title: [Analysis of migration of screwed acetabular components following revision arthroplasty of the hip joint. Results of single-image roentgen analysis].
abstract: Out of 57 revised acetabular components, which were regularly checked, 47 had been replaced by a cemented Müller's acetabular reinforcement ring resp. a cementless Müller's Sl-shell with flange. Both types of cups are anchored in the acetabular roof with cancellous bone screws (tab. 1). 42 cases with radiograph series permitted a detailed analysis with the EBRA-method, a computer aided method for the evaluation of acetabular spatial migration based on standard radiographs of the pelvis. The clinical results were very satisfying (tab. 6). The screwed acetabular components migrated little, although, some essential displacements of the center of rotation (in relation to the anatomical position) had to be accepted. As was recognizable with today's inaccurate methods of measuring the center of the head, the displacement too far towards cranial influenced the migration tendency less than an excessive lateralisation. Especially satisfying is the fact, that no increased migration was observed after reconstruction bone grafting of severe acetabular defects, provided that at least a partly direct contact between the acetabular component and the original bone stock was obtained. For the first time EBRA shall be introduced here as a method which shows the migration and the spatial inclination of the acetabular cup in a vector chart.
authors.affiliation: Orthopädische Klinik Kantonsspital Liestal, Schweiz.
authors.forename: S W
authors.initials: SW
authors.lastname: Dihlmann
authors.forename: P E
authors.initials: PE
authors.lastname: Ochsner
authors.forename: A
authors.initials: A
authors.lastname: Pfister
authors.forename: P
authors.initials: P
authors.lastname: Mayrhofer
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging* / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging*; D006622:Hip Prosthesis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012086:Reoperation; D013997:Time Factors
vernacular_title: Wanderungsanalyse verschraubter Hüftpfannen nach Revisionsarthroplastiken am Hüftgelenk. Ergebnisse der Einbildröntgenanalyse (EBRA).