Simulation of 3D architectural and mechanical changes in human trabecular bone during menopause

X. S. Liu, A. H. Huang, Paul Sajda, X. E. Guo

The increase in bone remodeling after menopause is responsible for both reduced bone mass and deterioration of the trabecular bone network, leading to an increased susceptibility to osteoporosis. In this study, we simulated
the dynamic and physiological process of trabecular bone remodeling, using parameters derived from recently published clinical data [1]. These simulations considered three types of microscopic bone loss in the pathophysiology of osteoporosis: perforation, breakage, and disconnection of trabeculae. The simulations were done using rigorous 3D digital topological analysis (DTA) [2]. The simulation included a bone remodeling cycle corresponded to a 200-day period (40 days resorption/160 days formation). Resorption cavities (42~tm
deep and 126~tm in diameter) were created in 40 days according to the current activation frequency [1] and distributed randomly over the bone surface. Every resorption cavity was refilled in 160 days unless it caused a perforation, or breakage of a trabecula while disconnected trabeculae removed [2]. New resorption cavities were continuously created in every 40-days. The simulation was started 5 years before and ended 15 years after menopause and applied to twelve human trabecular bone samples. The time course of the averaged bone volume fraction (BVF) of samples from two anatomical sites (spine and femoral neck) showed great agreement with
the corresponding clinical data [1]. Bone with higher initial BVF showed a slower bone loss time course, which was consistent with the fact that peak bone mass is one of the important risk factors in osteoporosis. The structural transition of each sample from plate-like to rod-like during menopause can be qualitatively observed and also quantitatively confirmed by the change of plate fraction. Furthermore, the results of this study suggest that the trabecular plate perforation accounts for more than 70% of bone loss during menopause.

Accepted 1 January 2006
Download Now

Latest News & Links

See All News