Implant stability, histology, RSA and wear--more critical questions are needed. A view point.

I discuss the radiostereometry (RSA) of prosthetic micromovement from clinical and histological viewpoints. Even in non-migrators there is a wide variety of interfaces with various resistances to trigger factors, such as mechanical forces and sequels of wear. I suggest that the various forms of bone resorption seen with conventional radiography are caused by such trigger factors and that their anatomical appearance is determined by the structure of the interface obtained at surgery.