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

Background: The radiographic characteristics and treatment of radiocarpal d islocation are not well defined. There have been only two reported series o f more than eight patients. Thus, there are many questions concerning treat ment 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 radiocar pal dislocation and an associated fracture of the radial styloid process th at involved more than one-third of the width of the scaphoid fossa. A retro spective review and a clinical evaluation were performed. Results: From 1975 to 1998, we observed twenty-seven cases of radiocarpal d islocation. Four were displaced volarly, and twenty-three were displaced do rsally. Fourteen patients presented with associated lesions. Four patients were treated with closed reduction and immobilization in a plaster cast; fi ve, with percutaneous Kirschner wire fixation and cast immobilization; and two, with an external fixator. Eleven patients had open reduction with Kirs chner 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 o f 26.8 months, pronation averaged 76 degrees; supination, 66 degrees; wrist flexion, 54 degrees; wrist extension, 54"; radial inclination, 15 degrees; and ulnar inclination, 18 degrees. The average grip strength was 27 kg. Gr oup 2 included twenty patients. Only thirteen, with dorsal dislocation, wer e evaluated at the time of follow-up, which averaged fifty-one months. At t hat time, six reported no pain; four, slight pain; and two, moderate pain. Pronation averaged 63 degrees; supination, 76 degrees; wrist flexion, 51 de grees; wrist extension, 56 degrees; radial inclination, 21 degrees; and uln ar inclination, 39 degrees. Grip strength averaged 38 kg. Seven patients ha d complications. Conclusions: On the basis of our experience and a review of the literature, we believe that patients with pure radiocarpal dislocation or with radioca rpal dislocation with a fracture of the tip of the radial styloid process s hould be treated with reattachment of the ligaments through a volar approac h. In patients with radiocarpal dislocation and a fracture of the radial st yloid process that involves more than one-third of the width of the scaphoi d fossa, the ligaments are still attached to the radial fragment. We believ e that in this group of patients, exact articular reduction should be perfo rmed through a dorsal approach. Additional studies are needed to support th ese hypotheses.