Vascular injury following fracture-dislocation of the humerus Is cluite common but rare in anterior dislocation without fracture. The elderly patient with atherosclerotic vessels is most at risk and the axillary artery is most prone to injury. Damage usually occurs at the time of injury but may be produced during reduction, particularly when a long-standing injury is mistaken for an acute dislocation. In these cases, reduction must be gentle and a general anesthetic may be necessary. In the acute case, pulses are usually a b s e n t and the signs and symptoms of vascular insufficiency will be present. There is often abundant collateral circulation in the healthy adult and the relative ischemia may be hard to diagnose. Early exploration and treatment are urged and angiography is reserved for cases in which the diagnosis is in doubt or circulation did not improve with gentle reduction. (Editor's n o t e : As is pointed out by these authors, this injury may be m~stakenly ascribed to neurologic injury of the brachial plexus. The neurologic deficit of vascular injury is usually delayed. It zs a common error to fail to search for either neurologic or vascular injury with this dislocation.