Can you help us understand what’s happening with our son? He’s 1200 miles away at college on a baseball scholarship. They say he needs surgery to repair a ruptured ligament in his pitching arm. What does this mean?

There are several important ligaments in the elbow. Ligaments are soft tissue structures that connect bones to bones. The ligaments around a joint usually combine together to form a joint capsule. A joint capsule is a watertight sac that surrounds a joint and contains lubricating fluid called synovial fluid.

In the elbow, two of the most important ligaments are the ulnar collateral ligament (UCL) and the lateral collateral ligament. The UCL is also known as the medial collateral ligament. It’s very likely that one of these two ligaments has been torn in your son’s elbow.

The ulnar collateral ligament is on the medial (the side of the elbow that’s next to the body) side of the elbow, and the lateral collateral is on the outside. The ulnar collateral ligament is a thick band of ligamentous tissue that forms a triangular shape along the medial elbow. It has an anterior bundle, posterior bundle, and a thinner, transverse ligament.

Together these two ligaments, the ulnar (or medial) collateral and the lateral collateral, connect the humerus to the ulna and keep it tightly in place as it slides through the groove at the end of the humerus.

These ligaments are the main source of stability for the elbow. They can be torn when there is an injury or dislocation of the elbow. If they do not heal correctly the elbow can be too loose or unstable. The ulnar collateral ligament can also be damaged by overuse and repetitive stress, such as the throwing motion used by baseball pitchers.

Surgical treatment is designed to restore medial stability of the elbow. Full return to previous activities is the main goal. This is especially true for those athletes who want to remain active and competitive in sports.