Dorsal intercalated segment instability (DISI) is a deformity of the

wrist In human anatomy, the wrist is variously defined as (1) the Carpal bones, carpus or carpal bones, the complex of eight bones forming the proximal skeletal segment of the hand; "The wrist contains eight bones, roughly aligned in two rows, known ...

where the

lunate bone The lunate bone (semilunar bone) is a carpal bone in the human hand. It is distinguished by its deep concavity and crescentic outline. It is situated in the center of the proximal row carpal bones, which lie between the ulna and radius and the han ...

angulates to the dorsal side of the hand.

Causes

The main causes of DISI are: *Wrist trauma, with or without a fracture **

Scaphoid fracture A scaphoid fracture is a break of the scaphoid bone in the wrist. Symptoms generally includes pain at the base of the thumb which is worse with use of the hand. The anatomic snuffbox is generally tender and swelling may occur. Complications may ...

: bony DISI **

Distal radius fracture A distal radius fracture, also known as wrist fracture, is a break of the part of the radius bone which is close to the wrist. Symptoms include pain, bruising, and rapid-onset swelling. The ulna bone may also be broken. In younger people, thes ...

: compensatory DISI **

Malunion A malunion is when a fractured bone does not heal properly. Some ways that it shows is by having the bone being twisted, shorter, or bent. Malunions can occur by having the bones improperly aligned when immobilized, having the cast taken off to ...

of radius fracture: adaptive DISI *

Scapholunate ligament instability The scapholunate ligament is a ligament of the wrist. Rupture of the scapholunate ligament causes scapholunate instability, which, if untreated, will eventually cause a predictable pattern of wrist osteoarthritis called scapholunate advanced coll ...

: ligamentous DISI

References

{{reflist Orthopedics