Tendon transfers for ulnar nerve palsy. Evaluation of results and practical treatment considerations

Tendon transfers for correction of clawing deformity in ulnar nerve palsy are only consistently successful in young ligamentously lax individuals. Correction of deformity is most inconsistent in the intrinsically stiff hands of older individuals. Correction of clawing is more difficult in the little finger than in the ring finger. While use of the flexor digitorum superficialis for intrinsic transfer simply corrects clawing deformity and restores synchronous finger flexion, grip strength will be further decreased by approximately 21 percent, and total active range of motion by 7 percent. Correction is best achieved by transfer of a wrist motor with tendon graft into index, middle, ring, and little digits, despite limitation of clawing to the ring and little digits. Pinch should be augmented by metacarpophalangeal joint fusion rather than by interphalangeal joint fusion. When combined with extensor carpi radialis brevis adductor plasty, pinch strength can be doubled.