Annular band

The annular ligament (orbicular ligament) is a strong band of fibers that encircles the head of the radius, and retains it in contact with the radial notch of the ulna.Per Terminologia Anatomica, the spelling is "anular", but the spelling "annular" is frequently encountered. Anatomy The annular ligament is attached by both its ends to the anterior and posterior margins of the radial notch of the ulna, together with which it forms the articular surface that surrounds the head and neck of the radius. [Source: Wikipedia ]