Presentation
High impact fall onto right hand. Unable to fully extend elbow.
Patient Data
Displaced elbow joint fat pads in the context of trauma indicate hemarthrosis, in this case due to subtle radial head/neck fracture.
Dorsal displacement of the distal ulna indicates distal radioulnar joint (DRUJ) dislocation.
Case Discussion
In this example of Essex-Lopresti injury the DRUJ dislocation is obvious. More commonly the radial head injury is easily recognized but the DRUJ dislocation and accompanying rupture of the interosseous membrane and ligament are overlooked. These structures transmit force from the distal radius to the proximal ulna providing longitudinal forearm stability and preventing proximal radial migration.
In cases where the radial head fracture is comminuted and treated by excision, the instability is exacerbated.
High index of suspicion and a good lateral view of the wrist in pronation aid detection.