The Effects of Physiological Biomechanical Loading on Intradiscal Pressure and Annulus Stress in Lumbar Spine: A Finite Element Analysis

Table 2

Material properties of the components in the osseoligamentous lumbar spine model.

Element set	Element type	Material properties	Reference
Cortical bone	3D tetrahedron	E = 12,000 MPa, ν = 0.3	[16]
Cancellous bone	3D tetrahedron	E = 100 MPa, ν = 0.2	[16]
Articular cartilage	3D Herman formulation, lower order tetrahedron	E = 35 MPa, ν = 0.4	[15]
Nucleus pulposus	3D Herman formulation, lower order tetrahedron	Mooney-Rivlin: C1 = 0.12, C2 = 0.03	[12]
Annulus fibrosis	3D Herman formulation, lower order tetrahedron	Mooney-Rivlin: C1 = 0.18, C2 = 0.045	[12, 16]
PLL	3D truss	E = 10.0 MPa (ɛ < 11%), E = 20 MPa (ɛ > 11%)	[15, 18]
ALL	3D truss	E = 7.8 MPa (ɛ < 12%), E = 20 MPa (ɛ > 12%)	[15, 18]
LF	3D truss	E = 15.0 MPa (ɛ < 6.2%), E = 19.5 MPa (ɛ > 6.2%)	[15, 18]
CL	3D truss	E = 7.5 MPa (ɛ < 25%), E = 32.9 MPa (ɛ > 25%)	[15, 18]
ITL	3D truss	E = 10.0 MPa (ɛ < 18%), E = 58.7 MPa (ɛ > 18%)	[15, 18]
ISL	3D truss	E = 10.0 MPa (ɛ < 14%), E = 11.6 MPa (ɛ > 14%)	[15, 18]
SSL	3D truss	E = 8.0 MPa (ɛ < 20%), E = 15.0 MPa (ɛ > 20%)	[15, 18]

E: Young’s modulus; ν: Poisson’s ratio; ɛ: strain; C₁ and C₂: material constant characterising the deviatoric deformation of material.