Ulnar collateral ligament of wrist joint
Ligamentum collaterale ulnare carpi
A rounded cord on the little-finger side of the wrist, joining the ulnar styloid process to the triquetrum and pisiform.
At a glance
- English
- Ulnar collateral ligament of wrist joint
- Latin (TA2)
- Ligamentum collaterale ulnare carpi
- System
- Ligament
- Region
- Hand
- Side
- Paired, left and right
About the ulnar collateral ligament of wrist joint
The ulnar collateral ligament reinforces the medial, or little-finger, side of the wrist. It is a rounded cord that starts at the apex of the ulnar styloid. As it descends it splits into two slips: one fixes to the medial, non-articular surface of the triquetrum, and the other passes to the pisiform and blends with the flexor retinaculum.
It is best understood as part of the soft-tissue complex that fills the gap between the end of the ulna and the carpus. The ulna does not touch the carpal bones directly; instead a fibrocartilaginous articular disc sits on its head, and around this disc lie the palmar ulnocarpal bands, the radioulnar ligaments and this collateral cord. Together these structures cushion and stabilise the ulnar side of the wrist. Just behind the ligament runs the tendon of extensor carpi ulnaris in its own sheath.
The ligament tightens when the hand is bent towards the thumb side, so its main role is to restrain radial deviation. Like its radial partner it is thin and partly capsular, and the wrist relies heavily on the palmar and dorsal ligaments and on muscle tone for its stability.
Pain on the ulnar side of the wrist is common and has many causes, among them tears of the articular disc complex, instability of the extensor carpi ulnaris tendon and fractures of the ulnar styloid. A styloid fracture that does not unite can loosen the ligament's anchorage. The dorsal branch of the ulnar nerve crosses near the styloid and can be irritated in this region.
Attachments and function
- Attaches from
- The apex of the ulnar styloid process.
- Attaches to
- By two slips: the medial surface of the triquetrum, and the pisiform together with the flexor retinaculum.
- Function
- Limits radial deviation of the hand and strengthens the medial part of the wrist joint capsule.
- Nerve supply
- Articular twigs from the dorsal and deep branches of the ulnar nerve.
Anthromica
See the ulnar collateral ligament of wrist joint 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.
