Arthritis is a general term covering numerous conditions where the joint surface or cartilage wears out. The joint surface is covered by a smooth articular surface that allows pain free movement in the joint. This surface can wear out for several reasons; of ten the definite cause is not known.
Osteoarthritis, also called degenerative joint disease is the most common form of arthritis. It occurs most of ten in older people. This disease affects the tissue covering the ends of bones in a joint (cartilage). In a person with osteoarthritis, the cartilage becomes damaged and worn out causing pain, swelling, stiffness and restricted movement in the affected joint. Although osteoarthritis may affect various joints including hips, knees, hands, and spine, hip joint is most commonly affected. Rarely, the disease may affect the shoulders, wrists and feet.
The term arthritis literally means inflammation of a joint, but it is generally used to describe any condition in which there is damage to the cartilage, the tissue that lines the ends of bones in a joint. When the damage is to the cartilage in the shoulder joint, it is called shoulder arthritis. Inflammation is the body's natural response to injury and presents as redness, swelling, heat and pain.