title: Effect of anteromedial portal entrance drilling angle during anterior cruciate ligament reconstruction: a three-dimensional computer simulation.
abstract: OBJECTIVE
  The object of this study was to evaluate entrance angle effects on femoral tunnel length and cartilage damage during anteromedial portal drilling using three-dimensional computer simulation.
  
  
  METHODS
  Data was obtained from an anatomic study performed using 16 cadaveric knees. The anterior cruciate ligament femoral insertion was dissected and the knees were scanned by computer tomography. Tunnels with different of three-dimensional entrance angles were identified using a computer simulation. The effects of different entrance angles on the femoral tunnel length and medial femoral cartilage damage were evaluated. Specifically, tunnel length and distance from the medial femoral condyle to a virtual cylinder of the femoral tunnel were measured.
  
  
  RESULTS
  In tunnels drilled at a coronal angle of 45°, an axial angle of 45°, and a sagittal angle of 45°, the mean femoral tunnel length was 39.5±3.7 mm and the distance between the virtual cylinder of the femoral tunnel and the medial femoral condyle was 9.4±2.6 mm. The tunnel length at a coronal angle of 30°, an axial angle of 60°, and a sagittal angle of 45°, was 34.0±2.9 mm and the distance between the virtual cylinder of the tunnel and the medial femoral condyle was 0.7±1.3 mm, which was significantly shorter than the standard angle (p<0.001).
  
  
  CONCLUSIONS
  Extremely low and high entrance angles in both of axial plane and coronal plane produced inappropriate tunnel angles, lengths and higher incidence of cartilage damage. We recommend that angles in proximity to standard angles be chosen during femoral tunnel drilling through the anteromedial portal.
authors.affiliation: Department of Orthopaedic Surgery, Military Hospital, Hongcheon, Korea.
authors.forename: Dong Kyu
authors.initials: DK
authors.lastname: Moon
authors.affiliation: Department of Rehabilitation Medicine and Institute of Health Sciences, School of Medicine, Gyeongsang National University, Gyeongsang National University Hospital, Jinju, Korea.
authors.forename: Chul Ho
authors.initials: CH
authors.lastname: Yoon
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, School of Medicine, Gyeongsang National University, Gyeongsang National University Hospital, Jinju, Korea.
authors.forename: Jin Seung
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, School of Medicine, Gyeongsang National University, Gyeongsang National University Hospital, Jinju, Korea.
authors.forename: Bun Jung
authors.initials: BJ
authors.lastname: Kang
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, School of Medicine, Gyeongsang National University, Gyeongsang National University Hospital, Jinju, Korea.
authors.forename: Seong Hee
authors.initials: SH
authors.lastname: Cho
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, School of Medicine, Gyeongsang National University, Gyeongsang National University Hospital, Jinju, Korea.
authors.forename: Ho Seung
authors.initials: HS
authors.lastname: Jo
authors.affiliation: Department of Orthopaedic Surgery and Institute of Health Sciences, School of Medicine, Gyeongsang National University, Gyeongsang National University Hospital, Jinju, Korea. hscspine@hanmail.net.
authors.forename: Sun Chul
authors.initials: SC
authors.lastname: Hwang
mesh_terms: D000368:Aged; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000295:instrumentation / Q000379:methods*; D002102:Cadaver; D003198:Computer Simulation; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000379:methods*; D010043:Outcome and Process Assessment, Health Care; D056888:Patient Positioning; D013525:Surgical Instruments; D014057:Tomography, X-Ray Computed
keywords: Anterior cruciate ligament; anteromedial portal; computer simulation; femoral tunnel; medial femoral condyle