Flexor digitorum superficialis lasso tendon transfer in isolated ulnar nerve palsy: a functional evaluation.

Twelve patients (23 digits) with isolated ulnar nerve palsy underwent flexor digitorum superficialis lasso tendon transfers for correction of claw deformity, weakness, and asynchronous digital flexion. The average follow-up period from date of injury was 5 years (range, 2-11 years) and from surgery was 3 years (range, 15 months to 7 years). Transfers successfully corrected the claw deformity in 19 of the 23 digits. Three of the four failures occurred in the small finger. Two of the four failures had uncorrected preoperative proximal interphalangeal joint flexion contractures. In 9 of the 12 patients with pre- and postoperative grip strength measurements no significant improvement in grip strength was noted. While this procedure is effective and predictable in correcting deformity and restoring synchronous pattern of finger flexion, it should be used with caution in patients requiring an increase in grip strength.