Understanding Total Shoulder Replacement

There are many myths and misconceptions regarding total shoulder replacement surgery. Joint replacement surgery is a safe and effective procedure to relieve shoulder pain when nonsurgical treatments are no longer effective. If you have decided to have shoulder joint replacement surgery or if you are exploring treatment options, this article will give you an overview of the procedure and the benefits and risks of the procedures.

Arthroplasty is the term used to describe reconstruction of a joint by providing new bearing surfaces. Thus, total shoulder arthroplasty (TSA), not total shoulder replacement, is the preferred term to describe such procedures. The “total” in the name refers to addressing both bearing surfaces (both the ball and the socket) of a diseased shoulder joint. Hemiarthroplasty refers to only addressing one of the two surfaces, typically the ball (humeral head).

 Background on Shoulder Replacement

The first documented shoulder arthroplasty was performed by Jean Pean, a French physician and surgeon in Paris in 1894. This prosthesis he implanted was made of wood and rubber and was implanted to treat a shoulder destroyed by chronic tuberculosis infection. We have come a long way since then, modern shoulder arthroplasty was pioneered by Dr. Charles S. Neer, an American orthopedic surgeon at Columbia Presbyterian Medical Center in New York City. Initial prosthesis designs in the 1950’s were used to treat severe fractures of the upper end of the humerus (arm) bone and did not include socket (glenoid) replacement. The first total shoulder arthroplasty utilizing a socket component was performed in 1972 by Dr. Neer. This form of arthroplasty, termed Anatomic TSA, is the preferred treatment for patients suffering from end stage degenerative arthritis with an intact rotator cuff tendon complex. As one would expect, significant improvements in prosthesis design and implantation technique have taken place over the last several decades. The procedure now replaces the worn out surfaces of the ball and socket with prosthetic components made of metal and plastic respectively.

Variations on Shoulder Replacement

When patients suffer from chronic shoulder pain and diminished function as a result of a chronic irreparable rotator cuff tear, with or without arthritis, a different type of shoulder arthroplasty, called reverse TSA (rTSA) is utilized. This prosthesis design concept was pioneered by Paul Grammont, a French orthopedic surgeon in the late 1970’s. Variations of his design have been used in Europe since the 1980’s. Reverse TSA was introduced into the US market in 2003. Over the last 12 years, rTSA has become a widely used tool to manage difficult shoulder pathology that, prior to its availability, had few treatment options.

Shoulder Replacement Procedure

The procedure for both shoulder surgery replacements are performed under general anesthesia with or without a regional nerve block. Most are still performed in the hospital setting, but select patients can have their surgery in an outpatient setting. Of those patients having their surgery in the hospital, over 90% go home the day following surgery. Both procedures are typically performed through a similar surgical approach with an approximately 5” incision on the front of the shoulder. The approach utilizes the interval between the deltoid and pectoralis major muscles to gain access to the shoulder joint. Surprisingly, very little bone is actually removed to perform the surgery. The hemisphere that comprises the upper end of the humerus is removed with a saw. This fragment is usually about 4 centimeters in diameter and about 1.5-2 centimeters in height. On the socket side, very little bone is removed, just enough to create a flat surface to place the prosthesis. Both operations require approximately 60-75 minutes of operative time to complete.

The biggest difference between anatomic and reverse arthroplasty involves the postoperative management. Formal physical therapy plays an important role with anatomic arthroplasty. A physical therapist usually sees the patient on the first postoperative day. During the first six weeks after surgery, the focus is on regaining range of shoulder motion. Beyond 6 six weeks, functional strengthening becomes the focus of therapy. Formal physical therapy with a therapist usually continues for three months after surgery. In contrast, with reverse TSA, typically no formal physical therapy is necessary and most all rehabilitation is performed by the patient with physician instruction.

Benefits of Shoulder Replacement

With both procedures, typically by three weeks after surgery patients have less pain than were experiencing before surgery. By three months postoperatively 70% of the entire recovery for both procedures occur, with maximal improvement achieved about one year after surgery.

Results for both pain relief and functional improvement are excellent for both procedures, thus one is not better than the other. The most important point is that the appropriate procedure be done for the right diagnosis.

Risks of Shoulder Replacement

Risks are a reality with any surgery and TSA is no exception. Infection is probably the most concerning complication and occurs at a rate of about 3%, despite taking every precaution to prevent it. Treatment for an infected TSA routinely requires further surgery and treatment with intravenous antibiotics. Blood loss is typically quite minimal and transfusion is very rarely required. Other long term complications include humeral fracture, component loosening and instability of the prosthesis with dislocation.

Both anatomic and reverse TSA offer excellent options for the treatment of the painful arthritic shoulder with or without an intact rotator cuff complex. The surgery is generally quite well tolerated and patient satisfaction rates are in the 90% range. Shoulder replacement can help reduce or eliminate shoulder pain and can allow you to regain range of motion, and may help you return to normal daily activities.

Submitted by Scott R. Jacobson, MD