Radial styloid process

The radial styloid process is a projection of bone on the lateral surface of the distal radius bone.

The radial styloid process is found on the lateral surface of the distal radius bone. It extends obliquely downward into a strong, conical projection. The tendon of the brachioradialis attaches at its base. The radial collateral ligament of the wrist attaches at its apex. The lateral surface is marked by a flat groove for the tendons of the abductor pollicis longus and extensor pollicis brevis.

Breakage of the radius at the radial styloid is known as a Chauffeur's fracture; it is typically caused by compression of the scaphoid bone of the hand against the styloid.

De Quervain syndrome causes pain over the styloid process of the radius. This is due to the passage of the inflamed extensor pollicis brevis tendon and abductor pollicis longus tendon around it.

The styloid process of the radius is a useful landmark during arthroscopic resection of the scaphoid bone.

A prominent styloid process of the radius makes applying a wrist splint more difficult.

This article incorporates text in the public domain from page 220 of the 20th edition of Gray's Anatomy (1918)

• Anatomy image: skel/hand2 at Human Anatomy Lecture (Biology 129), Pennsylvania State University