title: Use of a fluoroscopic overlay to guide femoral tunnel placement during posterior cruciate ligament reconstruction.
abstract: BACKGROUND
  Intraoperative recognition of the local anatomy of the posterior cruciate ligament (PCL) is difficult for many surgeons, and correct positioning of the graft can be challenging.
  
  
  OBJECTIVE
  To investigate the efficacy of an overlay system based on fluoroscopic landmarks in guiding femoral tunnel placement during PCL reconstruction.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twenty cadaveric knees were arthroscopically prepared, and their PCL femoral insertion sites were digitized. The digitized images were co-registered to computed tomography-acquired 3-dimensional bone models. Twenty surgeons with diverse backgrounds performed simulated arthroscopic reconstruction of the anterolateral (AL) and posteromedial (PM) bundles of the PCL, first without and then with the aid of a lateral fluoroscopic image on which the position of a target insertion site based on literature data was displayed as an overlay. The surgeons were allowed to adjust tunnel placement in accordance with the displayed target position. A 3-way comparison was made of the tunnel positions placed by the surgeons, the native insertion site positions, and the literature-based positions.
  
  
  RESULTS
  The overlay system was effective in helping surgeons to improve femoral tunnel placement toward the target and toward the anatomic insertion site (P < .05). For femoral AL tunnel placement, surgeons needed 2.35 ± 2.21 extra attempts, which added an extra 80.00 ± 67.95 seconds to the procedure. For PM tunnel placement, surgeons needed 1.80 ± 1.88 extra attempts, adding 66.00 ± 70.82 seconds to the simulated surgery. In their first attempts, more than half of the surgeons positioned either the AL or PM femoral tunnel >5 mm from the native insertion site. With the use of the overlay, 70% of the surgeons were <5 mm away from the PM and 75% from the AL native insertion site.
  
  
  CONCLUSIONS
  The use of a fluoroscopic overlay to guide intraoperative placement of the femoral tunnel(s) during PCL reconstruction can result in more anatomic reconstructions and therefore assist in re-creating native knee kinematics after PCL reconstruction.
  
  
  CONCLUSIONS
  Intraoperative fluoroscopy is an effective, easy, and safe method for improving femoral tunnel positioning during PCL reconstruction.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA Department of Biomechanics, Medicine and Rehabilitation of Locomotor System, Ribeirao Preto Medical School, São Paulo University, São Paulo, Brazil.
authors.forename: Paulo H
authors.initials: PH
authors.lastname: Araujo
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Gele
authors.initials: G
authors.lastname: Moloney
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Rincon
authors.affiliation: Department of Mechanical Engineering & Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Carey
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA Department of Mechanical Engineering & Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania, USA Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA xuz9@pitt.edu.
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Harner
mesh_terms: D000368:Aged; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D001178:Arthroplasty / Q000379:methods*; D002102:Cadaver; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery*; D005471:Fluoroscopy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D013997:Time Factors; D014057:Tomography, X-Ray Computed
keywords: PCL insertion sites; PCL reconstruction; computer-assisted surgery; fluoroscopy