Transstyloid perilunate carpal dislocation

Abstract

A 38-year-old motorcyclist was thrown over the Discussion handlebars in a traffic accident. He did not lose consciousness, but he had no immediate recollection of having injured his wrist. While in attendance in our hospital about 45 minutes after the injury, he complained of pain and stiffness of his dominant right wrist, where he had a dinner-fork deformity. Sensation was unimpaired, and there were no circulatory complications. He had no other injuries. A radiographic examination showed (Figure 1) a dorsal dislocation of the carpus at the wrist, with fractures of the radial and ulnar styloid processes. No carpal fracture was identified. Using intravenous regional analgesia, the dislocation was easily reduced by applying simple longitudinal traction to the wrist, and radiographs confirmed the reduction. The wrist was immobilized in an above-theelbow plaster cast for 5 weeks. The patient was A transstyloid perilunate dislocation of the carpus in which the h a t e retains its normal relation with the radius while the remaining carpus dislocates dorsally is well described (Russell 1949, Green and O’Brien 1978). However, it is distinctly unusual for the lunate to dislocate along with the rest of the carpus. A similar injury has been described by Weiss et a]. (1970) in cadaver wrists by applying longitudinal compression and torsional forces to a hyperextended, pronated wrist. A dorsal radiocarpal dislocation without a fracture was described by Wagner (1956). No other reports of this condition were found in the published English language literature of the past 30 years.