Slide 1
On the articular surface, it can be seen that there is erosion of the cartilage with some preservation laterally. The irregular surface may be comprised of bone, tufts of fibrocartilage and/or fibrous tissue with degenerating cartilage adjacent to the areas of most severe changes. Cross-section is remarkable for subchondral cysts which may have been filled with thick, viscous fluid, or fibromyxoid tissue, or in the superficial small cysts-fibrocartilage. There is extensive local remodeling as you've seen in your class microscopic slides with both osteoclastic and osteoblastic activity. There is usually increased vascularity related to the cysts under the subchondral bone.

Slide 2
A radiograph of a resected portion of the femoral head demonstrates numerous well-defined cysts in the immediate subchondral location. A single large cyst (Geodes) is also present. Such cysts are typical of osteoarthritis of the hip.