Distal Radioulnar Joint Subluxation following Distal Radius Fracture

The aim of this study was to assess whether some patients had clear distalradioulnar joint (DRUJ) subluxation at radiological follow-up following an extra-articular distal radius fracture testing the null hypothesis that there would be no cases of ulnar head subluxation.

We reviewed wrist radiographs of 192 consecutive, extra-articular (metaphyseal) distal radius fractures in 190 adults (13 men and 179 women) who presented to our hospital. We looked at the fracture patterns based upon the direction of the fractures on the postero-anterior (PA) and lateral radiographs, the location of the ulnar side of the distal radius fracture in relation to the DRUJ and the presence or absence of an ulnar styloid fracture. We also recorded patient demographics. We looked at the alignment of the ulnar head relative to the distal radius on the lateral radiographs and any mal-alignment or increased gap in the DRUJ on the PA radiographs. We recorded patient treatment.

In 14 patients there were no or inadequate longer-term radiographs. Of the remaining 178 distal radius fractures 21 (12%) had ulnar head subluxation. In ten cases the ulnar head subluxed dorsally by 25% subluxation in seven cases and 50% in three cases. In 11 cases the ulnar head subluxed volarly, by 25% in nine and 50% in three. In five cases with DRUJ subluxation there was an increased gap on the PA radiograph; in two the ulnar subluxation was dorsal and in three it was volar. was no increased association with fracture pattern or treatment.

The study further confirms that there is a continuum of instability from mild (typically minimally or asymptomatic) DRUJ instability through to acute subluxation and even in some cases DRUJ dislocation with an intermediate stage those patients with persistent (fixed or static rather than dynamic) DRUJ subluxation. The clinical significance is unclear; future studies should consider DRUJ subluxation as a possible parameter affecting outcome.