In young patients with early stages of shoulder arthritis, an arthroscopic surgery can be performed to clean up and remove degenerative cartilage and inflamed tissue lining the joint. It is important to understand that this procedure does not cure arthritis or stop it from progressing, but it can help alleviate some symptoms associated with early arthritis.

When the arthritis is more advanced, or after non-operative and arthroscopic interventions have failed, total shoulder replacement surgery, or shoulder arthroplasty, is recommended. The shoulder is replaced through an incision on the front of the shoulder. The worn-out ball and socket are replaced with new components made of metal and plastic. Most patients do very well after shoulder replacement surgery with elimination of pain, restoration of joint function, and improved motion.

There are two main types of shoulder arthroplasty: an anatomic total shoulder and a reverse total shoulder. The anatomic total shoulder maintains the native anatomy of the shoulder joint by replacing the ball with a ball and the socket with a socket. This type of shoulder replacement is indicated in patients with primary osteoarthritis and an intact rotator cuff. The rotator cuff is a group of muscles that helps compress the ball against the socket and allows for motion of the shoulder joint. When the rotator cuff is intact, an anatomic total shoulder arthroplasty can be performed to address arthritis in the shoulder.

The other type of shoulder replacement is called a reverse total shoulder arthroplasty. This type of surgery is performed in patients who have arthritis and do not have an intact rotator cuff. It may also be performed in older patients who have a massive rotator cuff tear that cannot be repaired even if they don’t have arthritis. Because the rotator cuff is torn or incompetent, it is not working to compress the ball against the socket and there is significant limitation in shoulder motion as a result. Typically, these patients are unable to elevate the arm above shoulder level (pseudoparesis), sometimes only being able to shrug the shoulder (pseudoparalysis). The surgery reverses the components in the shoulder, replacing the socket with a ball and the ball with a socket. By reversing the components, the center of rotation is moved towards the center of the body, allowing the deltoid muscle to power shoulder elevation, rather than the rotator cuff. With these changes, patients are able to elevate their arm after surgery, despite not having an intact rotator cuff.

Some patients who have had an anatomic total shoulder do very well after surgery and then may lose the ability to raise their arm above their head. This may happen if they develop a rotator cuff tear. Because the anatomic total shoulder relies on the rotator cuff for motion, if a tear develops, motion may be lost. Fortunately, an anatomic total shoulder can be converted to a reverse total shoulder, either through implant design or by removing the previously implanted components. This conversion to a reverse total shoulder construct allows compensation for the rotator cuff tear and restoration if shoulder motion.

Shoulder replacement surgery can be an inpatient or an outpatient procedure, though most patients are able to go home the same day once recovered from anesthesia. In older patients or patients with significant medical comorbidities, the surgery is performed in a hospital allowing for an overnight stay. In addition to being asleep for the surgery, a regional nerve block is performed pre-operatively to help with pain. The nerve block will numb the operative arm and last longer than the surgery itself. It is important to start taking pain medication prior to the block wearing off to ensure continued pain control after the effects of the block.

The operative arm is placed in a sling post-operatively to support the arm while healing. The sling helps with immobilization to take stress off the surgical site and to help the arm recover from surgery. Patients can expect to be in a sling for 4-6 weeks after an anatomic total shoulder replacement while the rotator cuff heals. If a reverse total shoulder replacement is performed, patients will be in a sling for 2 weeks.

Physical therapy is performed after surgery to regain motion and strength in the shoulder. Initially, exercises will focus on regaining passive range of motion. As passive motion is restored, therapy will advance to work on active range of motion and ultimately strengthening. Complete recovery after total shoulder replacement can take 6-9 months, and sometimes even longer, though most patients will typically feel better with daily activities sooner than that.