Reverse Total Shoulder Replacement Surgery

A shoulder joint without an intact rotator cuff may still function relatively well. Some patients will have weakness, some pain and may not be able to completely raise the arm. But, they get by without their rotator cuff fairly well. There are many people who choose not to have surgery to repair a rotator cuff tear and will simply live with the limitations. Patients with massive rotator cuff tears may not be able to lift the arm without significant pain and weakness. When the arm cannot be lifted, this is called apseudoparalytic shoulder.

The shoulder needs a functioning rotator cuff to remain stable as well as to create a joint capsule to hold the joint fluid that lubricates the joint. Over time, a shoulder without an intact rotator cuff becomes arthritic - the shoulder joint wears out due to the abnormal motion, the instability, and lack of lubrication from the joint fluid. This type of wear and tear arthritis in the shoulder is called (rotator) cuff tear arthropathy.

Cuff tear arthropathy is difficult to treat. The shoulder is weak and painful. Patients may not be able to raise the arm above shoulder level. Patients with this type of arthritis would seem to be good candidates for a shoulder replacement, but replacing the shoulder in the typical fashion has not been successful.

The normal artificial shoulder was designed to copy our real shoulder. The glenoid component (the socket) was designed to replace our normal shoulder socket with a thin, shallow plastic cup. The humeral head component was designed to replace the ball of the humerus with a metal ball that sits on top of the glenoid. This situation has been compared to placing a ball on a shallow saucer. Without something to hold it in place, the metal ball simply slides around on the saucer. In the shoulder that something is the rotator cuff and the muscles that attach to the tendons. Without a rotator cuff to hold the metal ball centered in the plastic socket, the metal quickly wore out the plastic socket and the joint became painful once again.

The answer to this dilemma was to rethink the mechanics of the shoulder joint and design an artificial shoulder that worked differently than the real shoulder joint. The solution was to reverse the socket and the ball, placing the ball portion of the shoulder where the socket use to be and the socket where the ball or humeral head use to be. This new design led to a much more stable shoulder joint that could function without a rotator cuff. The artificial joint itself provided more stability by creating a deeper socket that prevented the ball from sliding up and down as the shoulder was raised. The large deltoid muscle that covers the shoulder could be used to more effectively lift the arm, providing better function of the shoulder. The final result is a shoulder that functions better, is less painful and can last for years without loosening.

Other reasons to consider a reverse shoulder replacement include failed rotator cuff surgery leading to a pseudoparalytic shoulder even without arthritis. A pseudoparalytic shoulder refers to a situation where you can not raise the shoulder. Pseudomeans false and paralysis usually means that the nerves that control the muscle no longer control the muscles. A pseudoparalytic shoulder appears paralyzed, but the reason that you cannot raise the shoulder is because the rotator cuff tendons that attach the muscles (that raise the shoulder) to the humerus bone are torn. The power of the muscles cannot be transmitted to the humerus to raise the shoulder.

Older patients with very severe fractures of the head of the humerus appear to do very well with reverse shoulder replacements as opposed to a standard shoulder replacement. Patients who have had previous shoulder replacements that have failed of become loose will also require a reverse shoulder replacement to fix the loose or painful prosthesis.

In most cases, doctors see a shoulder replacement as the last option. Sometimes there is a benefit to delaying shoulder replacement surgery as long as possible. Your doctor will probably want you to try nonsurgical measures to control your pain and improve your shoulder movement, including medications and physical or occupational therapy.

Like any arthritic condition, cuff tear arthropathy of the shoulder may respond to anti-inflammatory medications such as aspirin or ibuprofen. Acetaminophen (Tylenol®) may also be prescribed to ease the pain. Some of the newer medications such as glucosamine and chondroitin sulfate are more commonly prescribed today. They seem to be effective in helping reduce the pain of arthritis in all joints. There are also new injectable medications that lubricate the arthritic joint. These medications have been studied mainly in the knee. It is unclear if they will help the arthritic shoulder. These lubrication injections are presently being studied in the shoulder. Although they are safe in the knee, they are not presently approved for use in the shoulder.

Physical or occupational therapy may be suggested to help you regain as much of the motion and strength in your shoulder as possible before you undergo surgery. In many cases, however, therapy may not be indicated for severe shoulder arthritis since it may aggravate the pain. This is a matter to be discussed with your orthopedic surgeon.