What finding would be expected during arthroscopy in a patient with late osteoarthritis?

In patients with late osteoarthritis, the presence of subchondral bone exposure is a significant finding during arthroscopy. As the disease progresses, cartilage wears away, leading to the exposure of the underlying bone. This exposure occurs because the articular surfaces have deteriorated to the point where they no longer cover the subchondral bone adequately.

The presence of exposed subchondral bone can lead to a variety of symptoms, including pain, decreased range of motion, and joint instability. It is often associated with the development of additional pathological changes such as osteophytes and changes in the joint architecture. In the context of late-stage osteoarthritis, observing this exposure during arthroscopy offers insight into the advanced degeneration and helps guide treatment planning, such as the need for potential joint replacement or reparative surgical techniques.

While osteophyte formation, joint effusion, and calcified cartilage can also be seen in osteoarthritis, they are more characteristic of earlier stages of the disease or represent other aspects of joint involvement rather than the direct result of advanced bone exposure due to the loss of cartilage.