title: Perkin's line
text: # Perkin's line
  
  Perkin's line is a line drawn on an AP radiograph of the pelvis perpendicular to Hilgenreiner's line at the lateral aspects of the triradiate cartilage of the acetabulum.
  
  ## Clinical use
  
  Used in conjunction with Hilgenreiner's line, Perkin's line is useful in the diagnosis of developmental dysplasia of the hip; the upper femoral epiphysis should be in the inferomedial quadrant on a normal radiograph. Lateral displacement relative to Perkin's line is indicative of DDH.
  
  