Investigations

The key investigation in Madelung's Deformity is radiography:

• AP film:
  • shows defect at the location of the distal radial facet where the lunate sits
  • radial epiphysis on its ulnar side narrows to a point
  • may be spike of bone in the metaphysis
  • radius shorter and bowed compared to ulna
  • carpus seems to overlap distal radius and ulna as it is subluxed
  • in chevron carpus:
    • lunate pyramidal
    • scaphoid ring sign as it flexes forward
• lateral:
  • bowing of radius
  • notch in distal radius, the position of which depends on the point of abnormal growth:
    • palmar in classical Madelung's deformity
    • dorsal in the less frequent reversed Madelung's deformity
    • central in chevron carpus
  • subluxation of carpus

MRI may help with the identification of soft tissue anomalies eg a thickened radiolunotriquetral ligament.