title: Precision of tunnel positioning in navigated anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  The aim of this study was to validate the precision of navigated tunnel positioning using a fluoroscopy-based computer-assisted technique.
  
  
  METHODS
  Ten human cadaveric knees were operated on under operating room conditions. After resection of the anterior cruciate ligament, referenced fluoroscopic images were acquired to plan the tunnel positions according to established radiologic measurement methods. Afterward, femoral and tibial K-wires were placed by use of navigated drill guides without arthroscopic control. Deviations between the planned and actually drilled tunnel positions at the joint level were analyzed by use of both navigated and radiologic assessment methods.
  
  
  RESULTS
  Navigated analysis between planned and actually drilled tunnel position showed mean deviations of 0.4 mm (range, 0 to 1 mm; SD, 0.52 mm) at the femur and 0.5 mm (range, 0 to 1 mm; SD, 0.5 mm) at the tibia. The radiologic analysis showed mean deviations for the femoral tunnel of 0.83 mm for the depth (range, 0 to 1.46 mm; SD, 0.46 mm) and 0.54 mm for the height (range, 0 to 1.08 mm; SD, 0.41 mm). At the tibia, deviation of 0.74 mm (range, 0 to 1.2 mm; SD, 0.46 mm) was found.
  
  
  CONCLUSIONS
  The fluoroscopy-based navigation system used in this study allows for precise tunnel positioning with deviations of 1 mm or less.
  
  
  CONCLUSIONS
  This technique provides accurate tunnel placement in anterior cruciate ligament surgery.
authors.affiliation: Department of Trauma and Orthopaedic Surgery, Cologne Merheim Medical Centre, University of Witten/Herdecke, Cologne, Germany. sven.shafizadeh@me.com
authors.forename: Sven
authors.initials: S
authors.lastname: Shafizadeh
authors.forename: Maurice
authors.initials: M
authors.lastname: Balke
authors.forename: Stefan
authors.initials: S
authors.lastname: Wegener
authors.forename: Thorsten
authors.initials: T
authors.lastname: Tjardes
authors.forename: Bertil
authors.initials: B
authors.lastname: Bouillon
authors.forename: Juergen
authors.initials: J
authors.lastname: Hoeher
authors.forename: Holger
authors.initials: H
authors.lastname: Baethis
mesh_terms: D059549:Anterior Cruciate Ligament Reconstruction; D000886:Anthropometry / Q000379:methods*; D001182:Arthroscopy; D001864:Bone Wires; D002102:Cadaver; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional; D015641:Radiography, Interventional / Q000295:instrumentation / Q000379:methods*; D012107:Research Design; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery