This research program is designed to investigate the functional relationship between the loading characteristics of total joint components and remodeling of the supporting trabecular bone. In order to investigate these relationships, a hydraulically activated implant has been developed which when interfaced with a plane of trabecular bone in the distal femoral metaphysis of large dogs enables experimental control of the loading magnitude, frequency, number of cycles, and loading rate. This implant has already been demonstrated to elicit significant trabecular bone remodeling at the loading platen bone interface. These remodeling responses are characterized utilizing three-dimensional microcomputed tomography, histologic analysis, and mechanical testing. The specific objective of this proposal is to evaluate the relationship between implant design characteristics and trabecular bone ingrowth and remodeling. The quality of bone ingrowth as well as the morphology and architecture of the adjacent bone will be documented as a function of controlled implant mediated load.