WHY can't I remember what this IS??? It's similar to an osselet.

My 15 yr. QH gelding with short pasterns and big body (good size feet, though) I just noticed has a hard, bony protrusion on his left front outside fetlock joint. Doesn't move when palpated, not hot, he's not lame.

I think it may be bothering him, anyhow.

What IS the silly condition called? It's neither ringbone or sidebone; too high up and in the fetlock joint.