Shoulder replacement

In a shoulder replacement, the damaged surfaces of the ball-and-socket joint are replaced with artificial components. The goal is to relieve the pain that comes from bone-on-bone arthritis and to improve how the shoulder functions, so that everyday activities become more comfortable.

Shoulder replacement is considered for advanced arthritis — or, in some situations, for certain fractures or failed previous surgery — when symptoms are limiting despite nonsurgical care. It is a significant operation and an individual decision, not an automatic step whenever arthritis is present.

There are two main designs of shoulder replacement, and they solve the problem in different ways:

• An anatomic total shoulder replacement keeps the normal arrangement of the joint — a ball on the arm side and a socket on the shoulder-blade side. It relies on a functioning rotator cuff to center and power the shoulder, so it is generally suited to arthritis in a shoulder whose cuff is intact.
• A reverse total shoulder replacement switches the positions — placing the ball on the shoulder-blade side and the socket on the arm side. This design allows a different muscle, the deltoid, to do more of the work of lifting the arm, which is why it is often used when the rotator cuff is deficient or in other specific situations.

Neither type is universally better than the other — each fits certain shoulders and situations. The choice between an anatomic and a reverse replacement, and whether replacement is the right step at all, depends on the whole picture, including:

• Your symptoms and how much they limit you
• The examination and what your imaging shows
• How your shoulder is functioning and what your goals and activity expectations are
• Your age
• The anatomy of the joint, including the shape and wear of the socket
• The condition of the rotator cuff — whether it is intact or deficient
• The quality of the bone
• Any prior surgery on the shoulder

Because so many factors matter, the decision about whether to have a shoulder replacement, and which type, is made together with your surgeon after weighing these considerations. The aim is to match the operation to your particular shoulder and your goals, rather than to apply a single rule to everyone.

Rehabilitation after a shoulder replacement is staged. In broad terms, it moves from an early period that protects the shoulder while it heals, to a gradual restoration of motion, to progressive strengthening, and then a return toward normal activity over time. Early on, the arm is usually protected, and certain movements are limited to allow healing.

The specifics — how the arm is protected, how and when motion and strengthening are advanced, and when particular activities may resume — are set by the protocol your surgical team selects, and they can differ between an anatomic and a reverse replacement and when other factors are involved. Those detailed restrictions and timelines are not reproduced here; your surgeon's protocol and operative note take precedence, and rebuilding comfort and strength takes time.

As with any major surgery, shoulder replacement carries risks and has limits. The possibilities below are for discussion with your surgeon and are not a complete list; which matter most depends on your situation:

• Infection
• Nerve or blood-vessel injury
• Stiffness or persistent pain
• Dislocation or instability of the replacement
• Loosening or wear of the implant components over time
• Fracture of the bone around the implant
• Problems related to the rotator cuff, depending on the type of replacement
• Blood clots
• The possible need for additional surgery, including revision of the replacement

Shoulder replacement aims to reduce arthritis pain and improve the use of the arm. For many people it can make daily activities more comfortable. It is a major operation with a real recovery, and what it can achieve is individual — a realistic picture for your specific situation, including which type of replacement suits your shoulder, is best discussed with your surgeon.