[Differential anterior interosseous nerve syndrome diagnosis].

The differential diagnosis of the rupture of flexor pollicis longus tendon and profundus tendon to index finger to the interosseus anterior nerve syndrome can be difficult and can lead to misinterpretation of the clinical impression. Two cases are reported to demonstrate this problem. In the first case a spontaneous rupture of flexor pollicis longus was found, when first an interosseus anterior nerve syndrome was suspected. In a second case surgical exploration of flexor pollicis longus tendon and profundus tendon to index finger was done on the assumption of a rupture, that revealed intact tendons. In a second operation neurolysis of the interosseus anterior nerve was carried out with full recovery of flexion of the thumb and index finger.