The traditional total shoulder replacement involves replacing the arthritic joint surfaces
with a highly polished metal ball attached to a stem, and a plastic socket. Patients with
bone-on-bone arthritis and intact rotator cuff tendons are generally good candidates for
conventional total shoulder replacement.
Reverse total shoulder replacement is used for people who have: completely torn rotator
cuffs and significant arthritis (cuff tear arthropathy), or had a previous shoulder
replacement that failed. In reverse total shoulder replacement, the socket and metal ball
are switched. That means a metal ball is attached to the shoulder bone and a plastic
socket is attached to the upper arm bone. This allows the patient to use the deltoid
muscle instead of the torn rotator cuff to lift the arm.
Some patients suffer from more than one problem in their shoulder. Other patients
continue to have pain despite previous operations. This can result in a complex problem
and sometimes an opinion from a shoulder specialist can help.
The rotator cuff is the network of four muscles and tendons that form a covering around
the top of the upper arm bone (humerus). The rotator cuff holds the humerus in place in
the shoulder joint and enables the arm to rotate/elevate. Rotator cuff tear is a common
cause of pain and disability among adults. Tears may be from a traumatic episode or
from overuse
Shoulder instability occurs when the head of the upper arm bone is forced out of the
shoulder socket. This can happen as a result of a sudden injury or from overuse. Once a
shoulder has dislocated, it is vulnerable to repeat episodes. Surgery is sometimes
necessary to repair torn or stretched ligaments so that they are better able to hold the
shoulder joint in place.
The AC joint is where the collarbone (clavicle) meets the highest point of the shoulder
blade (acromion). During an injury, the ligaments attaching to the underside of the
clavicle can tear. This causes the "separation" of the collarbone and wingbone. The
wingbone actually moves downward from the weight of the arm. This creates a "bump" or
bulge above the shoulder.
