Institute of Human Anatomy on Instagram: "The Sound of Severe Arthritis: Cartilage vs Bone-on-Bone Listen closely to this real knee joint dissection - the difference in sound tells the whole story. WHAT YOU'RE HEARING: Tapping on remaining cartilage = cushioned sound Tapping on exposed bone = hard, direct contact This is severe arthritis where the protective cartilage has worn away completely in some areas, leaving bone grinding directly on bone with every movement. BEYOND ARTICULAR CARTILAGE: A