Isolated flexor pollicis longus palsy in twin sisters treated by brachioradialis transfer.

Isolated paralysis of flexor pollicis longus is an uncommon variation of the anterior inter-osseous nerve compression syndrome. Two cases occurring in twin sisters were treated by brachioradialis tendon transfer when no recovery was evident after six months, with good results. Brachioradialis transfer is technically easy to perform, but complete mobilization of the tendon and muscle is necessary to achieve the desired excursion of the muscle-tendon unit.