Osteoarthritis is one of the leading causes of disability in the US today. The disease occurs when articular cartilage in a joint degenerates. Articular cartilage is the smooth, white tissue that covers the ends of bones where they come together to form joints. It doesn’t regenerate in the same way as other tissue in the body. Articular cartilage allows the bones to glide over each other with very little friction, and it’s essential to movement. As osteoarthritis takes hold, it becomes progressively more painful and difficult to move.