Biomechanical comparison of spinal column shortening - a finite element study

Table 1 Material properties used by finite element model

Component	Element type	Young’s modulus (MPa)	Poisson ratio	Cross-sectional area (mm²)
Vertebra
Cortical bone	C3D4	12,000	0.3
Cancellous bone	C3D4	100	0.2
Posterior element	C3D4	3500	0.25
Sacrum	C3D4	5000	0.2
Facet	C3D4	11	0.2
Disc
Endplate	C3D8R	24	0.4
Nucleus pulpous	C3D8RH	1	0.49
Annulus ground substance	C3D8RH	2	0.45
Annulus fibre	T3D2	360–550		0.15
Ligaments
ALL	T3D2	7.8		63.7
PLL	T3D2	10		20
LF	T3D2	15		40
CL	T3D2	7.5		30
ISL	T3D2	10		40
SSL	T3D2	8		30
ITL	T3D2	10		1.8
Implants	C3D4	110,000	0.3

ALL Anterior longitudinal ligament, PLL Posterior longitudinal ligament, LF Ligamentum flavum, CL Capsular ligament; ISL Interspinous ligament, SSL Supraspinal ligament; ITL Intertransverse ligament

ISSN: 1471-2474