Bilateral wrist computed tomography (CT) was performed in 30 patients
with suspected unilateral distal radioulnar joint (DRUJ) subluxation t
o evaluate dynamic DRUJ CT scanning with a straight elbow. Five CT cri
teria for diagnosing dorsovolar subluxation were examined, Maximum act
ive supination and pronation on a conventional scanning table yielded
satisfactory rotation (mean +/- SD, 119 degrees +/- 29 degrees) at the
DRUJ, thus permitting a dynamic diagnosis of DRUJ subluxation, The ra
dioulnar line method and the congruity method frequently yielded false
positive results compared with bilateral diagnosis and were unreliabl
e. Modifications of these two methods achieved sensitivity and specifi
city comparable to the epicenter method. We recommend the modified rad
ioulnar line method for diagnosing dorsovolar subluxation using unilat
eral CT because of its excellent sensitivity and specificity combined
with ease of technique.