Figure 4
From: Cells of the synovium in rheumatoid arthritis. Osteoclasts
Erosion of mineralized cartilage by osteoclasts. The image shows a section through a metocarpophalangeal joint of a patient with rheumatoid arthritis. A deep invasion into mineralized cartilage (double asterisks) by synovial inflammatory tissue (arrow) harbors osteoclasts at the front of the erosion. Unmineralized surface cartilage (single asterisk) appears intact, whereas subchondral bone (hash symbol) shows resorption lacunae.