5.Articular Cartilage
This slippery stuff covers the ends of your thigh and shin bones. It even lines the back of your kneecap. That ensures all those parts slide smoothly across each other as you bend, lift, and straighten your legs. Injury, inflammation, infection, and diseases like arthritis can damage this cartilage and cause pain and swelling in your knee.
6.Patella Fracture
You can crack or break any of the bones in your knee, but the kneecap, or patella, is the most common. Injuries here usually result from a sudden fall or a car accident. You’ll have pain and swelling in the front of the knee, and you may not be able to straighten your leg or even walk. The kneecap breaks more easily as you age, especially if you have brittle bones (osteoporosis).
