title: Height and Depth Guidelines for Anatomic Femoral Tunnels in Anterior Cruciate Ligament Reconstruction: A Cadaveric Study.
abstract: To develop guidelines for femoral tunnel placement based on height and depth on the lateral wall of the notch and to apply these guidelines arthroscopically to show tunnel placements within the anterior cruciate ligament (ACL) femoral insertion site.
  
  
  
  Twelve cadaveric knees were dissected to define the centers of the femoral ACL attachment and its anteromedial (AM) and posterolateral (PL) bundles. In 90° of flexion, the height and depth of each center were determined relative to the low point on the lateral intercondylar notch. Radiographic grid measurements were made to validate these measurements. Subsequently, the measurement guidelines were applied arthroscopically in 10 new cadaveric knees to evaluate their accuracy for an anatomic single-bundle femoral tunnel. Interobserver reliability analysis was evaluated with the intraclass correlation coefficient.
  
  
  
  In 90° of flexion, the height of the ACL center was 8.7 ± 0.6 mm from the low point of the lateral notch; PL center, 7.2 ± 1.2 mm; and AM center, 9.6 ± 1.1 mm. Relative to the low point, the ACL center was 1.7 ± 1.7 mm posterior, the PL center was 3.4 ± 1.5 mm anterior, and the AM center was 4.9 ± 1.7 mm posterior (intraclass correlation coefficient, 0.859). Radiographic grid measurements were consistent with the direct measurements. Application of the guidelines arthroscopically with or without the assistance of a 7-mm offset aimer placed all guide pins for tunnels within the femoral ACL footprint, with 90% within 4 mm of the ACL center.
  
  
  
  This study showed in cadaveric knees in 90° of flexion that the center of the ACL can be located on the lateral notch at a height of 8.7 ± 0.6 mm from the lowest point and anterior 11.5 ± 1.3 mm from the deepest point. How anatomic tunnels can be placed using these measurements was also shown in cadaveric knees.
  
  
  
  An anatomic femoral tunnel for ACL reconstruction can be placed using height and depth guidelines.
authors.affiliation: Orthopaedic Sports Medicine Section, New England Baptist Hospital, Boston, Massachusetts, U.S.A.
authors.forename: A David
authors.initials: AD
authors.lastname: Davis
authors.affiliation: Orthopaedic Sports Medicine Section, New England Baptist Hospital, Boston, Massachusetts, U.S.A.
authors.forename: Moiz I
authors.initials: MI
authors.lastname: Manaqibwala
authors.affiliation: International Knee & Joint Centre, Abu Dhabi, United Arab Emirates.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Brown
authors.affiliation: Orthopaedic Sports Medicine Section, New England Baptist Hospital, Boston, Massachusetts, U.S.A.. Electronic address: msteiner@uhs.harvard.edu.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Steiner
mesh_terms: D000070598:Anterior Cruciate Ligament Injuries / Q000000981:diagnostic imaging / Q000601:surgery; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D002102:Cadaver; D005269:Femur / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D011859:Radiography; D016059:Range of Motion, Articular; D015203:Reproducibility of Results