METALLOSIS CAUSED BY ALUMINA CERAMIC SCREW FIXATION OF GRAFTED BONE IN A BIPOLAR HIP ENDOPROSTHESIS

Citation
M. Watanabe et al., METALLOSIS CAUSED BY ALUMINA CERAMIC SCREW FIXATION OF GRAFTED BONE IN A BIPOLAR HIP ENDOPROSTHESIS, Archives of orthopaedic and trauma surgery, 112(6), 1993, pp. 296-298
Citations number
2
Language
INGLESE
art.tipo
Note
Categorie Soggetti
Orthopedics,Surgery
ISSN journal
0936-8051
Volume
112
Issue
6
Year of publication
1993
Pages
296 - 298
Database
ISI
SICI code
0936-8051(1993)112:6<296:MCBACS>2.0.ZU;2-2
Abstract
We report a case of metallosis due to ceramic fragments in the inner b earing surface of the polyethylene cup of a bipolar hip prosthesis wit h fracture of the alumina ceramic screws used for grafted bone fixatio n. After bone-grafting acetabuloplasty with a Bateman bipolar endopros thesis, gradual migration of the outer head occurred, and fracture of the screws was observed. Seven years after the operation, radiographs showed severe metallosis of the surrounding tissues. At revision, mark ed wear of the inner head was seen. Detailed examination revealed that many rough-edged ceramic particles originating from the fractured cer amic screws had become embedded in the inner surface of the polyethyle ne bearing insert. These extremely hard ceramic fragments had entered the prosthetic joint space during joint movement, thereafter causing c ontinuous abrasion of the metal head. After revision, the concentratio n of the constituents of the prosthesis alloy in the serum decreased t oward control levels. To prevent serious complications like those in t he present case, screws should be inserted more than 1 cm from the out er head of a bipolar endoprosthesis, and the outer head should be remo ved as soon as possible if it comes into contact with the screws.