.
The
problem
willwill
be be
divided
following
thesimulation
steps
for
using
the
Finite
Element
Method
thereby
to After
the
software.
The
problem
will
be
divided
transferred
to
the
simulation
software.
The
problem
modeling the whole, the geometric data will be transferred
generating
meshes
for
each
of
the
components
(nails,
shoes,
following
the
steps
for
using
the
Finite
Element
Method
will
be
divided
following
the
steps
for
using
thedivided
Fito the simulation software. The problem will bethereby
bolts,nite
screws
sos,meshes
bone
structure)
(Figure
2).
generating
forforeach
ofthe
theFinite
components
shoes,
following
the Method
steps
using
Element (nails,
Method
thereby
Element
thereby
generating
meshes
for
bolts,
screws sos,
bone for
structure)
(Figure
2).
generating
meshes
each of
the components
(nails, shoes,
each of the components (nails, shoes, bolts, screws,
bolts,
screws sos,(Figure
bone structure)
(Figure 2).
bone
structure)
2).
Figure 2 - Mesh Generation
Figure 2 - Mesh Generation
SILVESTRE
FILHO
[12], analyzed
by means
of tensile and
Figure
2 - Mesh
Generation
Figure2–MeshGeneration
bending
mechanicalFILHO
properties
castor oilby
polymer
SILVESTRE
[12],ofanalyzed
means reinforced
of tensile and
bending
mechanical
properties
of castor
oil
polymer
by carbon
fiber
rods
in(12),
hip analyzed
implants.
Were
also
carried
out and
SILVESTRE
FILHO
[12],
analyzed
by
means
ofreinforced
tensile
and
Silvestre
Filho
by means
of tensile
computer
simulations
of
the
stem,
along
with
the
test
device
by bending
carbon
fiber
rods
in
hip
implants.
Were
also
carried
out
mechanical properties
of castor
oil polymer
reinforced
bending
mechanical
properties
of
castor
oil
polymer
designed
comparison
with
thehip
experimental
results.
Intest
their
computer
simulations
of in
stem,
along with
the
deviceout
byforcarbon
fiber
rods
implants.
Were
also
carried
reinforced
carbon
fiber
rods
in
hip
implants.
simulations
were
used
as input
the
elastic
designed
for by
comparison
with
experimental
results.
InWere
their
computer
simulations
of data
thethestem,
along modulus
with
the and
test
device
also
carried
out
computer
simulations
of
the
stem,
simulations
were
used
as
input
data
the
elastic
modulus
Poisson's
ratio
of
materials
used
and
also
the
use
of
the
finite
designed for comparison with the experimental results. Inand
their
element
method.
Poisson's
ratiothe
of materials
anddata
alsothe
thefor
usecomparison
ofmodulus
the finiteand
along
with
test
device
designed
simulations
were
used
asused
input
elastic
element
method.
with
the
experimental
their
Poisson's
ratio of materialsresults.
used andInalso
the simulations
use of the finite
Figure 3 - Lateral Flexion tests and flexion-compression
Figure3–LateralFlexion tests and flexion-compression
Figure 3 - Lateral Flexion tests and flexion-compression
1
981Flexion tests and flexion-compression
Figure 3 - Lateral
Table 2 shows the different values of the loads to be applied in
2
1177
the internal
fixationtheofdifferent
the vertebral
column
(titanium
and in
Table 2 shows
values of
the loads
to be applied
3 polyurethane
1373
castor).
theTable
internal
fixation
of
the
vertebral
column
(titanium
and in
2 shows the different values of the loads to be applied
polyurethane
castor).
4
1569of the vertebral column (titanium and
the internal
fixation
Table
2 - 1765
Values for load tests
5
polyurethane
castor).
Table 2 - Values forLOAD(N)
load tests
TESTS
6
1961
TESTS
LOAD(N)
Table
2
Values
for
load
tests
1
981
7
2157
TESTS
LOAD(N)
1
981
2
1177
Table2–Valuesfor load tests
981
3 2 1
13731177
1177
4 3 2
15691373
The system of fixation
with titanium, 1569
commonly
5 4 3
1765 1373
implemented in patients,
using
screws
35
mm
1569 long
6 5 4
19611765
and 6 mm in diameter
(Figure
4),
which
is
applied
6 5
1765
21571961
at an angle of 760 degrees between the
two captive
7 6
2157
1961
Literature
[15]
screws
to thevalues
vertebrae,
and separate 10mm (16).
2157
Literature values7[15]
element
method.
The were
properties
theinput
materials
in internal
fixator of
thePoisusedof
as
dataused
the elastic
modulus
and
spineson’s
and properties
bone
are materials
presented
(Table
1).
The
of the
internal
fixator
of the
ratiostructure
of materials
usedused
andinalso
the use
of the
fispine
and
bone structure
presented
(Table
1). the fixator
Literature
[15] USSION
The
properties
of theare
materials
used
in internal
of the 3. RESU LTS
A Nvalues
Dwith
DISC
nite
element
method.
The
properties
of
materials
The system of fixation
titanium, commonly implemented
Model validation
will structure
be performed
flexion-compression
and
spine
bone
(Table
The
controversy
regarding
the and
methodology
for
used
inand
internal
fixatorareofpresented
the spine
and1).bone strucin
patients,
using
screws
35
mm titanium,
long
6 mm in diameter
The
system
of
fixation
with
commonly
implemented
lateralModel
bending
progressive
loading
(Figureflexion-compression
3), all degrees of and
validation
will be
performed
conducting
mechanical
tests
for
the
evaluation
of
ture
are
presented
(Table
1).
Model
validation
will
be
4), which
is of
applied
at 35
an
angle
of 60and
degrees
in The
patients,
using
screws
mm
long
6 mmbetween
inimplemented
diameter
freedom
lessbending
than
theprogressive
surface
the
bone(Figure
structure
lateral
3), (cylinder)
all degrees ofand (Figure
system
fixation
with
titanium,
commonly
Model
validation
will of
beloading
performed
flexion-compression
(Figure
4),
which
is
applied
at
an
angle
of
60
degrees
between
the
two
captive
screws
to
the
vertebrae,
and
separate
10mm
orthopedic
implants
is
basically
the
use
of
human
performed
fl
exion-compression
and
lateral
bending
freedom
less
than
the
surface
of
the
bone
structure
(cylinder)
locked
to
prevent
movement
of
the
whole.
in
patients,
using
screws
35
mm
long
and
6
mm
in
diameter
lateral bending progressive loading (Figure 3), all degrees of
[16]. the
two
captive
screws
to
the
vertebrae,
and
separate
bones
and
testing
machines
(17).
To
date
not
known
progressive
loading
(Figure
3),
all
degrees
of
freedom
locked
to
prevent
movement
of
the
whole.
(Figure 4), which is applied at an angle of 60 degrees10mm
between
freedom less than the surface of the bone structure (cylinder)
[16].
the
twoimplant
captive for
screws
andexperseparate 10mm
ideal
usetointhe
thevertebrae,
spine, and
less
thantothe
surface
of the
structure (cylinder) stiffness
locked
prevent
movement
of bone
the whole.
[16].
ACTA INFORM MED. 2014 APR 22(2): 120-122 / ORIGINAL PAPER
122
Proposed Use of the Computer as a Tool to Aid Analysis of Properties of Materials in Fixators of Spine
geometry
of the
object
can
geometry of the object
can be modified
through
software
bringing some savings bringing
in waste materials.
some savings in waste
be m
mate
Figure 5–Points of maximum and minimum stress
Figure 5 - Points of maximum and minimum stress
Figure 4 - Components of Fixation System [16]
3. RESULTS AND DISCUSSION
The
controversy
regardingof the
methodology
for conducting
Figure
4–Components
Fixation
System [16]
mechanical tests for the evaluation of orthopedic implants is
basically the use of human bones and testing machines [17].
could replace the titanium material is expensive.
4. the
CONCLUSION
Some critical points in
geometry of the object can
be modified
through
software
bringing some savings
From the sum of the results obtained in carrying out the tests
in waste
materials.
concluded that the simulation software proved efficient in
Figure 5 - Points of maximum
determining the values of compression and tension using the
finite element
method. The deformations of different materials
4.CONC
LUSION
were the
compared
andthe
theresults
necessary
changes for
improvements
From
sum of
obtained
in carrying
couldtests
be made
on the same
without the need
of building
out the
concluded
thatmodel
the simulation
software
a new one.
4. CONCLU
proved efficient in determining the values of comFrom
the
sum
results obtain
pression
tension
using
finiteand
element
method.
Basedand
on the
literature
of thethe
subject
withofthethe
collaboration
imental and clinical investigations indicate that in- The ofdeformations
of
different
materials
were
commedical professionals,
the results of that
this research
serve
concluded
the will
simulation
sof
creased
mechanical
stability
of thefor
system
accelerates
pared
and the
for improvements
to deliver
thenecessary
application changes
of polyurethane
derived from castor
To
date
not
known
stiffness
ideal
implant
use
in
the
spine,
determining
the
values of compres
Figure
4 - Components
of Fixation
System [16]could
oil be
in the
design
internal
fixators
of the
spine. the need
bone
healing
and
the
rate of pseudarthrosis,
made
onofthe
same
model
without
and
experimental
anddecrease
clinical investigations
indicate that
method.
The deforma
increased
mechanical
of the
accelerates
and based
on thisstability
evidence
thesystem
spinal
implantsbone
have of building a new one.finite
Based element
on the literature
of the
REFERENCES
healing
decrease (18).
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been and
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the spinalresults
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havestill
beenfar
developed
The practical
from [18].
ideal sur- sionals, the results of this
research
will serve
to same
decould
the
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thesuchevaluation
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takes placetakes
evenplace
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maintenance
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the
of the subjec
basicallyarthrodesis
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of human
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andin testing
machines
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toGeometric,
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thestrutural
application
of the current
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there
are clear
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not
known
stiffness
ideal
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can 2. rosa
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the side bars with
adjustments,
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mechanical
stability
of the
bone
3.
Basile JR, Barros R, Tep F. Lesões da coluna vertebral nos esportes. Rev Bras Ortop.
lated this
to the
screws,
use
with
solution
typealignment
of problem. of
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be and
very their
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at the
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rate
of pseudarthrosis,
[4] on
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Rossi,
JDBA.;R,Leivas,
TP;
Basile-Junior,
to abandon
the adjustments,
use
of systems
that
the longitudinal
the side
bars with
canuse
further
aid inand
the based
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CS
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Rev Hosp CAM;
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