About half of distal radius fractures occur in association with ulnar styloid fractures. The ulnar styloid is at the end of the other forearm bone, the ulna. While distal radius fractures usually require casting or surgery, the ulnar styloid is seldom addressed in treatment. Does a ulnar styloid fracture require treatment?
However, most distal radius fractures with associated ulnar styloid fractures occur without DRUJ instability. A recent study evaluated patients who had distal radius fractures, and found that their prognosis was not affected by the presence or absence of an ulnar styloid fracture.
Non-Union of Ulnar Styloid Fractures
This study also found that even if the ulnar styloid fracture was out of position (displaced), or if the ulnar styloid fracture did not heal (non-union), it did not affect the patient's prognosis. Again, this is all presuming that the DRUJ was stable.The results of this study would imply that routine surgical treatment of an ulnar styloid fracture (when occurring with a distal radius fracture) is not necessary. However, your doctor should evaluate your DRUJ for instability, and if that's found to be the case, your ulnar styloid fracture may need to be treated.
Source:
Pollack, P. "Styloid fractures may not affect outcomes of distal radius fractures." AAOS Now; Vol 4, No 1. January 2010.

