title: Method of fixation does not influence the overall risk of rerevision in first-time cup revisions.
abstract: BACKGROUND
  During the last two decades, uncemented fixation has been increasingly preferred worldwide during cup revision surgery. In Sweden, the number of uncemented cup revisions has been increasing during the last decade. However, it is unclear whether the risk of rerevision differs between cemented and uncemented cups.
  
  
  OBJECTIVE
  We determined (1) the risk of rerevision after cemented and uncemented fixation; (2) the influence of concomitant stem revision on the risk of rerevision of the cup; (3) the difference in risk of rerevision of an uncemented cup revision compared with liner revision only; and (4) whether the surgical incision influenced the risk of rerevision.
  
  
  METHODS
  Between 1979 and 2010, 19,342 first-time cup revisions were reported to the Swedish Hip Arthroplasty Register. From these, 749 were excluded (hip resurfacing, cases with tumor diagnoses, and missing data) leaving 18,593 (73% cemented) for further analysis. We used a Cox regression model adjusted for age, sex, primary diagnosis, method of fixation, concomitant stem revision, and cemented/uncemented fixation to assess risk of rerevision.
  
  
  RESULTS
  The relative risk for rerevision for any reason did not differ between cemented and uncemented fixation (relative risk [RR], 0.94). If the stem was not revised at index revision, the risk of further cup revision increased twofold (RR, 1.91). Liner revisions were associated with a 70% increased risk for rerevision of the cup as a result of any reason and especially because of dislocation (RR, 2.94). The surgical incision did not influence the overall risk for rerevision (direct lateral/posterolateral: RR, 1.02) or the risk of rerevision resulting from dislocation (RR, 0.91).
  
  
  CONCLUSIONS
  We found no difference in the overall risk of rerevision between cemented and uncemented fixation. Liner exchange had a higher risk for rerevision when compared with cases being rerevised with a new uncemented cup.
authors: Department of Orthopaedics, Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, NA, 413 45, Sweden, maziar.mohaddes_ardebili@vgregion.se.
authors: Maziar
authors: M
authors: Mohaddes
authors: Göran
authors: G
authors: Garellick
authors: Johan
authors: J
authors: Kärrholm
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods / Q000706:statistics & numerical data*; D001843:Bone Cements; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012042:Registries; D012086:Reoperation / Q000706:statistics & numerical data; D013548:Sweden; D016896:Treatment Outcome
chemical_list: D001843:Bone Cements