Aetiology

The aetiology of Madelung's Disease is genetically determined. There is an abnormality in the SHOX (short stature homoebox gene) that leads to bony dysplasia around the ulnar side of the lunate fossa of the radius. The palmar or dorsal sides may be affected and there is also an intervening state with poor development in the middle of the lunate fossa - chevron carpus when seen radiographically from the side. The ulnar palmar side is affected most frequently resulting in a bony bar and early closure of the distal radial physis. Growth is relatively tethered on the ulnar side resulting in relative overgrowth and bowing of the dorsal side. The radiolunotriquetral ligament may be abnormally thickened as it spans and tethers the radial physis to the carpus.

The SHOX gene may be affected primarily or in association with Leri-Weill Syndrome. However, it is possible to have Madelung's Disease without and abnormality in the SHOX gene and this indicates that other genes may be involved.