title: Dual mobility acetabular component in revision total hip arthroplasty for persistent dislocation: no dislocations in 50 hips after 1-5 years.
abstract: BACKGROUND
  A dual mobility cup has the theoretic potential to improve stability in primary total hip arthroplasty (THA) and mid-term cohort results are favorable. We hypothesized that use of a new-generation dual mobility cup in revision arthroplasty prevents dislocation in patients with a history of recurrent dislocation of the THA.
  
  
  METHODS
  We performed a retrospective cohort study of patients receiving an isolated acetabular revision with a dual mobility cup for recurrent dislocation of the prosthesis with a minimum follow-up of 1 year. Kaplan-Meier survival analyses were performed with dislocation as a primary endpoint and re-revision for any reason as a secondary endpoint.
  
  
  RESULTS
  Forty-nine consecutive patients (50 hips) were included; none of the patients was lost to follow-up. The median follow-up was 29 months (range 12-66 months). Two patients died from unrelated causes. Survival after 56 months was 100 % based on dislocation and 93 % (95 % CI 79-98 %) based on re-revision for any reason. Radiologic analysis revealed no osteolysis or radiolucent lines around the acetabular component during the follow-up period.
  
  
  CONCLUSIONS
  The dual mobility cup is an efficient solution for instability of THA with a favorable implant survival at 56 months.
  
  
  METHODS
  Level 4, retrospective case series.
authors.affiliation: Department of Orthopaedic Surgery, Sint Maartenskliniek, PO Box 9011, 6500 GM, Nijmegen, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: van Heumen
authors.forename: P J C
authors.initials: PJ
authors.lastname: Heesterbeek
authors.forename: B A
authors.initials: BA
authors.lastname: Swierstra
authors.forename: G G
authors.initials: GG
authors.lastname: Van Hellemondt
authors.forename: J H M
authors.initials: JH
authors.lastname: Goosen
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006617:Hip Dislocation / Q000503:physiopathology / Q000601:surgery*; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D013997:Time Factors