title: Influence of computer navigation on TKA revision rates.
abstract: OBJECTIVE
  We performed this study to determine whether the use of imageless navigation reduces revision rates after total knee arthroplasty (TKA).
  
  
  METHODS
  Data of 1,121 consecutive primary TKA with a follow-up of one to six years were retrospectively analysed. Following the conversion of the standard technique from conventional to navigated procedures, these data included the last 342 conventional and first 779 navigated procedures performed in our clinic. Demographic and perioperative covariates were recorded. All patients were asked by post to report instances of revisions.
  
  
  RESULTS
  Data of 1,054 patients (94 %) were complete. Mean follow-up was 3.9 years for conventional and 2.4 years for navigated operations. Cumulative revision rate averaged 4.7 % for conventional and 2.3 % for navigated procedures. Cox's proportional hazard model was used to assess the effect of covariates on survival, resulting in significantly lower revision rates for older patients (p < 0.001) and for the navigated technique (p = 0.012). The reduced revision rate for navigated operations was mainly caused by a significantly reduced rate of aseptic implant loosening (1.9 % vs. 0.1 %, p = 0.024).
  
  
  CONCLUSIONS
  Our study showed lower revision rates when computer navigation was used. However, due to the retrospective uncontrolled design, further prospective trials will be necessary to further evaluate this effect.
authors.affiliation: LVR Clinic of Orthopaedic Surgery, Horionstrasse 2, 41749 Viersen, Germany. christophschnurr@gmx.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Schnurr
authors.forename: Isabell
authors.initials: I
authors.lastname: Güdden
authors.forename: Peer
authors.initials: P
authors.lastname: Eysel
authors.forename: Dietmar Pierre
authors.initials: DP
authors.lastname: König
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D016016:Proportional Hazards Models; D011475:Prosthesis Failure / Q000209:etiology; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000009:adverse effects / Q000379:methods*