Complete articular (whole head) fractures of the radial head are divided in two fracture classes:
• 2R1C1 – Simple (left)
• 2R1C3 – Fragmentary (right)
They are either stable fractures with no associated elbow or forearm ligament injury, or unstable fractures associated with elbow dislocation, or part of an Essex-Lopresti (interosseous ligament of the forearm) injury. If there is a gap between fracture fragments, then there is usually an associated ligament injury or associated fracture.