This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
The MOST common type of dislocation of elbow joint is: 
Select and explain. 
A. Posterior, B. Posterolateral, C. Posteromedial, D. Lateral
A: Posterior
Answer: A: Posterior 
Explanation: In adults, the elbow is the second most frequently dislocated major joint, after the shoulder. It is the most commonly dislocated joint in children. More than 90% of all elbow dislocations are posterior dislocations. This injury entails disengagement of the coronoid process of the ulna from the trochlea of the humerus with movement posteriorly. The mechanism of injury is typically a fall onto an outstretched hand with the elbow in extension upon impact.