In this review article, surgeons from the Florida Orthopaedic Institute in Tampa, Florida give a step-by-step description of the surgery to implant a Reverse Shoulder Prosthesis (RSP). This mew implant is used with patients who have a torn rotator cuff that can’t be repaired. They also have severe shoulder arthritis.
During the operation, the top of the humeral head (upper arm bone) is cut off. A half-cup spherical shape is inserted into the bone. The cup side is against the bone. This forms a socket where the round head used to be.
On the scapular side, the normal socket is reamed out and a flat, base plate is inserted. A smooth, three-quarter spherical-shaped implant is attached to the base plate. This forms a round implant called a glenosphere where the shoulder socket used to be.
The authors report good results in terms of reduced pain and improved function. Increased shoulder motion and improved patient satisfaction were also positive outcomes of the RSP. The downside of this procedure was the complications afterwards.
Shoulder instability was common with mechanical failure of the implant. Since the early studies using the RSP, changes have been made in the size, shape, and design of the RSP. The goal is to improve fixation of the implant. Matching the right implant for each patient is important. Designs based on soft tissue tension and rotator cuff deficiency may also decrease problems.
More studies are needed to follow patients long-term and see what kind of results are possible 10 or more years later. How long will the implant last? How much improvement in function is possible? These and many more questions will be addressed.