Most commonly, the elbow dislocates posteriorly. Immediate reduction is essential to reduce the risk of neurovascular or cartilaginous complications. Both posterior and anterior dislocations occur. A fall on an extended abducted arm is the mechanism of injury seen in posterior dislocations of the elbow. An example of this is someone rollerblading who, falling backward, extends an arm behind to break the fall.
Posterior dislocations account for the majority of elbow dislocations.
A strong blow to the posterior aspect of a flexed elbow may result in anterior dislocation of the elbow. This force drives the olecranon forward in relation to the humerus. Obtain history that includes the mechanism of injury, type and location of pain, amount of immediate dysfunction, treatment prior to arrival in the emergency department, timing of effusion appearance, and history of prior elbow injury. Elbow is flexed, with an exaggerated prominence of the olecranon. The elbow is held in full extension.