Distal Radioulnar Joint Stress Radiography for Detecting Radioulnar Ligament Injury

PurposeTo determine the reliability and efficacy of clenched-fist stress radiographs in patients with radioulnar ligament injury.MethodsWe examined 30 patients with chronic radioulnar ligament injury. These patients underwent stress radiography, which included clenched-fist posteroanterior (PA) views in forearm pronation and computed tomography in pronation. We measured distal radioulnar joint (DRUJ) gap distance and ulnar variance using clenched-fist PA views. We measured the radioulnar ratio with pronated computed tomography to quantify dorsal translation of the ulnar head. We analyzed these radiographic data and compared them between the injured and contralateral sides. We examined test-retest reliability and interobserver and intraobserver reliability using intraclass correlation coefficients as a measurement of the DRUJ gap distance in clenched-fist PA views.ResultsThe DRUJ gap distance observed with clenched-fist PA views in injured wrists was significantly greater than in the contralateral side. The DRUJ gap distance observed with stress radiography significantly correlated with the magnitude of the radioulnar ratio in forearm pronation. We found a significant test-retest reliability for measuring DRUJ gap distance using clenched-fist PA views, as well as a significant level of intraobserver and interobserver reliability.ConclusionsThe DRUJ gap distance observed with clenched-fist PA radiography in forearm pronation was a reliable parameter and may be useful for evaluating DRUJ instability.Type of study/level of evidenceDiagnostic II.