title: Far anteromedial portal technique for posterolateral femoral tunnel drilling in anatomic double-bundle anterior cruciate ligament reconstruction: a cadaveric study.
abstract: OBJECTIVE
  To identify the relationship between knee flexion angle and femoral tunnel length, as well as the exit points of guidewires, when using a far anteromedial portal technique for posterolateral femoral tunnel drilling in double-bundle anterior cruciate ligament reconstruction.
  
  
  METHODS
  Using the far anteromedial portal technique in 8 cadaveric knees, femoral tunnel drilling for the posterolateral bundle was performed at 3 knee flexion angles: 90°, 110° and 130°. We measured the femoral tunnel length and the distances from each guidewire to the closest relevant structures.
  
  
  RESULTS
  The mean tunnel length at 90° knee flexion (25.8 ± 1.8 mm) was significantly shorter than the length at 110° and 130° knee flexion (32.1 ± 2.6 and 33.1 ± 2.5 mm, respectively). The average distance between the exit point of the guidewire and the posterior articular cartilage of the lateral femoral condyle was the shortest at 90° knee flexion (3.3 ± 2.2 mm). The distance between the guidewire and the centre of the origin of the lateral collateral ligament was the shortest at 130° knee flexion (8.0 ± 1.8 mm). The guidewires penetrated the origin of the lateral gastrocnemius tendon in 2 cases at 110° knee flexion and in 1 case each at 90° and 130° knee flexion.
  
  
  CONCLUSIONS
  When using the far anteromedial portal technique, more than 110° knee flexion is desirable to achieve ideal femoral tunnel length and avoid articular cartilage injury. In addition, the risk of damage to the origin of the lateral collateral ligament increases when the knee flexion angle increases to 130°. A knee flexion angle between 110° and 120° was recommended when using the far anteromedial portal technique.
authors.affiliation: Department of Orthopaedic Surgery, Integrated Health Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan, nakamae@hiroshima-u.ac.jp.
authors.forename: Atsuo
authors.initials: A
authors.lastname: Nakamae
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
authors.forename: Nobuo
authors.initials: N
authors.lastname: Adachi
authors.forename: Masataka
authors.initials: M
authors.lastname: Deie
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Nakasa
authors.forename: Goki
authors.initials: G
authors.lastname: Kamei
authors.forename: Atsushi
authors.initials: A
authors.lastname: Okuhara
authors.forename: Takuya
authors.initials: T
authors.lastname: Niimoto
authors.forename: Shingo
authors.initials: S
authors.lastname: Ohkawa
mesh_terms: D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D002102:Cadaver; D002358:Cartilage, Articular / Q000601:surgery; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000601:surgery*; D006801:Humans; D007719:Knee Joint / Q000502:physiology; D008297:Male; D013710:Tendons / Q000601:surgery