Bone mass, geometry, and tissue material
properties contribute to bone structural integrity. Thus, bone strength arises
from both bone quantity and quality. Bone quality encompasses the geometric and
material factors that contribute to fracture resistance. Although no single
method can completely characterize bone quality, current noninvasive imaging
techniques can be combined with ex vivo mechanical and compositional techniques
to provide a comprehensive understanding of bone quality.
Methods for assessing mechanical properties
include whole-bone, bulk tissue, microbeam, and micro- and nanoindentation
testing techniques. Outcomes include structural strength and material modulus.
Advantages include direct assessment of bone strength; disadvantages include
specimen destruction during testing.
Methods for characterizing bone geometry and
microarchitecture include quantitative CT, high-resolution peripheral
quantitative CT, high-resolution MRI, and micro-CT. Outcomes include
three-dimensional whole-bone geometry, trabecular morphology, and tissue
mineral density. The primary advantage is the ability to image noninvasively;
disadvantages include the lack of a direct measure of bone strength.
Methods for measuring tissue composition
include scanning electron microscopy, vibrational spectroscopy, nuclear
magnetic resonance imaging, and chemical and physical analytical techniques.
Outcomes include mineral density and crystallinity, elemental composition, and
collagen crosslink composition. Advantages include the detailed material
characterization; disadvantages include the need for a biopsy.
Clinical
Orthopaedics and Related Research, Volume 469, Number 8 (2011), 2128-2138.
