Isolated rotatory subluxation of the carpal navicular.

Rotatory subluxation of the carpal navicular can cause wrist pain and may lead to severe and disabling degenerative changes. Correct diagnosis depends on recognition of the typical roentgenographic signs. Sixteen patients with neither rheumatoid arthritis nor a lunate or a perilunate dislocation had rotatory subluxation in nineteen wrists. Many had only vague or remote histories of trauma. There were a navicular-lunate gap in all nineteen wrists, and foreshortening of the navicular in sixteen wrists, usually with a ring sign. The abnormalities were best demonstrated on well-centered posteroanterior roentgenograms of the wrist with the hand in slight radial deviation. In two patients, wrist arthrography demonstrated abnormal communication between radiocarpal and intercarpal joints.