title: Use of a fluoroscopic overlay to assist arthroscopic anterior cruciate ligament reconstruction.
abstract: BACKGROUND
  A growing body of evidence supports the importance of anatomic tunnel positioning in the success of anterior cruciate ligament (ACL) reconstruction, which stimulates the need for technologies to aid surgeons in achieving accurate anatomic tunnel placement. Intraoperative fluoroscopy is potentially one such technology, while its efficacy and usability have yet to be established.
  
  
  OBJECTIVE
  To investigate the performance of an intraoperative fluoroscopic overlay in guiding tunnel placement during ACL reconstruction.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twenty cadaveric knees underwent computed tomography (CT) scans and arthroscopic digitization of ACL insertion sites. The outlines of the digitized insertion sites were mapped to the corresponding CT-acquired bone models through a co-registration procedure. Twenty orthopaedic surgeons performed simulated ACL reconstructions, each on a randomly assigned cadaveric knee, first without and then with the aid of a fluoroscopic overlay system. The overlay system displayed on a lateral fluoroscopic image targets points representing the locations of the ACL insertion sites estimated from the literature data. Surgeons were allowed to adjust their tunnel positions under the guidance of the fluoroscopic image. Their initial, intermediate, and final positions were documented and compared with the target points as well as the native insertion sites.
  
  
  RESULTS
  Surgeons demonstrated significant (P < .01) improvements in femoral and tibial tunnel placements relative to the target points from an average distance of 3.9 mm to 1.6 mm on the femur and 2.1 mm to 0.9 mm on the tibia. The improvements toward the knee-specific actual insertion sites were significant on the tibial side but not on the femoral side.
  
  
  CONCLUSIONS
  Surgeons can be successfully guided with fluoroscopy to create more consistent femoral and tibial tunnels during ACL reconstruction. More research is warranted to develop better population representations of the locations of natural insertion sites.
  
  
  CONCLUSIONS
  Intraoperative fluoroscopy can be an effective, easy, and safe method for improving tunnel positioning during ACL reconstruction.
authors.affiliation: Orthopaedic Research Laboratories, 3820 South Water Street, Pittsburgh, PA 15203, USA.
authors.forename: Gele
authors.initials: G
authors.lastname: Moloney
authors.forename: Paulo
authors.initials: P
authors.lastname: Araujo
authors.forename: Stephen
authors.initials: S
authors.lastname: Rabuck
authors.forename: Robert
authors.initials: R
authors.lastname: Carey
authors.forename: Gustavo
authors.initials: G
authors.lastname: Rincon
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhang
authors.forename: Christopher
authors.initials: C
authors.lastname: Harner
mesh_terms: D059925:Anatomic Landmarks; D016118:Anterior Cruciate Ligament / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D001182:Arthroscopy; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D015588:Observer Variation; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013977:Tibia / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: ACL insertion sites; ACL reconstruction; computer-assisted surgery; fluoroscopy