title: Correlation between the distal anterior femoral cortical axis and femoral rotational alignment: an anatomic study.
abstract: To determine the correlation between the distal anterior femoral cortical axis (DAFCA) and the femoral rotational alignment/axis.
  
  
  
  Magnetic resonance images (MRI) of 82 knees in 34 men and 23 women aged 16 to 47 (mean, 33.4) years were reviewed by a musculoskeletal radiologist. Their diagnoses included meniscal tear (n=4), chondromalacia (n=25), anterior cruciate ligament tears (n=11), and normal (n=42). In all patients the collateral ligaments were intact. The transepicondylar axis (TEA), posterior condylar axis (PCA), Whiteside line (WL), and joint line were drawn on the images, and the condylar twist angle (CTA), TEA-WL angle, DAFCA, epicondylar cortical angle (ECA), and condylar cortical angle (CCA) were measured. The correlations among ECA, CCA, and CTA (control) were assessed.
  
  
  
  The mean distances between the joint line and the TEA, PCA, and DAFCA were 30.8, 22.1, and 62.2 mm, respectively. The angles subtended by the intersection between the standard axes (TEA, PCA, and WL) and the DAFCA were determined. There was correlation between the CTA and ECA (r=0.34, p<0.05), between the ECA and the CCA (r=0.80, p<0.0001), and between the CTA and the CCA (r=- 0.19, p=0.08).
  
  
  
  There was correlation between the DAFCA and TEA and PCA; DAFCA can be used to determine the femoral rotational alignment when the standard landmarks are distorted by severe soft tissue and bone loss.
authors: Department of Orthopaedic Surgery, Tan Tock Seng Hospital, National Healthcare Group, Singapore.
authors: S S
authors: SS
authors: Sathappan
authors: Department of Orthopaedic Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: M Wp
authors: MW
authors: Tan
authors: Department of Radiology, The University of Chicago, United States.
authors: D
authors: D
authors: Ginat
authors: Department of Epidemiology and Biostatistics, SUNY Downstate Medical Center, United States.
authors: M G
authors: MG
authors: Walsh
authors: Department of Radiology, Stony Brook School of Medicine, United States.
authors: M E
authors: ME
authors: Schweitzer
authors: Musculoskeletal Research Center, NYU-Hospital for Joint Diseases, United States.
authors: P E
authors: PE
authors: Di Cesare
mesh_terms: D000293:Adolescent; D000328:Adult; D001837:Body Weights and Measures; D017760:Bone Malalignment / Q000000981:diagnostic imaging*; D002357:Cartilage Diseases / Q000000981:diagnostic imaging; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging*; D006801:Humans; D007718:Knee Injuries / Q000000981:diagnostic imaging; D007719:Knee Joint / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012399:Rotation; D055815:Young Adult
keywords: anatomic landmarks; arthroplasty, replacement, knee; femur; magnetic resonance imaging