Radiocarpal dislocations: classification and proposal for treatment. A review of twenty-seven cases.

BACKGROUND

The radiographic characteristics and treatment of radiocarpal dislocation are not well defined. There have been only two reported series of more than eight patients. Thus, there are many questions concerning treatment and functional results.

METHODS

Two groups of patients were defined. Group 1 included all patients with pure radiocarpal dislocation and patients with only a fracture of the tip of the radial styloid process. Group 2 included patients with radiocarpal dislocation and an associated fracture of the radial styloid process that involved more than one-third of the width of the scaphoid fossa. A retrospective review and a clinical evaluation were performed.

RESULTS

From 1975 to 1998, we observed twenty-seven cases of radiocarpal dislocation. Four were displaced volarly, and twenty-three were displaced dorsally. Fourteen patients presented with associated lesions. Four patients were treated with closed reduction and immobilization in a plaster cast; five, with percutaneous Kirschner wire fixation and cast immobilization; and two, with an external fixator. Eleven patients had open reduction with Kirschner wire fixation and cast immobilization. The seven patients in Group 1 had a highly unstable injury, and four of the seven patients presented with ulnar translation of the carpus. At the time of follow-up, at an average of 26.8 months, pronation averaged 76 degrees; supination, 66 degrees; wrist flexion, 54 degrees; wrist extension, 54 degrees; radial inclination, 15 degrees; and ulnar inclination, 18 degrees. The average grip strength was 27 kg. Group 2 included twenty patients. Only thirteen, with dorsal dislocation, were evaluated at the time of follow-up, which averaged fifty-one months. At that time, six reported no pain; four, slight pain; and two, moderate pain. Pronation averaged 63 degrees; supination, 76 degrees; wrist flexion, 51 degrees; wrist extension, 56 degrees; radial inclination, 21 degrees; and ulnar inclination, 39 degrees. Grip strength averaged 38 kg. Seven patients had complications.

CONCLUSIONS

On the basis of our experience and a review of the literature, we believe that patients with pure radiocarpal dislocation or with radiocarpal dislocation with a fracture of the tip of the radial styloid process should be treated with reattachment of the ligaments through a volar approach. In patients with radiocarpal dislocation and a fracture of the radial styloid process that involves more than one-third of the width of the scaphoid fossa, the ligaments are still attached to the radial fragment. We believe that in this group of patients, exact articular reduction should be performed through a dorsal approach. Additional studies are needed to support these hypotheses.