Ulnar styloid process

The styloid process of the ulna is found at distal end of the forearm, and projects from the medial and back part of the bone; it descends a little lower than the head, and its rounded end affords attachment to the ulnar collateral ligament of the wrist.

The head is separated from the styloid process by a depression for the attachment of the apex of the triangular articular disk, and behind, by a shallow groove for the tendon of the extensor carpi ulnaris muscle.

Ulnar styloid fractures seldom require treatment when they occur in association with a distal radius fracture. The major exception is when the joint between these bones, the distal radioulnar joint (or DRUJ), is unstable. When the DRUJ is unstable, the ulnar styloid may require independent treatment.