Objective To measure the cancellous bone mineral density and axial elastic modulus from multiple anatomic sites, then build the constitutive equation between them, so as to provide specific data for finite element modeling of Chinese people. Methods Ten fresh adult cadavers were taken as sample sources. In every fresh cadaver, 5 different anatomic sites were selected: proximal tibia, greater trochanter, femoral neck, humeral head and lumbar vertebra. The raw samples were processed into standard specimens, which were approximately 6 mm in diameter and 30 mm or 40 mm in length. Both the size and volume for the cancellous bone specimens were measured, and their mineral densities were obtained with computed tomography. The mechanical properties of such specimens were tested with biomechanical testing machine for analyzing the elastic modulus of the cancellous bone at different anatomic sites. The linear and power regression between mineral density and axial elastic modulus were analyzed on SPSS 18.0. Results A total of 169 cancellous bone specimens which were availably tested were collected, including 52 proximal tibia, 31 greater trochanter, 15 femoral neck, 17 humeral head and 54 lumbar vertebrae. The analysis on measurement results showed that the mineral density and axial elastic modulus in cancellous bones from 5 anatomic sites were different, and had a solid linear relationship (0.850>r2>0.785), with 3 sites (proximal tibia, greater trochanter, lumbar vertebra) showing a solid power correlation (0.871>r2>0.825), and the other 2 sites (humeral head and femoral neck) showing relatively weak power correlation (0.671>r2>0.643). Conclusions There are solid linear and power relationship between mineral density and axial elastic modulus, while no significant difference is proved between the r2 values of the two regressions in this research. This discovery can be applied to detect patients’ bone quality in vitro and identify the precise position of bone loss, and further to predict fracture risk with the help of finite element modeling.
WANG Jing, LI Yuan-chao, WANG Fang, WANG Qiu-gen, WANG Dong-mei. Relationship between mineral density and elastic modulus of human cancellous bone[J]. Journal of medical biomechanics,2014,29(5):465-470Copy