Ringbone is the term used for osteoarthritis in horses, It is alsoreferred to as bony arthritis, of the pastern and/or coffin joints ringbone in the pastern joint is called high ringbone, and in the coffin joint is is referred to as low ringbone. Arthritis is any condition that causes inflammation of the joint. Osteoarthritis forms when the inflammation within the joint creates enough damage that the body lays down bone in an effort to heal the damaged tissue. This bony development development occurs at the joint surface or the attachment sites of the joint capsule to the bone. Another term to describe this type of damage to a joint is degenerative joint disease (DJD). The same sort of thing happens in humans after rheumatic inflammation