Ulnotriquetral ligament

At a glance

English

Ulnotriquetral ligament

Latin (TA2)

Ligamentum ulnotriquetrum

System

Ligament

Region

Hand

Side

Paired, left and right

About the ulnotriquetral ligament

The ulnotriquetral ligament belongs to the palmar ulnocarpal ligament, the cluster of bands joining the ulnar end of the forearm to the carpus. The other members are the ulnocapitate, ulnolunate and ulnopisiform ligaments. The ulnotriquetral band lies on the ulnar side of the ulnolunate band and deep to the ulnocapitate.

Like the ulnolunate ligament, it arises from the palmar radioulnar ligament, the front edge of the disc complex that covers the head of the ulna. It descends to the palmar surface of the triquetrum. Because its origin is on a structure that moves with the radius, the carpus can stay tied to the ulnar side throughout pronation and supination.

The band helps to suspend the ulnar part of the carpus from the forearm. It tightens when the hand is tilted towards the thumb side and when the wrist is extended, resisting the triquetrum pulling away from the ulna. With the ulnolunate fibres it forms a palmar wall in front of the disc complex.

As a group, these palmar ulnocarpal bands rank with the dorsal and palmar radiocarpal ligaments, the dorsal ulnocarpal ligament and the ulnar and radial collateral ligaments. Injuries of the ulnotriquetral band can accompany tears of the articular disc and instability between lunate and triquetrum, both well-known causes of pain on the ulnar side of the wrist.

Attachments and function

Attaches from

The palmar radioulnar ligament at the front of the articular disc complex.

Attaches to

The palmar surface of the triquetrum.

Function

Suspends the triquetrum and ulnar carpus from the forearm and resists their separation in radial deviation and extension.