Elbow Fractures

Elbow fractures are injuries of the radial head and neck, olecranon, distal humerus, coronoid and epicondyles, usually after a fall on the outstretched hand or a direct blow.

The radial head fracture is the commonest and often subtle on X-ray. Olecranon fractures disrupt the extensor mechanism, and coronoid fractures mark instability. Missed instability, associated injuries and neurovascular compromise carry high morbidity.

The elbow has 3 articulations: the ulnohumeral joint (flexion and extension), the radiocapitellar joint (rotation and load transmission) and the proximal radioulnar joint (pronation and supination). Stability comes from bony congruence (coronoid, olecranon and radial head) and the collateral ligaments: the medial ulnar collateral ligament resists valgus, and the lateral ulnar collateral ligament resists varus and posterolateral rotatory instability.

At risk are the brachial artery and the median, ulnar and radial nerves. The posterior interosseous nerve wraps the radial neck and is vulnerable in radial head and neck fractures and Monteggia injuries.

Classifications:

• •Mason (radial head): I non-displaced; II displaced single fragment; III comminuted; IV with dislocation
• •Mayo (olecranon): I non-displaced; II displaced stable; III displaced unstable
• •Regan-Morrey (coronoid): I tip; II under 50%; III over 50%
• •Gartland (paediatric supracondylar): I non-displaced; II displaced, posterior cortex intact; III completely displaced; IV multidirectional instability

Named associations:

• •Monteggia: proximal ulna fracture with radial head dislocation
• •Essex-Lopresti: radial head fracture with disruption of the interosseous membrane and distal radioulnar joint (DRUJ)