The association between ulnar styloid fractures and distal radius fractures has been noted for many years, but its significance has not been conclusively shown. Frykman’s eponymous fracture classification implied that the presence of a distal ulnar styloid fracture meant a higher, more complex classification level, but did not provide guidance in terms of treatment. Recent depictions of the ligamentous attachments about the ulnar head have shown that most of the ligaments originate from the fovea and the base of the ulnar styloid; the styloid is usually devoid of major ligaments (1).

The oft-quoted Knirk and Jupiter (2) article noted that 31 of 43 intra-articular fractures of the distal radius had an associated ulnar styloid fracture. Of the 31 ulnar styloids, 20 developed nonunion; 9 of the 11 that healed had good to excellent results, whereas only 10 of the 20 nonunions had good to excellent results (2).

Why is this seemingly trivial fracture of the ulnar styloid, the distal aspect of which has no ligamentous attachments., historically led to such poor clinical results (3)? Perhaps the presence of the fracture itself signifies a more complex ligamentous injury on the ulnar side of the wrist. Perhaps its mere presence should alert the clinician to the possibility of distal radioulnar joint (DRUJ) instability, and the need to correct this problem if it exists at the time of repair of the distal radius fracture.

Open reduction internal fixation should not be performed in the face of grossly contaminated wounds. It should be used judiciously in the face of clean open fractures as long as there is adequate soft-tissue coverage. Osteoporotic bone is a relative contraindication. Techniques that do not depend on screw fixation may be more effective with osteoporotic bone.

Open reduction internal fixation requires the use of intraoperative radiography and consequently should not be undertaken without ready access to a fluoroscopy unit.

No clear definitive indications exist as to which ulnar styloid fractures should be repaired, but it is generally accepted that ulnar styloid fractures associated with DRUJ instability should be reduced and stabilized. Instability should be suspected if preoperative radiographs demonstrate a displaced sigmoid notch fracture involving the dorsal or palmar ridge (Fig. 29-1), or a markedly displaced ulnar styloid fracture (Fig. 29-2) (4).

Moore et al. (5) offered four radiographic signs of DRUJ capsule and triangular fibrocartilage complex (TFCC) rupture:

This suspicion for instability should prompt an examination of the unaffected wrist in neutral, pronation, and supination to judge the ligamentous integrity of the intact wrist preoperatively (5).

Evaluate stability of the DRUJ in the injured wrist by manipulating the distal ulna in a dorsal-volar direction in all positions of rotation (Fig. 29-5A, B) after stabilizing the distal radius fracture. Compare the fractured wrist with the uninvolved wrist. With obvious laxity, stabilize the DRUJ. The chosen technique will depend on the radiographic appearance, patient demographics, and equipment available, as well as the experience of the surgeon.

In recent years, newer more anatomic and rigid fixation systems have been introduced to address distal radius fractures. Frequently with these techniques, sigmoid notch fragments are successfully reduced and rigidly held, and radial height is restored. Both of these factors are likely to result in increased stability of the DRUJ after radius fixation alone. In some instances, the ulna styloid fragment is seen to fall back toward its anatomic position with these newer techniques (Figs. 29-6 and 29-7).