Wrist Dislocation

Excerpt

Wrist dislocations can occur at the radiocarpal joint, the midcarpal joint, the distal radioulnar joint or may represent a combination of these injuries in severe trauma. Carpal instability in the form of lunate and perilunate dislocations are uncommon injuries but can be frequently missed. Distal radioulnar joint dislocations are most commonly associated with distal third radius fractures. This injury complex is called a Galeazzi fracture-dislocation. Radiocarpal dislocations are rare injuries accounting for 0.2% to 2.7% of wrist injuries.

Carpal instability represents about 7% to 10% of all reported injuries to the carpal bones. The carpal bones are held together by intrinsic ligaments and extrinsic ligaments connect the carpus to the radio- and ulnocarpal joints. Disruption of these ligaments results in wrist instability. Carpal instability can be classified as carpal instability dissociative, carpal instability non-dissociative (CIND), maladaptive carpal instability, and carpal instability complex. Carpal instability dissociative occurs within a carpal row. A common example is a scapholunate injury resulting in a dorsal intercalated segment instability (DISI) complex. In contrast, CIND is less common and occurs due to instability between carpal rows.

The majority of carpal instability is centered around the lunate, given its location in the middle of the wrist. Injuries progress sequentially depending on the severity, from scapholunate instability to lunate dislocation. Perilunate dislocations and lunate dislocations are high-energy wrist injuries involving falls from height, motor vehicle collisions, or athletic injuries. While not common, these injuries can result in a multitude of complications. Despite the great force typically required, up to 25% of these injuries are missed clinically and radiographically. Perilunate and lunate dislocations with an associated fracture are twice as prevalent as those without fracture.