Causes / typical injury mechanism: An olecranon fracture may be caused by a direct blow to the posterior elbow or by a fall onto an outstretched hand (FOOSH).

Classic history and presentation: The patient will typically present after a fall with pain, swelling, ecchymosis, and tenderness localized to the posterior elbow, with or without loss of active elbow extension. An elbow effusion will be present.

Prevalence: Olecranon fractures account for 10% of upper extremity fractures.

• Age – Mean age of occurrence is 57 years. Younger patients are more likely to sustain injury from a high-energy mechanism, whereas older patients are more likely to sustain injury from a fall from standing height.
• Sex / gender – No predominance exists, but males are more likely to sustain an olecranon fracture at a younger age.

Risk factors: There is no consensus regarding risk factors that predispose to olecranon fractures. However, decreased bone density is proposed as a factor in olecranon fractures caused by low-energy mechanisms, such as a fall.

Pathophysiology: Function and stability of the elbow depend on 3 separate articulations: the ulnohumeral, radiocapitellar, and proximal radioulnar joints. The olecranon articulates with trochlea of the distal humerus to form a hinge joint. During a fall, the sigmoid notch of the olecranon is driven against the trochlea as the triceps muscle contracts, avulsing the proximal bony fragment(s).

Grade / classification system: Colton classification.

• Nondisplaced
• Avulsion, displaced
• Oblique and transverse, displaced
• Comminuted, displaced
• Fracture-dislocation