One of the most serious complications of articular prostheses is loosening of the implant from the osseous bed leading to its failure. The assumed basic cause is the reaction of the organism to abrasion. During function of the articular prosthesis the abrasion of the contact surfaces occurs and abrasion particles such as polyethylene, polymethylacrylate, metal and possibly ceramics are produced. The abrased particles are not biocompatible for the organism. A reaction of the organism to the foreign body occurs. The abrasion material is phagocytosed by macrophages. Activated cells produce inflammatory mediators, which cause a cascade of so far not quite elucidated processes the result of which is a change of the ratio: new formation – resorption of bone with a predominance of breakdown. The clinical manifestation of the process is the development of an abrasion granuloma and periprosthetic osteolysis leading to loosening and failure of the endoprosthesis. Detailed understanding of the mentioned mechanism is essential for the improvement of long-term results of articular prostheses. They can be possibly influenced by changes in the construction of implants, the selection of new mechanically resistant and biologically inert materials and possible pharmacological interference with processes leading to osteolysis. The article is a review of hitherto known processes leading to osteolysis and working theories on this problem

        Key words: periprosthetic osteolysis, polyethylene abrasion, abrasion granuloma,