title: Similar early migration when comparing CR and PS in Triathlon™ TKA: A prospective randomised RSA trial.
abstract: OBJECTIVE
  The objective of this study was to compare the early migration of the cruciate retaining and posterior stabilising versions of the recently introduced Triathlon™ total knee system, with a view to predicting long term fixation performance.
  
  
  METHODS
  Sixty patients were prospectively randomised to receive either Triathlon™ posterior stabilised cemented knee prosthesis or Triathlon™ cruciate retaining cemented knee prosthesis. Tibial component migration was measured by radiostereometric analysis postoperatively and at three months, one year and two years. Clinical outcome was measured by the American Knee Society Score and Knee Osteoarthritis and Injury Outcome Score.
  
  
  RESULTS
  There were no differences in rotation around the three coordinal axes or in the maximum total point motion (MTPM) during the two year follow-up. The posterior stabilised prosthesis had more posterior-anterior translation at three months and one year and more caudal-cranial translation at one year and two years. There were no differences in functional outcome between the groups.
  
  
  CONCLUSIONS
  The tibial tray of the Triathlon™ cemented knee prosthesis showed similar early stability.
  
  
  METHODS
  Level I.
  Article focus: This was a prospective randomised trial aiming to compare the single radius posterior stabilised (PS) Triathlon™ total knee arthroplasty (TKA) to the cruciate retaining Triathlon™ TKA system with regard to fixation. Strengths and limitations of this study: Strength of this study was that it is a randomised prospective trial using an objective measuring tool. The sample size of 25-30 patients was reportedly sufficient for the screening of implants using RSA [1].
  
  
  BACKGROUND
  ClinicalTrials.gov Identifier: NCT00436982.
authors: Department of Orthopaedics Hässleholm-Kristianstad-Ystad, Hässleholm Hospital, Hässleholm, Sweden; Department of Clinical Sciences, Lund University, Lund, Sweden. Electronic address: mats.molt@skane.se.
authors: Mats
authors: M
authors: Molt
authors: Department of Orthopaedics Hässleholm-Kristianstad-Ystad, Hässleholm Hospital, Hässleholm, Sweden; Department of Clinical Sciences, Lund University, Lund, Sweden.
authors: Sören
authors: S
authors: Toksvig-Larsen
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation*; D002484:Cementation; D005260:Female; D005500:Follow-Up Studies; D005839:Gentamicins; D006801:Humans; D007720:Knee Prosthesis / Q000009:adverse effects*; D008297:Male; D008768:Methylmethacrylates; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000009:adverse effects*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D005839:Gentamicins; D008768:Methylmethacrylates; C030159:gentamicin-polymethylmethacrylate bead
keywords: Cruciate retaining; Posterior stabilised; RSA; Single radius; Total knee replacement