title: Arthroscopically pertinent landmarks for tunnel positioning in single-bundle and double-bundle anterior cruciate ligament reconstructions.
abstract: BACKGROUND
  Quantification of the overall anterior cruciate ligament (ACL) and anteromedial (AM) and posterolateral (PL) bundle centers in respect to arthroscopically pertinent bony and soft tissue landmarks has not been thoroughly assessed.
  
  
  OBJECTIVE
  A standardized anatomical measurement method can quantitate the locations of the ACL and AM and PL bundle centers in reference to each other and anatomical landmarks.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  Quantification of the ACL and its bundle attachments was performed on 11 cadaveric knees using a radio frequency-tracking device.
  
  
  RESULTS
  The tibial ACL attachment center was 7.5 mm medial to the anterior horn of the lateral meniscus, 13.0 mm anterior to the retro-eminence ridge, and 10.5 mm posterior to the ACL ridge. The femoral ACL attachment center was 1.7 mm proximal to the bifurcate ridge and 6.1 mm posterior to the lateral intercondylar ridge. The tibial AM attachment center was 8.3 mm medial to the anteromedial aspect of the lateral meniscus anterior horn, 17.8 mm anterior to the retro-eminence ridge, and 5.6 mm posterior to the ACL ridge. The femoral AM attachment center was 4.8 mm proximal to the bifurcate ridge and 7.1 mm posterior to the lateral intercondylar ridge. The tibial PL bundle attachment center was 6.6 mm medial to the posteromedial aspect of the lateral meniscus anterior horn, 10.8 mm anteromedial to the root attachment of the lateral meniscus posterior horn, and 8.4 mm anterior to the retro-eminence ridge. The femoral PL bundle attachment center was 5.2 mm distal to the bifurcate ridge and 3.6 mm posterior to the lateral intercondylar ridge.
  
  
  CONCLUSIONS
  The authors developed a comprehensive compilation of measurements of arthroscopically pertinent bony and soft tissue landmarks that quantitate the ACL and its individual bundle attachment centers on the tibia and femur.
  
  
  CONCLUSIONS
  These clinically relevant arthroscopic landmarks may enhance single- and double-bundle ACL reconstructions through improved tunnel placement.
authors.affiliation: Division of Sports Medicine, Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, USA.
authors.forename: Connor G
authors.initials: CG
authors.lastname: Ziegler
authors.forename: Sean D
authors.initials: SD
authors.lastname: Pietrini
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Westerhaus
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Anderson
authors.forename: Coen A
authors.initials: CA
authors.lastname: Wijdicks
authors.forename: Steinar
authors.initials: S
authors.lastname: Johansen
authors.forename: Lars
authors.initials: L
authors.lastname: Engebretsen
authors.forename: Robert F
authors.initials: RF
authors.lastname: LaPrade
mesh_terms: D000368:Aged; D016118:Anterior Cruciate Ligament / Q000033:anatomy & histology* / Q000601:surgery*; D001182:Arthroscopy; D002102:Cadaver; D005260:Female; D005269:Femur / Q000033:anatomy & histology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013977:Tibia / Q000033:anatomy & histology