title: [Acetabular reinforcement rings in revision total hip arthroplasty: midterm results in 298 cases].
abstract: BACKGROUND
  Acetabular revision in total hip arthroplasty (THA), especially for loose or migrated cup components with collateral bone loss, remains a great surgical challenge. The aim should always be a functionally favorable reconstruction of the rotation center with sufficient load capacity of the acetabulum. Commonly used implants in Europe are the Mueller ring, the Ganz ring, and the Burch-Schneider cage.
  
  
  METHODS
  We report our results of 298 patients (298 hips) with a median follow-up period of 4 (range 0-17) years in a retrospective series.
  
  
  RESULTS
  Follow-up data were available in 224 cases (75%). A radiographic examination was performed in 176 (59%) patients. Another 54 patients (18%) had died in the follow-up period, while another three patients (1%) were lost to follow-up. Eighteen patients (16%) underwent re-revision, in nine cases for aseptic loosening and in the remaining nine cases for infection. In seven additional cases (2%), radiological and clinical failure was found during follow-up. The overall survival rate was 94% at 5 years and 89% at 8 years.
  
  
  CONCLUSIONS
  Revision THA using acetabular reinforcement rings results in acceptable midterm results. However, septic complications and lysis of the bone graft with consecutive failure of the reinforcement ring remain problematic.
authors.affiliation: Klinik und Poliklinik für Orthopädie, Klinikum der Universität zu Köln, Joseph-Stelzmann-Strasse 9, 50924 Köln, Deutschland. ulf.schlegel@gmx.net
authors.forename: U J
authors.initials: UJ
authors.lastname: Schlegel
authors.forename: R G
authors.initials: RG
authors.lastname: Bitsch
authors.forename: M
authors.initials: M
authors.lastname: Pritsch
authors.forename: P R
authors.initials: PR
authors.lastname: Aldinger
authors.forename: H
authors.initials: H
authors.lastname: Mau
authors.forename: S J
authors.initials: SJ
authors.lastname: Breusch
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016459:Prosthesis-Related Infections / Q000000981:diagnostic imaging / Q000601:surgery; D011859:Radiography; D012086:Reoperation