ulnar drift

ulnar drift [L, ulna, elbow; AS, drifan, to drive] , a change in the metacarpophalangeal joints because of rheumatoid arthritis and chronic synovitis. The long axes of the fingers make an angle with the long axis of the wrist so that the fingers are deviated to the ulnar side of the hand. Also called ulnar deviation.

Ulnar drift (Finkbeiner, Ursell, and Davis, 2009)
Ulnar drift (Lewis et al, 2011)