The elemental concentration, shape and chemical state of debris contained in the articular capsules of metal-on-metal hip joints were examined. Co derived from Co-Cr alloy was detected with high concentration. By TEM observation, some larger debris in several hundred nanometers and a lot of smaller debris smaller than several ten nanometers were observed. The debris could be observed in the severe metallosis region. Most of Co contained in the articular capsules could be estimated as the metallic state by fluorescence XAFS analysis, which provides high sensitivity for chemical state analysis. Therefore, the metallosis of the articular capsule could be assumed as mainly caused by the metallic debris.
Key words: wear debris, hip joint, Co-Cr alloy, XAFS