title: Potential risks of femoral tunnel drilling through the far anteromedial portal: a cadaveric study.
abstract: OBJECTIVE
  The purpose of this study was to estimate the potential risks when drilling femoral tunnels through the far anteromedial portal in double-bundle anterior cruciate ligament reconstruction in cadaveric knees.
  
  
  METHODS
  Ten cadaveric knees were used. We drilled the anteromedial bundle (AMB) and posterolateral bundle (PLB) through the far anteromedial portal at 3 different knee flexion angles: 70 degrees, 90 degrees, and 110 degrees. We measured the shortest distance to the common peroneal nerve and the posterior articular cartilage of the lateral femoral condyle and the femoral tunnel length.
  
  
  RESULTS
  At 70 degrees, the distance to the nerve was less than 10 mm in 7 AMB cases and in 9 PLB cases, and the distance to the cartilage was less than 10 mm in all the AMB and PLB cases. At 90 degrees, the distance to the nerve was less than 10 mm in 1 AMB and 5 PLBs, and the distance to the cartilage was less than 10 mm in 2 AMBs and all the PLBs. On the other hand, at 110 degrees , the distance to the nerve was greater than 10 mm in all the AMBs and PLBs, and the distance to the cartilage did not exceed 10 mm in just 2 of the PLBs.
  
  
  CONCLUSIONS
  In our cadaveric study we found that the low knee flexion angles when drilling femoral tunnels through the far anteromedial portal might have the potential risks of damage to the common peroneal nerve and the posterior articular cartilage, and the risks would be decreased at higher degrees of knee flexion. However, we found there was a 20% risk of damage to the cartilage while drilling the PLB at 110 degrees.
  
  
  CONCLUSIONS
  High knee flexion angles are recommended to avoid damage to the nerve and the cartilage when drilling femoral tunnels through the far anteromedial portal in double-bundle anterior cruciate ligament reconstruction.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan. mitsuhiro@m3.dion.ne.jp
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Nakamura
authors.forename: Masataka
authors.initials: M
authors.lastname: Deie
authors.forename: Hayatoshi
authors.initials: H
authors.lastname: Shibuya
authors.forename: Atsuo
authors.initials: A
authors.lastname: Nakamae
authors.forename: Nobuo
authors.initials: N
authors.lastname: Adachi
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Aoyama
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D002102:Cadaver; D002358:Cartilage, Articular / Q000293:injuries; D005260:Female; D005269:Femur / Q000601:surgery; D006801:Humans; D007431:Intraoperative Complications / Q000517:prevention & control; D007718:Knee Injuries / Q000601:surgery*; D008297:Male; D019637:Orthopedic Procedures / Q000009:adverse effects* / Q000379:methods*; D010543:Peroneal Nerve / Q000033:anatomy & histology / Q000293:injuries; D019651:Plastic Surgery Procedures / Q000379:methods