Dorsal transscaphoid transtriquetral perilunate dislocation with pseudoarthrosis of the scaphoidy.

All perilunate fracture-dislocations combine ligament ruptures, bone avulsions, and fractures in a variety of clinical forms. Two mechanisms of the injury may result in a carpal dislocation: direct and indirect. Most dorsal perilunate dislocations are the result of an indirect mechanism of injury, usually consisting of an extreme extension of the wrist joint, associated with variable degree ulnar deviation and radiocarpal or midcarpal supination. Many factors may explain the occurrence of one or another type of injury: age, differences in direction and magnitude of the deforming forces, and differences in position of the wrist joint at the time of impact.