Knee arthritis is inflammation and deterioration of knee joint cartilage. Cartilage is the slippery coating on the ends of bones that serves as a cushion and allows the knee to smoothly bend and straighten.

膝关节炎是膝关节软骨的炎症和恶化。 软骨是骨骼末端的光滑涂层，起到缓冲作用，使膝盖能够平滑地弯曲和伸直。