title: Intramedullary versus extramedullary alignment of the tibial component in the Triathlon knee.
abstract: BACKGROUND
  Long term survivorship in total knee arthroplasty is significantly dependant on prosthesis alignment. Our aim was determine which alignment guide was more accurate in positioning of the tibial component in total knee arthroplasty. We also aimed to assess whether there was any difference in short term patient outcome.
  
  
  METHODS
  A comparison of intramedullary versus extramedullary alignment jig was performed. Radiological alignment of tibial components and patient outcomes of 103 Triathlon total knee arthroplasties were analysed.
  
  
  RESULTS
  Use of the intramedullary was found to be significantly more accurate in determining coronal alignment (p = 0.02) while use of the extramedullary jig was found to give more accurate results in sagittal alignment (p = 0.04). There was no significant difference in WOMAC or SF-36 at six months.
  
  
  CONCLUSIONS
  Use of an intramedullary jig is preferable for positioning of the tibial component using this knee system.
authors.affiliation: Department of Orthopaedics, Cappagh National Orthopaedic Hospital, Finglas, Dublin 13, Ireland. james.cashman@gmail.com
authors.forename: James P
authors.initials: JP
authors.lastname: Cashman
authors.forename: Fiona L
authors.initials: FL
authors.lastname: Carty
authors.forename: Keith
authors.initials: K
authors.lastname: Synnott
authors.forename: Paddy J
authors.initials: PJ
authors.lastname: Kenny
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D017760:Bone Malalignment / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery; D007720:Knee Prosthesis; D008297:Male; D011859:Radiography; D012189:Retrospective Studies; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome