Clinical and experimental studies on the effect of extensor carpi radialis longus transfer in the rheumatoid hand.

Digital ulnar drift in the rheumatoid hand is a complex problem. The radial deformity of the wrist causes abnormal forces on the extrinsic flexor and extensor tendons which aggravate metacarpophalangeal ulnar drift. Analysis of the results of the transfer of the extensor carpi radialis longus to the extensor carpi ulnaris in 20 wrists showed that 13 of 20 had significant correction of the wrist deformity. The transferred tendon did not contract during active ulnar deviation. Laboratory studies of the transfer on cadaveric rheumatoid wrist models showed correction of the wrist deformity. The dorsal ulnar capsule was determined to be a stabilizer of wrist position, as evidenced by deformity after transection.