A rthritis is a generic condition indicating inflammation of a joint . Inflammation is the general response of the body to injury of any type. The signs of inflammation are pain, swelling, warmth, and sometimes redness. There are many causes of arthritis. These include a sudden, or acute, injury such as might occur when playing sports.
Acute trauma is actually the most common cause of arthritis.
In most cases, however, the injury does not cause permanent damage, the inflammation subsides over a few weeks, and the joint functions normally for the rest of that person's life. Arthritis can also develop after many years of certain activities performed over and over, which can be considered a form of chronic injury. The most common form of arthritis, which necessitates knee replacement, is osteoarthritis . In this condition, the articular cartilage, which is the smooth gliding surface of the joint, has worn away. This can occur for a number of reasons.