Joints contain cartilage, a soft, rubbery gel-like coating on the ends of bones, where they articulate, that protects joints and facilitates movement. Over time, or if the joint has been injured, the cartilage wears away and the bones of the joint start rubbing together. As the bones rub together, bone spurs may form, and the joint becomes stiff and painful. Most people have joint replacement surgery when they can no longer control the pain with medication and other treatments and the pain is significantly interfering with their lives.
