Ulnar variance as a predictor of persistent instability following Galeazzi fracture-dislocations

Abstract

BackgroundWe investigated the radiographic parameters that may predict distal radial ulnar joint (DRUJ) instability in surgically treated radial shaft fractures. In our clinical experience, there are no previously reported radiographic parameters that are universally predictive of DRUJ instability following radial shaft fracture.Materials and methodsFifty consecutive patients, ages 20–79 years, with unilateral radial shaft fractures and possible associated DRUJ injury were retrospectively identified over a 5-year period. Distance from radial carpal joint (RCJ) to fracture proportional to radial shaft length, ulnar variance, and ulnar styloid fractures were correlated with DRUJ instability after surgical treatment.ResultsTwenty patients had persistent DRUJ incongruence/instability following fracture fixation. As a proportion of radial length, the distance from the RCJ to the fracture line did not significantly differ between those with persistent DRUJ instability and those without (p = 0.34). The average initial ulnar variance was 5.5 mm (range 2–12 mm, SD = 3.2) in patients with DRUJ instability and 3.8 mm (range 0–11 mm, SD = 3.5) in patients without. Only 4/20 patients (20 %) with DRUJ instability had normal ulnar variance (−2 to +2 mm) versus 15/30 (50 %) patients without (p = 0.041).ConclusionIn the setting of a radial shaft fracture, ulnar variance greater or less than 2 mm was associated with a greater likelihood of DRUJ incongruence/instability following fracture fixation.

A Case of Bilateral Galeazzi Fracture-Dislocations

“…Tsismenakis T and Tornetta P [ 11 ] on the contrary, reported that the radiographic parameters of >5 mm shortening and fractures within 7.5 cm of the joint are not reliable predictors of instability as their positive predictive values were 29% and 19% in respect; the presence of an ulnar styloid fracture may be more helpful (4/7 such cases had an instability). Takemoto R et al [ 12 ] reported that ulnar variance, rather than the absolute distance between the DRUJ and the fracture, is the most reliable predictor of post-fixation persistent DRUJ instability; for each 1 mm of variance away from neutral, there was a 26 % increase in the odds of having DRUJ instability with a 95% CI. In rare instances, the DRUJ joint remains irreducible after fixation of the radial shaft fracture.…”

Distal Radioulnar Joint Instability: Assessment of Three Intraoperative Radiographic Stress Tests

“…Multiple provocative maneuvers and preoperative radiographic parameters have been demonstrated to have high sensitivity for detecting DRUJ instability. [10][11][12][13][14][15][16][17][18][19] These include the RU stress test (also known as the piano key or shuck tests), ulno-carpal stress tests, and the ballottement test but are limited secondary to their subjective assessment of laxity 1,3,5 with low inter-rater reliability. 20 Moriya and colleagues examined the ability of these tests to detect the effect of TFCC tears on the DRUJ stability.…”

Radial shaft fracture obliquity as a predictor of distal radioulnar joint instability

“…After surgery, all patients deemed having DRUJ instability were immobilized for 6 weeks before initiating therapy. Patients were assessed as having persistent DRUJ instability if there was dorsal subluxation of the ulna on the lateral radiographs of the wrist, difference in laxity compared with the contralateral side as determined by the treating surgeon, magnetic resonance imaging evidence of a TFCC injury, or a dorsally prominent ulnar head in the setting of decreased supination (Takemoto et al., 2014).…”

“…Several radiographic methods of diagnosis have been used to evaluate DRUJ instability in radial shaft fractures. These include radial shortening greater than 5 mm (Moore et al., 1985; Schneiderman et al., 1993), a fracture line within 7.5 cm of the lunate fossa (Rettig and Raskin, 2001; Tsismenakis and Tornetta, 2016), ulna variance of greater than 2 mm (Takemoto et al., 2014), and ulna styloid fractures (Giannoulis and Sotereanos, 2007; Tsismenakis and Tornetta, 2016).…”