ABSTRACT
It has long been recognized that the placement of rigid metallic devices into bone alters peri-implant stress patterns, depriving bone of physiologic stress levels and causing bone resorption or disuse atrophy. A common example of this phenomenon is the loss of cortical bone density under fracture fixation plates fixed with screws, due to remodeling that can cause bone fracture after plate removal because of structural weakening. This problem has stimulated the development of more flexible plates that allow more physiologic bone loading, an engineering approach that has also been pursued in hip and knee joint implant design, as discussed later in this chapter.
