Mechanical loading is known to strongly influence the external shape and internal density distribution of both developing and m ature bones. The mature bone morphology is, to some extent, a physical history of the mechanical forces applied to the bone. If the dominant loads remain consistent, the bone should reach a state in which the bone tissue removal and replacement are essentially equal, resulting in no net increase or decrease in density throughout the bone.

This dissertation examines bone remodeling using two different approaches. The com putational simulation approach of Beaupre et al. (1990c) is used to investigate the long-term remodeling process. The dependency of the final solution on the initial density distribution is examined, and the same density solution is found regardless of the initial conditions. W hether or not different sets of loading conditions can produce the same density distribution is also examined, and, from a practical perspective, two different set of loads can produce essentially the same density distribution.

In addition, the inverse of the remodeling problem is studied. Instead of assuming the loading conditions and predicting the density, the density distribution and the remodeling equations of Beaupre et al. (19906) are used to estim ate the loading. The technique is first dem onstrated on a simplified generic long bone finite element model and then with two-dimensional finite element models of the proximal femur, which were constructed from quantitative CT data. Several performance characteristics of this density-based bone load estimation procedure are examined. An example of using the procedure to estim ate joint load pressure distributions is also presented. This body of work represents the first attem pt to estim ate bone loading from the external shape and internal density distribution of a bone.