title: Volumetric injury of the distal femoral physis during double-bundle ACL reconstruction in children: a three-dimensional study with use of magnetic resonance imaging.
abstract: BACKGROUND
  Double-bundle anterior cruciate ligament (ACL) reconstruction was developed to produce a more "anatomic" reproduction of the anteromedial and posterolateral bundles of the ACL. The purpose of this study was to determine the volume of injury to the physis during double-bundle ACL reconstruction in children with open physes.
  
  
  METHODS
  Magnetic resonance images (MRIs) of ten knees of children were converted into three-dimensional models. Computer-aided design/computer-aided manufacturing software placed drill-holes of 6, 7, 8, and 9 mm in diameter in these models, simulating tunnels in the femur used for anatomic double-bundle ACL reconstruction. Computer-aided design/computer-aided manufacturing software was used to calculate the total physeal volume and the volume of physis that was removed by creation of the tunnels. The ratio of the physeal volume that had been removed to the total physeal volume was subsequently determined.
  
  
  RESULTS
  With use of 6, 7, 8, and 9-mm-diameter drill-holes in the femur, the average physeal volume removed, as a percentage of the total physeal volume, was 1.5%, 2.0%, 2.5%, and 2.9%, respectively, for the anteromedial tunnels; 2.2%, 2.9%, 3.6%, and 4.2% for the posterolateral tunnels; and 3.7%, 4.8%, 5.7%, and 6.5% for the anteromedial and posterolateral tunnels combined. The volume of physeal damage caused by the posterolateral drill-holes was greater than that produced by the anteromedial drill-holes in all subjects.
  
  
  CONCLUSIONS
  Drill-hole placement during ACL reconstruction produces a zone of physeal injury. Double-bundle techniques substantially increase the volume of injury to the physis, which appears to increase the risk of abnormal growth in the distal femoral physis following this surgical procedure.
authors.affiliation: Intermountain Orthopaedics, 600 North Robbins Road, Suite 401, Boise, ID 83702, USA.
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Shea
authors.forename: Nathan L
authors.initials: NL
authors.lastname: Grimm
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Belzer
mesh_terms: D016118:Anterior Cruciate Ligament / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D002648:Child; D017076:Computer-Aided Design; D005260:Female; D005269:Femur / Q000293:injuries*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007719:Knee Joint / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008953:Models, Anatomic; D019651:Plastic Surgery Procedures / Q000009:adverse effects*