DISI
Pronunciation: DIH-see
Also written as: DISI — Dorsal intercalated segment instability
Dorsal intercalated segment instability - a wrist instability pattern where the lunate bone tilts backward relative to the radius.
Full Definition
Dorsal intercalated segment instability (DISI) is a specific pattern of carpal instability characterized by dorsal tilting of the lunate bone, typically resulting from scapholunate ligament injury. In this condition, the scapholunate angle exceeds 70 degrees on lateral radiographs, and the lunate appears tilted toward the dorsal aspect of the wrist. DISI represents a progressive carpal collapse pattern that can lead to degenerative arthritis if left untreated. This condition is commonly associated with scapholunate advanced collapse (SLAC) wrist and requires careful radiographic analysis for proper diagnosis and staging.
Usage
Usage note: Always distinguish from VISI (volar intercalated segment instability) which shows opposite tilting pattern.
In Context
- "Lateral wrist radiographs demonstrated classic DISI pattern with increased scapholunate angle." — Imaging interpretation
- "The patient developed progressive DISI deformity following untreated scapholunate ligament injury." — Follow-up examination note