[Carpal instabilities].

The ligaments of the wrist and the bony configuration--beside muscles and tendons--are responsible for stability in the wrist joint, which is impaired in certain pathological conditions: unstable fractures of the scaphoid, scapholunate dissociations, perilunate fracture-dislocations, malunited Colles' fractures, Kienböcks disease, rheumatoid arthritis and posttraumatic laxity of ligaments. The differentiation between dorsal and palmar instability is made by radiological examination and measuring of the scapholunate, capitolunate and radiolunate angles. The understanding of normal anatomy and (post-)traumatic conditions is facilitated by the concept of dynamic action of the ligaments and the bones of the wrist as articular and extraarticular slings.