What is the term for the polished, "ivory-like" appearance of bone at cartilage erosion?

Eburnation is the term used to describe the smooth, polished, "ivory-like" appearance of bone that occurs at sites of cartilage erosion, particularly in conditions like osteoarthritis. This phenomenon arises due to the exposure of subchondral bone when articular cartilage degrades and wears away. As the cartilage erodes, the underlying bone becomes more prominent and often responds by undergoing changes that lead to a dense, glossy appearance known as eburnation. This sign is indicative of chronic stress and wear on the joint surface.

In the context of osteoarthritis, eburnation reflects the degenerative process affecting the cartilage and bone. It serves as a visual marker of the underlying pathology, illustrating the interaction between joint mechanics and bone response to trauma or wear.