Palmar scaphotriquetral ligament
Ligamentum scaphotriquetrum palmare
A palmar wrist ligament that arches from the triquetrum to the scaphoid, crossing the front of the midcarpal joint distal to the lunate.
At a glance
- English
- Palmar scaphotriquetral ligament
- Latin (TA2)
- Ligamentum scaphotriquetrum palmare
- System
- Ligament
- Region
- Hand
- Side
- Paired, left and right
About the palmar scaphotriquetral ligament
The palmar scaphotriquetral ligament is an intrinsic ligament on the palm side of the carpus. It joins the two outer bones of the proximal row, the triquetrum on the ulnar side and the scaphoid on the radial side, without attaching to the lunate between them. Its path takes it across the palmar side of the midcarpal joint, distal to the lunate, where it lies against the palmar surface of the head of the capitate.
It belongs to the arch of palmar fibres that cradles the capitate head. On the radial side of this arch runs the radiocapitate ligament and on the ulnar side the triquetrocapitate and triquetrohamate ligaments. Proximal to the arch, between it and the long radiolunate ligament, is a thin area of capsule over the joint between capitate and lunate, the space of Poirier, through which the tear passes in perilunate dislocation and through which the lunate itself may be pushed forwards.
From its position the ligament acts as a palmar sling for the head of the capitate and links the movement of the scaphoid with that of the triquetrum, so that the proximal row moves as a coordinated whole as the wrist bends and tilts. Laxity of the palmar midcarpal ligaments that support the capitate head is associated with midcarpal instability, in which the proximal row shifts abruptly with a painful clunk as the wrist moves from radial to ulnar deviation.
Attachments and function
- Attaches from
- Palmar surface of the triquetrum.
- Attaches to
- Palmar surface of the scaphoid, towards its distal part.
- Function
- Spans the palmar side of the midcarpal joint, supporting the head of the capitate and linking the scaphoid to the triquetrum.
- 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 scaphotriquetral 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.
