Predictors of Distal Radioulnar Joint Instability in Distal Radius Fractures

Abstract

A radiographic finding of a normalized DRUJ gap on posteroanterior views was the most important predictor to identify DRUJ instability accompanying unstable distal radius fractures. The relative risk of instability increases by 50% when the ratio of DRUJ widening increases by 1%.

Clinical and Radiographic Factors Associated With Distal Radioulnar Joint Instability in Distal Radius Fractures

“…However, well-designed studies consistently denied the association between symptomatic DRUJ instability and the ulnar styloid fracture in distal radius fractures [15,35,39,44]. Recently widening of the DRUJ gap was identified as an independent risk factor for DRUJ instability in distal radius fractures [8]. In this study, we tried to identify clinical and radiographic factors associated with DRUJ instability in distal radius fractures.…”

“…Few studies investigate the factors associated with DRUJ instability in the setting of distal radius fractures. Lindau and Aspenberg found no radiographic parameters associated with DRUJ instability [24], but Fujitani et al [8] reported that widening of the DRUJ gap was the only risk factor for DRUJ instability. These discrepancies between studies arise from differences in study setting.…”

“…The clinical assessment methods we used also were used in multiple previous studies [8,16,26,36,42]. Furthermore, physical evaluation methods correlate with intraoperative findings better than CT and show higher interobserver reliability in the assessment of DRUJ instability [8,16,36,42]. Second, we could not use more advanced statistical methods like logistic regression analysis because the number of observations available as a dependent variable was insufficient.…”

“…First, methods of measurement for radiographic parameters are different. Fujitani et al measured ulnar variance as a distance from the volar margin of the sigmoid notch to the tip of the ulnar head, regardless of the direction of fracture displacement [8]. This method is likely to give an underestimation of ulnar variance, because the dorsal margin of the sigmoid notch is more proximally located than the volar one in fractures with dorsal tilt greater than 0°.…”

“…In addition, factors other than ulnar styloid fractures have been investigated only rarely in distal radius fractures for DRUJ instability. Recently widening of the DRUJ gap was identified as a risk factor for DRUJ instability [8].…”