Biomedical Engineering Reference
In-Depth Information
Age-Related Changes in Whole-Bone
Structure and Strength
Matthew J. Silva and Karl J. Jepsen
Abstract We review data on age-related changes in bone geometry of relevance
to whole-bone strength, as well as the limited data on changes in strength. Con-
sistently across many sites, women have bones that are smaller (by 15-30 %) than
age-matched men, and thus are weaker. In both women and men, modest periosteal
expansion of the diaphysis occurs throughout life, but this is accompanied by a
faster rate of medullary expansion, especially in women. The net result is an age-
related decrease in cortical bone at most sites in women, but negligible changes in
men. At metaphyseal sites there is also modest periosteal expansion as well as
endosteal expansion and net cortical bone loss. But the dominant change with
aging is decreased trabecular bone density, with most studies showing greater rates
of decline in women than men. These effects are especially pronounced at the
proximal femur and vertebra. Changes in whole-bone strength with aging are less
well documented. Available data (from mechanical tests and computer models)
suggest modest declines in diaphyseal strength in women but not men, and much
greater declines in strength of the proximal femur and vertebra. Women and men
appear to lose proximal femur strength at similar rates, although the decline starts
earlier in women. Also, both women and men lose vertebral strength with aging,
with
some
data
indicating
a
faster
decline
in
women
but
other
indicating
M. J. Silva (
&
)
Department of Orthopaedic Surgery, Washington University School of Medicine,
Saint Louis, Missouri 63110, USA
e-mail: silvam@wustl.edu
K. J. Jepsen
Department of Orthopaedic Surgery, University of Michigan Ann Arbor,
Michigan 48109, USA
e-mail: kjepsen@umich.edu
Search WWH ::
Custom Search