Radiocapitate ligament
Ligamentum radiocapitatum
A strong palmar ligament of the wrist running obliquely from the radial styloid, across the waist of the scaphoid, to the capitate.
At a glance
- English
- Radiocapitate ligament
- Latin (TA2)
- Ligamentum radiocapitatum
- System
- Ligament
- Region
- Hand
- Side
- Paired, left and right
About the radiocapitate ligament
The radiocapitate ligament is one of the extrinsic palmar ligaments of the wrist, linking the radius to the carpus. It is the most radial of the strong palmar radiocarpal bands. It arises from the palmar surface of the radial styloid process and runs obliquely, distally and towards the ulnar side. On its way it crosses the waist of the scaphoid, to which some of its fibres attach, and then passes across the front of the midcarpal joint to end on the palmar surface of the capitate near its centre. Because of the scaphoid attachment it is often called the radioscaphocapitate ligament.
Just ulnar to it lies the long radiolunate ligament, which runs from the radius to the lunate. Distally the two diverge, leaving a weak area of capsule without ligament in front of the joint between capitate and lunate, known as the space of Poirier. The radiocapitate ligament also forms the radial arm of the palmar arcuate ligament, a V-shaped arrangement whose ulnar arm comes from the triquetrum and whose two arms meet on the capitate.
The scaphoid turns around this ligament as around a sling as the wrist flexes and extends, and the ligament helps stop the carpus sliding towards the ulna on the sloping surface of the radius. In perilunate dislocation the tear runs through the space of Poirier, and the lunate itself may be pushed out through it, while the radiocapitate ligament usually stays intact. In operations on the radial styloid, removing too much bone can detach the ligament and allow the carpus to drift towards the ulna.
Attachments and function
- Attaches from
- Palmar surface of the radial styloid process.
- Attaches to
- Palmar surface of the capitate near its centre, with some fibres to the waist of the scaphoid.
- Function
- Supports the waist of the scaphoid as a sling, steadies the capitate and helps prevent ulnar translation of the carpus on the radius.
- 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
- Branches of the palmar carpal arch, fed by the radial and ulnar arteries.
Anthromica
See the radiocapitate 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.
