**6. Conclusions** *(Gallo)*

Aseptic loosening is the leading cause of THA failure in the intermediate and long-term postoperative period. Causally it is associated with rapid wear rate inducing adverse host reaction to wear debris and to repetitive mechanical stresses and strains of the bone-implant interface. Here, we introduced the concept of failure of local tissue homeostasis as underlying the majority of processes leading to aseptic loosening. Given that the implant is stable in the second postoperative year and no gross pathology of bone-implant interface is seen on x-ray, then the fate of implant depends on the ability of host tissues (both, bone and soft tissues) to maintain homeostasis with minimum inflammation despite the occurrence of chronic mechanical and particle load. In this connection, the problem is the inability to maintain the balance at bone-implant interface and resolve inflammation in the periprosthetic tissues that can induce the excessive bone resorption around the implant (osteolysis) leading eventually to aseptic loosening. The increased knowledge of the mechanisms regulating the balance in periprosthetic tissues might open new avenues to prevent aseptic loosening and periprosthetic osteolysis.
