title: A biomechanical study of L5-S1 low-grade isthmic spondylolisthesis using a personalized finite element model.
abstract: The pars interarticularis lesions in isthmic spondylolisthesis result generally from mechanical stresses in the neural arch due to repetitive overload during daily activities or to trunk imbalance resulting from spino-pelvic morphology. The L5-pelvis junction of a low-grade isthmic spondylolisthesis patient was modeled using a personalized finite element model to investigate the biomechanical behavior of the L5-S1 motion segment. Stress distribution and facet contact pressure in the altered segment were analyzed under 500 N simulating the gravitational load. High von Mises stresses were located in the pars interarticularis, in the pedicle, and in the outer region of the annulus. A high contact pressure was obtained at the facet surfaces. Influenced by the pelvic morphology, the inclination of L5-S1 junction affects the resulting shear forces and may play a crucial role in spondylolisthesis development.
authors.affiliation: Ecole Polytechnique, Dept. Mechanical Engineering, Canada.
authors.forename: Marwan
authors.initials: M
authors.lastname: El-Rich
authors.forename: Carl-Eric
authors.initials: CE
authors.lastname: Aubin
authors.forename: Isabelle
authors.initials: I
authors.lastname: Villemure
authors.forename: Hubert
authors.initials: H
authors.lastname: Labelle
mesh_terms: D001696:Biomechanical Phenomena; D020342:Finite Element Analysis; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology*; D010388:Pelvis; D011792:Quebec; D013168:Spondylolisthesis / Q000503:physiopathology*