Ultrastructural Analysis of Retrieved Ceramic Ball Heads

Surface modification of alumina heads retrieved for aseptic loosening (6 cases) has been analysed using scanning electron microscopy, coupled with energy dispersive X-ray microanalysis. Ultrastructural analysis showed the presence of voids with grain detachment on all the retrieved cups and also in those cases in which macroscopic signs of wear were absent. The preservation of the macroscopic integrity of ceramic structure is an essential condition for long-time survival of total hip replacement, even if ceramic may also play a role in PE damage for the abrasive effects of grains. Macroscopic wear observed in two cases is not related to degradation of ceramic material but to other factors connected to surgery.