[Narrowing of the third extensor tendon compartment in minimal displaced distal radius fractures with impending rupture of the EPL tendon].

Delayed ruptures of the extensor pollicis longus tendon (EPL) occur in about 0.7 percent following undisplaced distal radius fractures. Two possible mechanisms are mainly discussed in the literature: A mechanical irritation of the tendon caused by a sharp edge of the fractured bone and a direct microvascular compromise of the poorly vascularized tendon. In undisplaced fractures, however, a mechanical irritation seems less likely. In the cases here described we were able to demonstrate a fragment displacement in the area of Lister's tubercle suspected by the native X-ray and further evaluated by a CT scan. The use of CT scans even in minor displaced distal radius fractures involving Lister's tubercle may demonstrate a direct contact of the EPL tendon with a sharp edge of this fractured bone and make adequate surgery possible.