Table 1. Material properties of the tissues and implants.

	Young's modulus (MPa)	Poisson's ratio	Element type	Reference
Cancellous bone	150	0.2	10-node tetrahedral solid element	[19]
Cortical bone	18,000	0.3	8-node hexahedral solid element	[19]
Nucleus pulposus	2	0.45	8-node hexahedral solid element	[22]
Annulus fibrosus	8	0.49	8-node hexahedral solid element	[22]
Implant (Ti-6Al-4V)	114,000	0.3	8-node hexahedral solid element	[19]