Authors: Hidenobu Miki Nobuhiko Sugano Mitsuyoshi Yamamura Nobuo Nakamura Takashi Nishii Hideki Yoshikawa
Publish Date: 2006/02/24
Volume: 126, Issue: 3, Pages: 192-196
Abstract
We reported a rare revision case necessitated by massive metallosis of a metal head due to a fragmented ceramic screw which had been extraarticularily used in the primary THA here and reviewed previous literature about metallosis of metal heads associated with ceramic materials The ceramic screw had been used for the fixation of a bone graft and reattachment of the greater trochanter in the primary THA Scanning electron microscope analysis revealed large alumina ceramic particles embedded on the bearing surface of the polyethylene It has previously been pointed out that metallosis of an inner head occurred in bipolar case due to a fracture of the ceramic screws in contact with a proximally migrated outer head However this case showed that if a ceramic screw fragmented even though it was used outside of the hip joint the fragments could migrate into bearing surface and cause serious metallosis of the metal head Thus we recommend that surgeons should pay special attention to the radiographic signs of ceramic failure or metallosis such as a change of the metal head contour if an aseptic loosening or severe osteolysis is observed in a THA in which ceramic materials were used near the hip joint And when a surgical revision is planned the surgeon should be prepared to exchange with a new ceramic head
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