A cartilage injury, medically termed an osteochondral injury, involves damage to both the articular cartilage (the smooth, protective surface covering the ends of bones) and the subchondral bone (the bone layer just beneath the cartilage). In the ankle, these injuries commonly affect the talus bone (the bone that connects the foot to the lower leg and allows ankle movement). The cartilage acts as a cushion to reduce friction and enable smooth movement of the joint, so damage to this tissue can cause pain, swelling, and reduced ankle motion.
Ankle cartilage injuries are common among active individuals and athletes. These injuries may range from minor cartilage softening to deeper damage involving the bone, and many cases go undiagnosed initially because early symptoms can be mild or mistaken for a simple ankle sprain.