The standard total shoulder replacement involves replacing the arthritic joint surfaces with a highly polished metal ball and a plastic socket.
A total shoulder joint replacement.
These components come in various sizes. They may be either cemented or press fit into the bone.
Implantation of a glenoid component is not advised if:
Patients with bone-on-bone osteoarthritis and intact rotator cuff tendons are generally good candidates for conventional total shoulder replacement.
These X-rays were taken before and after total shoulder replacement surgery for osteoarthritis.
A conventional shoulder replacement device mimics the normal anatomy of the shoulder: A plastic cup is fitted into the shoulder socket (glenoid), and a metal ball is attached to the top of the upper arm bone (humerus).
In a reverse total shoulder replacement, the socket and metal ball are switched. The metal ball is fixed to the socket, and the plastic cup is fixed to the upper end of the humerus.
In a healthy shoulder, the ball of the humerus is held in the shoulder socket by several muscles and tendons, including the rotator cuff tendons.
A reverse total shoulder replacement works better for people with cuff tear arthropathy because it relies on different muscles to move the arm.
In a healthy shoulder, the rotator cuff muscles help position and power the arm during range of motion. A conventional replacement device also uses the rotator cuff muscles to function properly.
In a patient with a large rotator cuff tear and cuff tear arthropathy, these muscles no longer function. The reverse total shoulder replacement relies on the deltoid muscle, instead of the rotator cuff, to power and position the arm. It essentially re-creates the function of the torn rotator cuff.
This surgery was originally designed in the 1980s in Europe. The Food and Drug Administration (FDA) approved its use in the U.S. in 2003.
(Left) Rotator cuff arthropathy. (Right) The reverse total shoulder replacement allows other muscles — such as the deltoid — to do the work of the damaged rotator cuff tendons.
Reverse total shoulder replacement may be recommended if you have:
Your doctor may also recommend surgery if nonsurgical treatments, such as rest, medications, cortisone injections, and/or physical therapy, have not relieved your shoulder pain.
