title: Lateral Radiographic Landmarks for ACL and LCL Footprint Origins During All-Epiphyseal Femoral Drilling in Skeletally Immature Knees.
abstract: BACKGROUND
  This study was conducted to evaluate the spatial relationship of the anterior cruciate ligament (ACL) and lateral collateral ligament (LCL) femoral footprint origins in knee specimens from skeletally immature donors as viewed on lateral radiographs.
  
  
  METHODS
  Fourteen cadaver specimens of skeletally immature knees from children between 7 and 11 years old at the time of death were examined through gross dissection. Metallic pins were placed at the center of the ACL and LCL femoral footprints, and computed tomography (CT) scans were performed. Sagittal plane CT images were merged to create a view analogous to an intraoperative C-arm image with overlaid ACL and LCL ligament footprints. Ligament origins were then measured as a percent of the epiphyseal depth (% P-A [posterior-anterior]) and height (% P-D [proximal-distal]).
  
  
  RESULTS
  The ACL origin was centered at a point located 14% (14% P-A) of the total lateral femoral condyle (LFC) depth from the most posterior aspect of the LFC and 38% (38% P-D) of the LFC height from the most proximal aspect of the posterior physis. The LCL origin was centered at a point 27% P-A and 37% P-D. When viewed on a sagittal CT reconstruction analogous to a perfect lateral intraoperative fluoroscopic view, the ACL footprint origin is posterior and slightly inferior to the LCL origin. Both origins are distal to the distal femoral physis and are posterior to the origin of the popliteus.
  
  
  CONCLUSIONS
  This study demonstrates a consistent relationship between the origin of the ACL and LCL, which may be useful in guiding safe tunnel placement during all-epiphyseal ACL reconstruction in skeletally immature knees.
  
  
  CONCLUSIONS
  This anatomic reference can be used intraoperatively to guide and radiographically evaluate ACL tunnel placement while avoiding the LCL origin in skeletally immature patients.
authors.affiliation: 1St. Luke's Sports Medicine, Boise, Idaho 2Hospital for Special Surgery, New York, NY 3Georgetown University School of Medicine, Washington, DC 4Children's Health Andrews Institute, Plano, Texas 5Elite Sports Medicine, Connecticut Children's Medical Center, Farmington, Connecticut 6Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 7Tennessee Orthopaedic Alliance, Nashville, Tennessee.
authors.forename: Kevin G
authors.initials: KG
authors.lastname: Shea
authors.forename: Peter C
authors.initials: PC
authors.lastname: Cannamela
authors.forename: Peter D
authors.initials: PD
authors.lastname: Fabricant
authors.forename: E Bailey
authors.initials: EB
authors.lastname: Terhune
authors.forename: John D
authors.initials: JD
authors.lastname: Polousky
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Milewski
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Ganley
authors.forename: Allen F
authors.initials: AF
authors.lastname: Anderson
mesh_terms: D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging* / Q000601:surgery; D002648:Child; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D014057:Tomography, X-Ray Computed