[Titanium deposits on the ceramic heads of dislocated total hip replacements]. / Titanauflagerungen auf Keramikköpfen bei luxierten Hüftendoprothesen.

ABSTRACT

INTRODUCTION: In cases of revision total hip replacement (THR) having acetabular titanium components with dislocations in the past, metallic deposits are frequently found on the ceramic heads. The aim of this study was to determine whether the metallic deposits increase surface roughness in definite areas. MATERIALS AND METHODS: Ten ceramic heads of revised THR which showed metallic deposits were investigated. The patients suffered from one to six dislocations. The prosthesis lifetime ranged from 2 weeks to 12 years. Surface structure was investigated in a scanning electron microscope (LEO 1525), and the metallic deposits characterised by means of energy dispersive x-ray analysis (EDX). RESULTS: In the area of the metallic deposits, titanium was detected by EDX. Edges with a significant increase in surface roughness were observed, partially accompanied by damage to the surface structure and loosening of Al(2)O(3) particles. DISCUSSION: Titanium deposits increase surface roughness in definite areas, which probably causes wear to the ceramic-ceramic or ceramic-polyethylene articulations due to different roughness values and surface properties. Further investigations are necessary in order to determine the importance of these findings with respect to wear and loosening of total hip arthroplasty.