A pseudometallosis cyst associated with a Moore prosthesis. A case report

A Moore prosthesis that had been in place for 28 years was revised. Apparent metallosis resulted from contact between the collar and the calcar. A supra-acetabular cyst was found packed with black stained debris. Metallurgical examination failed to reveal any metallic debris in the cyst material. This case indicates that all black staining in and of itself is not necessarily indicative of metallosis.