Overview

Healthy shoulder jointEnlarge image

Shoulder replacement removes damaged areas of bone and replaces them with parts made of metal and plastic (implants). This surgery is called shoulder arthroplasty (ARTH-row-plas-tee).

The shoulder is a ball-and-socket joint. The round head (ball) of the upper arm bone fits into a shallow socket in the shoulder. Damage to the joint can cause pain, weakness and stiffness.

Shoulder implants are available in a few different shapes and a range of sizes. Replacement options include partial and total using either anatomic or reverse implants.

Why it’s done

Anatomic total shoulder replacementEnlarge image

Reverse total shoulder replacementEnlarge image

Shoulder replacement surgery is done to relieve pain and other symptoms that result from damage to the shoulder joint.

Conditions that can damage the joint include:

• Osteoarthritis. Known as wear-and-tear arthritis, osteoarthritis damages the cartilage that covers the ends of bones and helps joints move smoothly.
• Rotator cuff injuries. The rotator cuff is a group of muscles and tendons that surround the shoulder joint. Rotator cuff injuries sometimes can result in damage to cartilage and bone in the shoulder joint.
• Fractures. Fractures of the upper end of the humerus may require replacement, either as a result of the injury or when the prior surgery for fracture fixation has failed.
• Rheumatoid arthritis and other inflammatory disorders. Caused by an overactive immune system, the inflammation associated with rheumatoid arthritis can damage the cartilage and occasionally the underlying bone in the joint.
• Osteonecrosis. Some types of shoulder conditions can affect blood flow to the humerus. When a bone is starved of blood, it can collapse.

Shoulder replacement procedures

Depending on the type of joint damage you have, your doctor may recommend one of the following shoulder replacement options:

• Anatomic total shoulder replacement. Both the ball and the socket are replaced. The implants resemble the natural shape of the bones.
• Reverse total shoulder replacement. Both the ball and the socket are replaced, but the implants are reversed. The ball is attached to the shoulder blade and the socket is attached to the upper arm bone. This option typically is preferred if the rotator cuff is severely damaged.
• Partial shoulder replacement. Only the head (ball) of the joint is replaced. It may be recommended when only the ball side of the joint is damaged.