Distal radioulnar articulation

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== Distal Radioulnar Articulation ==

The distal radioulnar articulation is a joint located between the distal ends of the radius and ulna bones in the forearm. This joint plays a crucial role in the pronation and supination movements of the forearm, allowing the hand to rotate so that the palm can face up or down.

Anatomy

The distal radioulnar articulation is a type of synovial joint, specifically a pivot joint. It is formed by the head of the ulna and the ulnar notch of the radius. The joint is enclosed by a fibrous capsule and is supported by several important ligaments:

• The palmar radioulnar ligament, which extends from the anterior margin of the ulnar notch of the radius to the anterior surface of the head of the ulna.
• The dorsal radioulnar ligament, which extends from the posterior margin of the ulnar notch of the radius to the posterior surface of the head of the ulna.

Function

The primary function of the distal radioulnar articulation is to facilitate the rotational movements of the forearm. During pronation, the radius crosses over the ulna, and during supination, the radius and ulna are parallel. This joint, along with the proximal radioulnar articulation, allows for the full range of rotational motion.

Clinical Significance

Injuries or conditions affecting the distal radioulnar articulation can significantly impair forearm and wrist function. Common issues include:

• Distal radioulnar joint instability, which can result from trauma or ligamentous injury.
• Arthritis, which can cause pain and limited motion in the joint.
• Fractures of the distal radius or ulna, which can disrupt the normal function of the joint.

Related Structures

The distal radioulnar articulation is closely associated with other structures in the forearm and wrist, including:

• The triangular fibrocartilage complex (TFCC), which provides additional support and stability to the joint.
• The interosseous membrane of forearm, which connects the radius and ulna along their lengths and helps distribute forces between the two bones.

See Also

• Proximal radioulnar articulation
• Radius (bone)
• Ulna
• Pronation
• Supination
• Triangular fibrocartilage complex