Using computer models based on Finite Element Analysis (FEA), Wolff's paradigm of mechanically-controlled adaptive bone remodeling can be simulated. These simulation models use empirical mathematical rules that describe the assumed relationships between local bone loads and bone mass. These models are particularly valuable for preclinical testing of orthopaedic implants, relative to their bone-maintaining capacities. In this Chapter the question of validity of these models for these purposes is considered. Furthermore, an overview is presented of validation studies that were performed by the research group of the author.