Congenital clasped thumb.

Congenital clasped thumb is a disorder characterized by flexion posture of the thumb secondary to extensor side underdevelopment, flexor side tightness, or both. Mild cases may be treated by splintage whereas more advanced cases require tendon transfer or a combination of tendon transfer and flexor side releases. Clasped thumb can be seen in conjunction with syndromes such as arthrogryposis and, in these cases, recognition of the abnormal anatomic structures is required to effect satisfactory reconstruction.