Palmar lunotriquetral ligament
Ligamentum lunotriquetrum palmare
The palmar band of the ligament complex that joins the lunate to the triquetrum in the proximal row of carpal bones.
At a glance
- English
- Palmar lunotriquetral ligament
- Latin (TA2)
- Ligamentum lunotriquetrum palmare
- System
- Ligament
- Region
- Hand
- Side
- Paired, left and right
About the palmar lunotriquetral ligament
The lunate and the triquetrum lie side by side in the proximal row of the carpus, the lunate in the middle and the triquetrum on the ulnar side. They are held together by a lunotriquetral interosseous ligament which, like the scapholunate ligament, is C-shaped in section. It covers the dorsal, proximal and palmar edges of the joint, leaving the distal side open to the midcarpal joint. The palmar lunotriquetral ligament is the palmar segment of this complex.
Here the palmar segment is the thickest and strongest part, the reverse of the arrangement at the scapholunate joint, where the dorsal segment is the strongest. The proximal segment between them is thin and membranous and faces the radiocarpal joint. On its palmar surface the ligament lies close to the strong palmar ligaments that run from the triquetrum towards the capitate.
No tendons attach to the proximal row, so it moves only in response to the forces around it. The scaphoid tends to flex and the triquetrum to extend, and the lunate between them is kept in balance by its two interosseous ligaments. When the lunotriquetral complex tears, the triquetrum loses its hold on the lunate, which then follows the scaphoid into flexion. On a lateral radiograph this shows as volar intercalated segment instability (VISI). Tears cause pain on the ulnar side of the wrist, often after a fall on the outstretched hand, and can be tested by shearing the triquetrum against the lunate between finger and thumb.
Attachments and function
- Attaches from
- Palmar margin of the ulnar facet of the lunate.
- Attaches to
- Palmar margin of the facing (radial) facet of the triquetrum.
- Function
- Binds lunate to triquetrum on the palm side and is the main restraint of the lunotriquetral joint, passing the extension tendency of the triquetrum to the lunate.
- 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 palmar lunotriquetral 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.
