Overview
The distal radioulnar joint is a synovial pivot joint located proximal to the wrist joint.
Surfaces
- Articular surface of the ulnar
- Ulnar notch on the medial surface of the distal radius
- Articular disc
- Part of the triangular fibrocartilage complex
- Binds the radius and ulna together, and holds them together during movement at the joint.
- Separates the distal radioulnar joint from the wrist joint.
Movements
The ulnar notch of the radius slides anteriorly over the head of the ulnar during pronation and supination.
- Pronation: Produced by the pronator quadratus and pronator teres
- Supination: Produced by the supinator and biceps brachii
Ligaments
- Anterior and posterior radioulnar ligaments
- Major stabilisers of the distal radioulnar joint
- Formed by the proximal condensations of the triangular fibrocartilage complex
- Arise from anterior and posterior medial borders of distal radius, insert into ulnar styloid and fovea, anchoring the triangular fibrocartilage complex
- Interosseous membrane
Arterial Supply
- Anterior interosseous arteries – branch of the common interosseous artery, derived from the ulnar artery
- Posterior interosseous arteries – branch of the common interosseous artery, derived from the ulnar artery
Innervation
- Anterior interosseous nerve (branch of the median nerve)
- Posterior interosseous nerve (branch of the radial nerve)
Anatomical Variants
- Os triangulare
- Lunula
- Persistent ulnar styloid ossicle