title: Serious metallosis of a metal head due to fragmented ceramic screws in a cemented THA.
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.
authors.affiliation: Department of Orthopedic Surgery, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Osaka, Japan. hmiki@ort.med.osaka-u.ac.jp
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Miki
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sugano
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Yamamura
authors.forename: Nobuo
authors.initials: N
authors.lastname: Nakamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishii
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
mesh_terms: D001863:Bone Screws / Q000009:adverse effects*; D002516:Ceramics / Q000009:adverse effects*; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D006622:Hip Prosthesis; D006801:Humans; D008670:Metals; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D013499:Surface Properties
chemical_list: D008670:Metals