Capitate-lunate instability: recognition by manipulation under fluoroscopy

Abstract
Videotape fluoroscopy was used to diagnose a previously undescribed carpal dissociation, the capitate lunate instability pattern. In eight patients with midcarpal pain and clicking, the examiner simultaneously applied pressure to the scaphoid tuberosity while applying longitudinal traction and flexion to the wrist under fluoroscopic control. This maneuver revealed dorsal subluxation of the proximal carpal row and capitate lunate subluxation in each of the eight patients. Plain radiography and arthrography were not helpful in the diagnosis. All eight cases were managed conservatively. Videotape fluoroscopy is the best radiologic method of diagnosing capitate-lunate instability.