Traumatic Ulnar Translocation of the Carpus

Ulnar translocation of the carpus is a form of wrist instability where the entire carpus translates medially along the inclined plane of the distal radius. This pattern of instability has been well recognized in patients with rheumatoid arthritis as a result of articular erosions and attenuation of wrist ligaments. In contrast, ulnar translocation of the carpus following trauma is seemingly rare, with published accounts limited to case reports and small case series. The radiographic features of traumatic ulnocarpal translocation have been described and the instability pattern has been reproduced in cadaveric models. However, the recognition of radiocarpal malalignment may be unintentionally missed or delayed owing due to the uncommon nature of the this injury. The investigators present 11 cases of posttraumatic ulnar translocation of the carpus and review criteria for early recognition of the injury and the results following varying treatment methods.