486
P. Jain and J. F. Xavier
the novel implant like awesome dynamic rod implant was developed and compared
with rigid fixation with cage and result contributed in increased range of motion and
facet forces. In the context of rigid fixation, Ambati et al. [3] investigated different
types of unilateral and bilateral construct to analyse the impact over the lumbar
region L4-L5 and increased posterior stresses were observed with the unilateral
screws in flexion and extension cases. Divya et al. [4] performed the finite element
analysis (FEA) on L1-L5 to find out the mechanical properties of each vertebra and
compared relatively to identify the spine disorders. Prior to any analysis or operation,
identification of bone trajectory and morphometric study is very essential for proper
insertion of pedicle screw, selection of puncture point, disc entry point, and pedicle
instrumentation orientation [5]. Finite element method has been proven the effective
method and computational tool to represent complex structure, non-regularities in
loading, materials in the field of biomechanical engineering [6]. Bone mineral density
and insertion of any needle in the bone depend upon the selection of entry points
with respect to technical and anatomical aspects [7]. L3-L4-L5 was modelled, and
FEA is done to identify the effective diameter of pedicle screw with various loading
conditions and various bone material properties [8].
In the same context, Erbulut et al. [9] investigated the effect of various rigid,
semi-rigid and dynamic stabilization systems on validated FE model of L1-S1 and
concluded with the lesser stress level at adjacent area of vertebrae in case of semirigid and dynamic stabilization as compared to rigid fixation. An effect over the
intervertebral disc was identified by Ashtiani et al. [10] using 3 different types of
implant and results in the form of stress and displacement. Various authors have also
proposed to generate the FE model of vertebra to perform the finite element analysis
[11–14]. Various researchers are carrying out research in the field of bio-mechanics
and spinal implants, but no one has revealed the method utilized in detail. Hence,
the present work aims to elaborate and communicate a simplest method to generate
surface model of vertebrae L2-L4 segments followed by solid modelling to perform
FE analysis for future studies.
2 Materials and Method
2.1 Inclusion Criteria
A 30-year-old healthy Indian male was considered for the study. Fifty-five multisliced (4.975 slice thickness) computed tomography (CT) images (DICOM format)
of spinal column with a slice width of 512 pxi and height of 539 pxi, and pixel size
was 0.703 mm were considered.
P. Jain and J. F. Xavier
the novel implant like awesome dynamic rod implant was developed and compared
with rigid fixation with cage and result contributed in increased range of motion and
facet forces. In the context of rigid fixation, Ambati et al. [3] investigated different
types of unilateral and bilateral construct to analyse the impact over the lumbar
region L4-L5 and increased posterior stresses were observed with the unilateral
screws in flexion and extension cases. Divya et al. [4] performed the finite element
analysis (FEA) on L1-L5 to find out the mechanical properties of each vertebra and
compared relatively to identify the spine disorders. Prior to any analysis or operation,
identification of bone trajectory and morphometric study is very essential for proper
insertion of pedicle screw, selection of puncture point, disc entry point, and pedicle
instrumentation orientation [5]. Finite element method has been proven the effective
method and computational tool to represent complex structure, non-regularities in
loading, materials in the field of biomechanical engineering [6]. Bone mineral density
and insertion of any needle in the bone depend upon the selection of entry points
with respect to technical and anatomical aspects [7]. L3-L4-L5 was modelled, and
FEA is done to identify the effective diameter of pedicle screw with various loading
conditions and various bone material properties [8].
In the same context, Erbulut et al. [9] investigated the effect of various rigid,
semi-rigid and dynamic stabilization systems on validated FE model of L1-S1 and
concluded with the lesser stress level at adjacent area of vertebrae in case of semirigid and dynamic stabilization as compared to rigid fixation. An effect over the
intervertebral disc was identified by Ashtiani et al. [10] using 3 different types of
implant and results in the form of stress and displacement. Various authors have also
proposed to generate the FE model of vertebra to perform the finite element analysis
[11–14]. Various researchers are carrying out research in the field of bio-mechanics
and spinal implants, but no one has revealed the method utilized in detail. Hence,
the present work aims to elaborate and communicate a simplest method to generate
surface model of vertebrae L2-L4 segments followed by solid modelling to perform
FE analysis for future studies.
2 Materials and Method
2.1 Inclusion Criteria
A 30-year-old healthy Indian male was considered for the study. Fifty-five multisliced (4.975 slice thickness) computed tomography (CT) images (DICOM format)
of spinal column with a slice width of 512 pxi and height of 539 pxi, and pixel size
was 0.703 mm were considered.