Reverse Total Shoulder Replacement
A reverse total shoulder replacement is an orthopaedic procedure used to maintain the shoulder joint for people who have arthritis of the shoulder joint and also an irreparable, retracted rotator cuff tear. The rotator cuff is the collective term for a group of tendons that blend together to help stabilise the shoulder and which keep the ball of the humerus centred in the shoulder socket.
The rotator cuff tendons
The rotator cuff is what enables us to lift our arms up thus loss of integrity of the rotator cuff is a common cause of shoulder weakness. Those patients with large rotator cuff defects have difficulty raising the arm or rotating it out towards the side.
Tears of the rotator cuff tendons occur with increasing frequency as people age. It is unusual for a patient younger than 40 years to have a tear whereas up to 50% of patients over the age of 75 years have a tear in one or other rotator cuff tendon.
Traditional shoulder replacements replicate with metal the typical bony structure of the shoulder - a ball shaped end at the top of the humerus or upper arm bone, fitting into a cup shaped shoulder socket as shown below.
Why can’t a standard shoulder replacement be used?
The answer to this dilemma was to reverse the socket and the ball, placing the ball portion of the shoulder where the socket used to be and the socket where the ball or humeral head used to be (ie. the reverse total shoulder replacement).
With this new configuration, existing muscles such as the deltoid can adequately support the joint in the absence of a functioning rotator cuff. The deltoid muscle that covers the shoulder is used to lift the arm, providing better function of the shoulder. The result is a better functioning shoulder with less pain.
The reverse shoulder replacement was originally designed in France in the late 1980’s and has slowly become available in Australia since the early 2000’s. With newer designs and a better understanding of the mechanics of the prosthesis, the outcome from such surgery has become much more predictable and with less complications for the patients.
What are the symptoms?
How is a diagnosis made?
An MRI is also used in the diagnosis to assess the rotator cuff, specifically looking for chronic tearing, retraction and atrophy of the cuff. These findings confirm that a reverse replacement is the best option as surgical repair of such poor tissue would fail.
How are these problems treated?
- Pathway for total hip replacement and resurfacing hip replacement
- Bearings for hip replacement
- Hip replacement in the young