The Journal of Bone and Joint Surgery, Vol 66, Issue 7 1024-1031, Copyright © 1984 by Journal of Bone and Joint Surgery, Inc
Bone-mineral content in the lower limb. Relationship to cross-sectional geometry
CB Ruff and WC Hayes
For this study, bone-mineral content and bone-mineral width were measured
using photon absorptiometry at eleven locations in forty excised femora and
tibiae obtained from an archaeological sample. An additional seventy-nine
femora were scanned at the middle of the shaft and through the femoral
neck. After scanning, the bones were sectioned at each location and
cross-sectional areas and other geometrical properties were determined
directly from section tracings. The results indicated that locational, sex,
and age-related differences in bone-mineral content were largely determined
by variation in cortical area. Due to differences in bone geometry,
variation in bone width does not reflect variation in cortical area, and as
a consequence the use of bone width to standardize for volumetric or bone
"size" differences produces misleading results in sex and age comparisons.
In this study, decreases with age in the bone-mineral content and
bone-mineral content:bone width ratio were similar to those observed in
living populations. However, the bone-mineral content:cortical area ratio
showed no significant decline with age for any cross section. Thus, the
age-related changes in compact cortical bone appeared to be mainly
volumetric, not densitometric.