The acutely injured wrist and its residuals.

Carpal injuries are confusing and treacherous. Understanding the mechanisms are important in diagnosis and treatment. The mechanisms of extension, intercarpal supination and ulnar deviation can lead to most of the fractures and dislocations of the carpus and distal radius. Internal fixation of some avulsion type fractures will stabilize the wrist. Most carpal fractures and dislocations occur in the vulnerable perilunar zone consisting of the trapezium scaphoid, the head of the capitate and the tail of the hamate and the lunar border of the triquetrum. Carpal injuries occur in 3 stages. They start on the radial side, progress to the central carpals and end on the ulnar side. Stress roentgenographic views obtained acutely can aid in determining the type of injury present and its stability. Chronic residuals include: articular damage, carpal collapse, and contractures, intercarpal, radiocarpal and radioulnarinstability and skeletal loss or defects.