A Hybrid Uniplanar Pedicle Screw System with a New Intermediate Screw for Minimally Invasive Spinal Fixation: A Finite Element Analysis

Table 2

Material properties in the FEA.

Spinal site	Young’s Modulus (MPa) [10, 15]	Poisson’s ratio
Cortical bone/endplate	12000	0.3
Cancellous bone	100	0.2
Annulus	4.2	0.4
Nucleus pulposus	1	0.49
Posterior element	3500	0.25
Pedicle screws and rods	110000	0.3