[Isolated palsy of the flexor pollicis longus in anterior interosseous nerve syndrome].

Anterior interosseous nerve palsy are relatively rare, specialy in traumatic cases. Two case of incomplete anterior interosseous nerve palsy with isolated total loss of function of flexor pollicis longus are reported. Partial palsy of the A.I.N. have been previously reported, but their mechanism is unclear. The incomplete anterior interosseous nerve palsy has to be known. They can be mistaken with tendon rupture, specialy in traumatic cases, and lead to unnecessary surgery.