Loosening and Periprosthetic Osteolysis of Articular Prostheses

Overview

One of the most serious complications of articular prostheses is loosening of the implant from theosseous bed leading to its failure. The assumed basic cause is the reaction of the organism toabrasion. During function of the articular prosthesis the abrasion of the contact surfaces occursand abrasion particles such as polyethylene, polymethylacrylate, metal and possibly ceramics areproduced. The abrased particles are not biocompatible for the organism. A reaction of the organismto the foreign body occurs. The abrasion material is phagocytosed by macrophages. Activated cellsproduce inflammatory mediators, which cause a cascade of so far not quite elucidated processes theresult of which is a change of the ratio: new formation – resorption of bone with a predominance ofbreakdown. The clinical manifestation of the process is the development of an abrasion granulomaand periprosthetic osteolysis leading to loosening and failure of the endoprosthesis. Detailedunderstanding of the mentioned mechanism is essential for the improvement of long-term resultsof 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 pharmacologicalinterference with processes leading to osteolysis. The article is a review of hitherto knownprocesses leading to osteolysis and working theories on this problem

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