[Scaphoid bone].

The scaphoid is the most important carpal bone due to the frequency of its pathological involvement. Two points of radiological anatomy are stressed: the presence of the scaphoid tubercle whose projection gives rise to the scaphoid ring, the solid radio-capitatum ligament which bridges the scaphoid. Scaphoid fracture represents 70% of all carpal bone fractures and its presence must therefore be meticulously investigated on appropriate x-rays or on tomographies or CT scans, rather than by the classical repeat examination a fortnight later. CT provides good analysis of scaphoid fragments when consolidation is delayed (pseudarthrosis), allowing earlier and more justified indications for surgery. The wrist ligaments are poorly visualised by MRI at the present time; but it allows study of the cartilage and, most importantly, is a decisive examination when there is a doubt about bone vitality.