Bone strength: the whole is greater than the sum of its parts.
OBJECTIVE
To summarize the current knowledge regarding the various determinants of bone strength.


METHODS
Relevant English-language articles acquired from Medline from 1966 up to January 2005 were reviewed. Searches included the keywords bone AND 1 of the following: strength, remodeling, microcrack, structur*, mineralization, collagen, organic, crystallinity, osteocyte, porosity, diameter, anisotropy, stress risers, or connectivity. Abstracts from applicable conference proceedings were also reviewed for pertinent information.


RESULTS
Bone strength is determined from both its material and its structural properties. Material properties such as its degree of mineralization, crystallinity, collagen characteristics, and osteocyte viability have substantial impacts on bone strength. Structural properties such as the diameter and thickness of the cortices, the porosity of the cortical shell, the connectivity and anisotropy of the trabecular network, the thickness of trabeculae, and the presence of trabecular stress risers and microcracks impact bone strength in diverse manners. Remodeling activity either directly or indirectly impacts all of these processes.


CONCLUSIONS
Bone strength is dependent on numerous, interrelated factors. Remodeling activity has a direct impact on almost all of the components of bone strength and requires further investigation as to its impact on these factors in isolation and in unison.
Davison
K Shawn
KS
Clinical Research Scientist, Department of Medicine, Laval University, Sainte Foy, Quebec, Canada. ebmedicine@gmail.com
Siminoski
Kerry
K
Adachi
J D
JD
Hanley
David A
DA
Goltzman
David
D
Hodsman
Anthony B
AB
Josse
Robert
R
Kaiser
Stephanie
S
Olszynski
Wojciech P
WP
Papaioannou
Alexandra
A
Ste-Marie
Louis-George
LG
Kendler
David L
DL
Tenenhouse
Alan
A
Brown
Jacques P
JP
D015519:Bone Density; D016723:Bone Remodeling / Q000502:physiology*; D001842:Bone and Bones / Q000502:physiology*; D002113:Calcification, Physiologic / Q000502:physiology; D019245:Compressive Strength / Q000502:physiology*; D006801:Humans