Shoulderreplacement prostheses

Total shoulder replacement removes the damaged areas of bone from your shoulder joint and replaces them with an artificial ball and socket joint.

The head of the humerus (arm bone), which is shaped like a ball, is replaced with an artificial ball and stem. The stem fits into your arm bone and bone cement may be used to fix it in place. The socket, which is part of the shoulder and shaped like a small bowl, is replaced with an artificial cup.

How the prosthesis is chosen

There are many different types and brands of shoulder replacement prostheses available in Australia. The prosthesis that your surgeon recommends may depend on your age, lifestyle, anatomy and your surgeon’s preference.

Surgeons choose prostheses with the aim of giving you the best result for the longest time. They generally also use a prosthesis they have a lot of experience with and are comfortable using. Talk to your surgeon about the different types and why the one they’re recommending is best for you.

The Australian Orthopaedic Association National Joint Replacement Registry records the safety and effectiveness of all shoulder replacement prostheses. You can check if the prosthesis your surgeon is planning to use is associated with a higher than normal rate of ‘revision’. (Revision is the term used when a surgery has to be redone.)

The components

A total shoulder replacement prosthesis consists of 2 components:

• The cup (glenoid) component, which attaches to the shoulder bone (glenoid).
• The ball (humeral) component (usually on a stem), which attaches to the arm bone (humerus).

For a reverse total shoulder replacement procedure, the ball component is attached to the glenoid, and a cup component, (usually on a stem) is attached to the top of the arm bone.

Standard stem, mini stem or no stem?

Some humeral components have a stem, some have a mini stem and some have no stem. There are advantages and disadvantages to each of these and you may wish to discuss them with your surgeon.

Methods of fixing to the bone

There are 2 main ways of fixing the components to the bone: cemented and cementless.

Cemented fixation is when the components are fixed to bone using bone cement. Cementless fixation is when the components are fixed to bone by shaping it to provide a tight fit, which is strengthened when bone grows into the surface of the prosthesis. For the traditional total shoulder replacement, results are showing an increased need for reoperation after surgery using cementless glenoid components. Also, people who had cemented fixation of a stemmed humeral component are reporting better quality of life, strength and range of motion.

For reverse total shoulder replacement, an uncemented stem appears to give similar results to a cemented stem.

Cost and safety

The prosthesis won’t normally cost you anything. If you have private health insurance, your health fund pays. If you’re a public patient, Medicare pays. HCF funds prostheses listed on the Federal Government’s approved prostheses list. All the devices on the list have been approved for use by the Australian regulator of medical devices (Therapeutic Goods Administration).

The Australian Orthopaedic Association National Joint Replacement Registry records the safety and effectiveness of all shoulder replacement prostheses on the Federal Government’s list. On its website you can check if the prosthesis your surgeon is planning to use is associated with a higher than normal rate of ‘revision’. (Revision is the term used when a surgery has to be redone because of complications.)

Some surgeons use custom-made prostheses that may cost extra and may not be covered by HCF.

Print this page and take it with you when you discuss your procedure with your surgeon.