Anular ligament of radius

In Men and Carnivorous, an annular ligament (Ligamentum anulare radii) surrounds the head of the radius and attaches on the border of the radial notch of the ulna by its extremities . It completes therefore this hollow and constitutes a ring with it, nearly circular in Men and in Cats, elliptic with a great transversal axis in Dogs. To turn in this ring, the head of the radius is covered with cartilage on its whole perimeter, which allows its sliding on both the radial hollow of the ulna and on the annular ligament. On the lateral side, it passes beneath the lateral collateral ligament of the elbow, to which it adheres intimately thickening. Its proximal border gives attach to the cranial part of the articular capsule of the elbow and to the more cranial beams of the collateral ligaments; its distal border is free and thickened.