Shoulder replacement

Shoulder replacement is surgery that replaces the damaged ball and socket of the shoulder joint with implants. Depending on the problem, the surgeon may replace both surfaces in their natural arrangement, replace only the ball, or use a reverse design that switches the positions of the ball and socket. The goal is to relieve pain and improve how the arm moves.

Shoulder replacement may be worth discussing when:

• Shoulder pain interferes with daily tasks such as reaching, dressing, or washing your hair
• Pain is present at rest or keeps you awake at night
• The shoulder has lost motion or strength
• Medication, injections, and physical therapy no longer give enough relief

Conditions that can damage the shoulder joint enough to need replacement include:

• Osteoarthritis
• Rheumatoid and other inflammatory arthritis
• Arthritis after an earlier injury or surgery
• Rotator cuff tear arthropathy, a form of arthritis that develops with a large, long-standing rotator cuff tear
• Osteonecrosis, a loss of blood supply to the ball of the upper arm bone
• Severe fractures of the upper arm bone near the shoulder
• A failed earlier shoulder replacement

The evaluation includes your history, an examination of shoulder motion and strength with particular attention to the rotator cuff, and X-rays. A CT scan or MRI is often used to look at the shape of the socket and the condition of the rotator cuff, which helps determine which type of replacement fits your shoulder.

For most shoulder arthritis, non-surgical treatment comes first: activity changes, physical therapy, anti-inflammatory and other pain-relieving medications, and steroid injections.

When symptoms persist, the main types of shoulder replacement are:

• Total (anatomic) shoulder replacement — the ball is replaced with a metal ball and the socket with a plastic surface; this design depends on a working rotator cuff
• Reverse total shoulder replacement — a metal ball is attached on the socket side and a cup on the arm bone, so the deltoid muscle can lift the arm when the rotator cuff is torn or not working; it is also used for some complex fractures and failed earlier replacements
• Partial shoulder replacement (hemiarthroplasty) — only the ball is replaced, in selected situations where the socket is in good condition

The operation is done under general anesthesia, regional anesthesia, or both. Risks include infection, blood clots, nerve injury, fracture during surgery, dislocation, and, over time, loosening or wear of the implant that may need further surgery.

Many people go home the same day or after a short hospital stay. The arm is kept in a sling for several weeks, and gentle motion exercises begin early under the guidance of your surgeon or therapist. Strengthening usually starts later, once the tissues have healed, and improvement continues for months.

For a period after surgery you will be asked to avoid lifting, pushing yourself up from a chair or bed with the arm, and extreme arm positions. Driving is restricted until your surgeon says it is safe. Over the long term, heavy lifting and contact sports are generally discouraged to protect the implant.