title: Biomechanics of high-grade spondylolisthesis with and without reduction.
abstract: The clinical advantages of reducing spondylolisthesis over fusion in situ have several intuitive reasons such as restore the spinal column into a more anatomic relationship and alignment. However, there is only little evidence in the literature supporting the theoretical advantages of reduction, and its effect on spinopelvic alignment remains poorly defined. In this study, a comprehensive finite element model was developed to analyze the biomechanics of the spine after spinal fusion at L5-S1 in both types of high-grade spondylolisthesis (balanced and unbalanced pelvis). The relevant clinical indices (i.e. spondylolisthesis grade and Dubousset lumbosacral angle), the displacement of L4-L5, pressure within the annulus and nucleus, and stress at L4-L5 were evaluated and compared. The model can well predict the changes of the important clinical indices during the surgery. For a balanced pelvis, the reduction has a minimal effect on the biomechanical conditions at the adjacent level during postsurgical activities. In the unbalanced case, reduction induced larger deformation in the lumbosacral region and a higher stress concentration at adjacent level. Whether such a stress concentration can lead to long-term disc degeneration is not known. The results provide additional information for the clinician considering reduction of high-grade spondylolisthesis.
authors.affiliation: Sainte-Justine University Hospital Center (University of Montreal), 3175 Côte-Ste-Catherine Rd., Montreal, QC, H3T 1C5, Canada.|College of Engineering, Temple University, 1947N 12th Street, Philadelphia, PA, 19122, USA.
authors.forename: Wenhai
authors.initials: W
authors.lastname: Wang
authors.affiliation: Sainte-Justine University Hospital Center (University of Montreal), 3175 Côte-Ste-Catherine Rd., Montreal, QC, H3T 1C5, Canada. carl-eric.aubin@polymtl.ca.|Department of Mechanical Engineering, Polytechnique Montreal, P.O. Box 6079, Station "Centre-ville", Montreal, QC, H3C 3A7, Canada. carl-eric.aubin@polymtl.ca.
authors.forename: Carl-Eric
authors.initials: CE
authors.lastname: Aubin
authors.affiliation: Shriners Hospitals for Children-Philadelphia, 3551 North Broad Street, Philadelphia, PA, 19140, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Cahill
authors.affiliation: College of Engineering, Temple University, 1947N 12th Street, Philadelphia, PA, 19122, USA.
authors.forename: George
authors.initials: G
authors.lastname: Baran
authors.affiliation: Laboratoire de Biomécanique Appliquée, UMRT24 IFSTTAR/Aix-Marseille Université, Boulevard Pierre Dramard, 13916, Marseille Cedex 20, France.
authors.forename: Pierre-Jean
authors.initials: PJ
authors.lastname: Arnoux
authors.affiliation: Sainte-Justine University Hospital Center (University of Montreal), 3175 Côte-Ste-Catherine Rd., Montreal, QC, H3T 1C5, Canada.
authors.forename: Stefan
authors.initials: S
authors.lastname: Parent
authors.affiliation: Sainte-Justine University Hospital Center (University of Montreal), 3175 Côte-Ste-Catherine Rd., Montreal, QC, H3T 1C5, Canada.
authors.forename: Hubert
authors.initials: H
authors.lastname: Labelle
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D003198:Computer Simulation; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D011312:Pressure; D013123:Spinal Fusion / Q000379:methods*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*
keywords: Balanced/unbalanced pelvis; Finite element method; High-grade spondylolisthesis; Spine biomechanics; Spondylolisthesis reduction