- radial fracture in distal 2 cm
- +/- ulnar styloid fracture
- dorsal displacement of distal fragment
- "silver-fork" deformity
Causes of Colles fracture:
Wrist fractures occur most often in a fall or in a motor vehicle accident, but any sufficiently strong force on the hand can break the wrist. The wrist can be broken from a sudden force pushing the hand backwards.
A strong force pushing the hand into the forearm can also cause a Colles fracture, which often involves a break of the radius bone near its end. There is a natural weak spot in the radius where it widens.
If the pieces don't lock back together like a jigsaw puzzle, the pull of the forearm muscles can pull the larger end over the smaller like a sleeve, and the bone can shorten like a collapsible drinking cup.
Wrist arthritis may occur following a distal radius fracture. This can be the result of cartilage injury at the time of the break, or wear and tear from changes in the joint alignment after the bone is healed.