Explanation:
The terrible triad of the elbow is a severe, highly unstable injury pattern consisting of a posterior elbow dislocation, a radial head fracture, and a coronoid process fracture. This combination disrupts both the primary (ulnohumeral joint) and secondary (radial head, lateral collateral ligament complex) static stabilizers of the elbow, making non-operative treatment prone to chronic instability. Reference: Campbell's Operative Orthopaedics, 14th Edition.