title: Femoral graft-tunnel angles in posterior cruciate ligament reconstruction: analysis with 3-dimensional models and cadaveric experiments.
abstract: OBJECTIVE
  The purpose of this study was to compare four graft-tunnel angles (GTA), the femoral GTA formed by three different femoral tunneling techniques (the outside-in, a modified inside-out technique in the posterior sag position with knee hyperflexion, and the conventional inside-out technique) and the tibia GTA in 3-dimensional (3D) knee flexion models, as well as to examine the influence of femoral tunneling techniques on the contact pressure between the intra-articular aperture of the femoral tunnel and the graft.
  
  
  METHODS
  Twelve cadaveric knees were tested. Computed tomography scans were performed at different knee flexion angles (0°, 45°, 90°, and 120°). Femoral and tibial GTAs were measured at different knee flexion angles on the 3D knee models. Using pressure sensitive films, stress on the graft of the angulation of the femoral tunnel aperture was measured in posterior cruciate ligament reconstructed cadaveric knees.
  
  
  RESULTS
  Between 45° and 120° of knee flexion, there were no significant differences between the outside-in and modified inside-out techniques. However, the femoral GTA for the conventional inside-out technique was significantly less than that for the other two techniques (p<0.001). In cadaveric experiments using pressure-sensitive film, the maximum contact pressure for the modified inside-out and outside-in technique was significantly lower than that for the conventional inside-out technique (p=0.024 and p=0.017).
  
  
  CONCLUSIONS
  The conventional inside-out technique results in a significantly lesser GTA and higher stress at the intra-articular aperture of the femoral tunnel than the outside-in technique. However, the results for the modified inside-out technique are similar to those for the outside-in technique.
authors.affiliation: Department of Orthopaedic Surgery, Arthroscopy and Joint Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Sung-Jae
authors.initials: SJ
authors.lastname: Kim
authors.forename: Yong-Min
authors.initials: YM
authors.lastname: Chun
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Kim
authors.forename: Hong-Kyo
authors.initials: HK
authors.lastname: Moon
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Jang
mesh_terms: D002102:Cadaver; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000601:surgery; D008953:Models, Anatomic; D016119:Posterior Cruciate Ligament / Q000000981:diagnostic imaging / Q000601:surgery*; D019651:Plastic Surgery Procedures / Q000379:methods*; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed
keywords: 3-dimensional; Posterior cruciate ligament; graft-tunnel angle; reconstruction