Volar intercalated segment instability (VISI) is a type of instability involving the wrist. It is less often encountered than dorsal intercalated segment instability (DISI).
It presents in most cases with nonspecific wrist pain and a "clunking" on the ulnar deviation of the wrist.
VISI can occur because of a disruption of radiocarpal ligaments on the ulnar side of the wrist. The main ligaments involved in this instability are thought to be the ulnar half of the volar arcuate ligament and the lunotriquetral ligament . It may be static or dynamic.
The main radiographic features are a volar rotation of the lunate and dorsal rotation of the capitate and hamate.
Abnormal carpal angles are seen on any lateral or sagittal imaging of the wrist when the wrist is in a neutral position:
Treatment and prognosis
The mainstay of treatment is surgery, either by early reduction and casting with K-wires or by capitolunate fusion.