title: Intersurgeon variance in computer-assisted planning of anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  To test the hypothesis that computer-controlled virtual planning will prohibit tunnel malpositioning and minimize variance in tunnel placement in anterior cruciate ligament (ACL) reconstruction, thereby providing us with a more accurate and reproducible procedure.
  
  
  METHODS
  In vitro cadaver study.
  
  
  METHODS
  Three orthopaedic surgeons with different levels of experience in ACL reconstruction were asked to position tunnel placement K-wires in a predefined "optimal" position using both computer-assisted surgery (CAS) and conventional techniques in 12 fresh-frozen cadaver knees. Virtual cylindrical 8-mm grafts were virtualized as the computer system outlined an impingement area and visualized graft elongation. CAS positioning and conventional techniques were compared between surgeons and correlated to experience level.
  
  
  RESULTS
  The difference in virtual planning was 5.02 mm (SD, 2.40; range, 1.77 to 9.64 mm) between the tibial tunnels and 4.61 mm (SD, 2.13; range, 2.06 to 8.42 mm) between the femoral tunnels. The mean difference between the CAS and conventional procedures was 6.20 mm (SD, 2.49; range, 3.00 to 10.39 mm) for the femoral tunnel and 6.46 mm (SD, 2.27; range, 2.65 to 10.47 mm) for the tibia tunnel. The 2 less-experienced surgeons were responsible for 3 cases of impingement when using a conventional procedure. No elongation or impingement was seen when using CAS.
  
  
  CONCLUSIONS
  This cadaver study shows that computer assisted planning may reduce intersurgical variance.
  
  
  CONCLUSIONS
  Computer navigation and virtual ligament reconstruction constitute a good arthroscopic surgery teaching tool. This technique enables residents and less experienced surgeons to control positioning and limit complications caused by tunnel misplacement.
authors.affiliation: Department of Surgery, University Medical Center, Utrecht, The Netherlands.
authors.forename: Niels W L
authors.initials: NW
authors.lastname: Schep
authors.forename: Michel H J
authors.initials: MH
authors.lastname: Stavenuiter
authors.forename: Carel H
authors.initials: CH
authors.lastname: Diekerhof
authors.forename: Eric P
authors.initials: EP
authors.lastname: Martens
authors.forename: Col Michiel
authors.initials: CM
authors.lastname: van Haeff
authors.forename: Ivo A M J
authors.initials: IA
authors.lastname: Broeders
authors.forename: Daniël B F
authors.initials: DB
authors.lastname: Saris
mesh_terms: D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D005269:Femur / Q000601:surgery*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D009985:Orthopedics / Q000379:methods*; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D016037:Single-Blind Method; D025321:Surgery, Computer-Assisted; D013710:Tendons / Q000637:transplantation; D013977:Tibia / Q000601:surgery*; D014584:User-Computer Interface