title: RSA prediction of high failure rate for the uncoated Interax TKA confirmed by meta-analysis.
abstract: OBJECTIVE
  In a previous radiostereometric (RSA) trial the uncoated, uncemented, Interax tibial components showed excessive migration within 2 years compared to HA-coated and cemented tibial components. It was predicted that this type of fixation would have a high failure rate. The purpose of this systematic review and meta-analysis was to investigate whether this RSA prediction was correct.
  
  
  METHODS
  We performed a systematic review and meta-analysis to determine the revision rate for aseptic loosening of the uncoated and cemented Interax tibial components.
  
  
  RESULTS
  3 studies were included, involving 349 Interax total knee arthroplasties (TKAs) for the comparison of uncoated and cemented fixation. There were 30 revisions: 27 uncoated and 3 cemented components. There was a 3-times higher revision rate for the uncoated Interax components than that for cemented Interax components (OR = 3; 95% CI: 1.4-7.2).
  
  
  CONCLUSIONS
  This meta-analysis confirms the prediction of a previous RSA trial. The uncoated Interax components showed the highest migration and turned out to have the highest revision rate for aseptic loosening. RSA appears to enable efficient detection of an inferior design as early as 2 years postoperatively in a small group of patients.
authors.affiliation: Department of Orthopaedics, Leiden University Medical Centre, the Netherlands. b.g.c.w.pijls@lumc.nl
authors.forename: Bart G
authors.initials: BG
authors.lastname: Pijls
authors.forename: Marc J
authors.initials: MJ
authors.lastname: Nieuwenhuijse
authors.forename: Jan W
authors.initials: JW
authors.lastname: Schoones
authors.forename: Saskia
authors.initials: S
authors.lastname: Middeldorp
authors.forename: Edward R
authors.initials: ER
authors.lastname: Valstar
authors.forename: Rob G H H
authors.initials: RG
authors.lastname: Nelissen
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007720:Knee Prosthesis / Q000145:classification; D008297:Male; D011237:Predictive Value of Tests; D011475:Prosthesis Failure; D059869:Radiostereometric Analysis; D012086:Reoperation