Carpal Instability Adaptive in Distal Radius Malunions

Malunion is the most common complication following treatment of distal radius fractures. Distal radius malunion can lead to changes in carpal alignment as a result of adaptive responses to changes in the articular contact. This is known as carpal instability adaptive (CIA). Type 1 is midcarpal instability where the lunate is tilted dorsally in line with the dorsally angulated distal radius, and flexion of the capitate, leading to a zigzag deformity of the wrist. Type 2 is dorsal translation of the carpus in relation to the distal radius. Patients with symptomatic CIA can benefit from corrective osteotomy with reliable correction of the distal radius radiographic parameters, as well as correction of the carpal malalignment with restoration of radiolunate and capitolunate alignment and capitate shift.