  This article describes the application of recently introduced complex
networks concepts and methods to the characterization and analysis of cortical
bone structure. Three-dimensional reconstructions of the system of channels
underlying bone structure are obtained by using histological and computer
graphics methods and then represented in terms of complex networks.
Con&#64258;uences of two or more channels are represented as nodes, while the
interconnecting channels are expressed as edges. The hierarchical backbone (the
tree with maximum depth) of such a network is obtained and understood to
correspond to the main structure underlying the channel system. The remainder
of the network is shown to correspond to geographical communities, suggesting
that the bone channel structure involves a number of regular communities
appended along the hierarchical backbone. It is shown that such additional
edges play a crucial role in enhancing the network resilience and in reducing
the shortest paths in both topology and geometry.The recently introduced
concept of fractal dimension of a network (cond-mat/0503078) is then correlated
with the resilience of the several components of the bone channel structure to
obstruction and failure, with important implications for the understanding of
the organization and robustness of cortical bone structure.
