title: Excellent long-term results of the Müller acetabular reinforcement ring in primary total hip arthroplasty: A prospective study on radiology and survival of 321 hips with a mean follow-up of 11 years.
abstract: OBJECTIVE
  The original Müller acetabular reinforcement ring (ARR) shows favorable medium-term results for acetabular reconstruction in total hip arthroplasty, where it is used when the acetabular bone stock is deficient. However, there are no data regarding long-term survival of the device. We therefore investigated long-term survival and analyzed radiological modes of failure.
  
  
  METHODS
  Between 1984 and 2002, 321 consecutive primary arthroplasties using an ARR were performed in 291 patients. The mean follow-up time was 11 (0-25) years, and 24 hips were lost to follow-up. For survival analysis, we investigated 321 hips and the end of the follow-up was the date of revision, date of death, or the last patient contact date with implant still in situ. Radiological assessment was performed for 160 hips with a minimum of 10 years of follow-up and with radiographs of sufficient quality. It included evaluation of osteolysis, migration, and loosening.
  
  
  RESULTS
  12 ARR THAs were revised: 1 isolated ARR revision for aseptic loosening, 4 revisions of the ARR and the stem for aseptic loosening, 6 for infection, and 1 for recurrent dislocation. The cumulative revision rate for all components, for any reason, at 20 years was 15% (95% CI: 10-22), while for the ARR only it was 7% (95% CI: 4-12) for any reason and 3.4% (95% CI: 1-9) for aseptic loosening. 21 (13%) of 160 ARR THAs examined had radiological changes: 7 had osteolysis but were not loose, and 14 were radiologically loose but were not painful and not revised.
  
  
  CONCLUSIONS
  Our data suggest that the long-term survival of the ARR is excellent.
authors.affiliation: a Department of Orthopedics and Trauma Surgery , Kantonsspital Baselland , Liestal , Switzerland.|b Department of Orthopedics , Lithuanian University of Health Sciences , Kaunas , Lithuania.|c Department of Orthopedics , Lund University and Lund University Hospital , Lund , Sweden.
authors.forename: Aurimas
authors.initials: A
authors.lastname: Sirka
authors.affiliation: a Department of Orthopedics and Trauma Surgery , Kantonsspital Baselland , Liestal , Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: Clauss
authors.affiliation: b Department of Orthopedics , Lithuanian University of Health Sciences , Kaunas , Lithuania.
authors.forename: Sarunas
authors.initials: S
authors.lastname: Tarasevicius
authors.affiliation: c Department of Orthopedics , Lund University and Lund University Hospital , Lund , Sweden.
authors.forename: Hans
authors.initials: H
authors.lastname: Wingstrand
authors.affiliation: a Department of Orthopedics and Trauma Surgery , Kantonsspital Baselland , Liestal , Switzerland.|b Department of Orthopedics , Lithuanian University of Health Sciences , Kaunas , Lithuania.
authors.forename: Justinas
authors.initials: J
authors.lastname: Stucinskas
authors.affiliation: c Department of Orthopedics , Lund University and Lund University Hospital , Lund , Sweden.
authors.forename: Otto
authors.initials: O
authors.lastname: Robertsson
authors.affiliation: a Department of Orthopedics and Trauma Surgery , Kantonsspital Baselland , Liestal , Switzerland.
authors.forename: Peter Emil
authors.initials: PE
authors.lastname: Ochsner
authors.affiliation: a Department of Orthopedics and Trauma Surgery , Kantonsspital Baselland , Liestal , Switzerland.|d Department of Orthopedics , Hirslanden Klinik Birshof , Münchenstein , Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Ilchmann
mesh_terms: D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D011446:Prospective Studies; D011475:Prosthesis Failure / Q000639:trends*; D011859:Radiography; D012086:Reoperation / Q000706:statistics & numerical data; D016896:Treatment Outcome