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. 2012;20(1):17-20.
doi: 10.1590/S1413-78522012000100003.

Photoelastic analisys in the lower region of vertebral body L4

Sarah Fakher Fakhouri  1 , Ariane Zamarioli  1 , Marcos Massao Shimano  2 , Helton Luiz Aparecido Defino  1 , Cleudmar Amaral Araujo  3 , Antonio Carlos Shimano  1
Affiliations

Photoelastic analisys in the lower region of vertebral body L4

Sarah Fakher Fakhouri et al. Acta Ortop Bras. 2012.

Abstract

Objective: To analyze the shear forces on the vertebral body L4 when submitted to a compression force by means of transmission photoelasticity.

Methods: Twelve photoelastic models were divided into three groups, with four models per group, according to the positioning of the sagittal section vertebrae L4-L5 (sections A, B and C). The simulation was performed using a 15N compression force, and the fringe orders were evaluated in the vertebral body L4 by the Tardy compensation method.

Results: Photoelastic analysis showed, in general, a homogeneous distribution in the vertebral bodies. The shear forces were higher in section C than B, and higher in B than A.

Conclusion: The posterior area of L4, mainly in section C, showed higher shear concentrations, corresponding to a more susceptible area for bone fracture and spondylolisthesis. Economic and Decision Analyses - Development of an Economic or Decision Model. Level I.

Keywords: Biomechanics; Spine; Tension.

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Conflict of interest statement

All the authors declare that there is no potential conflict of interest referring to this article.

Figures

Figure 1
Figure 1
Diagram of the three unilateral sagittal sections (A, B and C) created in vertebral body L4 to obtain the geometries of the photoelastic models. I- Location of the sagittal sections (A, B and C) in vertebral body L4. II– Geometry of sections A, B and C. III– Photoelastic models of sections A, B and C.
Figure 2
Figure 2
Diagram of a polytetrafluorethylene (Teflon®) mold with the disc made of T-208 resin, positioned in the center of the mold.
Figure 3
Figure 3
Diagram of the points selected for analysis of the shear forces in the three vertebral sections.
Figure 4
Figure 4
Distribution of shears in sections A, B and C. In section A, the shear concentration was higher in the anterior and posterior regions of the vertebra (arrows). In sections B and C, the shear concentration was higher in the posterior region (arrows).
See this image and copyright information in PMC

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