Assessment of bone quality using finite element analysis based upon micro-CT images.
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 (sigma(s)) 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.
Rhee
Yumie
Y
Department of Internal Medicine, Endocrinology, Yonsei University, Seoul, Korea.
Hur
June-Huyck
JH
Won
Ye-Yeon
YY
Lim
Sung-Kil
SK
Beak
Myong-Hyun
MH
Cui
Wen-Quan
WQ
Kim
Kwang-Gyoun
KG
Kim
Young Eun
YE
D000704:Analysis of Variance; D000818:Animals; D005260:Female; D020342:Finite Element Analysis; D010024:Osteoporosis / Q000000981:diagnostic imaging* / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013131:Spine / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D055114:X-Ray Microtomography / Q000379:methods*