Basic Study
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Orthop. Nov 18, 2017; 8(11): 829-835
Published online Nov 18, 2017. doi: 10.5312/wjo.v8.i11.829
Biomechanical assessment of new surgical method instead of kyphoplasty to improve the mechanical behavior of the vertebra: Micro finite element study
Seyed Aref Hosseini Faradonbeh, Nima Jamshidi
Seyed Aref Hosseini Faradonbeh, Nima Jamshidi, Department of Biomedical Engineering, Faculty of Engineering, University of Isfahan, Isfahan 81746-73441, Iran
Author contributions: Hosseini Faradonbeh SA and Jamshidi N substantially contributed to the conception and design of the study, acquisition, analysis and interpretation of data; all authors drafted the article and made critical revisions related to the intellectual content of the manuscript, and approved the final version of the article to be published.
Institutional review board statement: The study was approved by the head of animal care center at Department of Biomedical Engineering at the University of Isfahan.
Institutional animal care and use committee statement: The fresh ovine vertebrae were harvested from the dead sheep Carcasses without meaning any harm or pain to the living animals; approved by the University of Isfahan’s Animal Care Committee at the time of adoption.
Conflict-of-interest statement: To the best of our knowledge no conflict of interest exists.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Correspondence to: Nima Jamshidi, Assistant Professor, Department of Biomedical Engineering, Faculty of Engineering, University of Isfahan, Azadi Square, Hezar jarib Street, Isfahan 81746-73441, Iran.
Telephone: +98-313-7935613 Fax: +98-313-6276652
Received: March 7, 2017
Peer-review started: March 10, 2017
First decision: June 30, 2017
Revised: July 5, 2017
Accepted: September 12, 2017
Article in press: September 13, 2017
Published online: November 18, 2017

To reduce post treatments of kyphoplasty, as a common treatment for osteoporotic vertebrae.


This study suggests a new method for treating vertebrae by setting the hexagonal porous structure instead of the rigid bone cement mass in the kyphoplasty (KP). The KP procedure was performed on the fresh ovine vertebra of the level L1. Micro finite element modeling was performed based on micro computed tomography of ovine trabecular cube. The hexagonal porous structure was set on one cube instead of the bone cement mass. For the implant designing, two geometrical parameters were considered: Spacing diameter and thickness.


The results of micro finite element analyses indicated the improvement in the mechanical behavior of the vertebra treated by the hexagonal porous structures, as compared to those treated by vertebroplasty (VP) and KP under static loading. The improvement in the mechanical behavior of the vertebra, was observed as 54% decrease in the amount of maximum Von Misses stress (improvement of stress distribution), in trabecular cube with embedded hexagonal structure, as compared to VP and KP. This is comparable to the results of the experimental study already performed; it was shown that the improvement of mechanical behavior of the vertebra was observed as: 83% increase in the range of displacements before getting to the ultimate strength (increasing the toughness) after setting hexagonal pearls inside vertebrae. Both the material and geometry of implant influenced the amount of Von Mises stress in the structure.


The new proposed method can be offered as a substitute for the KP. The implant geometry had a more obvious effect on the amount of Von Mises stress, as compared to the implant material.

Keywords: Vertebroplasty, Kyphoplasty, Micro finite element modeling, Hexagonal porous structure, Von mises stress

Core tip: By embedding the hexagonal porous structure with two variable parameters including spacing diameter and thickness, as a substitute for the bone cement mass in the vertebral kyphoplasty, lower levels of maximum Von Mises stress could be achieved, thereby indicating the reduction of stress concentration in the interface area between the bone cement mass and the cancellous bone, as well as the reduction of post treatments. Furthermore, setting porous structures with different geometries inside vertebrae could provide the possibility of bone regeneration, the transfer of growth factors and recreation of mechanical properties.