Revision of the shoulder prosthesis

Painful shoulder prostheses | Causes | Treatment methods | Follow-up | Costs | Consultation

Shoulder prostheses that were once implanted can fail over time. This can lead to pain or to the arm no longer being able to be raised and therefore used. There are many causes for such failures and these depend on the type of prosthesis and the rotator cuff. Actual degradation of the prosthesis at the shoulder is rare. As we do not walk on our arms, the stresses on the shoulder are smaller.

WHAT IF THE SHOULDER PROSTHESIS HURTS?

If a shoulder prosthesis begins to cause pain, this is usually a sign something is no longer right. The artificial joint itself has no nerves. The pain therefore comes from surrounding tissues, which may indicate damage. However, it is not only the pain that impairs the function of the prosthesis, but the mobility as well. The arm can no longer be raised and everyday activities are more difficult. Even dressing is a problem, and eating becomes a challenge. It is time to talk to your orthopaedic surgeon.

WHAT ARE THE REASONS FOR A PAINFUL SHOULDER PROSTHESIS?

As always, the pain varies from person to person both in its origin as well as its extent. The cause of the pain is often to be found in the rotator cuff. This needs to be intact when implanting an anatomic prosthesis. However, it may also be that it has since degraded and led to a tear in one of the tendons. The shoulder hurts and the arm becomes weak.

Shoulder prostheses degrade less than knee and hip prostheses. However, the fixation of the joint cavity in the shoulder is a major challenge. In contrast to the hip, there is no bony rim around the socket that allows us to push in an artificial socket firmly. Rather, the flat socket must be attached to a small, flat bone and fixed. The anchoring can loosen and the artificial socket start to wobble. The underlying bone then receives uneven stress. It starts to hurt and can break down.

It is easy to imagine that if the socket is no longer stable then the head of the humerus is no longer guided properly. Depending on the forces acting upon it, it can move away from the centre of the joint and further stress this unevenly. This leads to an asymmetrical degradation which further promotes uneven stresses. This can proceed to the extent that the head of the humerus is practically fixed in an incorrect position, i.e. dislocated.

It is of course unfavourable if the prosthesis fully dislocates from the shoulder. Luckily, this happens very rarely. However, it may be that the previously well-functioning rotator cuff then tears. Or that the artificial socket detaches.

Falls or accidents represent a particular concern for elderly patients. Uncontrollable factors are in effect when someone falls on a prosthesis. A predetermined break point forms as the bone and metal of the prosthesis do not share the same material properties. A periprosthetic fracture can arise. This then leads to the prosthesis no longer being held in the bone. It therefore needs to be exchanged, but the bone that should receive it is broken. This is a delicate situation that often requires major surgery.

A special situation arises if a previously fractured humerus was treated with a hemiprosthesis. In this event, only the fractured head of the humerus is replaced, not the healthy glenoid cavity. However, because an artificial head made of chromium steel is now opposite a natural socket, the cartilage of the glenoid cavity will degrade over time and an artificial socket will need to be implanted.

If the joint is suddenly not only painful but also swollen and reddened, the cause may be an infection. Particularly in the early phase after an implantation, but in principle for the rest of your life, it is possible that bacteria circulating in the blood can establish themselves on a prosthesis, for example after dental treatment. Such an infection is enormously difficult to diagnose as it requires puncture of the joint. It is even more difficult to treat, as the bacteria hide themselves under a protective film that they make. Sometimes the only help is to remove the prosthesis.

HOW ARE THE CAUSES IDENTIFIED?

If you have a prosthesis, a serious physician will examine you annually and take an X-ray. This can help to see possible problems before they develop and to react before it is too late. If you have sudden, persistent or unusual shoulder pain, you should quickly consult an orthopaedic surgeon. They will examine you and certainly order an X-ray. This is often used for the diagnosis, although a CT scan is sometimes also required. MRI is used less often as the metal in the prosthesis distorts the image. In case of uncertainty, a so-called SPECT-CT may be prepared. This examination focuses on the activity of the white blood cells. These can provide information on a small, local inflammation which cannot be detected otherwise.

HOW IS PROSTHESIS PAIN TREATED?

If someone has shoulder pain owing to a problem with the prosthesis, they should act quickly: the prosthesis probably needs to be revised. This is another operation where the damaging components are replaced. This may sound like changing a flat tyre but is far more involved than this. This is because the new prosthesis must be fixed in the joint and be functional again. It therefore needs not only new material, but the biology to accept it. However, as a painful prosthesis has often damaged the bone and soft tissues, it is not always the case that the replacement will be as good as the original. Furthermore, the second operation is usually more difficult than the first.

If the original was an anatomic prosthesis, it can probably be replaced with an inverse prosthesis. The function is then often as good as it was beforehand. Modern implants are equipped for this event; they have components that can simply be replaced and others that can be left as is. However, the revision is significantly more challenging if an inverse prosthesis has lost its fixation or function: the results are often merely reduction of the pain without improvement in function.

If the prosthesis dislocates owing to an accident, it can be repositioned (usually under anaesthetic), the joint immobilised for a few days and then the progression observed. If there is a fracture around the prosthesis, the bone needs to be mended. If the prosthesis is stable, it can be left alone. However, one component is usually replaced with another that provides better fixation because it is bigger.

WHAT HAPPENS IN FOLLOW-UP?

Naturally, a revision operation is a larger and more challenging surgery than the primary implantation. Both for the surgeon and the patient. It takes longer to heal and restore the joint. More care must accordingly be taken in the follow-up treatment. However, in this case the aim is also to move the joint a little as soon as possible to try to prevent it from becoming stiff. Physiotherapy is decisive. During the time the arm cannot be actively moved, patients occasionally need help at home, or they can enter rehabilitation. There then follows a time when strength and coordination are re-established. The arm can now be used in (lighter) everyday activities. Finally, the situation re-normalises and even stressful work is possible again.

COSTS AND REIMBURSEMENT

The costs of a revision operation depend on various factors apart from the implant, such as the duration and complexity of the procedure and the length of the hospitalisation. Health insurance usually reimburses all costs if you have the appropriate insurance coverage. For the Pyramid Clinic you will require private or semi-private supplementary insurance.

As shown above, subsequent rehabilitation is only rarely needed. Simple physiotherapy is sufficient. Both are reimbursed by health insurance.

If you wish to finance the operation yourself, we will provide you with a quote on request following a comprehensive examination. This also applies especially to patients from abroad.

WE WILL BE PLEASED TO GIVE YOU A PRIVATE CONSULTATION

Our doctors have extensive experience and expertise in joint and sport surgery. Dr. med. Gregor Szöllösy is a certified shoulder and elbow expert with extensive know-how in the area of artificial shoulder joints. He is also a lecturer on the Basel Elbow Surgery Course.