Fluid pressure may cause periprosthetic osteolysis. Particles are not the only thing

Early prosthesis migration predicts late clinical failure, as also does the shape or position of, e.g., a femoral stem. These factors appear unrelated to wear particles. Thus, the initiation of the loosening process has other causes. After this process has started (i.e., the prosthesis migrates), particles may play a role, at least by inhibiting new bone formation at the membrane, but the hypothesis of pressure-induced bone resorption appears easier to support by animal experiments and accords with mechanical risk factors.