Pisotriquetral ligament
Ligamentum pisotriquetrum
The capsular ligament of the small joint between the pisiform and the palmar surface of the triquetrum, on the ulnar side of the wrist.
At a glance
- English
- Pisotriquetral ligament
- Latin (TA2)
- Ligamentum pisotriquetrum
- System
- Ligament
- Region
- Hand
- Side
- Paired, left and right
About the pisotriquetral ligament
The pisiform is a small, pea-shaped sesamoid bone that develops within the tendon of flexor carpi ulnaris and rests on the palmar surface of the triquetrum. The two bones meet at their own small synovial joint, the pisiform joint, which has a thin, loose capsule. The pisotriquetral ligament is the fibrous thickening of this capsule, joining the margins of the facet on the pisiform to the palmar surface of the triquetrum around it.
Distally the pisiform is anchored by two further bands that continue the line of pull of flexor carpi ulnaris: the pisohamate ligament to the hook of the hamate and the pisometacarpal ligament to the base of the fifth metacarpal. The pisiform also gives attachment to the flexor retinaculum and to abductor digiti minimi. The pisohamate ligament forms part of the floor of the ulnar canal (Guyon's canal), through which the ulnar nerve and artery pass into the hand.
Because the capsule is loose, the pisiform can glide on the triquetrum and can be moved from side to side when the wrist is relaxed. The ligament keeps the bone seated on its facet while flexor carpi ulnaris pulls on it, so that the pisiform acts as a lever for that tendon. Arthritis or instability of the pisotriquetral joint causes pain on the palmar ulnar side of the wrist, typically made worse by pressing the pisiform against the triquetrum and grinding it.
Attachments and function
- Attaches from
- Margins of the articular facet on the dorsal surface of the pisiform.
- Attaches to
- Palmar surface of the triquetrum, around its facet for the pisiform.
- Function
- Reinforces the capsule of the pisiform joint and keeps the pisiform seated on the triquetrum while allowing it to glide.
- Nerve supply
- Twigs of the ulnar nerve, which supply the ulnar side of the wrist.
- Blood supply
- Branches of the ulnar artery and the palmar carpal arch.
Anthromica
See the pisotriquetral 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.
