Northwestern University Feinberg School of Medicine

Orthopedic Teaching

Wrist Case 3 Background

Ulnar Styloid Fractures


There are two types of ulnar styloid fractures: type I is a fracture of the tip of the styloid, while type II is a fracture through the base of the ulnar styloid. The Triangular Fibrocartilage Complex (TFCC) is the major stabilizer of the distal radio-ulnar joint (DRUJ) and attaches at the base of the ulnar styloid. Therefore, type I fractures (distal to insertion) are stable fractures whereas type II (proximal to insertion) are often associated with instability of the DRUJ.