Acute true trigger wrist following partial extensor carpi radialis brevis tendon rupture.

Triggering in association with movements of the wrist or "true trigger wrist" due to the extensor tendon is rare. There are only few case reports in literature, but none were associated with the acute partial tendon rupture. We present a case of true trigger wrist originating from partial rupture of extensor carpi radialis brevis tendon (ECRB). In contrast to the other reports, the interval between an initial injury and development of triggering was short because the partial tendon rupture was bunching and forming a nodule. The triggering was attributed to the snapping of the nodule under the extensor pollicis longus tendon (EPL).