Radioscaphocapitate ligament
Ligamentum radioscaphocapitatum
A strong palmar wrist ligament running from the radial styloid across the waist of the scaphoid to the capitate.
At a glance
- English
- Radioscaphocapitate ligament
- Latin (TA2)
- Ligamentum radioscaphocapitatum
- System
- Ligament
- Region
- Hand
- Side
- Paired, left and right
About the radioscaphocapitate ligament
The radioscaphocapitate ligament is the most lateral and one of the strongest of the ligaments that make up the palmar radiocarpal ligament. It springs from the front of the radial styloid process and runs obliquely downwards and towards the ulnar side. On its way it crosses the palmar hollow at the waist of the scaphoid, where some of its fibres attach, and it ends on the centre of the palmar surface of the capitate.
Beside it, on its ulnar side, run the other palmar radiocarpal bands, the long and short radiolunate ligaments. Between the radioscaphocapitate and the long radiolunate there is a thin area of capsule over the joint between capitate and lunate, often called the space of Poirier. At the capitate the radioscaphocapitate meets fibres of the ulnocapitate ligament coming from the other side, and together they form an inverted V that cradles the head of the capitate.
In front, the ligament is covered by the capsule and by the tendons of flexor pollicis longus and flexor digitorum profundus in the carpal tunnel. Small vessels pass through openings in it to reach the carpal bones. Mechanically, it acts as a sling around the scaphoid waist, a fulcrum about which the scaphoid rotates as the wrist flexes and extends, and it resists the carpus sliding towards the ulna down the slope of the distal radius.
The ligament matters to wrist surgeons. If too much of the radial styloid is removed, its origin is lost and the carpus can drift towards the ulna. The weak capsular gap beside it is where the capitate escapes in perilunate dislocations, and repair of the palmar ligaments is part of treating these injuries.
Attachments and function
- Attaches from
- The palmar surface of the radial styloid process.
- Attaches to
- The palmar surface of the capitate, with some fibres attaching to the waist of the scaphoid on the way.
- Function
- Supports the scaphoid as a sling and pivot, stabilises the midcarpal joint and resists ulnar translation of the carpus.
Anthromica
See the radioscaphocapitate 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.
