Elbow instability is common and may occur after a variety of injuries, including falls or direct blows.

Instability can be classified as either acute or chronic. Acute instability is classified as simple (without fracture) or complex (with associated fracture). Chronic instability is classified as a chronically dislocated or recurrently unstable elbow. Recurrent instability commonly presents as isolated medial or lateral collateral ligament insufficiency. A chronically dislocated elbow is often more complex, involving both osseous and ligamentous injuries. 

The treatment of simple dislocations typically involves closed reduction and nonsurgical management. Complex instability usually requires surgery, which includes open reduction and internal fixation of coronoid and olecranon fractures, repair or replacement of radial head fractures, and lateral collateral ligament repair.