Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
ulnar collateral ligament
References
Images
Anatomical illustration of the human elbow showing the ulnar collateral ligament (UCL) connecting the humerus and ulna, with labeled ligament bundles, and two panels depicting the reconstruction process used in Tommy John surgery.
Britannica AI Icon

ulnar collateral ligament

anatomy
Also known as: UCL, medial collateral ligament
Written by
The Information Architects of Encyclopaedia Britannica

The Information Architects maintain a master list of the topics included in the corpus of  Encyclopædia Britannica, and create and manage the relationships between them.
The Information Architects of Encyclopaedia Britannica
Last updated

Quick Summary

Anatomical illustration of the human elbow showing the ulnar collateral ligament (UCL) connecting the humerus and ulna, with labeled ligament bundles, and two panels depicting the reconstruction process used in Tommy John surgery.
Tommy John surgery explained The ulnar collateral ligament (UCL) connects the ulna and the humerus at the elbow. When the UCL is damaged or destroyed, Tommy John surgery is used to repair it. The image on the left shows the UCL (also called the medial collateral ligament) intact. The image in the middle shows Tommy John surgery in process, with the damaged ligament absent and several holes drilled through the ulna and humerus. These holes are used as anchors for the tendon graft, which the surgeon threads through the holes to connect the bones. The image on the right shows the graft threaded using a figure-eight method, though a variety of other techniques can be used.

The ulnar collateral ligament (UCL) is a triangular ligament located on the inner side of the elbow. It connects the humerus (upper arm bone) to the ulna (forearm bone), helping to stabilize the elbow joint. This ligament is particularly vulnerable to injury in sports involving repetitive overhand throwing, such as baseball.1

The UCL can also refer to a ligament in the wrist that stabilizes the wrist joint, or a ligament at the base of the thumb that helps stabilize it. The elbow joint itself is formed by the humerus, radius, and ulna, and is reinforced by ligaments that prevent dislocation.12

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
3 Britannica Sources
  1. ulnar collateral ligament
  2. elbow
  3. UCL

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.