Arthritic shoulder. Coloured frontal X-ray image of the right shoulder of a 60-year-old patient with osteoarthritis. The arthritic nature of the joint is shown in this X-ray by the mottled appearance of the head of the humerus and the lack of separation between the humerus and the socket it connects with in the scapula (shoulder blade). Normally, cartilage separates the bones in a joint, but here this has been worn down, one of the characteristics of osteoarthritis.