The shoulder joint surfaces are formed by the humerus (arm bone) and the scapula. The surfaces are covered by cartilage.

Certain conditions may indicate the need for a replacement for the shoulder joint such as: osteoarthritis, persistent shoulder pain, severe loss of joint function, osteonecrosis and fractures.

A replacement joint can help alleviate pain and improve function. The replacement joint usually has two parts that replace the joint surfaces and is made of a combination of metal and plastic.

Shown here is both the shoulder joint installed and a zoom-in highlighting the different components – artifical humoral head and artificial socket – and how the artificial socket is inserted into the scapula.