Clin Orthop Surg.  2009 Mar;1(1):40-47. 10.4055/cios.2009.1.1.40.

Assessment of Bone Quality using Finite Element Analysis Based upon Micro-CT Images

• Rhee Y
• Hur JH
• Won YY
• Lim SK
• Beak MH
• Cui WQ
• Kim KG
• Kim YE

• KMID: 1127913
• DOI: http://doi.org/10.4055/cios.2009.1.1.40

Abstract

BACKGROUND: To evaluate the feasibility of a micro-image based finite element model to determine the efficacy of sequential treatments on the bone quality in a rat osteoporosis model.
METHODS
Rat osteoporosis and treated osteoporosis models were established with the bone loss, restore and maintain concept. Thirty Sprague-Dawley rats were used in this study. A sham operation or ovariectomy was performed at 20 weeks after birth, which was followed by the respective sequential trials as follows: (1) sham-operation only, (2) ovariectomy only, (3) ovariectomized rats with parathyroid hormone maintenance, (4) ovariectomized rats treated with PTH for 5 weeks and then withdrawal, (5) ovariectomized rats treated with PTH for 5 weeks and then with 17 beta-estradiol, and (6) ovariectomized rats treated with parathyroid hormone for 5 weeks and then treated with zoledronate. The histomorphometry indices were determined using the micro-images from a micro-computed tomogram. Finite element analysis was carried out to determine the mechanical properties (Stiffness and Young's modulus) of the vertebra bodies. The differences in properties between the groups were compared using ANOVA and a Bonferroni's multiple group comparison procedure.
RESULTS
The histomorphometry and mechanical properties were significantly better in groups (3) and (6) than in the groups (1) and (2) (p < 0.05). The stiffness (sigmas) and Young's modulus (E) was highest in group (3) following by group (6).
CONCLUSIONS
Finite element analysis based on micro-images provides a useful tool that reflects the changes in micro-structural and mechanical properties of a rat vertebral body with the bone loss, restore and maintain concept.

Keyword

Osteoporosis; Vertebral body; Microstructure; Micro-CT; Finite element analysis; Rat

MeSH Terms

Analysis of Variance
Animals
Female
*Finite Element Analysis
Osteoporosis/*pathology/*radiography
Rats
Rats, Sprague-Dawley
Spine/*pathology/*radiography
Tomography, X-Ray Computed/methods
X-Ray Microtomography/*methods

Figure

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  Fig. 1 X-ray transmission image.

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  Fig. 2 Three dimensional model (L1 Spine).

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  Fig. 3 Three dimensional models of the vertebral bodies after treatment. (A) OVX: Ovariectomy group, (B) SHAM: Sham operation group, (C) PTH-M: PTH maintenance group, (D) PTH-W: PTH withdraw group, (E) PTH-E: PTH following estradiol group, (F) PTH-Z: PTH following zoledronate group, PTH: Parathyroid hormone group.

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  Fig. 4 Hexahedral mesh model.

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  Fig. 5 Finite element analysis model.

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  Fig. 6 Two dimensional images (sagittal view). (A) OVX: Ovariectomy group, (B) SHAM: Sham operation group, (C) PTH-M: PTH maintenance group, (D) PTH-W: PTH withdraw group, (E) PTH-E: PTH following estradiol group, (F) PTH-Z: PTH following zoledronate group, PTH: Parathyroid hormone group.

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