Similarities and differences in the mass-structure scaling relations of the trabecular bone taken from different locations in the femur
Dokumenttyp:
Proceedings Paper
Autor(en):
Raeth, Christoph; Baum, Thomas; Sidorenko, Irina; Monetti, Roberto; Eckstein, Felix; Matsuura, Maiko; Lochmueller, Eva-Maria; Zysset, Philippe K.; Bauer, Jan
Abstract:
According to Wolff's law bone remodels in response to the mechanical
stresses it experiences so as to produce a minimal-weight structure that
is adapted to its applied stresses. Consequently, the inner bone
structure should show signs of adaptation to external forces acting on
the bone. To test this paradigm, we investigate the relations between
bone volume and structure for the trabecular bone using 3D mu CT images
taken from two different sites in the femur in vitro, namely from the
femoral neck (88 specimens) and femoral trochanter (126 specimens). We
determine the local structure of the trabecular network as well as its
alignment with the direction of the external force acting on the bone by
calculating isotropic (alpha) and anisotropic scaling indices
(alpha(z)). Comparing global structure measures derived from the scaling
indices (mean, variance) with the bone mass (BV/TV) we find that all
correlations obey very accurately power laws with scaling exponents of
0.48 and 0.45 (), -1.45 and -1.59 (var(alpha)), 0.50 and 0.44
() and -1,47 and -1.32 (var(alpha(z))) (neck and trochanter
respectively). Thus, the relations for the isotropic scaling indices
turn out to be site-independent, albeit the mechanical stress to which
the femoral neck is exposed is much larger than that for the trochanter.
We find, however, differences in the degree of alignment of the
trabeculae as reflected by the moments of the distribution of the
anisotropic scaling indices. In summary, the mass-structure scaling
relations of the bone probes taken from the two different sites of the
femur show surprisingly small variations. Thus, a naive interpretation
of Wolff's law may not universally valid.
Stichworte:
Osteoporosis; femur; trabecular bone; Wolff's law; scaling indices
Herausgeber:
Molthen, RC; Weaver, JB
Kongress- / Buchtitel:
MEDICAL IMAGING 2012: BIOMEDICAL APPLICATIONS IN MOLECULAR, STRUCTURAL, AND FUNCTIONAL IMAGING
Kongress / Zusatzinformationen:
Conference on Medical Imaging - Biomedical Applications in Molecular,
Structural and Functional Imaging, San Diego, CA, FEB 05-07, 2012
Band / Teilband / Volume:
8317
Ausrichter der Konferenz:
SPIE; Agilent Technol; Diamond SA; DQE Instruments Inc; eMagin; Isuzu
Glass Co Ltd; Medtron Inc; Ocean Thin Films Inc
Verlag / Institution:
SPIE-INT SOC OPTICAL ENGINEERING
Verlagsort:
1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA