Classification and treatment of ulnar styloid nonunion.

Symptomatic nonunion of the ulnar styloid is an uncommon problem that is usually best treated by simple excision of the ulnar styloid fragment. Two types of nonunion of the ulnar styloid are described here on an anatomic basis, and their treatment differs. Type 1 is defined as a nonunion associated with a stable distal radioulnar joint. Type 2 is defined as a nonunion associated with subluxation of the distal radioulnar joint. The postoperative follow-up period for the two types ranged from 4 months to 13 years, with a mean of 5 years 2 months. Eleven type 1 wrists were treated with excision of the fragment, and all patients had satisfactory relief of pain. Nine type 2 wrists required restoration of the anatomy of the traingular fibrocartilage complex. Three of these had large fragments that were treated by open reduction and internal fixation. All three patients were completely relieved of their discomfort. Six other patients underwent excision of the fragment and repair of the triangular fibrocartilage complex to the distal ulna. This group had four excellent, one good, and one fair result. If the distal radioulnar joint is stable on presentation or if its stability is restored, then long-term relief of pain from ulnar styloid nonunion is achieved by treatment of the nonunion.