The distal ligaments of the proximal sesamoids are short, thick ligaments on the back of the pastern that attach the sesamoid bones on the rear of the fetlock joint to the pastern bones. There are several sets of ligaments, any of which can be injured.

These are relatively uncommon injuries that are better recognized today with the development of modern ultrasound equipment and techniques that can adequately image this anatomically complicated area.

These injuries can still be difficult to tell from other injuries in the pastern area - the ultrasound changes are notoriously subtle in many cases. MRI is the gold standard for precise diagnosis of these injuries.

Signs may not be obvious but may consist of slight swelling, pain to pressure on the back of the pastern, and positive response to lower limb flexion. Lameness is localizes to this region using nerve blocks. X-ray is usually negative and ultrasound makes the diagnosis (sometimes).

Prolonged rest is the cornerstone of treatment, although many other treatments are used today in the interest of providing higher quality and faster healing.