title: Implementation of a 3D porcine lumbar finite element model for the simulation of monolithic spinal rods with variable flexural stiffness.
abstract: Monolithic superelastic-elastoplastic spinal rods (MSER) are promising candidates to provide (i) dynamic stabilisation in spinal segments prone to mechanical stress concentration and adjacent segment disease and (ii) to provide fusion-ready stabilization in spinal segments at risk of implant failure. However, the stiffness distributions along the rod's longitudinal axis that best meet clinical requirements remain unknown. The present study is part of a mixed numerical experimental research project and aims at the implementation of a 3D finite element model of the porcine lumbar spine to study the role of MSER material properties and stiffness distributions on the intradiscal pressure distribution in the adjacent segment. In this paper, preliminary intradiscal pressure predictions obtained at one functional spinal unit are presented. Due to a lack of porcine material property data, these predictions were obtained on the basis of uncalibrated human vertebral disc data which were taken from the literature. The results indicate that human annulus and nucleus data predict experimental porcine in vivo and in vitro data reasonably well for the compressive forces of varying magnitudes.
authors.forename: Martin
authors.initials: M
authors.lastname: Brummund
authors.forename: Vladimir
authors.initials: V
authors.lastname: Brailovski
authors.forename: Yann
authors.initials: Y
authors.lastname: Facchinello
authors.forename: Yvan
authors.initials: Y
authors.lastname: Petit
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Mac-Thiong
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D020342:Finite Element Analysis; D006801:Humans; D007403:Intervertebral Disc; D008159:Lumbar Vertebrae; D008161:Lumbosacral Region; D013123:Spinal Fusion; D013314:Stress, Mechanical; D013552:Swine