A shoulder replacement is a surgical procedure that removes damaged parts of your shoulder joint and replaces them with artificial components made of metal and plastic. It’s most commonly performed when arthritis has worn down the cartilage in your shoulder to the point where pain and stiffness no longer respond to physical therapy, injections, or medication. About nine out of ten shoulder replacements last at least a decade, and the procedure reliably reduces pain while restoring range of motion.
How the Shoulder Joint Works
Your shoulder is a ball-and-socket joint. The rounded top of your upper arm bone (the humerus) fits into a shallow cup on your shoulder blade (the glenoid). A layer of smooth cartilage covers both surfaces so they glide against each other without friction, and a group of four muscles and tendons called the rotator cuff holds everything in place while powering movement.
When that cartilage wears away or the rotator cuff tears beyond repair, bone grinds against bone. The result is deep, persistent pain that worsens with activity and eventually disrupts sleep. That’s the point at which surgery enters the conversation.
Conditions That Lead to Surgery
Osteoarthritis is the most common reason people get a shoulder replacement. Years of wear gradually thin the cartilage until it’s gone entirely. Rheumatoid arthritis and other inflammatory joint diseases can cause the same destruction faster because the immune system actively attacks the joint lining. A condition called avascular necrosis, where the bone loses its blood supply and begins to collapse, can also destroy the joint surface.
Severe fractures are another path to replacement. When the upper arm bone breaks into several pieces, especially in older adults with weaker bone, putting the fragments back together with plates and screws sometimes isn’t feasible. A replacement gives the surgeon a more reliable way to restore a functional shoulder. Rotator cuff tear arthropathy, a combination of a massive irreparable tendon tear and arthritis, is increasingly treated with a specific type of replacement designed for that problem.
In all cases, surgery is considered after conservative treatments have failed. That typically means months of physical therapy, anti-inflammatory medications, and possibly cortisone injections without adequate relief.
Types of Shoulder Replacement
Total Shoulder Replacement (Anatomic)
An anatomic total shoulder replacement mirrors your natural anatomy. The surgeon caps the ball of the upper arm bone with a smooth metal dome, usually a cobalt-chromium alloy, attached to a titanium stem that fits down into the bone’s hollow center. The socket side gets a new lining made of high-density plastic (polyethylene) that snaps or cements into the shoulder blade. This design works well when your rotator cuff is intact and healthy enough to keep the new joint stable and centered.
Reverse Shoulder Replacement
A reverse replacement flips the geometry. A metal ball is attached to the shoulder blade, and a plastic socket is placed on the upper arm bone. This clever switch changes the biomechanics so the large deltoid muscle on the outside of your shoulder can power arm movement even when the rotator cuff is torn or nonfunctional. Originally designed only for people with severe rotator cuff damage, the reverse replacement is now used more broadly, including for some patients with intact rotator cuffs who may benefit from its mechanics, particularly older adults with complex fractures.
Partial Shoulder Replacement
A partial replacement (hemiarthroplasty) replaces only the ball side of the joint, leaving your natural socket intact. This option fits patients whose socket cartilage is still in reasonable shape, such as those with avascular necrosis or certain fracture patterns. It’s also sometimes chosen for younger, more active patients because preserving the natural socket avoids the risk of a plastic socket component wearing out or loosening over time. The tradeoff is that pain relief tends to be somewhat less predictable than with a total replacement, and the remaining natural socket can continue to wear down.
What the Implants Are Made Of
Shoulder replacement implants use two primary metals. Cobalt-chromium-molybdenum alloy forms the bearing surfaces, the parts that actually slide against each other, because it’s extremely hard and resists wear. Titanium alloy is used for the stem and any components that sit directly against bone, because bone grows into titanium’s slightly rough surface and bonds with it over time.
The plastic socket component is made from ultra-high-molecular-weight polyethylene, an industrial-grade plastic engineered to withstand millions of repetitive movements. Wear of this plastic surface is the most common long-term concern with any joint replacement, and advances in manufacturing continue to improve its durability.
How Long Implants Last
A large analysis by the UK’s National Institute for Health and Care Research found that total shoulder replacements have a ten-year survival rate of 92 to 95 percent. Reverse total shoulder replacements perform similarly, at about 94 percent. Partial replacements trail slightly at 86 to 90 percent at the ten-year mark. One limitation of the current data is a lack of extended follow-up. Reliable 15- and 20-year survival figures are still limited, which is particularly relevant for younger patients who may outlive their first implant and eventually need a revision surgery.
Preparing for Surgery
Preparation starts well before the operating room. Your surgeon will likely order imaging of the shoulder, including X-rays and often a CT scan, to map the bone loss and plan implant sizing. You may need a preoperative medical evaluation from your primary care doctor, ideally scheduled at least 30 days before surgery, to make sure conditions like heart disease or diabetes are well controlled.
A dental exam six months beforehand is commonly recommended. Bacteria from untreated dental infections can enter the bloodstream and settle on a new implant, so clearing up any dental issues in advance reduces that risk. Any vaccines you need should be given at least two weeks before surgery, and always in the arm that isn’t being operated on.
Home preparation matters more than most people expect. For weeks after surgery, your operative arm will be in a sling and essentially off-limits. Before your surgery date, rearrange frequently used items so you can reach them with one hand. Remove throw rugs and clutter that could cause falls. Install night-lights between your bedroom and bathroom, and consider grab bars near the toilet and in the shower. A practical exercise: spend a day doing your normal routine without using the arm that will be operated on. You’ll quickly discover which tasks need a workaround. Pick up prescribed medications ahead of time, along with a stool softener, since pain medication commonly causes constipation.
Recovery Timeline
You’ll wake up with your arm immobilized in a sling. Most patients go home the same day or after one night in the hospital. The sling stays on for roughly four to six weeks, depending on the type of replacement and your surgeon’s protocol. During this phase, a physical therapist will guide you through gentle pendulum exercises and passive movements where someone else moves your arm for you to prevent stiffness.
Active motion, where you start moving the arm under your own power, typically begins around six weeks. Strengthening exercises ramp up gradually over the following months. Most people notice significant pain improvement within the first few weeks, though full recovery of strength and range of motion takes four to six months. Some patients continue to see gains up to a year after surgery.
Driving is usually off the table for about six weeks. Returning to desk work can happen in two to three weeks for some people, while physically demanding jobs may require three months or more. Activities like swimming and golf are generally realistic goals, though high-impact sports and heavy overhead lifting carry a risk of accelerating implant wear.
Risks and Complications
Infection is the most serious complication. It occurs in up to 4 percent of standard total shoulder replacements and about 2.4 percent of reverse replacements. The risk varies by the reason for surgery: fracture-related replacements for acute breaks carry about a 0.9 percent infection rate, while replacements done for the aftermath of a prior fracture have a higher rate near 3.7 percent. A deep infection around the implant often requires additional surgery and a prolonged course of antibiotics.
Instability, where the ball slips out of the socket, is more of a concern with reverse replacements because the design relies on soft tissue tension rather than the deep socket of a natural joint. Loosening of the implant from the bone can develop over years as the interface between metal and bone gradually breaks down. Nerve injury, blood clots, and fractures of the bone around the implant are possible but uncommon. Stiffness from inadequate rehabilitation is one of the more preventable complications, which is why consistent physical therapy matters so much.