Shoulder replacement, or shoulder arthroplasty, is a surgical procedure whereby the surfaces of your bones are replaced with artificial implants. Your shoulder is a ball and socket joint made up through the articulations (joints) of the head of humerus (ball-like section of arm bone) and glenoid (shallow cavity located on the scapula - socket). Surrounding this joint is a layer of articular cartilage, muscles, tendons and ligaments which help provide support, stability and movement. Degenerative changes (arthritis) occur at the shoulder causing the cartilage to be worn away. This results in the bone surfaces rubbing together causing pain and decreased movement. This condition can be treated conservatively (non-operative); however when there are severe arthritic changes to the joint a shoulder arthroplasty is performed to replace the damaged cartilage and bone. Other reasons shoulder arthroplasty’s are performed are severe fractures, failed previous shoulder arthroplasty, tumours and avascular necrosis (bone dies due to obstruction of blood supply).

There are 4 types of surgery performed depending on the extent and severity of your injury. These are:

• Shoulder Arthroplasty – the humeral head is cut away and replaced with a metal ball and a long stem which is inserted and cemented inside your humerus. The glenoid surface is replaced and screwed into the scapula
• Reverse Shoulder Arthroplasty – here the joint is reversed and the glenoid is replaced with a ball like surface and the humerus replaced with a concave, glenoid like, surface. This is usually performed when there is a deficient rotator cuff.
• Hemiarthroplasty – here only the humeral head is replaced. A prosthetic metal implant is placed into the humerus forming the humeral head
• Joint Surface Replacement – only the surface of the humerus is replaced. Usually performed when the cause is arthritic.