title: Computer navigation did not improve alignment in a lower-volume total knee practice.
abstract: Postoperative alignment of the implanted prosthesis in computer-navigated TKA has been reported to be superior to that using the conventional technique. There is an assumption that use of computer navigation techniques can make an inexperienced or occasional TKA surgeon perform more like an expert TKA surgeon. To assess improved accuracy in recreation of mechanical alignment in TKA performed using computer navigation, a retrospective review of the experience of one of the authors (WPY) before and after using computer navigation was performed. We reviewed the radiographic results of 104 TKAs (52 computer navigation, 52 conventional technique) and found the accuracy of postoperative radiographic alignment of the implanted prosthesis was not improved by using computer navigation as judged by (1) overall limb alignment (case: varus 1.3 degrees ; control: varus 0.3 degrees ); (2) femoral component alignment (case: 90.3 degrees ; control: 90.3 degrees ); and (3) tibial component alignment (case: 89 degrees ; control: 90 degrees ). Significant factors that affected postoperative overall mechanical alignment in the current navigation series included severity of the preoperative deformity, amount of error in making bone cuts, and experience of the surgeon in using the computer navigation system.
  
  
  METHODS
  Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic and Traumatology, Queen Mary Hospital, The University of Hong Kong, No 102, Pokfulam Road, Pokfulam, Hong Kong. peterwpy@hkucc.hku.hk
authors.forename: W P
authors.initials: WP
authors.lastname: Yau
authors.forename: K Y
authors.initials: KY
authors.lastname: Chiu
authors.forename: J L
authors.initials: JL
authors.lastname: Zuo
authors.forename: W M
authors.initials: WM
authors.lastname: Tang
authors.forename: T P
authors.initials: TP
authors.lastname: Ng
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000601:surgery*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D016022:Case-Control Studies; D002983:Clinical Competence; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery*; D011859:Radiography; D012189:Retrospective Studies; D012720:Severity of Illness Index; D025321:Surgery, Computer-Assisted; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome