title: Computer navigation in the reduction and fixation of femoral shaft fractures: a randomized control study.
abstract: OBJECTIVE
  We investigated the accuracy of reduction of intramedullary nailed femoral shaft fractures in human cadavers, comparing conventional and computer navigation techniques.
  
  
  METHODS
  Twenty femoral shaft fractures were created in human cadavers, with segmental defects ranging from 9 to 53 mm in length (Winquist 3-4, AO 32C2). All fractures were fixed with antegrade 9 mm diameter femoral nails on a radiolucent operating table. Five fractures ("Fluoro" group) were fixed with conventional techniques and fifteen fractures ("Nav 1" and "Nav 2" groups) with computer navigation, using fluoroscopic images of the normal femur to correct for length and rotation. Postoperative CT scans compared femoral length and rotation with the normal leg.
  
  
  RESULTS
  Mean leg length discrepancy in the computer navigation groups was smaller, namely, 3.6 mm for Nav 1 (95% CI: 1.072 to 6.128) and 4.2 mm for Nav 2 (95% CI: 0.63 to 7.75) vs. 9.8 mm for Fluoro (95% CI: 6.225 to 13.37) (p<0.023). Mean rotational discrepancies were 8.7° for Nav 1 (95% CI: 4.282 to 13.12) and 5.6° for Nav 2 (95% CI: -0.65 to 11.85) vs. 9.0° for Fluoro (95% CI: 2.752 to 15.25) (p=0.650).
  
  
  CONCLUSIONS
  Computer navigation significantly improves the accuracy of femoral shaft fracture fixation with regard to leg length, but not rotational deformity.
authors.affiliation: Conquest Hospital, Hastings, United Kingdom.
authors.forename: Oliver
authors.initials: O
authors.lastname: Keast-Butler
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lutz
authors.forename: Mark
authors.initials: M
authors.lastname: Angelini
authors.forename: Nick
authors.initials: N
authors.lastname: Lash
authors.forename: Dawn
authors.initials: D
authors.lastname: Pearce
authors.forename: Meghan
authors.initials: M
authors.lastname: Crookshank
authors.forename: Rad
authors.initials: R
authors.lastname: Zdero
authors.forename: Emil H
authors.initials: EH
authors.lastname: Schemitsch
mesh_terms: D002102:Cadaver; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary / Q000379:methods*; D006801:Humans; D007870:Leg Length Inequality / Q000000981:diagnostic imaging / Q000517:prevention & control*; D008297:Male; D058638:Operating Tables; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed