Shoulder Replacement Surgeries (Shoulder Arthroplasty)
Shoulder replacement at a glance
- Shoulder replacement surgery is a procedure that creates a new joint surface in the shoulder and connecting arm bones to replace damaged bone, cartilage and joints.
- Shoulder replacement surgeries help relieve arthritic pain and improve shoulder range of motion.
- Types of shoulder replacements include total shoulder replacement, reverse shoulder replacement, partial shoulder replacement and resurfacing hemiarthroplasty—each for specific circumstances.
- Recovering from shoulder replacement takes several months and will require prolonged physical therapy. Patients spend a couple of nights in the hospital following surgery.
What is shoulder replacement?
Shoulder replacement is a surgery to replace the loss of cartilage and damaged bone ends around the shoulder joint with new joint surfaces at the end of the arm and near a damaged shoulder joint. The shoulder girdle consists of three major bones. This includes the collar bone (clavicle), shoulder blade (scapula) and upper arm bone (humerus). The collar bone attaches the shoulder blade and arm bone to the chest by way of the sternum.
The shoulder joint has the widest range of motion of all joints in the body. Shoulder replacements were initially performed to treat severe fractures of the humerus. As surgical methods progressed, the surgery was used to treat chronic conditions of the shoulder such as arthritis, which causes pain, loss of motion and decreased function.
The upper portion of the arm bone (humerus) is ball shaped and muscles and ligaments hold it against the scapula. A total shoulder replacement will typically replace the top upper arm bone with a prosthetic metal piece that has a stem and rounded head that mimics the humerus.
A total shoulder replacement surgery is usually reserved for cases where physical therapy and medication fail to relieve pain, improve mobility or function. Shoulder replacements are less common than other joint replacement surgeries. About 53,000 Americans get a shoulder replacement each year compared with the nearly one million who get knee or hip replacement surgery.
Patients should talk with their orthopedist about whether a shoulder replacement surgery is appropriate.
Types of shoulder replacements
There are different types of shoulder replacement surgeries and the type will depend on the symptoms, the type of damage to the shoulder, joint or tendons and the patient’s age.
Total shoulder replacement. The surgeon replaces the entire arthritic joint with a prosthetic ball attached to a stem that goes into the humerus and a plastic socket. This procedure commonly treats arthritis effectively as long as the rotator cuff muscles are intact and working.
Reverse shoulder replacement. The surgeon switches the ball and socket positions in the shoulder. A socket-shaped prosthetic stem replaces the humerus (the upper arm bone) and a prosthetic ball replaces the shoulder socket. This procedure is appropriate for patients with large rotator cuff tears, and those who experience cuff tear arthropathy (a type of arthritis). A total shoulder replacement for these patients will fail, loosen and cause more pain. The reverse shoulder replacement enables the deltoid muscle, not the rotator cuff, to power and control the arm.
Partial shoulder replacement. Depending on the condition of the shoulder, the ball portion (humeral head) of the arm bone is replaced, leaving the natural socket. Partial shoulder replacement is also known as a stemmed hemiarthroplasty. This method is reserved for younger patients without a bejoined socket.
Resurfacing hemiarthroplasty. In this procedure, a cap is fitted onto the shoulder socket or a curved cap is fitted to the humerus head on the arthritic portion to improve joint mobility and reduce pain. Unlike the partial shoulder replacement, resurfacing does not require removing the humeral head, only patching the small areas where there is loss of cartilage.
Recovering from shoulder replacement surgery
Most patients leave the hospital after one to three days following a shoulder replacement surgery. Recovering from a shoulder replacement surgery takes about three months. Rehabilitation usually begins after surgery, except in reverse shoulder replcaements, where patients are restricted for about six weeks.
In all but reverse total shoulder replacements, physical therapy is started to maintain range of motion and activity in the shoulder muscles, as well as other muscles. Each type of shoulder replacement has a specific set of physical therapy guidelines. Strength training doesn’t start until six weeks following the surgery.
Risks of shoulder replacements
Infection after shoulder replacement surgery occurs in about one percent of cases, but can be higher if the patient has diabetes or is obese. Infection will require surgery to clean out the infection and sometimes remove the implant. Antibiotics and additional surgery may preserve the implant. There is also a risk of nerve injury which could cause damage and weaken the muscles.
As in all major surgeries, there is always the risk of heart attack, stroke or death. All of these risks are low.