What is a terrible triad elbow injury? Our nephew is having surgery for this but we don't really understand what it is.

A terrible triad elbow injury is a fracture and dislocation of the elbow joint. In particular, the elbow has dislocated in a posterior (backward) direction (away from the hand). The coronoid bone is fractured.

The coronoid is a curved, triangular piece of the ulna (forearm bone). It is along the upper and front part of the ulna and fits around the bottom of the humerus (upper arm bone) to form the hinge joint of the elbow.

The third part of this injury is a fracture of the radial head. The radius is the second bone of the forearm. Rotation of the radial head allows the hand to turn into a palm up or palm down position.

This term is used because of a high rate of complications that often occur. Damage to the bone and surrounding soft tissues (especially the ligaments) can lead to elbow instability, malunion, or nonunion. Synostosis of the radius and ulna at the elbow is also possible. This means the two bones form a bony bridge between them. This union forms a joint where there shouldn't be one.

Surgery is needed with this type of injury to repair and reconstruct the elbow. A rehab program is usually started early in recovery to help avoid these problems.