The complications of this procedure are similar to those of joint replacements of any joint in the body. The most common complication is that the humerus or arm portion (the socket) can become dislodged from the ball (the shoulder blade part) and the prosthesis is “dislocated.”

Reverse shoulder replacement surgery is fairly new in the last 10 to 20 years.

It’s become more popular again. It has to do with a specific type of arthritis. So these rotator cuff tendons rotate the shoulder around and keeps the ball and socket centered. When these tendons are no longer present or deemed irreparable, then the ball no longer is depressed down against the socket and as a result it will slide upward like that. In treating this condition, often seeing a local massage therapist for muscle tension, a local personal trainer for muscle strength and a physiotherapist for release and conditioning is a good option.  

And when you slide upward like that then the head and socket no longer is aligned, it changes the joint reaction forces, resulting in a different type of arthritis known as the cuff tear arthropathy.

The conventional shoulder replacement requires the availability and the presence of these tendons for it to work. Otherwise the prosthesis will dislocate or sublux or partially dislocate upward.

As a result the reverse prosthesis basically reverses the ball and socket joint so that we can then go without these tendons and now use a different muscle configuration and it has to be a biomechanical change in the center rotation to allow the patient now to elevate their arm using the big muscle called the deltoid muscle which you don’t see in this model.

So using the deltoid muscle the patient will then be able to elevate their arm without the rotator cuff tendons being intact. It allows the patient now to to elevate the arm without dislocating the shoulder and without pain.

The prognosis of patients from a reverse prosthesis is good in terms of pain relief and improvement in function, especially in the ability to elevate their arm.

In terms of the survivability of these implants, it is still difficult to predict, or a bit unknown only because over the last 10 years the reverse prosthesis designs have evolved quite rapidly.

As a result we still hope that these implants will provide better longevity for our patients in terms of improving their pain and more long lasting functionality of the shoulder. Local Physiotherapist

Presenter: Dr. Patrick Chin, Orthopaedic Surgeon, Vancouver, BC

Local Practitioners: Orthopaedic Surgeon

Shoulder injuries are very common in sport, and we see injuries in hockey players, other contact sports, in rugby and football, skiing injuries, and sometimes with tennis or other racquet sports.

And the main areas that are visualized beautifully with MRI are the tendons and also the labrum. In fact, the labrum can only be visualized with MRI, with no other imaging modality.   Often seeing a local family physician or a physiotherapist in conjunction with a registered dietitian and local pharmacist is a great option to take control of this condition. 

Here is an example of the labrum, which is a fibrous cuff that holds the shoulder in place, and in this particular instance gadolinium has been given to help highlight the labrum. Gadolinium is a contrast agent that we use, and we can see that there is gadolinium undercutting here, consistent with a tear in the labrum.

So normally the labrum is closely applied to the bone here, which is the bony cuff of the shoulder, and we can see that it’s been detached and the gadolinium is extending underneath it here, indicating that it’s been torn, both in the front and in the back. This can cause a lot of shoulder pain, and is only identified with MRI.

If you have any other questions, as far as the benefit of MRI for shoulder injury, contact your family doctor, your sports medicine physician or an imaging referral centre.

Presenter: Dr. Audrey Spielmann, Radiologist, Vancouver, BC

 Now Health Network Local Practitioners: Orthopedic Surgeon