Osteochondritis Dissecans of the elbow, more commonly known as Capitellar OCD, involves a loss of blood supply to part of the cartilage within the elbow joint. When this cartilage ceases to perform its shock absorption duties, the elbow joint can become stiff, inflamed, and generally painful.
Your Capitellum is: A smooth, round, knob on the end of the humerus joined with the radius bone to form a hinge, with a shape similar to a knob and a cup.
Articular cartilage is: A slick, smooth material that protects bone ends from friction when they rub together. Articular cartilage is soft enough to act as a shock absorber.