title: Dislocation after the first and multiple revision total hip arthroplasty: comparison between acetabulum-only, femur-only and both component revision hip arthroplasty.
abstract: BACKGROUND
  Dislocation may complicate revision total hip arthroplasty (THA). We examined the correlation between the components revised during hip arthroplasty (femur only, acetabulum only and both components) to the rates of dislocation in the first and multiple revision THA.
  
  
  METHODS
  We obtained data from consecutive revision THAs performed between January 1982 and December 2005. Patients were grouped into femur-only revision, acetabulum-only revision and revision THA for both components.
  
  
  RESULTS
  A total of 749 revision THAs performed during the study period met our inclusion criteria: 369 first-time revisions and 380 repeated revisions. Dislocation rates in patients undergoing first-time revisions (5.69%) were significantly lower than in those undergoing repeated revisions (10.47%; p = 0.022). Within the group of first-time revisions, dislocation rates for acetabulum-only revisions (10.28%) were significantly higher than those for both components (4.61%) and femur-only (0%) reconstructions (p = 0.025).
  
  
  CONCLUSIONS
  Although patients undergoing first-time revisions had lower rates of dislocations than those undergoing repeated revisions, acetabulum-only reconstructions performed at first-time revision arthroplasty entailed an increased risk for instability.
authors.affiliation: The Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ont.
authors.forename: Yona
authors.initials: Y
authors.lastname: Kosashvili
authors.affiliation: The Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ont.
authors.forename: Michael
authors.initials: M
authors.lastname: Drexler
authors.affiliation: The Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ont.
authors.forename: David
authors.initials: D
authors.lastname: Backstein
authors.affiliation: The Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ont.
authors.forename: Oleg
authors.initials: O
authors.lastname: Safir
authors.affiliation: The Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ont.
authors.forename: Dror
authors.initials: D
authors.lastname: Lakstein
authors.affiliation: The Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ont.
authors.forename: Alex
authors.initials: A
authors.lastname: Safir
authors.affiliation: The Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ont.
authors.forename: Raja
authors.initials: R
authors.lastname: Chakravertty
authors.affiliation: The Department of Orthopaedic Sports Medicine, University of Toronto, Women's College Hospital, Toronto, Ont.
authors.forename: Tim
authors.initials: T
authors.lastname: Dwyer
authors.affiliation: The Division of Orthopaedic Surgery, Mount Sinai Hospital, Toronto, Ont.
authors.forename: Allan
authors.initials: A
authors.lastname: Gross
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D006617:Hip Dislocation / Q000453:epidemiology*; D006622:Hip Prosthesis; D006801:Humans; D007592:Joint Diseases / Q000209:etiology / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D055815:Young Adult