The reverse shoulder total arthroplasty (rTSA) is used for older adults who have disabling shoulder pain and loss of function due to severe rotator cuff damage. In fact, for these patients, the rotator cuff (needed for a traditional total shoulder replacement) is beyond repair.
The rotator cuff is a group of four muscles, tendons, and connective tissue that envelopes the shoulder. The rotator cuff both moves and stabilizes the shoulder. Stabilizes means it holds the shoulder in the socket and prevents dislocations.
The reverse shoulder replacement has a round sphere called a glenosphere that inserts into the area where the socket used to be. The patient’s own round head of the humerus (upper arm) is cut off and replaced with a polyethylene (plastic) cup.
With this new configuration, the center of rotation changes. The angle of pull for some of the shoulder muscles also changes. Although the outcome is pain free motion, there are some limitations. For example, the patient no longer has full adduction (moving the arm across the body).
Patients do recover faster after rTSA when compared with patients who have a standard total shoulder replacement. There is some belief that protection and rehab after a rTSA is not as important as with a total shoulder replacement.
But many patients who receive a rTSA still have poor external rotation. They may have regained shoulder flexion (overhead) motion, but the shoulder complex is far from normal in terms of motion and function.
Physical therapists are studying this question looking for answers. Who will need postoperative rehab? What type of protocol would have the best results? Early case studies published suggest that the physical therapist can be instrumental in helping the patient regain motion without creating shoulder instability.
Early pain management through the use of joint mobilizations (tiny passive movements performed on the shoulder) and modalities such as cold and electrical stimulation can also help. Later, (usually from week six to 12), the focus is on restoring normal biomechanical and neuromuscular control. During this phase, the goals are to regain full motion and start working on strengthening.
After 12 weeks post-operatively, activity level is advanced. The patient resumes functional activities of daily living and progresses to leisure activities. High-impact activities, sudden lifting, and any pushing or pulling are not allowed. When maximal improvement has been made, then exercise therapy is continued through an appropriate home exercise program.
Studies are needed to compare patients who have therapy with those who do not. If treatment is warranted, finding the best rehab management protocol is the next step. This may vary from patient to patient, thus requiring research to compare the benefits and effectiveness of the program for many different patients getting a rTSA.