The influence of wrist position on finger deviation in the rheumatoid hand. A clinical and radiological study.

Recently a new theory about the cause of ulnar deviation of the fingers in the rheumatoid hand has been suggested, in which the position of the wrist plays an important role (Shapiro 1968). Shapiro has suggested that ulnar phalangeal drift is part of the zigzag pattern which occurs when the carpus-metacarpus acts as an intercalated bone as in the biarticular system of Landsmeer (Landsmeer 1961). Shapiro’s theory was based on the examination of 100 rheumatoid hands. He correlated the radio-metacarpal angle with the metacarpo-phalangeal angle in hands where the wrist was movable. In order to exclude possible resultant errors we have studied fifty-six patients with sixty-nine arthrodesed wrists. Thirty-one of these (thirty-seven hands) were examined clinically and radiologically, and twenty-five (thirty-two hands) were assessed from the radiographs alone.