title: Rotational alignment in total knee arthroplasty: intraoperative inter- and intraobserver reliability of Whiteside's line.
abstract: BACKGROUND
  Proper rotational alignment is a critical step of total knee arthroplasty. For intraoperative determination of femoral rotation, Whiteside suggests a perpendicular line to the axis of the center of the trochlea and the intercondylar notch (Whiteside's line).
  
  
  METHODS
  In a prospective clinical study, the intraoperative position of Whiteside's line was measured in 30 patients with the help of a navigation system.
  
  
  RESULTS
  Whiteside's line was 2.1° ± 1.5° externally rotated compared to a navigation based computer calculated preliminary AP axis of the femur. The intraobserver-reliability after 3 repeated measurements each was 1.6° for the senior surgeon and 1.4° for the junior surgeon (p = 0.598, p = 0.968). The interobserver reliability between the measurements by the senior and junior surgeon was 1.4° (p = 0.547).
  
  
  CONCLUSIONS
  Navigated intraoperative measurements of Whiteside's line showed a high inter- and intraobserver reliability. Considering the variability between Whiteside's line and the transepicondylar axis, intraoperative assessment of both the methods is recommended.
authors.affiliation: Trauma Department, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany. Vanin.Nicolas@mh-hannover.de
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vanin
authors.forename: Martin
authors.initials: M
authors.lastname: Panzica
authors.forename: Gregory
authors.initials: G
authors.lastname: Dikos
authors.forename: Christian
authors.initials: C
authors.lastname: Krettek
authors.forename: Stefan
authors.initials: S
authors.lastname: Hankemeier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods* / Q000706:statistics & numerical data*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D015203:Reproducibility of Results; D012399:Rotation; D025321:Surgery, Computer-Assisted