title: More accurate component alignment in navigated total knee arthroplasty has no clinical benefit at 5-year follow-up.
abstract: OBJECTIVE
  Computer navigation in total knee arthroplasty is somewhat controversial. We have previously shown that femoral component positioning is more accurate with computed navigation than with conventional implantation techniques, but the clinical impact of this is unknown. We now report the 5-year outcome of our previously reported 2-year outcome study.
  
  
  METHODS
  78 of initially 84 patients (80 of 86 knees) were clinically and radiographically reassessed 5 (5.1-5.9) years after conventional, image-based, and image-free total knee arthroplasty. The methodology was identical to that used preoperatively and at 2 years, including the Knee Society score (KSS) and the functional score (FS), and AP and true lateral standard radiographs.
  
  
  RESULTS
  Although a more accurate femoral component positioning in the navigated groups was obtained, clinical outcome, number of reoperations, KSS, FS, and range of motion were similar between the groups.
  
  
  CONCLUSIONS
  The increased costs and time for navigated techniques did not translate into better functional and subjective medium-term outcome compared to conventional techniques.
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, University of Bern, Inselspital, Bern, Switzerland. sven.hoppe@insel.ch
authors.forename: Sven
authors.initials: S
authors.lastname: Hoppe
authors.forename: Jens D
authors.initials: JD
authors.lastname: Mainzer
authors.forename: Lars
authors.initials: L
authors.lastname: Frauchiger
authors.forename: Peter M
authors.initials: PM
authors.lastname: Ballmer
authors.forename: Rolf
authors.initials: R
authors.lastname: Hess
authors.forename: Matthias A
authors.initials: MA
authors.lastname: Zumstein
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D017760:Bone Malalignment / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects / Q000379:methods; D016343:Monitoring, Intraoperative / Q000379:methods; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery; D010147:Pain Measurement; D011182:Postoperative Care / Q000379:methods; D011474:Prosthesis Design; D011475:Prosthesis Failure; D017755:Prosthesis Fitting / Q000379:methods; D016059:Range of Motion, Articular / Q000502:physiology; D012016:Reference Values; D012086:Reoperation / Q000706:statistics & numerical data; D018570:Risk Assessment; D025321:Surgery, Computer-Assisted / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome