Dorsal intercalated segment instability explained

Dorsal intercalated segment instability (DISI) is a deformity of the wrist where the lunate bone angulates to the dorsal side of the hand.^{[1] [2]}

Causes

The main cause of DISI is^[3] wrist trauma, with or without a fracture:

• Scaphoid fracture

bony DISI

• Distal radius fracture

compensatory DISI

• Malunion of radius fracture: adaptive DISI
• Scapholunate ligament instability

ligamentous DISI

Notes and References

1. Shah. CM. Stern PJ . Scapholunate advanced collapse (SLAC) and scaphoid nonunion advanced collapse (SNAC) wrist arthritis. Current Reviews in Musculoskeletal Medicine. 2013. 6. 9–17. 23325545. 10.1007/s12178-012-9149-4. 1. 3702758.
2. Omori. S. Moritomo, H . Omokawa, S . Murase, T . Sugamoto, K . Yoshikawa, H . In vivo 3-dimensional analysis of dorsal intercalated segment instability deformity secondary to scapholunate dissociation: a preliminary report.. The Journal of Hand Surgery. July 2013. 38. 7. 1346–55. 23790423. 10.1016/j.jhsa.2013.04.004.
3. Web site: Dorsal intercalated segment instability. Yair Glick and Yuranga Weerakkody. etal. Radiopaedia. 2018-01-26.