Osteoarthritis (OA) is a common condition which can affect any joint. As part of normal life, your joints are exposed to a constant level of stress, which causes some wear and tear on the joint. In most cases, your body repairs this itself and you do not experience any symptoms but in osteoarthritis, this process becomes painful and can cause swelling and stiffness in the joint. Bony growths can develop, and the area can become inflamed (red and swollen).OA can occur at the end of the collar bone or inside the shoulder joint itself.
The shoulder joint is a ball and socket joint and the joint is surrounded by a structure called a joint capsule. The joint capsule is usually very mobile and flexible, moving freely as you move your arm. A frozen shoulder is when the joint capsule becomes inflamed, thickened and stiffer, subsequently causing pain and loss of movement at the shoulder joint. A frozen shoulder is also described as adhesive capsulitis, a stiff shoulder or a contracted shoulder.