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Elbow (Olecranon) Fracture

An olecranon (oh-LEK-rah-nun) fracture is a break in the bony "tip" of the elbow. This pointy segment of bone is part of the ulna, one of the three bones that come together to form the elbow joint.

The olecranon is located under the skin of the elbow, without much protection from muscles or other soft tissues. It can break easily if you experience a direct blow to the elbow or fall on an outstretched arm. A fracture can be very painful and make elbow motion difficult or impossible.

Olecranon fractures are fairly common. Although they usually occur on their own, with no other injuries, they can also be part of a more complex elbow injury. In an olecranon fracture, the bone can crack just slightly or break into many pieces. The broken pieces of bone may line up straight or may be far out of place (displaced fracture).

In some cases, the bone breaks in such a way that bone fragments stick out through the skin. This is called an open fracture. Open fractures are particularly serious because, once the skin is broken, infection in both the wound and the bone are more likely to occur. Immediate treatment is required to prevent infection.

What is the anatomy of the elbow?

Elbow Anatomy

Your elbow is a joint made up of three bones:

  • The humerus (upper arm bone)
  • The radius (forearm bone on the thumb side)
  • The ulna (forearm bone on the pinky side)

The elbow joint bends and straightens like a hinge. It also helps you to turn your hand palm up (like accepting change from a cashier) or palm down (like typing or playing the piano).

The elbow consists of portions of all three bones:

  • The distal humerus is the lower end of the humerus. It forms the upper part of the elbow and makes it possible for your forearm to bend and straighten.
  • The radial head is the knobby end of the radius where it meets the elbow. It glides up and down the front of the distal humerus when you bend your arm and rotates around the ulna when you turn your wrist up or down.
  • The olecranon is the part of the ulna that "cups" the lower end of the humerus, creating a hinge for elbow movement. The bony "point" of the olecranon can be easily felt beneath the skin because it is covered by just a thin layer of tissue.

The elbow is held together by its bony architecture, as well as ligaments, tendons, and muscles. Three major nerves cross the elbow joint.

What causes olecranon fractures?

Olecranon fractures are most often caused by:

  • Falling directly on the elbow
  • Receiving a direct blow to the elbow from something hard, like a baseball bat or a dashboard or car door during a vehicle collision.
  • Falling on an outstretched arm with the elbow held tightly to brace against the fall. In this situation, the triceps muscle, which attaches to the olecranon, can pull a piece of the bone off of the ulna. Injuries to the ligaments around the elbow may occur with this type of injury, as well.

What are the symptoms of olecranon fractures?

An olecranon fracture usually causes sudden, intense pain and can prevent you from moving your elbow. Other signs and symptoms of a fracture may include:

  • Swelling over the "tip" or back of the elbow
  • Bruising around the elbow. Sometimes, this bruising travels up the arm towards the shoulder or down the forearm towards the wrist.
  • Tenderness to the touch
  • Numbness in one or more fingers
  • Pain with movement of the elbow or with rotation of the forearm
  • A feeling of instability in the joint, as if your elbow is going to "pop out."