An ulna fracture is a

break Break or Breaks or The Break may refer to: Time off from duties * Recess (break), time in which a group of people is temporarily dismissed from its duties * Break (work), time off during a shift/recess ** Coffee break, a short mid-morning res ...

in the ulna bone, one of the two bones in the

forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in ...

. It is often associated with a fracture of the other forearm bone, the

radius In classical geometry, a radius ( : radii) of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the latin ''radius'', meaning ray but also the ...

. An ulna fracture can be a single break as in a so called nightstick fracture, which can be caused by someone being hit on the inside of the forearm often by a stick, notably when they are holding their arm up to protect their head from injury. The ulna bone can also break after falling on the forearm or falling on an outstretched arm. Ulna fractures are more common in both men and women before age 40 and women after age 60. Adolescents who play sports are at higher risk.

Cause

An ulna fracture can be a single break as in a so called "nightstick fracture", which can be caused by someone being hit on the inside of the forearm often by a stick, notably when they are holding their arm up to protect their head from injury. An ulna fracture can also result from falling on the forearm or falling on an outstretched arm. Other causes of ulna fractures include sporting injuries, road traffic incidents, falls from a height, and conditions such as osteoporosis and potentially both primary and secondary

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

Diagnosis

The diagnosis of an ulna fracture is made after taking the persons history, which usually includes a history of forearm pain following trauma, and then examining the injured forearm followed by an

x-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

of the relevant part.

Types

Fractures of the ulna can occur at different levels of the bone: near the wrist, in the middle or near the elbow. The fracture may be confined to the ulna or accompanied with damage to the radius or the wrist or elbow joints. * Nightstick fracture is a fracture of the middle portion of the ulna without other fractures. * Distal ulna fractures typically occur along with

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 ...

s. *

Hume fracture The Hume fracture is an injury of the elbow comprising a Bone fracture, fracture of the olecranon with an associated Anatomical terms of location#Anterior and posterior, anterior Joint dislocation, dislocation of the Head of radius, radial head whi ...

- a fracture of the

olecranon The olecranon (, ), is a large, thick, curved bony eminence of the ulna, a long bone in the forearm that projects behind the elbow. It forms the most pointed portion of the elbow and is opposite to the cubital fossa or elbow pit. The olecranon ...

with an associated anterior

dislocation In materials science, a dislocation or Taylor's dislocation is a linear crystallographic defect or irregularity within a crystal structure that contains an abrupt change in the arrangement of atoms. The movement of dislocations allow atoms to s ...

of the radial head. * Monteggia fracture - a fracture of the near to elbow end of the ulna with the dislocation of the

head of the radius The head of the radius has a cylindrical form, and on its upper surface is a shallow cup or fovea for articulation with the capitulum of the humerus. The circumference of the head is smooth; it is broad medially where it articulates with the ra ...

at the elbow joint. *

Galeazzi fracture The Galeazzi fracture is a fracture of the distal third of the radius with dislocation of the distal radioulnar joint. It classically involves an isolated fracture of the junction of the distal third and middle third of the radius with associated ...

- not a fracture of the ulna but a displaced fracture of the radius accompanied by a dislocation of the ulna at the wrist, where the radius and ulna come together. File:Monteggia-Fraktur 23W - CR ap - 001.jpg, Monteggia Fracture (fracture of proximal ulna) File:Galeazzifraktur 1 THWZ.jpg, Galeazzi facture (displaced fracture of the radius)

Treatment

If the fracture is not displaced, is stable, and is not associated with another fracture, it may be treated with a cast for around five to six weeks. During the recovery period healing can be followed up with x-rays. Heavy lifting should be avoided. After the cast has been removed exercises are encouraged and full strength is regained over time. Treatment may also be with splinting and early movement. When there is a displaced fracture and also when the radioulnar joints are involved an operation is often performed, using either flexible rods or screws and plates in order to reduce the fracture and immobilise the bone.

Epidemiology

Ulna fractures are more common in both men and women before age 40 and women after age 60, which is related to osteoporosis. Adolescents who play sports are also particularly at risk of an ulna fracture.

History

The term "nightstick fracture" originated from the notion that a person hit by a police truncheon would hold their arms up to protect their heads from injury. Historically they were treated without surgery, but this resulted in a high risk of the broken parts not joining properly, unless the broken parts were generally aligned and the skin intact.

References

{{Bones of upper extremity Bones of the upper limb