Fracture of the distal radius

Hand and wrist are displaced dorsally.

Commonly caused by people falling onto a hard surface and breaking their fall with outstretched arms (falling with wrist flexed is Smith's fracture)

Used to be a common fracture in the era when cars had hand-crank engines.

Common in people with osteoporosis.

Radial angulation of the wrist.

- A Colles fracture is a common injury occurring at the wrist in the elderly and usually osteoporotic population.  It classically follows a fall on the outstretchhed hand.  The fracture line is usually about 2.5cm proximal to the wrist and the distal fragment displaces posteriorly (dinnerfork deformity when viewed from the side) and radially.  Some degree of shortening often occurs due to impaction of the component parts.

Reference:
1. Anatomy at a Glance. Omar Faiz and David Moffat.  Blackwell Science. 2002.