Dorsal radiocarpal ligament

At a glance

English

Dorsal radiocarpal ligament

Latin (TA2)

Ligamentum radiocarpeum dorsale

System

Ligament

Region

Hand

Side

Paired, left and right

About the dorsal radiocarpal ligament

The dorsal radiocarpal ligament, sometimes called the posterior ligament of the wrist, strengthens the back of the radiocarpal joint. It is thinner and weaker than the palmar radiocarpal ligaments on the front. Its upper end is fixed along the posterior border of the lower end of the radius, and from there its fibres slope downwards and towards the ulnar side. They reach the backs of the scaphoid and lunate and end mainly on the triquetrum, the most strongly anchored point; for this reason it is also known as the dorsal radiotriquetral ligament.

On the back of the wrist the ligament forms one limb of a sideways V. The other limb is the dorsal intercarpal ligament, which runs from the triquetrum across to the scaphoid and trapezium, and the two blend at their shared attachment on the triquetrum. Superficial to the ligament lie the finger and wrist extensor tendons in their sheaths, held down by the extensor retinaculum. On its deep side it merges with the joint capsule and, towards the ulna, with the articular disc of the distal radioulnar joint.

Because its fibres run obliquely, the ligament is well placed to stop the carpus sliding towards the ulnar side down the slope of the distal radius. It also limits excessive flexion of the wrist and helps to hold the lunate and scaphoid steady as the proximal row rotates. Together with the palmar radiocarpal and ulnocarpal ligaments and the collateral ligaments, it keeps the hand aligned on the forearm.

Damage to this ligament contributes to carpal instability patterns that follow wrist sprains and falls. Surgeons approaching the back of the wrist often split the capsule along the line of this ligament and the dorsal intercarpal ligament so as to preserve both.

Attachments and function

Attaches from

The back edge of the lower end of the radius.

Attaches to

The backs of the scaphoid and lunate, ending chiefly on the triquetrum.

Function

Reinforces the back of the wrist joint, resists ulnar sliding of the carpus on the radius, limits excessive flexion and helps steady the proximal carpal row.

Nerve supply

Articular branches of the posterior interosseous nerve.

Blood supply

Branches of the dorsal carpal arch, fed by the radial and ulnar arteries.