Classification and management of carpal dislocations.

A classification and plan of management for carpal dislocations are presented, based upon the following basic premises: perilunate and lunate dislocations are different stages of the same injury and are therefore managed identically; displacement may be either dorsal or volar; anatomic restoration of the 3 key elements (scaphoid, lunate, and capitate) is essential. Following initial closed reduction, rotary subluxation of the scaphoid and intercalary segment instability must be specifically looked for and corrected in the patient with perilunate or lunate dislocation without fracture of the scaphoid. In transcaphoid perilunate dislocation, anatomic reduction of the scaphoid fracture and maintenance of that reduction is necessary to prevent nonunion of the fracture and/or late dorsiflexion instability of the carpus. As with all ligamentous injuries, early diagnosis and treatment are essential. Failure to obtain or maintain anatomic position by closed methods is an indication for open reduction and internal fixation. Combined dorsal and volar approaches are recommended for perilunate and lunate dislocations. In some cases of transscaphoid perilunate dislocation, a limited Russe approach to stabilize the scaphoid fracture may be sufficient. Frequent concomitant injuries include median nerve damage, osteochondral fractures of the carpal bones, and fracture of the radial styloid. Isolated rotary subluxation of the scaphoid without perilunate dislocation is a more subtle injury which may require special radiographic views, and also demands early diagnosis and treatment.