Analysis of Trabecular Bone Strength using Finite Element Analysis

Baek, Myong Hyun; Kim, Kwang Kyoun; Han, Seung yun; Hwang, Cheol Mog

Abstract

OBJECTIVES
The purpose of this study is to develop a method of evaluation based on finite element analysis (FEA) using micro-CT images for the measurement of trabecular bone strength.
METHODS
The primary compressive trabeculae were obtained from the human femoral head of three cadavers (21 year old male (M/21), 51 year old male (M/51), 51 year old female (F/51). All bone specimens were scanned using micro-CT at 24.9microm of spatial resolution under 70 kV's voltage and current of 141microA. The percent bone volume was calculated from the CTAn (SKYSCAN, Belgium) software, it's represented the bone mineral density (BMD). After scanning, the finite element model was reconstructed based on micro-CT images. All models were applied to be linear elastic, isotropic, and uniform with a tissue modulus of 5.17 GPa and a tissue Poisson's ratio of 0.3.
RESULTS
The percent bone volume(%) were 31.819 (+/-0.648), 21.513 (+/-2.489), 20.280 (+/-1.891) and Bone strength (MPa) were 187.741 (+/-13.006), 61.585 (+/-11.094), 61.266 (+/-16.744) in M/20, M/51 and F/51. The trabecular bone strength of the primary compressive trabeculae in M/20 was 3 times more than the trabecular bone strength in M/51 and F/51. The percent bone volume in M/20 was 148% and 157% higher than the percent bone volume in M/51 and F/51.
CONCLUSIONS
The finite element analysis is more sensitive than the percent bone volume in reflecting the morphometry index of primary compressive trabeculae. The high resolution FEA reconstructed from high resolution MRI or high resolution CT may improve the evaluation of trabecular bone strength in the medical field.