Triquetrocapitate ligament
Ligamentum triquetrocapitatum
A palmar ligament crossing the ulnar side of the midcarpal joint from the triquetrum to the capitate.
At a glance
- English
- Triquetrocapitate ligament
- Latin (TA2)
- Ligamentum triquetrocapitatum
- System
- Ligament
- Region
- Hand
- Side
- Paired, left and right
About the triquetrocapitate ligament
The triquetrocapitate ligament is an intrinsic palmar ligament of the wrist. It arises from the palmar surface of the triquetrum, on the ulnar side of the proximal carpal row, and runs obliquely towards the radial side and distally across the front of the midcarpal joint to reach the palmar surface of the capitate.
Together with the triquetrohamate ligament, which runs more directly to the hamate, it forms the ulnar arm of the palmar arcuate ligament. The radial arm of this V-shaped arrangement is the radiocapitate ligament, and the two arms converge on the capitate. Proximal to the arc lies a weak area of capsule over the joint between capitate and lunate, the space of Poirier.
The ulnar arm of the arcuate ligament links the proximal row to the distal row on the ulnar side and controls how the triquetrum moves on the hamate. As the wrist moves from radial to ulnar deviation, the proximal row should swing smoothly from flexion into extension. When the ulnar arm is lax or torn, the proximal row stays flexed and then jumps suddenly into extension with a painful clunk, a disorder called palmar midcarpal instability. Treatment ranges from splinting and training of the muscles that steady the wrist, such as flexor carpi ulnaris, to ligament repair or limited fusion of the carpal bones.
Attachments and function
- Attaches from
- Palmar surface of the triquetrum.
- Attaches to
- Palmar surface of the capitate.
- Function
- Links the triquetrum to the capitate across the midcarpal joint and, as part of the ulnar arm of the arcuate ligament, guides the proximal row from flexion into extension.
- Nerve supply
- Articular twigs from the anterior interosseous nerve and the deep branch of the ulnar nerve, which supply the palmar side of the carpus.
- Blood supply
- Small branches of the palmar carpal arch, reinforced by recurrent branches from the deep palmar arch.
Anthromica
See the triquetrocapitate ligament where it really sits, with every layer of the body around it.
- Every layer, one body. Peel from muscle to bone, nerve, vessel and organ, and turn it any way.
- English and Latin. Every structure named the way your exam names it.
- Quiz until it sticks. Short drills on the structures you keep missing.
Free to start. No card.
