Dorsal radioulnar ligament

The dorsal radioulnar ligament (DRUL) is one of the two principal ligamentous components of the triangular fibrocartilage complex (TFCC), which together with the palmar (volar) radioulnar ligament forms the thickened dorsal and palmar margins that enclose the central fibrocartilaginous articular disc of the distal radioulnar joint (DRUJ). It arises from posterior margin of the ulnar notch at the distal radius to the posterior portion of the head of the ulna

Function: The dorsal radioulnar ligament is a primary dynamic stabilizer of the dorsal radioulnar joint. It is the principal restraint against palmar (volar) translation of the distal ulna relative to the radius. It tightens and stabilizes the joint in pronation, when it reaches maximal length; conversely, the palmar radioulnar ligament tightens in supination. When the interosseous membrane is disrupted, the DRUL becomes the more important of the two radioulnar ligaments for stabilizing the DRUJ in pronation.