Mch. Vandermeulen et al., DETERMINANTS OF FEMORAL GEOMETRY AND STRUCTURE DURING ADOLESCENT GROWTH, Journal of orthopaedic research, 14(1), 1996, pp. 22-29
Our goal was to understand developmental determinants of femoral struc
ture during growth and sexual maturation by relating femoral measureme
nts to gender and developmental factors (age, pubertal stage, height,
and body mass). The bone mineral content of the femur was measured by
dual energy x-ray absorptiometry in 101 healthy Caucasian adolescents
and young adults, 9-26 years of age. After some simplifying assumption
s had been made, cross-sectional geometric properties of the femoral m
idshaft were estimated. Two geometry-based structural indicators, the
section modulus and whole bone strength index, were calculated to asse
ss the structural characteristics of the femur. Femoral strength, as d
escribed by these structural indicators, increased dramatically from c
hildhood through young adulthood. Regressions were performed between t
hese femoral measurements and the developmental factors. Our data show
that of age, pubertal stage, body mass, and height, body mass is the
strongest predictor of femoral cross-sectional properties, and the cor
relation of body mass with femoral cross sectional structure is indepe
ndent of gender. A model including all four developmental factors and
gender did not substantially increase the accuracy of predictions comp
ared with the model with body mass alone. Ln light of previous researc
h? we hypothesize that body mass is an indicator of in vivo loading an
d that this in vivo loading influences the cross-sectional growth of t
he long bones.