The dorsal horizon view: detecting screw protrusion at the distal radius

Extensor tendon injury after osteosynthesis of distal radius fractures is a well-documented complication. It has been shown to be associated with screw protrusion through the dorsal cortex, or plunging of the drill bit into the overlying tendon. It is difficult to determine screw length and protrusion using the standard anteroposterior and lateral intraoperative fluoroscopic images because of the triangular configuration of the distal radius and Lister tubercle. In fractures with a coronal split, it may be necessary to lag the dorsal fragment, necessitating longer screws and risking screw protrusion beyond the dorsal cortex. For these fractures, we use a radiographic view aimed along the long axis of the radius to detect screw protrusion.

This was a retrospective case series involving 15 distal radius fractures. To obtain the dorsal horizon view, the wrist is hyperflexed and the beam of the image intensifier is aimed along the long axis of the radius. We evaluated 15 distal radius fractures with a coronal split component, where the dorsal horizon view was used to detect dorsal cortex screw protrusion. This view was used intraoperatively following the use of the standard views. We evaluated records and imaging to ascertain whether the use of this radiograph led to a change in intraoperative screw selection.

Of the 15 cases, we changed screw selection as a result of the additional view in 4 patients. In 3 of these cases, the screw length was long, which was not apparent on standard intraoperative fluoroscopic views.

The use of the dorsal horizon view is a useful adjunct to prevent screw protrusion beyond the dorsal cortex when performing osteosynthesis of the distal radius.