Nightstick fractures are isolated fractures of the ulna, typically transverse and located in the mid-diaphysis and usually resulting from a direct blow. It is a characteristic defensive fracture when the patient tries to ward off an overhead blow from an assailant (or local law enforcement officer) branding a bar-like weapon.

Treatment and prognosis

Although typically a closed fracture, they have a higher rate of delayed union or non-union.

History and etymology

Historically this fracture was seen not infrequently due to a strike from a policeman’s baton (known as a nightstick in the USA).