Bifid rib

Case contribution: Dr Radhiana Hassan


  • An 11 years old boy
  • Admitted with clinical diagnosis of acute appendicitis
  • Chest radiograph performed as pre operative assessment.
Chest radiograph PA erect view

Radiographic findings:

  • No focal lung lesion or consolidation.
  • The mediastinal contour is preserved.
  • The heart is not enlarged. Both costophrenic angles are sharp.
  • The anterior aspect of right 4th rib appears bifid.
  • The rest of the visualised bones and soft tissue are unremarkable.  Impression: Incidental finding of bifid of right 4th rib.

Diagnosis: Incidental finding of bifid right rib.


  • A bifid rib is a rare congenital anomaly of the rib cage.
  • It is also called forked or bifurcated rib.
  • Bifid ribs are also called Luschka’s rib.
  • It is usually unilateral. However bilateral bifid ribs can also occur.
  • It is more common on the right than on the left side.
  • It is more common in males than females.
  • It usually involve the third and fourth ribs (incidence: third or fourth > fifth > sixth > second).
  • Two types have been identified:
    • long and slender bifid spaces (fork type)
    • rounded bifid spaces (hole type)
  • Bifid ribs are usually asymptomatic and are often discovered incidentally
  • Association:
    • Gorlin syndrome (nevoid basal carcinoma)
    • Truncus arteriosus
    • Tetralogy of Fallot
Author: radhianahassan