Surveying a quantity of 25 prostheses type Judet by stereoscopy and scanning electron microscopy in all specimen contaminations of the surface were found. By X-ray microanalysis these contaminations were ascertained to be mainly residues of the casting mould. Furthermore, tooling residues from the sandblast (e.g. grains of corundum or glass) were found. A metallographic investigation, which was performed thereupon on two randomly selected specimen, shows clusters of microporosities in the cross sections and carbides in the grain boundaries.