Radiographic observation of the scaphoid shift test.

The movements of the carpal bones during the scaphoid shift test were evaluated radiographically in 60 wrists. The clinical results were graded according to the degree of subluxation of the scaphoid and pain on the dorsum of the wrist. Lateral radiographs at rest and under stress were taken and the relative movements of the scaphoid with respect to the radius and lunate, and the rotation of the scaphoid and lunate were calculated. Dorsal displacement of the scaphoid with respect to the radius was significantly associated with the clinical grade of subluxation. There was correlation between the amount of pain and the displacement of the scaphoid from the lunate, but not from the radius. The wrists with a painful shift test had greater relative displacement of the scaphoid from the lunate than those with painless subluxation. These observations support the view that pain associated with subluxation of the scaphoid during the shift test is a significant finding, and that radiographic analysis of the test may confirm a positive result when dynamic scaphoid instability is suspected.