Arthritis (or arthrosis) is a term that is commonly used to denote a condition affecting joints, for example a knee joint. It is a condition where the smooth cartilage lining of a joint wears down, resulting in pain, stiffness, swelling, and a gradual deformity of the affected joint. The outcome is joint dysfunction, that is a reduced ability to use that joint.

What causes arthritis? Most patients have so called 'primary osteo-arthritis', this term denotes degeneration of the joint surfaces with no specific injury or trauma in the past. Many people term this 'wear-and-tear' joint damage, it has resulted from mechanical activity over many years.

Other patients have so-called 'secondary osteo-arthritis'. This implies that is has an identifiable cause, such as a major injury to that joint, infection, or other disease process etc.

Please see other headings in the lists to see how specific arthritic joints are approached and treated.