Olecranon fracture is a

fracture Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displa ...

of the bony portion of the

elbow The elbow is the region between the arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), and the lateral and the media ...

. The injury is fairly common and often occurs following a fall or direct trauma to the elbow. The olecranon is the proximal extremity of the

ulna The ulna (''pl''. ulnae or ulnas) is a long bone found in the forearm that stretches from the elbow to the smallest finger, and when in anatomical position, is found on the medial side of the forearm. That is, the ulna is on the same side of t ...

which is articulated with the

humerus The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...

bone and constitutes a part of the elbow articulation. Its location makes it vulnerable to direct trauma.

Signs and symptoms

People with olecranon fractures present with intense elbow pain after a direct blow or fall. Swelling over the bone site is seen and an inability to straighten the elbow is common. Due to the proximity of the olecranon to the ulnar nerve, the injury and swelling may cause numbness and tingling at the fourth and fifth fingers. Examination can bring out a palpable defect at the site of the fracture.

Mechanism

Olecranon fractures are common. Typically they are caused by direct blows to the elbow (e.g. motor vehicle accidents), and due to falls when the triceps are contracted. "Side-swipe" injury when driving a motor vehicle with an elbow projecting outside the vehicle resting on an open window's edge is an example. Direct trauma: This can happen in a fall with landing on the elbow or by being hit by a solid object. Trauma to the elbow often results in

comminuted fracture A bone fracture (abbreviated FRX or Fx, Fx, or #) is a medical condition in which there is a partial or complete break in the continuity of any bone in the body. In more severe cases, the bone may be broken into several fragments, known as a '' ...

s of the olecranon. Indirect trauma: by falling and landing with an outstretched arm. Powerful pull of the

triceps muscle The triceps, or triceps brachii (Latin for "three-headed muscle of the arm"), is a large muscle on the back of the upper limb of many vertebrates. It consists of 3 parts: the medial, lateral, and long head. It is the muscle principally responsib ...

can also cause

avulsion fracture An avulsion fracture is a bone fracture which occurs when a fragment of bone tears away from the main mass of bone as a result of physical trauma. This can occur at the ligament by the application of forces external to the body (such as a fall ...

Diagnosis

To assess an olecranon fracture, a careful skin exam is performed to ensure there is no open fracture. Then a complete neurological exam of the upper limb should be documented. Frontal and lateral

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 ...

views of the elbow are typically done to investigate the possibility of an olecranon fracture. A true lateral x-ray is essential to determine the fracture pattern, degree of displacement, comminution, and the degree of articular involvement.

Classifications

There are several classifications that describe different forms of olecranon fractures, yet none of them have gained widespread acceptance:

Mayo classification

Based on the stability, the displacement and the comminution of the fracture. It is composed of three types, and each type is divided in two subtypes: subtype A (non-comminuted) and subtype B (comminuted). * Type I: Non-displaced fracture – It can be either non-comminuted ones (Type IA) or comminuted (Type IB). * Type II: Displaced, stable fractures – In this pattern, the proximal fracture fragment is displaced more than 3 mm, but the collateral ligaments are intact. That is why there is no elbow instability. It can be either non-comminuted ones (Type IIA) or comminuted (Type IIB). * Type III: Displaced unstable fracture – In this case, the fracture fragments are displaced and the forearm is unstable in relation to the humerus. It is a fracture -dislocation. It also may be either non-comminuted (Type IIIA) or comminuted (Type IIIB).

AO classification

This classification incorporates all fractures of the proximal ulna and radius into one group, subdivided into three patterns: * Type A: Extra-articular fractures of the metadiaphysis of either the radius or the ulna * Type B: Intra-articular fractures of either the radius or ulna * Type C: Complex fractures of both the proximal radius and ulna

Colton Classification

* Type I - Nondisplaced - Displacement does not increase with elbow flexion * Type II - Avulsion (displaced) * Type III - Oblique and Transverse (displaced) * Type IV - Comminuted (displaced) * Type V - Fracture dislocation

Schatzker Classification

* Type A - Simple transverse fracture * Type B - Transverse impacted fracture * Type C - Oblique fracture * Type D - Communuted fracture * Type E - More distal fracture, extra-articular * Type F - Fracture-dislocation

Treatment

Fracture of Olecranon pre and post typical surgery

Nondisplaced fractures

In fractures with little or no displacement, immobilization with a posterior splint may be sufficient. Elbows may be immobilized at 45°–90° of flexion for 3 weeks, followed by limited (90°) flexion exercises.

Displaced fractures

Most olecranon fractures are displaced and are best treated surgically:

Tension band fixation

Tension band fixation is the most common form of internal fixation used for non-comminuted olecranon fractures. It is typically reserved for noncomminuted fractures that are proximal to the coronoid. This procedure is performed using

Kirschner wire Kirschner wires or K-wires or pins are sterilized, sharpened, smooth stainless steel pins. Introduced in 1909 by Martin Kirschner, the wires are now widely used in orthopedics and other types of medical and veterinary surgery. They come in differ ...

(K-wires) which converts tensile forces into compressive force.

Intramedullary fixation and plates

Single intramedullary screws can be used to treat simple transverse or oblique fractures. Plates can be used for all proximal ulna fracture types including Monteggia fractures, and comminuted fractures.

Excision and triceps advancement

This method is indicated for cases when open reduction and internal fixation is unlikely to be successful. For example: extensive comminutions, elderly patients with osteoporotic bone, and small or non-union fractures.

Epidemiology

Olecranon fractures are rare in children, constituting only 5 to 7% of all elbow fractures. This is because in early life, olecranon is thick, short and much stronger than the lower extremity of the humerus. However, olecranon fractures are a common injury in adults. This is partly due to its exposed position on the point of the elbow.

References

External links

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